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1.  Infection of Macrophages and Dendritic Cells with Primary R5-Tropic Human Immunodeficiency Virus Type 1 Inhibited by Natural Polyreactive Anti-CCR5 Antibodies Purified from Cervicovaginal Secretions▿  
Heterosexual contact is the primary mode of human immunodeficiency virus (HIV) type 1 (HIV-1) transmission worldwide. The chemokine receptor CCR5 is the major coreceptor that is associated with the mucosal transmission of R5-tropic HIV-1 during sexual intercourse. The CCR5 molecule is thus a target for antibody-based therapeutic strategies aimed at blocking HIV-1 entry into cells. We have previously demonstrated that polyreactive natural antibodies (NAbs) from therapeutic preparations of immunoglobulin G and from human breast milk contain NAbs directed against CCR5. Such antibodies inhibit the infection of human macrophages and T lymphocytes by R5-tropic isolates of HIV in vitro. In the present study, we demonstrate that human immunoglobulins from the cervicovaginal secretions of HIV-seronegative or HIV-seropositive women contain NAbs directed against the HIV-1 coreceptor CCR5. Natural affinity-purified anti-CCR5 antibodies bound to CCR5 expressed on macrophages and dendritic cells and further inhibited the infection of macrophages and dendritic cells with primary and laboratory-adapted R5-tropic HIV but not with X4-tropic HIV. Natural anti-CCR5 antibodies moderately inhibited R5-tropic HIV transfer from monocyte-derived dendritic cells to autologous T cells. Our results suggest that mucosal anti-CCR5 antibodies from healthy immunocompetent donors may hamper the penetration of HIV and may be suitable for use in the development of novel passive immunotherapy regimens in specific clinical settings of HIV infection.
doi:10.1128/CVI.00463-07
PMCID: PMC2394833  PMID: 18353923
2.  Antiretroviral Pre-exposure Prophylaxis Prevents Vaginal Transmission of HIV-1 in Humanized BLT Mice 
PLoS Medicine  2008;5(1):e16.
Background
Worldwide, vaginal transmission now accounts for more than half of newly acquired HIV-1 infections. Despite the urgency to develop and implement novel approaches capable of preventing HIV transmission, this process has been hindered by the lack of adequate small animal models for preclinical efficacy and safety testing. Given the importance of this route of transmission, we investigated the susceptibility of humanized mice to intravaginal HIV-1 infection.
Methods and Findings
We show that the female reproductive tract of humanized bone marrow–liver–thymus (BLT) mice is reconstituted with human CD4+ T and other relevant human cells, rendering these humanized mice susceptible to intravaginal infection by HIV-1. Effects of HIV-1 infection include CD4+ T cell depletion in gut-associated lymphoid tissue (GALT) that closely mimics what is observed in HIV-1–infected humans. We also show that pre-exposure prophylaxis with antiretroviral drugs is a highly effective method for preventing vaginal HIV-1 transmission. Whereas 88% (7/8) of BLT mice inoculated vaginally with HIV-1 became infected, none of the animals (0/5) given pre-exposure prophylaxis of emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) showed evidence of infection (Chi square = 7.5, df = 1, p = 0.006).
Conclusions
The fact that humanized BLT mice are susceptible to intravaginal infection makes this system an excellent candidate for preclinical evaluation of both microbicides and pre-exposure prophylactic regimens. The utility of humanized mice to study intravaginal HIV-1 transmission is particularly highlighted by the demonstration that pre-exposure prophylaxis can prevent intravaginal HIV-1 transmission in the BLT mouse model.
J. Victor Garcia and colleagues show that mice with immune systems reconstituted from human bone marrow, liver, and thymus transplants provide a model for prevention of intravaginal HIV infection.
Editors' Summary
Background.
Since the first cases of acquired immunodeficiency syndrome (AIDS) in 1981, the AIDS epidemic has spread rapidly. About 33 million people are now infected with the human immunodeficiency virus (HIV), the cause of AIDS. More than half of newly acquired infections now occur in women, mostly through unprotected vaginal sex with an infected male partner. Women are biologically more susceptible than men to HIV infection during vaginal intercourse and often cannot persuade their partner to use a condom. Consequently, alternative strategies that prevent intravaginal transmission of HIV (infection through the vagina) are urgently needed, particularly strategies that women can use without their partner's agreement. A vaccine would be ideal but it could be many years before an effective HIV vaccine is available so researchers are investigating other preventative strategies such as the use of microbicides—compounds that protect against HIV when applied inside the vagina—and pre-exposure treatment (prophylaxis) with antiretroviral drugs.
Why Was This Study Done?
Before any new strategy to prevent intravaginal HIV transmission is tried by women, it has to be tested in animals. Currently, this can only be done in macaques, an expensive option. In this study, the researchers have investigated whether “humanized BLT” mice could be used instead. When HIV enters the human body during vaginal intercourse, it sticks to dendritic cells (a type of immune system cell) in the vaginal lining. These cells carry the virus to the body's lymphoid tissues (collections of immune cells), where it infects and kills CD4+ T cells (another type of immune cell). Dendritic cells and CD4+ T cells have molecules on their surface that HIV recognizes. Mice are not normally susceptible to infection with HIV because their immune system cells lack these molecules. Humanized BLT mice have a nearly human immune system—BLT stands for bone marrow, liver, thymus. They are produced by implanting pieces of human fetal liver and thymus (the organ where T cells learn to recognize foreign invaders) under the kidney capsule of immunodeficient mice (animals born without an immune system) and then transplanting human hematopoietic stem cells (the source of the major immune system cells) into the mice.
What Did the Researchers Do and Find?
When the researchers examined the female reproductive tract of humanized BLT mice for human immune system cells, they found CD4+ T cells, dendritic cells and macrophages, all of which are involved in HIV infection. Furthermore, half of the blood cells of the BLT mice were human. Most of the BLT mice, the researchers report, were susceptible to intravaginal HIV infection as shown, for example, by a rapid loss of human CD4+ T cells from their blood. However, BLT mice pretreated with antiretroviral drugs (a mixture of emtricitabine and tenofovir disoproxil fumarate) were resistant to intravaginal HIV infection. As in human HIV infections, CD4+ T cells were also depleted in several other organs of the BLT mice after intravaginal HIV infection. Again, this depletion was prevented by antiretroviral pre-exposure prophylaxis. Finally, human CD4+ T cells also disappeared from the gut-associated lymphoid tissue (an important site for HIV replication and CD4+ T cell depletion during human HIV disease) of the BLT mice after infection with HIV.
What Do These Findings Mean?
These findings show that humanized BLT mice are susceptible to intravaginal infection with HIV and that many aspects of HIV infection in these mice closely mimic infection in people. In addition, by showing that pre-exposure prophylaxis with antiretroviral drugs prevents HIV infection, these results suggest that humanized BLT mice could be used to test new strategies designed to prevent intravaginal infection. As with all animal models, any approach that works in humanized BLT mice will still have to be tested in people. Nevertheless, these findings provide preclinical evidence that pre-exposure prophylaxis with antiretroviral drugs may be an effective way to prevent intravaginal transmission of HIV and, therefore, provide valuable support for clinical trials of this approach.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050016.
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS and on HIV infection in women
HIVInSite has comprehensive information on all aspects of HIV/AIDS, including articles on women and HIV and on safer sex, which includes information on pre-exposure prophylaxis and microbicides
Information is available from Avert, an international AIDS charity, on HIV prevention, on women, HIV, and AIDS, and on microbicides
The US Centers for Disease Control and Prevention provides information on HIV/AIDS, including information on HIV/AIDS among women and on CDC trials of pre-exposure prophylaxis for HIV prevention (in English and some information in Spanish)
PrEP Watch is a comprehensive information source on pre-exposure prophylaxis for HIV prevention
doi:10.1371/journal.pmed.0050016
PMCID: PMC2194746  PMID: 18198941
3.  Prevention of SIV Rectal Transmission and Priming of T Cell Responses in Macaques after Local Pre-exposure Application of Tenofovir Gel 
PLoS Medicine  2008;5(8):e157.
Background
The rectum is particularly vulnerable to HIV transmission having only a single protective layer of columnar epithelium overlying tissue rich in activated lymphoid cells; thus, unprotected anal intercourse in both women and men carries a higher risk of infection than other sexual routes. In the absence of effective prophylactic vaccines, increasing attention is being given to the use of microbicides and preventative antiretroviral (ARV) drugs. To prevent mucosal transmission of HIV, a microbicide/ARV should ideally act locally at and near the virus portal of entry. As part of an integrated rectal microbicide development programme, we have evaluated rectal application of the nucleotide reverse transcriptase (RT) inhibitor tenofovir (PMPA, 9-[(R)-2-(phosphonomethoxy) propyl] adenine monohydrate), a drug licensed for therapeutic use, for protective efficacy against rectal challenge with simian immunodeficiency virus (SIV) in a well-established and standardised macaque model.
Methods and Findings
A total of 20 purpose-bred Indian rhesus macaques were used to evaluate the protective efficacy of topical tenofovir. Nine animals received 1% tenofovir gel per rectum up to 2 h prior to virus challenge, four macaques received placebo gel, and four macaques remained untreated. In addition, three macaques were given tenofovir gel 2 h after virus challenge. Following intrarectal instillation of 20 median rectal infectious doses (MID50) of a noncloned, virulent stock of SIVmac251/32H, all animals were analysed for virus infection, by virus isolation from peripheral blood mononuclear cells (PBMC), quantitative proviral DNA load in PBMC, plasma viral RNA (vRNA) load by sensitive quantitative competitive (qc) RT-PCR, and presence of SIV-specific serum antibodies by ELISA. We report here a significant protective effect (p = 0.003; Fisher exact probability test) wherein eight of nine macaques given tenofovir per rectum up to 2 h prior to virus challenge were protected from infection (n = 6) or had modified virus outcomes (n = 2), while all untreated macaques and three of four macaques given placebo gel were infected, as were two of three animals receiving tenofovir gel after challenge. Moreover, analysis of lymphoid tissues post mortem failed to reveal sequestration of SIV in the protected animals. We found a strong positive association between the concentration of tenofovir in the plasma 15 min after rectal application of gel and the degree of protection in the six animals challenged with virus at this time point. Moreover, colorectal explants from non-SIV challenged tenofovir-treated macaques were resistant to infection ex vivo, whereas no inhibition was seen in explants from the small intestine. Tissue-specific inhibition of infection was associated with the intracellular detection of tenofovir. Intriguingly, in the absence of seroconversion, Gag-specific gamma interferon (IFN-γ)-secreting T cells were detected in the blood of four of seven protected animals tested, with frequencies ranging from 144 spot forming cells (SFC)/106 PBMC to 261 spot forming cells (SFC)/106 PBMC.
Conclusions
These results indicate that colorectal pretreatment with ARV drugs, such as tenofovir, has potential as a clinically relevant strategy for the prevention of HIV transmission. We conclude that plasma tenofovir concentration measured 15 min after rectal administration may serve as a surrogate indicator of protective efficacy. This may prove to be useful in the design of clinical studies. Furthermore, in vitro intestinal explants served as a model for drug distribution in vivo and susceptibility to virus infection. The finding of T cell priming following exposure to virus in the absence of overt infection is provocative. Further studies would reveal if a combined modality microbicide and vaccination strategy is feasible by determining the full extent of local immune responses induced and their protective potential.
Martin Cranage and colleagues find that topical tenofovir gel can protect against rectal challenge with SIV in a macaque model, and can permit the induction of SIV-specific T cell responses.
Editors' Summary
Background.
About 33 million people are now infected with the human immunodeficiency virus (HIV), which causes AIDS by killing immune system cells. As yet, there is no cure for AIDS, although HIV infections can be held in check with antiretroviral drugs. Also, despite years of research, there is no vaccine available that effectively protects people against HIV infection. So, to halt the AIDS epidemic, other ways of preventing the spread of HIV are being sought. For example, pre-exposure treatment (prophylaxis) with antiretroviral drugs is being investigated as a way to prevent HIV transmission. In addition, because HIV is often spread through heterosexual penile-to-vaginal sex with an infected partner, several vaginal microbicides (compounds that protect against HIV when applied inside the vagina) are being developed, some of which contain antiretroviral drugs.
Why Was This Study Done?
Because HIV can cross the membranes that line the mouth and the rectum (the lower end of the large intestine that connects to the anus) in addition to the membrane that lines the vagina, HIV transmission can also occur during oral and anal sex. The lining of the rectum in particular is extremely thin and overlies tissues rich in activated T cells (the immune system cells that HIV targets), so unprotected anal intercourse carries a high risk of HIV infection. Anal intercourse is common among men who have sex with men but is also more common in heterosexual populations than is generally thought. Tenofovir (an antiretroviral drug that counteracts HIV after it has entered human cells) given by mouth partly protects macaques against rectal infection with simian immunodeficiency virus (SIV; a virus that induces AIDS in monkeys and apes) so the researchers wanted to know whether this drug might be effective against rectal SIV infection if applied at the site where the virus enters the body.
What Did the Researchers Do and Find?
To answer this question, the researchers rectally infected several macaques with SIV up to 2 h after rectal application of a gel containing tenofovir, after rectal application of a gel not containing the drug, or after no treatment. In addition, a few animals were treated with the tenofovir gel after the viral challenge. Most of the animals given the tenofovir gel before the viral challenge were partly or totally protected from SIV infection, whereas all the untreated animals and most of those treated with the placebo gel or with the drug-containing gel after the viral challenge became infected with SIV. High blood levels of tenofovir 15 min after its rectal application correlated with protection from viral infection. The researchers also collected rectal and small intestine samples from tenofovir-treated macaques that had not been exposed to SIV and asked which samples were resistant to SIV infection in laboratory dishes. They found that only the rectal samples were resistant to infection and only rectal cells contained tenofovir. Finally, activated T cells that recognized an SIV protein were present in the blood of some of the animals that were protected from SIV infection by the tenofovir gel.
What Do These Findings Mean?
These findings, although based on experiments in only a few animals, suggest that rectal treatment with antiretroviral drugs before rectal exposure to HIV might prevent rectal HIV transmission in people. However, results from animal experiments do not always reflect what happens in people. Indeed, clinical trials of a potential vaginal microbicide that worked well in macaques were halted recently because women using the microbicide had higher rates of HIV infection than those using a control preparation. The finding that immune-system activation can occur in the absence of overt infection in animals treated with the tenofovir gel additionally suggests that a combination of a local antiretroviral/microbicide and vaccination might be a particularly effective way to prevent HIV transmission. However, because HIV targets activated T cells, viral rechallenge experiments must be done to check that the activated T cells induced by the virus in the presence of tenofovir do not increase the likelihood of infection upon re-exposure to HIV before this potential microbicide is tried in people.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050157.
Read the accompanying PLoS Medicine Perspective by Florian Hladik
An overview of HIV infection and AIDS is available from the US National Institute of Allergy and Infectious Diseases
HIVInSite has comprehensive information on all aspects of HIV/AIDS, including an article on safer sex, which includes information on the risks associated with specific types of sex and on microbicides and other methods to prevent the sexual transmission of HIV
Information on all aspects of HIV/AIDS is available from Avert, an international AIDS charity, including information on HIV prevention and on microbicides
The World Health Organization has a fact sheet on microbicides
The UK charity NAM also provides detailed information on microbicides
PrEP Watch is a comprehensive information source on pre-exposure prophylaxis for HIV prevention
Global Campaign for Microbicides is an international coalition of organisations dedicated to accelerating access to new HIV prevention options
doi:10.1371/journal.pmed.0050157
PMCID: PMC2494562  PMID: 18684007
4.  Production of Interferons and β-Chemokines by Placental Trophoblasts of HIV-1-Infected Women 
Objective: The mechanism whereby the placental cells of a human immunodeficiency virus (HIV)-1-infected mother protect the fetus from HIV-1 infection is unclear. Interferons (IFNs) inhibit the replication of viruses by acting at various stages of the life cycle and may play a role in protecting against vertical transmission of HIV-1. In addition the β-chemokines RANTES (regulated on activation T cell expressed and secreted), macrophage inflammatory protein-1-α (MIP-1α), and MIP-1β can block HIV-1 entry into cells by preventing the binding of the macrophage-trophic HIV-1 strains to the coreceptorCCR5. In this study the production of IFNs and β-chemokines by placental trophoblasts of HIV-1-infected women who were HIV-1 non-transmitters was examined.
Methods: Placental trophoblastic cells were isolated from 29 HIV-1-infected and 10 control subjects. Supernatants of trophoblast cultures were tested for the production of IFNs and β-chemokines by enzyme linked immunosorbent assay (ELISA). Additionally, HIV-1-gag and IFN-β transcripts were determined by a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) assay.
Results: All placental trophoblasts of HIV-1-infected women contained HIV-1-gag transcripts. There were no statistical differences in the median constitutive levels of IFN-α and IFN-γ produced by trophoblasts of HIV-1- infected and control subjects. In contrast, trophoblasts of HIV-1-infected women constitutively produced significantly higher levels of IFN-β protein than trophoblasts of control subjects. Furthermore, the median levels of β-chemokines produced by trophoblasts of HIV-infected and control women were similar.
Conclusions: Since there was no correlation between the placental HIV load and the production of interferons or β-chemokines, the role of trophoblast-derived IFNs and β-chemokines in protecting the fetus from infection with HIV-1 is not clear.
doi:10.1155/S1064744901000175
PMCID: PMC1784647  PMID: 11495560
5.  Impact of Round-the-Clock, Rapid Oral Fluid HIV Testing of Women in Labor in Rural India 
PLoS Medicine  2008;5(5):e92.
Background
Testing pregnant women for HIV at the time of labor and delivery is the last opportunity for prevention of mother-to-child HIV transmission (PMTCT) measures, particularly in settings where women do not receive adequate antenatal care. However, HIV testing and counseling of pregnant women in labor is a challenge, especially in resource-constrained settings. In India, many rural women present for delivery without any prior antenatal care. Those who do get antenatal care are not always tested for HIV, because of deficiencies in the provision of HIV testing and counseling services. In this context, we investigated the impact of introducing round-the-clock, rapid, point-of-care HIV testing and counseling in a busy labor ward at a tertiary care hospital in rural India.
Methods and Findings
After they provided written informed consent, women admitted to the labor ward of a rural teaching hospital in India were offered two rapid tests on oral fluid and finger-stick specimens (OraQuick Rapid HIV-1/HIV-2 tests, OraSure Technologies). Simultaneously, venous blood was drawn for conventional HIV ELISA testing. Western blot tests were performed for confirmatory testing if women were positive by both rapid tests and dual ELISA, or where test results were discordant. Round-the-clock (24 h, 7 d/wk) abbreviated prepartum and extended postpartum counseling sessions were offered as part of the testing strategy. HIV-positive women were administered PMTCT interventions. Of 1,252 eligible women (age range 18 y to 38 y) approached for consent over a 9 mo period in 2006, 1,222 (98%) accepted HIV testing in the labor ward. Of these, 1,003 (82%) women presented with either no reports or incomplete reports of prior HIV testing results at the time of admission to the labor ward. Of 1,222 women, 15 were diagnosed as HIV-positive (on the basis of two rapid tests, dual ELISA and Western blot), yielding a seroprevalence of 1.23% (95% confidence interval [CI] 0.61%–1.8%). Of the 15 HIV test–positive women, four (27%) had presented with reported HIV status, and 11 (73%) new cases of HIV infection were detected due to rapid testing in the labor room. Thus, 11 HIV-positive women received PMTCT interventions on account of round-the-clock rapid HIV testing and counseling in the labor room. While both OraQuick tests (oral and finger-stick) were 100% specific, one false-negative result was documented (with both oral fluid and finger-stick specimens). Of the 15 HIV-infected women who delivered, 13 infants were HIV seronegative at birth and at 1 and 4 mo after delivery; two HIV-positive infants died within a month of delivery.
Conclusions
In a busy rural labor ward setting in India, we demonstrated that it is feasible to introduce a program of round-the-clock rapid HIV testing, including prepartum and extended postpartum counseling sessions. Our data suggest that the availability of round-the-clock rapid HIV testing resulted in successful documentation of HIV serostatus in a large proportion (82%) of rural women who were unaware of their HIV status when admitted to the labor room. In addition, 11 (73%) of a total of 15 HIV-positive women received PMTCT interventions because of round-the-clock rapid testing in the labor ward. These findings are relevant for PMTCT programs in developing countries.
Nitika Pant Pai and colleagues report the results of offering a round-the-clock rapid HIV testing program in a rural labor ward setting in India.
Editors' Summary
Background.
Since the first reported case of AIDS (acquired immunodeficiency syndrome) in 1981, the number of people infected with the human immunodeficiency virus (HIV), which causes AIDS, has risen steadily. Now, more than 33 million people are infected, almost half of them women. HIV is most often spread through unprotected sex with an infected partner, but mother-to-child transmission (MTCT) of HIV is also an important transmission route. HIV-positive women often pass the virus to their babies during pregnancy, labor and delivery, and breastfeeding, if nothing is done to prevent viral transmission. In developed countries, interventions such as voluntary testing and counseling, safe delivery practices (for example, offering cesarean delivery to HIV-positive women), and antiretroviral treatment of the mother during pregnancy and labor and of her newborn baby have minimized the risk of MTCT. In developing countries, the prevention of MTCT (PMTCT) is much less effective, in part because pregnant women often do not know their HIV status. Consequently, in 2007, nearly half a million children became infected with HIV mainly through MTCT.
Why Was This Study Done?
In many developing countries, women do not receive adequate antenatal care. In India, for example, nearly half the women living in rural areas do not receive any antenatal care until they are in labor. This gives health care providers very little time in which to counsel women about HIV infection, test them for the virus, and start interventions to prevent MTCT. Furthermore, testing pregnant women in labor for HIV and counseling them is a challenge, particularly where resources are limited. In this study, therefore, the researchers investigate the feasibility and impact of introducing round-the-clock, rapid HIV testing and counseling in a busy labor ward in a rural teaching hospital in Sevagram, India.
What Did the Researchers Do and Find?
Women admitted to the labor ward between January and September 2006 were offered two rapid HIV tests—one that used a saliva sample and the other that used blood taken from a finger prick. Blood was also taken from a vein for conventional HIV testing. All the women were given a 15-minute counseling session about how HIV is transmitted, the importance of HIV testing, and information on PMTCT before their child was born (prepartum counseling), and a longer postpartum counseling session. HIV-positive women were given a cesarean delivery where possible and antiretroviral drug treatment to reduce MTCT. 1,222 women admitted to the labor ward during the study period (1,003 of whom did not know their HIV status) accepted HIV testing. Of 15 study participants who were HIV positive, 11 learnt of their HIV status in the labor room. Two babies born to these HIV-positive women were HIV positive and died within a month of delivery; the other 13 babies were HIV negative at birth and at 1 and 4 months after delivery. Finally, the rapid HIV tests missed only one HIV-positive woman (no false-positive results were given), and the time from enrolling a woman into the study through referring her for PMTCT intervention where necessary averaged 40–60 minutes.
What Do These Findings Mean?
These findings show the feasibility and positive impact of the introduction of round-the-clock pre- and postpartum HIV counseling and rapid HIV testing into a busy rural Indian labor ward. Few of the women entering this ward knew their HIV status previously but the introduction of these facilities in this setting successfully informed these women of their HIV status. In addition, the round-the-clock counseling and testing led to 11 women and their babies receiving PMTCT interventions who would otherwise have been missed. These findings need to be confirmed in other settings and the cost-effectiveness and sustainability of this approach for the improvement of PMTCT in developing countries needs to be investigated. Nevertheless, these findings suggest that round-the-clock rapid HIV testing might be an effective and acceptable way to reduce MTCT of HIV in many developing countries.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050092.
Read a related PLoS Medicine Perspective article
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS and on HIV infection in women
HIV InSite has comprehensive information on all aspects of HIV/AIDS
Women, Children, and HIV provides extensive information on the prevention of mother-to-child transmission of HIV in developing countries
Information is available from Avert, an international AIDS charity, on HIV and AIDS in India, on women, HIV, and AIDS, and on HIV and AIDS prevention, including the prevention of mother-to-child transmission
AIDSinfo, a service of the US Department of Health and Human Services provides health information for HIV-positive pregnant women (in English and Spanish)
doi:10.1371/journal.pmed.0050092
PMCID: PMC2365974  PMID: 18462011
6.  Distribution of CCR5-Delta32, CCR5 promoter 59029 A/G, CCR2-64I and SDF1-3’A genetic polymorphisms in HIV-1 infected and uninfected patients in the West Region of Cameroon 
BMC Research Notes  2013;6:288.
Background
Genetic variants of the genes encoding Human Immunodeficiency Virus-1 (HIV-1) co-receptors and their ligands, like CC-Chemokine Receptor 5 delta 32 mutation (CCR5-Delta32), CCR5 promoter A/G (Adenine/Guanine), CC-Chemokine Receptor 2 mutation 64 isoleucine (CCR2-64I) and the Stromal cell-derived Factor 3’A mutation (SDF1-3’A), are involved in the susceptibility to HIV-1 infection and progression. The prevalence of these mutations varies by Region. However, little is known about their distribution in the population of Dschang, located in the West Region of Cameroon. The prevalence of HIV in the West Region of Cameroon is lower than elsewhere in Cameroon. The objectives of this study were to determine the distribution of four AIDS Related Gene (ARG) variants in HIV-infected and non-infected population of Cameroon especially in the West Region and to estimate the contribution of these variants to the susceptibility or resistance to HIV infection. We also aimed to evaluate the effectiveness of genotyping using dried blood spot (DBS) samples.
Methods
A total of 179 participants were recruited from two hospitals in Dschang in the West Region of Cameroon. Their genotypes for CCR5-Delta32, CCR5 promoter 59029A/G, CCR2-64I and SDF1-3’A were analyzed using polymerase chain reaction (PCR) and restriction fragment length polymorphisms.
Results
A total of 179 participants were enrolled in the study. Among them, 32 (17.9%) were HIV positive and 147 (82.1%) were HIV negative. The allelic frequencies of these genes were: 0%, 49.72%, 17.6% and 100% respectively for CCR5-Delta32, CCR5 promoter 59029A/G, CCR2-64I and SDF1-3’A. No individual was found to carry the CCR5-Delta 32 mutation. All participants recruited were heterozygous for the SDF1-3’A allele.
Conclusion
Our data suggest that the CCR5-Delta32 cannot account for the protection as it was completely absent in our population. SDF1-3’A variants, may be in association with other polymorphisms, may account for the overall protection from HIV-1 infection in participants recruited as everyone carries this allele. The CCR5 promoter 59029 G/G genotype may be associated with the risk for HIV-1 infection in this population, while the CCR2-64I (A/A genotype) may account for the protection against HIV infection. The results of genotyping from fresh blood and DBS were comparable.
doi:10.1186/1756-0500-6-288
PMCID: PMC3733889  PMID: 23880174
HIV; AIDS related gene variants; Allelic frequency; Cameroon
7.  Influence of the CCR2-V64I Polymorphism on Human Immunodeficiency Virus Type 1 Coreceptor Activity and on Chemokine Receptor Function of CCR2b, CCR3, CCR5, and CXCR4 
Journal of Virology  1998;72(9):7450-7458.
The chemokine receptors CCR5 and CXCR4 are used by human immunodeficiency virus type 1 (HIV-1) in conjunction with CD4 to infect cells. In addition, some virus strains can use alternative chemokine receptors, including CCR2b and CCR3, for infection. A polymorphism in CCR2 (CCR2-V64I) is associated with a 2- to 4-year delay in the progression to AIDS. To investigate the mechanism of this protective effect, we studied the expression of CCR2b and CCR2b-V64I, their chemokine and HIV-1 coreceptor activities, and their effects on the expression and receptor activities of the major HIV-1 coreceptors. CCR2b and CCR2b-V64I were expressed at similar levels, and neither molecule affected the expression or coreceptor activity of CCR3, CCR5, or CXCR4 in cotransfected cell lines. Peripheral blood mononuclear cells (PBMCs) from CCR2-V64I heterozygotes had normal levels of CCR2b and CCR5 but slightly reduced levels of CXCR4. CCR2b and CCR2b-V64I functioned equally well as HIV-1 coreceptors, and CCR2-V64I PBMCs were permissive for HIV-1 infection regardless of viral tropism. The MCP-1-induced calcium mobilization mediated by CCR2b signaling was unaffected by the polymorphism, but MCP-1 signaling mediated by either CCR2b- or CCR2-V64I-encoded receptors resulted in heterologous desensitization (i.e., limiting the signal response of other receptors) of both CCR5 and CXCR4. The heterologous desensitization of CCR5 and CXCR4 signaling by both CCR2 allele receptor types provides a mechanistic link that might help explain the in vivo effects of CCR2 gene variants on progression to AIDS as well as the reported antiviral activity of natural CCR2 ligands.
PMCID: PMC109977  PMID: 9696841
8.  Combined Effect of CCR5-Δ32 Heterozygosity and the CCR5 Promoter Polymorphism −2459 A/G on CCR5 Expression and Resistance to Human Immunodeficiency Virus Type 1 Transmission 
Journal of Virology  2005;79(18):11677-11684.
Exposed seronegative individuals (ES) with persistent high-risk sexual behavior may be less susceptible to human immunodeficiency virus type 1 (HIV-1) infection because they carry the chemokine receptor (CR) gene alleles CCR5 open reading frame (ORF) Δ32, CCR5 promoter −2459G, or CCR2 ORF 64I (CCR2-64I), all of which have been found to diminish HIV-1 infectivity and/or disease progression. To investigate this, we determined the haplotypes for these three genetic loci in 93 ES and 247 low-risk control individuals. To test if protective haplotypes exert their effect by modulating CR expression, we measured the protein expression of CCR5 and CXCR4 on circulating CD4+ T cells and CD14+ monocytes in 71 ES and 92 controls. To avoid investigator bias, the analysis was performed without knowledge of each subject's risk and genotype. The CCR5 −2459G allele was significantly enriched in ES Caucasian men, who constituted the majority (84%) of the ES cohort, compared to the control Caucasian men (P = 0.02). This increase was mostly attributable to a higher frequency of the −2459 A/G versus the −2459 A/A genotype in individuals heterozygous for the Δ32 allele (P = 0.012). No protective influence of the CCR2-64I allele was observed. The haplotypes CCR5 ORF Δ32/CCR5 −2459A (in complete linkage disequilibrium) and CCR5 ORF wt/CCR5 −2459G had a cumulative negative effect on the expression of CCR5, since we measured significantly reduced CCR5 densities on both T-helper cells and monocytes only when both haplotypes were present. Densities of CCR5 on lymphocytes and monocytes were correlated (r = 0.59; P < 0.0001), indicating concordance of CCR5 expression patterns across different cell types. We conclude that the CCR5 ORF Δ32/wt-CCR5 −2459 A/G genotype combination offers an advantage in resisting sexual HIV-1 transmission and that this effect is mediated by a relative paucity of CCR5 on potential target cells of HIV-1.
doi:10.1128/JVI.79.18.11677-11684.2005
PMCID: PMC1212613  PMID: 16140745
9.  Bacterial Vaginosis Associated with Increased Risk of Female-to-Male HIV-1 Transmission: A Prospective Cohort Analysis among African Couples 
PLoS Medicine  2012;9(6):e1001251.
In a prospective study, Craig Cohen and colleagues investigate the association between bacterial vaginosis and the risk of female-to-male HIV-1 transmission.
Background
Bacterial vaginosis (BV), a disruption of the normal vaginal flora, has been associated with a 60% increased risk of HIV-1 acquisition in women and higher concentration of HIV-1 RNA in the genital tract of HIV-1–infected women. However, whether BV, which is present in up to half of African HIV-1–infected women, is associated with an increase in HIV-1 transmission to male partners has not been assessed in previous studies.
Methods and Findings
We assessed the association between BV on female-to-male HIV-1 transmission risk in a prospective study of 2,236 HIV-1–seropositive women and their HIV-1 uninfected male partners from seven African countries from a randomized placebo-controlled trial that enrolled heterosexual African adults who were seropositive for both HIV-1 and herpes simplex virus (HSV)-2, and their HIV-1–seronegative partners. Participants were followed for up to 24 months; every three months, vaginal swabs were obtained from female partners for Gram stain and male partners were tested for HIV-1. BV and normal vaginal flora were defined as a Nugent score of 7–10 and 0–3, respectively. To reduce misclassification, HIV-1 sequence analysis of viruses from seroconverters and their partners was performed to determine linkage of HIV-1 transmissions. Overall, 50 incident HIV-1 infections occurred in men in which the HIV-1–infected female partner had an evaluable vaginal Gram stain. HIV-1 incidence in men whose HIV-1–infected female partners had BV was 2.91 versus 0.76 per 100 person-years in men whose female partners had normal vaginal flora (hazard ratio 3.62, 95% CI 1.74–7.52). After controlling for sociodemographic factors, sexual behavior, male circumcision, sexually transmitted infections, pregnancy, and plasma HIV-1 RNA levels in female partners, BV was associated with a greater than 3-fold increased risk of female-to-male HIV-1 transmission (adjusted hazard ratio 3.17, 95% CI 1.37–7.33).
Conclusions
This study identified an association between BV and increased risk of HIV-1 transmission to male partners. Several limitations may affect the generalizability of our results including: all participants underwent couples HIV counseling and testing and enrolled in an HIV-1 prevention trial, and index participants had a baseline CD4 count ≥250 cells/mm3 and were HSV-2 seropositive. Given the high prevalence of BV and the association of BV with increased risk of both female HIV-1 acquisition and transmission found in our study, if this association proves to be causal, BV could be responsible for a substantial proportion of new HIV-1 infections in Africa. Normalization of vaginal flora in HIV-1–infected women could mitigate female-to-male HIV-1 transmission.
Trial Registration: ClinicalTrials.com NCT00194519
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Since the first reported case of AIDS in 1981, the number of people infected with HIV, the virus that causes AIDS, has risen steadily. By the end of 2010, 34 million people were living with HIV/AIDS. At the beginning of the epidemic more men than women were infected with HIV. Now, however, 50% of all adults infected with HIV are women and in sub-Saharan Africa, where two-thirds of HIV-positive people live, women account for 59% of people living with HIV. Moreover, among 15–24 year-olds, women are eight times more likely than men to be HIV-positive. This pattern of infection has developed because most people in sub-Saharan Africa contract HIV through unprotected heterosexual sex. The risk of HIV transmission for both men and women in Africa and elsewhere can be reduced by abstaining from sex, by only having one or a few partners, by always using condoms, and by male circumcision. In addition, several studies suggest that antiretroviral therapy (ART) greatly reduces HIV transmission.
Why Was This Study Done?
Unfortunately, in sub-Saharan Africa, only about a fifth of HIV-positive people are currently receiving ART, which means that there is an urgent need to find other effective ways to reduce HIV transmission in this region. In this prospective cohort study (a type of study that follows a group of people for some time to see which personal characteristics are associated with disease development), the researchers investigate whether bacterial vaginosis—a condition in which harmful bacteria disrupt the normal vaginal flora—increases the risk of female-to-male HIV transmission among African couples. Bacterial vaginosis, which is extremely common in sub-Saharan Africa, has been associated with an increased risk of HIV acquisition in women and induces viral replication and shedding in the vagina in HIV-positive women, which may mean that HIV-positive women with bacterial vaginosis are more likely to transmit HIV to their male partners than women without this condition. If this is the case, then interventions that reduce the incidence of bacterial vaginosis might be valuable HIV prevention strategies.
What Did the Researchers Do and Find?
The researchers analyzed data collected from 2,236 heterosexual African couples enrolled in a clinical trial (the Partners in Prevention HSV/HIV Transmission Study) whose primary aim was to investigate whether suppression of herpes simplex virus infection could prevent HIV transmission. In all the couples, the woman was HIV-positive and the man was initially HIV-negative. The female partners were examined every three months for the presence of bacterial vaginosis and the male partners were tested regularly for HIV infection. The researchers also determined whether the men who became HIV-positive were infected with the same HIV strain as their partner to check that their infection had been acquired from this partner. The HIV incidence in men whose partners had bacterial vaginosis was 2.9 per 100 person-years (that is, 2.9 out of every 100 men became HIV-positive per year) whereas the HIV incidence in men whose partners had a normal vaginal flora was 0.76 per 100 person-years. After controlling for factors that might affect the risk of HIV transmission such as male circumcision and viral levels in female partner's blood, the researchers estimated that bacterial vaginosis was associated with a 3.17-fold increased risk of female-to-male HIV transmission in their study population.
What Do These Findings Mean?
These findings suggest that HIV-positive African women with bacterial vaginosis are more than three times as likely to transmit HIV to their male partners as those with a normal vaginal flora. It is possible that some unknown characteristic of the men in this study might have increased both their own risk of HIV infection and their partner's risk of bacterial vaginosis. Nevertheless, because bacterial vaginosis is so common in Africa (half of the women in this study had bacterial vaginosis at least once during follow-up) and because this condition is associated with both female HIV acquisition and transmission, these findings suggest that bacterial vaginosis could be responsible for a substantial proportion of new HIV infections in Africa. Normalization of vaginal flora in HIV-infected women by frequent presumptive treatment with antimicrobials (treatment with a curative dose of antibiotics without testing for bacterial vaginosis) or possibly by treatment with probiotics (live “good” bacteria) might, therefore, reduce female-to-male HIV transmission in sub-Saharan Africa.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001251.
Information is available from the US National Institute of Allergy and infectious diseases on all aspects of HIV infection and AIDS and on bacterial vaginosis
The US Centers for Disease Control and Prevention has information on all aspects of HIV/AIDS, including specific information about HIV/AIDS and women; it also has information on bacterial vaginosis (in English and Spanish)
NAM/aidsmap provides basic information about HIV/AIDS, and summaries of recent research findings on HIV care and treatment, and information on bacterial vaginosis and HIV transmission (in several languages)
Information is available from Avert, an international AIDS nonprofit group on many aspects of HIV/AIDS, including detailed information on HIV and AIDS prevention, on women, HIV and AIDS and on HIV/AIDS in Africa (in English and Spanish); personal stories of women living with HIV are available; the website Healthtalkonline also provides personal stories about living with HIV
More information about the Partners in Prevention HSV/HIV Transmission Study is available
doi:10.1371/journal.pmed.1001251
PMCID: PMC3383741  PMID: 22745608
10.  Polymorphisms in the CCR5 genes of African green monkeys and mice implicate specific amino acids in infections by simian and human immunodeficiency viruses. 
Journal of Virology  1997;71(11):8642-8656.
CCR5, a receptor for the CC chemokines RANTES, Mip1alpha, and Mip1beta, has been identified as a coreceptor for infections by macrophage-tropic isolates of human immunodeficiency virus type 1 (HIV-1). To study its structure and function, we isolated cDNA clones of human, African green monkey (AGM), and NIH/Swiss mouse CCR5s, and we quantitatively analyzed infections by macrophage-tropic HIV-1 and SIVmac251 after transfecting human HeLa-CD4 cells with the CCR5 expression vectors. The AGM and NIH/Swiss mouse CCR5 proteins are 97.7 to 98.3% and 79.8% identical to the human protein, respectively. In addition, we analyzed site-directed mutants and chimeras of these CCR5s. Cell surface expression of CCR5 proteins was monitored by using a specific rabbit antiserum and by binding the chemokine [125I]Mip1beta. Our major results were as follows. (i) Two distinct AGM CCR5 sequences were reproducibly found in DNA from CV-1 cells. The AGM clone 1 CCR5 protein differs from that of clone 2 by two substitutions, Y14N in the amino-terminal extracellular region and L352F at the carboxyl terminus. Interestingly, AGM clone 1 CCR5 was inactive as a coreceptor for all tested macrophage-tropic isolates of HIV-1, whereas AGM clone 2 CCR5 was active. As shown by chimera studies and site-directed mutagenesis, the Y14N substitution in AGM clone 1 CCR5 was solely responsible for blocking HIV-1 infections. In contrast, both AGM CCR5 clones were active coreceptors for SIVmac251. Studies of DNA samples from other AGMs indicated frequent additional CCR5 polymorphisms, and we cloned an AGM clone 2 variant with a Q93R substitution in the extracellular loop 1 from one heterozygote. This variant CCR5 was active as a coreceptor for SIVmac251 but was only weakly active for macrophage-tropic isolates of HIV-1. In addition, SIVmac251 appeared to be dependent on the extracellular amino terminus and loop 2 regions of human CCR5 for maximal infection. Our results suggest major differences in the interactions of SIVmac251 and macrophage-tropic HIV-1 isolates with 19, N13, and Y14 in the amino terminus; with Q93 in extracellular loop 1; and with extracellular loop 2 of human CCR5. (ii) The NIH/Swiss mouse CCR5 protein differs at multiple positions from sequences recently reported for other inbred strains of mice. This CCR5 was inactive as a coreceptor for HIV-1 and SIVmac251. Studies of chimeras that contained different portions of NIH/Swiss mouse CCR5 substituted into human CCR5, as well as the reciprocal chimeras, indicated that the amino-terminal region and extracellular loops 1 and 2 of human CCR5 contribute to its coreceptor activity for macrophage-tropic isolates of HIV-1. Specific differences with previous CCR5 chimera results occurred because the NIH/Swiss mouse CCR5 contains a unique substitution corresponding to P183L in extracellular loop 2 that is nonpermissive for coreceptor activity. We conclude that diverse CCR5 sequences occur in AGMs and mice, that SIVmac251 and macrophage-tropic HIV-1 isolates interact differently with specific CCR5 amino acids, and that multiple regions of human CCR5 contribute to its coreceptor functions. In addition, we have identified naturally occurring amino acid polymorphisms in three extracellular regions of CCR5 (Y14N, Q93R, and P183L) that do not interfere with cell surface expression or Mip1beta binding but prevent infections by macrophage-tropic isolates of HIV-1. In contrast to previous evidence, these results suggest that CCR5 contains critical sites that are essential for HIV-1 infections.
PMCID: PMC192328  PMID: 9343222
11.  Polyclonal B Cell Differentiation and Loss of Gastrointestinal Tract Germinal Centers in the Earliest Stages of HIV-1 Infection 
PLoS Medicine  2009;6(7):e1000107.
Studying the effects of early HIV infection on human antibody responses, M. Anthony Moody and colleagues find rapid polyclonal B cell differentiation and structural damage to gut-associated lymphoid tissue.
Background
The antibody response to HIV-1 does not appear in the plasma until approximately 2–5 weeks after transmission, and neutralizing antibodies to autologous HIV-1 generally do not become detectable until 12 weeks or more after transmission. Moreover, levels of HIV-1–specific antibodies decline on antiretroviral treatment. The mechanisms of this delay in the appearance of anti-HIV-1 antibodies and of their subsequent rapid decline are not known. While the effect of HIV-1 on depletion of gut CD4+ T cells in acute HIV-1 infection is well described, we studied blood and tissue B cells soon after infection to determine the effect of early HIV-1 on these cells.
Methods and Findings
In human participants, we analyzed B cells in blood as early as 17 days after HIV-1 infection, and in terminal ileum inductive and effector microenvironments beginning at 47 days after infection. We found that HIV-1 infection rapidly induced polyclonal activation and terminal differentiation of B cells in blood and in gut-associated lymphoid tissue (GALT) B cells. The specificities of antibodies produced by GALT memory B cells in acute HIV-1 infection (AHI) included not only HIV-1–specific antibodies, but also influenza-specific and autoreactive antibodies, indicating very early onset of HIV-1–induced polyclonal B cell activation. Follicular damage or germinal center loss in terminal ileum Peyer's patches was seen with 88% of follicles exhibiting B or T cell apoptosis and follicular lysis.
Conclusions
Early induction of polyclonal B cell differentiation, coupled with follicular damage and germinal center loss soon after HIV-1 infection, may explain both the high rate of decline in HIV-1–induced antibody responses and the delay in plasma antibody responses to HIV-1.
Please see later in the article for Editors' Summary
Editors' Summary
Background
Acquired immunodeficiency syndrome (AIDS) has killed more than 25 million people since 1981 and more than 30 million people are now infected with the human immunodeficiency virus (HIV), which causes AIDS. HIV infects and kills a type of immune system cell called CD4+ T lymphocytes. These cells are needed to maintain a vigorous immune response, so people infected with HIV eventually become susceptible to other infections and develop full-blown AIDS. However, early during HIV infection, other parts of the immune system attempt to fight off the virus. Soon after infection, immune system cells called B lymphocytes begin to produce HIV-specific antibodies (proteins that recognize viral molecules called antigens). The first antibodies to HIV usually appear two to seven weeks after infection; from about 12 weeks after infection, antibodies are made that can kill the specific HIV type responsible for the infection (neutralizing antibodies).
Why Was This Study Done?
Unfortunately, by this time, it is too late for the antibody (“humoral”) immune response to clear HIV from the body. Indeed, the humoral immune response to HIV is very slow; for most viruses, neutralizing antibodies appear within days of infection. To help them design an effective HIV vaccine, scientists need to understand how the virus delays humoral responses to HIV infection (and how it later causes the production of HIV-specific antibodies to decline). Little is known, however, about the early effects of HIV infection on B lymphocytes. These cells are born and mature in the bone marrow. “Naïve” B lymphocytes, each of which carries an antigen-specific receptor (a protein that binds to a specific antigen), then enter the blood and circulate around the body, passing through the “peripheral lymphoid organs”. Exposure to antigens in these organs, which include lymph nodes and gut-associated lymphoid tissues, activates the subset of B lymphocytes that recognize the specific antigens that are present. Finally, with the help of activated T lymphocytes, the activated B lymphocytes proliferate and change (differentiate) into antibody-secreting cells and memory B lymphocytes (which respond more quickly to antigen than naïve B lymphocytes). In this study, the researchers investigate the effects of early HIV-1 infection on B lymphocytes in blood and in gut-associated lymphoid tissues.
What Did the Researchers Do and Find?
The researchers collected blood from patients as early as 17 days after HIV-1 infection and tissue samples from the lower portion of the small intestine (a region rich in gut-associated lymphoid structures called Peyer's patches) from 47 days after infection onward. When they analyzed the B lymphocytes in these samples (which were collected during two trials organized by the US Center for HIV/AIDS Vaccine Immunology [CHAVI]), they found that HIV-1 infection rapidly induced the activation of many different B cells that recognized a variety of antigens (polyclonal activation), as well as the appearance of differentiated B cells in blood and in gut-associated lymphoid tissue. The B lymphocytes that were activated in the gut made HIV-specific antibodies but also antibodies against unrelated antigens (such as flu virus proteins). Finally, the structure of Peyer's patches was altered early in HIV-1 infection. More specifically, most of the lymphoid follicles (organized collections of lymphocytes and antigen-presenting cells) in the Peyer's patches showed signs of damage and T- and B-lymphocyte death and the number of germinal centers (regions in lymphoid follicles in which B lymphocytes proliferate) was reduced.
What Do These Findings Mean?
Although the depletion of gut-associated CD4+ T lymphocytes in early HIV-1 infection is well known, these new results demonstrate the effects of early HIV-1 infection on gut-associated and circulating B lymphocytes. The results of this study are limited by the methods used to analyze the antibodies induced by HIV infection and by only taking tissue samples from one region of the gut. Nevertheless, the findings of polyclonal B-cell activation and damage to gut-associated lymphoid follicles soon after HIV-1 infection may have implications for HIV-1 vaccine design. Specifically, these findings suggest that an effective HIV-1 vaccine will need to ensure that significant levels of neutralizing antibodies are present in people before HIV-1 infection and that other protective immune defenses are fully primed so that, in the event of HIV-1 infection, the virus can be dealt with effectively before it disables any part of the immune system.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000107.
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
HIV InSite has comprehensive information on all aspects of HIV/AIDS, including an article about how HIV-1 infection affects the immune system
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on the stages of HIV infection, and on AIDS vaccines (in English and Spanish)
The US Center for HIV/AIDS Vaccine Immunology (CHAVI) Web site provides information on research designed to solve major problems in HIV vaccine development and design
doi:10.1371/journal.pmed.1000107
PMCID: PMC2702159  PMID: 19582166
12.  CCR6 Functions as a New Coreceptor for Limited Primary Human and Simian Immunodeficiency Viruses 
PLoS ONE  2013;8(8):e73116.
More than 12 chemokine receptors (CKRs) have been identified as coreceptors for the entry of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2), and simian immunodeficiency viruses (SIVs) into target cells. The expression of CC chemokine receptor 6 (CCR6) on Th17 cells and regulatory T cells make the host cells vulnerable to HIV/SIV infection preferentially. However, only limited information is available concerning the specific role of CCR6 in HIV/SIV infection. We examined CCR6 as a coreceptor candidate in this study using NP-2 cell line-based in-vitro studies. Normally, CD4-transduced cell line, NP-2/CD4, is strictly resistant to all HIV/SIV infection. When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6. Viral antigens in infected cells were detected by IFA and confirmed by detection of proviral DNA. Infection-induced syncytia in NP-2/CD4/CCR6 cells were detected by Giemsa staining. Amount of virus release through CCR6 has been detected by RT assay in spent culture medium. Sequence analysis of proviral DNA showed two common amino acid substitutions in the C2 envelope region of HIV-2MIR clones propagated through NP-2/CD4/CCR6 cells. Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region. The substitutions in the C2 region for HIV-2MIR and the V1 region of SIVsmE660 may confer selection advantage for CCR6-use. Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner. The alteration of CCR6 uses by viruses may influence the susceptibility of CD4+ CCR6+ T-cells and dendritic cell subsets in vivo and therefore, is important for viral pathogenesis in establishing latent infections, trafficking, and transmission. However, clinical relevance of CCR6 as coreceptor in HIV/SIV infections should be investigated further.
doi:10.1371/journal.pone.0073116
PMCID: PMC3757016  PMID: 24009735
13.  Inherited resistance to HIV-1 conferred by an inactivating mutation in CC chemokine receptor 5: studies in populations with contrasting clinical phenotypes, defined racial background, and quantified risk. 
Molecular Medicine  1997;3(1):23-36.
BACKGROUND: CC chemokine receptor 5 (CCR5) is a cell entry cofactor for macrophage-tropic isolates of human immunodeficiency virus-1 (HIV-1). Recently, an inactive CCR5 allele (designated here as CCR5-2) was identified that confers resistance to HIV-1 infection in homozygotes and slows the rate of progression to AIDS in heterozygotes. The reports conflict on the effect of heterozygous CCR5-2 on HIV-1 susceptibility, and race and risk levels have not yet been fully analyzed. Here we report our independent identification of CCR5-2 and test its effects on HIV-1 pathogenesis in individuals with contrasting clinical outcomes, defined race, and quantified risk. MATERIALS AND METHODS: Mutant CCR5 alleles were sought by directed heteroduplex analysis of genomic DNA from random blood donors. Genotypic frequencies were then determined in (1) random blood donors from North America, Asia, and Africa; (2) HIV-1+ individuals; and (3) highly exposed-seronegative homosexuals with quantified risk. RESULTS: CCR5-2 was the only mutant allele found. It was common in Caucasians, less common in other North American racial groups, and not detected in West Africans or Tamil Indians. Homozygous CCR5-2 frequencies differed reciprocally in highly exposed-seronegative (4.5%, n = 111) and HIV-1-seropositive (0%, n = 614) Caucasians relative to Caucasian random blood donors (0.8%, n = 387). This difference was highly significant (p < 0.0001). By contrast, heterozygous CCR5-2 frequencies did not differ significantly in the same three groups (21.6, 22.6, and 21.7%, respectively). A 55% increase in the frequency of heterozygous CCR5-2 was observed in both of two cohorts of Caucasian homosexual male, long-term nonprogressors compared with other HIV-1+ Caucasian homosexuals (p = 0.006) and compared with Caucasian random blood donors. Moreover, Kaplan-Meier estimates indicated that CCR5-2 heterozygous seroconvertors had a 52.6% lower risk of developing AIDS than homozygous wild-type seroconvertors. CONCLUSIONS: The data suggest that homozygous CCR5-2 is an HIV-1 resistance factor in Caucasians with complete penetrance, and that heterozygous CCR5-2 slows the rate of disease progression in infected Caucasian homosexuals. Since the majority (approximately 96%) of highly exposed-seronegative individuals tested are not homozygous for CCR5-2, other resistance factors must exist. Since CCR5-2 homozygotes have no obvious clinical problems, CCR5 may be a good target for the development of novel antiretroviral therapy.
Images
PMCID: PMC2230106  PMID: 9132277
14.  CCR5 Levels and Expression Pattern Correlate with Infectability by Macrophage-tropic HIV-1, In Vitro 
The Journal of Experimental Medicine  1997;185(9):1681-1692.
Chemokine receptors serve as coreceptors for HIV entry into CD4+ cells. Their expression is thought to determine the tropism of viral strains for different cell types, and also to influence susceptibility to infection and rates of disease progression. Of the chemokine receptors, CCR5 is the most important for viral transmission, since CCR5 is the principal receptor for primary, macrophage-tropic viruses, and individuals homozygous for a defective CCR5 allele (Δ32/ Δ32) are highly resistant to infection with HIV-1. In this study, CCR5-specific mAbs were generated using transfectants expressing high levels of CCR5. The specificity of these mAbs was confirmed using a broad panel of chemokine receptor transfectants, and by their non-reactivity with T cells from Δ32/Δ32 individuals. CCR5 showed a distinct pattern of expression, being abundant on long-term activated, IL-2–stimulated T cells, on a subset of effector/memory T cells in blood, and on tissue macrophages. A comparison of normal and CCR5 Δ32 heterozygotes revealed markedly reduced expression of CCR5 on T cells from the heterozygotes. There was considerable individual to individual variability in the expression of CCR5 on blood T cells, that related to factors other than CCR5 genotype. Low expression of CCR5 correlated with the reduced infectability of T cells with macrophage-tropic HIV-1, in vitro. Anti-CCR5 mAbs inhibited the infection of PBMC by macrophage-tropic HIV-1 in vitro, but did not inhibit infection by T cell–tropic virus. Anti-CCR5 mAbs were poor inhibitors of chemokine binding, indicating that HIV-1 and ligands bind to separate, but overlapping regions of CCR5. These results illustrate many of the important biological features of CCR5, and demonstrate the feasibility of blocking macrophage-tropic HIV-1 entry into cells with an anti-CCR5 reagent.
PMCID: PMC2196298  PMID: 9151905
15.  Causes of Acute Hospitalization in Adolescence: Burden and Spectrum of HIV-Related Morbidity in a Country with an Early-Onset and Severe HIV Epidemic: A Prospective Survey 
PLoS Medicine  2010;7(2):e1000178.
Rashida Ferrand and colleagues show that HIV infection is the commonest cause of hospitalization among adolescents in a high HIV prevalence setting.
Background
Survival to older childhood with untreated, vertically acquired HIV infection, which was previously considered extremely unusual, is increasingly well described. However, the overall impact on adolescent health in settings with high HIV seroprevalence has not previously been investigated.
Methods and Findings
Adolescents (aged 10–18 y) systematically recruited from acute admissions to the two public hospitals in Harare, Zimbabwe, answered a questionnaire and underwent standard investigations including HIV testing, with consent. Pre-set case-definitions defined cause of admission and underlying chronic conditions. Participation was 94%. 139 (46%) of 301 participants were HIV-positive (median age of diagnosis 12 y: interquartile range [IQR] 11–14 y), median CD4 count = 151; IQR 57–328 cells/µl), but only four (1.3%) were herpes simplex virus-2 (HSV-2) positive. Age (median 13 y: IQR 11–16 y) and sex (57% male) did not differ by HIV status, but HIV-infected participants were significantly more likely to be stunted (z-score<−2: 52% versus 23%, p<0.001), have pubertal delay (15% versus 2%, p<0.001), and be maternal orphans or have an HIV-infected mother (73% versus 17%, p<0.001). 69% of HIV-positive and 19% of HIV-negative admissions were for infections, most commonly tuberculosis and pneumonia. 84 (28%) participants had underlying heart, lung, or other chronic diseases. Case fatality rates were significantly higher for HIV-related admissions (22% versus 7%, p<0.001), and significantly associated with advanced HIV, pubertal immaturity, and chronic conditions.
Conclusion
HIV is the commonest cause of adolescent hospitalisation in Harare, mainly due to adult-spectrum opportunistic infections plus a high burden of chronic complications of paediatric HIV/AIDS. Low HSV-2 prevalence and high maternal orphanhood rates provide further evidence of long-term survival following mother-to-child transmission. Better recognition of this growing phenomenon is needed to promote earlier HIV diagnosis and care.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Acquired immunodeficiency syndrome (AIDS) has killed more than 25 million people since 1981, and more than 30 million people are now infected with the human immunodeficiency virus (HIV) that causes AIDS. HIV destroys the cells in the immune system that normally provide protection against disease-causing organisms. Consequently, people infected with HIV are susceptible to so-called opportunistic infections, including tuberculosis and pneumonia. HIV is most commonly spread through unprotected sex with an infected partner but another major route of transmission is mother-to-child (vertical transmission) during pregnancy or delivery or during breast feeding. Mother-to-child transmission can be prevented by giving antiviral drugs to HIV-positive mothers during their pregnancy and to their newborn children. But, although most mothers in developed countries have access to this intervention, fewer than half of HIV-positive mothers in low- and middle-income countries receive this treatment and, every year, nearly half a million children become infected with HIV.
Why Was This Study Done?
It is generally thought that HIV infections in infants progress rapidly and that half of the children who acquire HIV from their mothers will die before their second birthday if not treated with antiretroviral drugs. However, as the AIDS epidemic matures, more children are surviving to adolescence with untreated, vertically acquired HIV infection in sub-Saharan Africa, the region where most children with HIV/AIDS live. Little is known about the burden of HIV infection and its contribution to illness and death in adolescents in sub-Saharan Africa but this information is needed to help health care providers prepare for this new aspect of the AIDS epidemic. In this study, the researchers examine the causes of acute hospital admissions (admissions for conditions with a sudden onset and usually a short course) among adolescents in Zimbabwe, a country where the HIV epidemic started early and where one in seven adults is HIV-positive and more than 17,000 children are infected with HIV every year, mainly through vertical transmission.
What Did the Researchers Do and Find?
The researchers recruited 301 10–18-year olds who were admitted to each of the two public hospitals in Harare (Zimbabwe) for acute illnesses between September 2007 and April 2008. Each patient completed a questionnaire about themselves and their health and underwent standard investigations, including HIV testing. Nearly half the participants were HIV positive; about a quarter of these HIV-positive individuals only found out about their status during the study. HIV-positive participants were more likely to be stunted, to have pubertal delay, and to be maternal orphans or have an HIV-infected mother than HIV-negative participants. 69% of HIV-positive participants were admitted to hospital because of infections, often tuberculosis or pneumonia whereas only 19% of the HIV-negative participants were admitted for infections. More than a quarter of all the participants had underlying heart, lung, or other chronic conditions. Finally, 22% of the HIV-positive participants died while in hospital compared to only 7% of the HIV-negative participants. Factors that increased the risk of death among all the participants were advanced HIV infection, pubertal immaturity, and chronic conditions.
What Do These Findings Mean?
These findings indicate that HIV infection is the commonest cause of acute adolescent admission to hospital in Harare (and probably elsewhere in Zimbabwe). Most of these admissions are due to opportunistic infections similar to those seen in HIV-positive adults and to long-term complications of having HIV/AIDS as an infant such as delayed puberty. Other findings indicate that most of the HIV-positive adolescents who participated in this study were infected via vertical transmission, which supports the idea that long-term survival after vertical infection is possible. Because the AIDS epidemic started early in Zimbabwe, there is likely to be a lag before adolescent survivors of vertical HIV transmission become common elsewhere. Nevertheless, all African countries and other places where HIV infection in adults is common need to recognize that the burden of HIV in their acutely unwell adolescents is likely to increase over the next few years. To deal with this emerging aspect of the AIDS epidemic, measures must be introduced to ensure early diagnosis of HIV in this previously neglected age group so that treatment can be started before HIV-positive adolescents become critically ill.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000178.
This study is further discussed in a PLoS Medicine Perspective by Glenda Gray
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
HIV InSite has comprehensive information on all aspects of HIV/AIDS, including a list of articles and other sources of information about the primary care of adolescents with HIV
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on the HIV and AIDS in Zimbabwe, and on children, HIV, and AIDS (in English and Spanish)
UNICEF also has information about children and HIV and AIDS (in several languages)
doi:10.1371/journal.pmed.1000178
PMCID: PMC2814826  PMID: 20126383
16.  When Do HIV-Infected Women Disclose Their HIV Status to Their Male Partner and Why? A Study in a PMTCT Programme, Abidjan 
PLoS Medicine  2007;4(12):e342.
Background
In Africa, women tested for HIV during antenatal care are counselled to share with their partner their HIV test result and to encourage partners to undertake HIV testing. We investigate, among women tested for HIV within a prevention of mother-to-child transmission of HIV (PMTCT) programme, the key moments for disclosure of their own HIV status to their partner and the impact on partner HIV testing.
Methods and Findings
Within the Ditrame Plus PMTCT project in Abidjan, 546 HIV-positive and 393 HIV-negative women were tested during pregnancy and followed-up for two years after delivery. Circumstances, frequency, and determinants of disclosure to the male partner were estimated according to HIV status. The determinants of partner HIV testing were identified according to women's HIV status. During the two-year follow-up, disclosure to the partner was reported by 96.7% of the HIV-negative women, compared to 46.2% of HIV-positive women (χ2 = 265.2, degrees of freedom [df] = 1, p < 0.001). Among HIV-infected women, privileged circumstances for disclosure were just before delivery, during early weaning (at 4 mo to prevent HIV postnatal transmission), or upon resumption of sexual activity. Formula feeding by HIV-infected women increased the probability of disclosure (adjusted odds ratio 1.54, 95% confidence interval 1.04–2.27, Wald test = 4.649, df = 1, p = 0.031), whereas household factors such as having a co-spouse or living with family reduced the probability of disclosure. The proportion of male partners tested for HIV was 23.1% among HIV-positive women and 14.8% among HIV-negative women (χ2 = 10.04, df = 1, p = 0.002). Partners of HIV-positive women who were informed of their wife's HIV status were more likely to undertake HIV testing than those not informed (37.7% versus 10.5%, χ2 = 56.36, df = 1, p < 0.001).
Conclusions
In PMTCT programmes, specific psychosocial counselling and support should be provided to women during the key moments of disclosure of HIV status to their partners (end of pregnancy, weaning, and resumption of sexual activity). This support could contribute to improving women's adherence to the advice given to prevent postnatal and sexual HIV transmission.
In a mother-to-child HIV prevention program in Côte d'Ivoire, Annabel Desgrées-du-Loû and colleagues identify three junctures at which women tend to disclose their HIV status to partners.
Editors' Summary
Background.
Since the first reported case of AIDS (acquired immunodeficiency syndrome) in 1981, the number of people infected with the human immunodeficiency virus (HIV), which causes AIDS, has risen steadily. By the end of 2006, nearly 40 million people were infected, 25 million of them in sub-Saharan Africa. HIV is most often spread by having unprotected sex with an infected partner. In Africa, most sexual transmission of HIV is between partners in stable relationships—many such couples do not adopt measures that prevent viral transmission, such as knowing the HIV status of both partners and using condoms if one partner is HIV-positive. HIV can also pass from a mother to her baby during pregnancy, labor, or delivery, or through breastfeeding. Mother-to-child transmission (MTCT) of HIV can be reduced by giving anti-HIV drugs to the mother during pregnancy and labor and to her newborn baby, and by avoiding breastfeeding or weaning the baby early.
Why Was This Study Done?
Many African countries have programs for prevention of MTCT (PMTCT) that offer pregnant women prenatal HIV counseling and testing. As a result, women are often the first member of a stable relationship to know their HIV status. PMTCT programs advise women to disclose their HIV test result to their partner and to encourage him to have an HIV test. But for many women, particularly those who are HIV-positive, talking to their partner about HIV/AIDS is hard because of fears of rejection (which could mean loss of housing and food) or accusations of infidelity. Knowing more about when women disclose their HIV status and what makes them decide to do so would help the people running PMTCT programs to support women during the difficult process of disclosure. In this study, the researchers have investigated when and why women participating in a PMTCT research project in Abidjan (Côte d'Ivoire) told their partner about their HIV status and the impact this disclosure had on their partner's uptake of HIV testing.
What Did the Researchers Do and Find?
At regular follow-up visits, the researchers asked women in the Abidjan PMTCT project whether they had told their partners their HIV status and whether they were breast-feeding or had resumed sexual activity. Nearly all the women who tested negative for HIV, but slightly fewer than half of the HIV-positive (infected) women had told their partner about their HIV status by two years after childbirth. Two-thirds of the HIV-positive women who disclosed their status did so before delivery. Other key times for disclosure were at early weaning (4 months after birth) for women who breast-fed their babies, and when sexual activity resumed. HIV-positive women who bottle fed their babies from birth were more likely to tell their partners of their status than women who breast-fed. Factors that prevented women disclosing their HIV status included living in a polygamous relationship or living separately from their partners. Finally, the researchers report that the partners of HIV-positive women who disclosed their HIV status were about three times more likely to take an HIV test than the partners of HIV-positive women who did not disclose.
What Do These Findings Mean?
These findings identify three key times when women who have had an HIV test during pregnancy are likely to disclose their HIV status to their partner. The main one is before delivery and relates, in part, to how the mother plans to feed her baby. To bottle feed in Abidjan, women need considerable support from their partners and this may be the impetus for disclosing their HIV status. Disclosure at early weaning may reflect the woman's need to enlist her partner's support for this unusual decision—the normal time for weaning in Abidjan is 17 months. Finally, disclosure when sexual activity resumes may be necessary so that the woman can explain why she wants to use condoms. Although these findings need confirmation in other settings, targeting counseling and support within PMTCT programs to these key moments might help HIV-positive women to tell their partners about their status. This, hopefully, would help to reduce sexual transmission of HIV within stable relationships in sub-Saharan Africa.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040342.
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS and on HIV infection in women
HIV InSite has comprehensive information on all aspects of HIV/AIDS
Women Children and HIV provides extensive information on prevention of mother-to-child transmission of HIV in developing countries
Information is available from Avert, an international AIDS charity, on HIV and AIDS in Africa and on HIV and AIDS prevention
AIDSinfo, a service of the US Department of Health and Human Services provideshealth information for HIV-positive pregnant women (in English and Spanish)
doi:10.1371/journal.pmed.0040342
PMCID: PMC2100145  PMID: 18052603
17.  A Multi-targeted Drug Candidate with Dual Anti-HIV and Anti-HSV Activity 
PLoS Pathogens  2013;9(7):e1003456.
Human immunodeficiency virus (HIV) infection is often accompanied by infection with other pathogens, in particular herpes simplex virus type 2 (HSV-2). The resulting coinfection is involved in a vicious circle of mutual facilitations. Therefore, an important task is to develop a compound that is highly potent against both viruses to suppress their transmission and replication. Here, we report on the discovery of such a compound, designated PMEO-DAPym. We compared its properties with those of the structurally related and clinically used acyclic nucleoside phosphonates (ANPs) tenofovir and adefovir. We demonstrated the potent anti-HIV and -HSV activity of this drug in a diverse set of clinically relevant in vitro, ex vivo, and in vivo systems including (i) CD4+ T-lymphocyte (CEM) cell cultures, (ii) embryonic lung (HEL) cell cultures, (iii) organotypic epithelial raft cultures of primary human keratinocytes (PHKs), (iv) primary human monocyte/macrophage (M/M) cell cultures, (v) human ex vivo lymphoid tissue, and (vi) athymic nude mice. Upon conversion to its diphosphate metabolite, PMEO-DAPym markedly inhibits both HIV-1 reverse transcriptase (RT) and HSV DNA polymerase. However, in striking contrast to tenofovir and adefovir, it also acts as an efficient immunomodulator, inducing β-chemokines in PBMC cultures, in particular the CCR5 agonists MIP-1β, MIP-1α and RANTES but not the CXCR4 agonist SDF-1, without the need to be intracellularly metabolized. Such specific β-chemokine upregulation required new mRNA synthesis. The upregulation of β-chemokines was shown to be associated with a pronounced downmodulation of the HIV-1 coreceptor CCR5 which may result in prevention of HIV entry. PMEO-DAPym belongs conceptually to a new class of efficient multitargeted antivirals for concomitant dual-viral (HSV/HIV) infection therapy through inhibition of virus-specific pathways (i.e. the viral polymerases) and HIV transmission prevention through interference with host pathways (i.e. CCR5 receptor down regulation).
Author Summary
To contain the HIV-1 epidemic, it is necessary to develop antivirals that prevent HIV-1 transmission. It is well known that HIV infection might be accompanied by other pathogens, which often are engaged with HIV-1 in a vicious circle of mutual facilitation. One of the most common of these pathogens is herpes simplex virus (HSV) type 2. Since there is an urgent need for a next generation antivirals that are multi-targeted, we can now report on the development of the first antiviral of this new generation that efficiently suppresses both HIV-1 and HSV-2. We found that the dual-targeted antiviral drug affects several targets for viral replication. It uniquely combines in one molecule three important abilities: (i) to efficiently suppress HSV-encoded DNA polymerase, (ii) to efficiently suppress HIV-1-encoded reverse transcriptase, and (iii) to stimulate secretion of CC-chemokines that downregulate the HIV-1 coreceptor CCR5. The compound suppresses both viruses in a wide-range of in vitro, ex vivo, and in vivo experimental models. The ability of one molecule to suppress HIV-1 and HSV-2 by combining direct activity against their two key enzymes and indirect immunomodulatory effects is unique in the antiviral field.
doi:10.1371/journal.ppat.1003456
PMCID: PMC3723632  PMID: 23935482
18.  A formylpeptide receptor, FPRL1, acts as an efficient coreceptor for primary isolates of human immunodeficiency virus 
Retrovirology  2008;5:52.
Background
More than 10 members of seven-transmembrane G protein-coupled receptors (GPCRs) have been shown to work as coreceptors for human immunodeficiency virus type 1 (HIV-1), HIV type 2 (HIV-2), and simian immunodeficiency viruses (SIVs). As a common feature of HIV/SIV coreceptors, tyrosine residues are present with asparagines, aspartic acids or glutamic acids in the amino-terminal extracellular regions (NTRs).
We noticed that a receptor for N-formylpeptides, FPRL1, also contains two tyrosine residues accompanied by glutamic acids in its NTR. It was reported that monocytes expressing CCR5 and FPRL1 in addition to CD4 are activated by treatment with ligands or agonists of FPRL1. Activated monocytes down-modulate CCR5 and become resistant to infection by HIV-1 strains. Thus, FPRL1 plays important roles in protection of monocyptes against HIV-1 infection. However, its own coreceptor activity has not been elucidated yet. In this study, we examined coreceptor activities of FPRL1 for HIV/SIV strains including primary HIV-1 isolates.
Results
A CD4-transduced human glioma cell line, NP-2/CD4, is strictly resistant to HIV/SIV infection. We have reported that when NP-2/CD4 cells are transduced with a GPCR having coreceptor activity, the cells become susceptible to HIV/SIV strains. When NP-2/CD4 cells were transduced with FPRL1, the resultant NP-2/CD4/FPRL1 cells became markedly susceptible to some laboratory-adapted HIV/SIV strains. We found that FPRL1 is also efficiently used as a coreceptor by primary HIV-1 isolates as well as CCR5 or CXCR4.
Amino acid sequences linked to the FPRL1 use could not be detected in the V3 loop of the HIV-1 Env protein. Coreceptor activities of FPRL1 were partially blocked by the forymyl-Met-Leu-Phe (fMLF) peptide.
Conclusion
We conclude that FPRL1 is a novel and efficient coreceptor for HIV/SIV strains. FPRL1 works as a bifunctional factor in HIV-1 infection. Namely, the role of FPRL1 in HIV-1 infection is protective and/or promotive in different conditions. FPRL1 has been reported to be abundantly expressed in the lung, spleen, testis, and neutrophils. We detected mRNA expression of FPRL1 in 293T (embryonal kidney cell line), C8166 (T cell line), HOS (osteosarcoma cell line), Molt4#8 (T cell line), U251MG (astrocytoma cell line), U87/CD4 (CD4-transduced glioma cell line), and peripheral blood lymphocytes. Roles of FPRL1 in HIV-1 infection in vivo should be further investigated.
doi:10.1186/1742-4690-5-52
PMCID: PMC2453146  PMID: 18577234
19.  Heterozygosity for a defective gene for CC chemokine receptor 5 is not the sole determinant for the immunologic and virologic phenotype of HIV-infected long-term nonprogressors. 
Journal of Clinical Investigation  1997;100(6):1581-1589.
HIV-1-infected long-term nonprogressors are a heterogeneous group of individuals with regard to immunologic and virologic markers of HIV-1 disease. CC chemokine receptor 5 (CCR5) has recently been identified as an important coreceptor for HIV-1 entry into CD4+ T cells. A mutant allele of CCR5 confers a high degree of resistance to HIV-1 infection in homozygous individuals and partial protection against HIV disease progression in heterozygotes. The frequency of CCR5 heterozygotes is increased among HIV-1- infected long-term nonprogressors compared with progressors; however, the host defense mechanisms responsible for nonprogression in CCR5 heterozygotes are unknown. We hypothesized that nonprogressors who were heterozygous for the mutant CCR5 gene might define a subgroup of nonprogressors with higher CD4+ T cell counts and lower viral load compared with CCR5 wild-type nonprogressors. However, in a cohort of 33 HIV-1-infected long-term nonprogressors, those who were heterozygous for the mutant CCR5 gene were indistinguishable from CCR5 wild-type nonprogressors with regard to all measured immunologic and virologic parameters. Although epidemiologic data support a role for the mutant CCR5 allele in the determination of the state of long-term nonprogression in some HIV-1- infected individuals, it is not the only determinant. Furthermore, long-term nonprogressors with the wild-type CCR5 genotype are indistinguishable from heterozygotes from an immunologic and virologic standpoint.
PMCID: PMC508340  PMID: 9294127
20.  Insensitivity of Paediatric HIV-1 Subtype C Viruses to Broadly Neutralising Monoclonal Antibodies Raised against Subtype B 
PLoS Medicine  2006;3(7):e255.
Background
A Phase I clinical trial has been proposed that uses neutralising monoclonal antibodies (MAbs) as passive immunoprophylaxis to prevent mother-to-child transmission of HIV-1 in South Africa. To assess the suitability of such an approach, we determined the sensitivity of paediatric HIV-1 subtype C viruses to the broadly neutralising MAbs IgG1b12, 2G12, 2F5, and 4E10.
Methods and Findings
The gp160 envelope genes from seven children with HIV-1 subtype C infection were cloned and used to construct Env-pseudotyped viruses that were tested in a single-cycle neutralisation assay. The epitopes defining three of these MAbs were determined from sequence analysis of the envelope genes. None of the seven HIV-1 subtype C pseudovirions was sensitive to 2G12 or 2F5, which correlated with the absence of crucial N-linked glycans that define the 2G12 epitope and substitutions of residues integral to the 2F5 epitope. Four viruses were sensitive to IgG1b12, and all seven viruses were sensitive to 4E10.
Conclusions
Only 4E10 showed significant activity against HIV-1 subtype C isolates, while 2G12 and 2F5 MAbs were ineffective and IgG1b12 was partly effective. It is therefore recommended that 2G12 and 2F5 MAbs not be used for passive immunization experiments in southern Africa and other regions where HIV-1 subtype C viruses predominate.
Editors' Summary
Background.
AIDS is caused by HIV. By killing the cells of the body's immune system, HIV infection makes people vulnerable to many potentially fatal bacterial and viral diseases. HIV is most commonly spread through unprotected sex with an infected partner but it can also pass from mother to child during late pregnancy or birth, or through breast milk. At least one in four infected women will transmit HIV to their babies if left untreated. But if infected women are treated with drugs that fight HIV—so-called antiretrovirals—during late pregnancy and if breastfeeding does not occur, only one to two babies in 100 will become infected with HIV. In addition, elective Caesarian section has been found to be protective against HIV infection. Implementation of this approach has greatly reduced mother-to-child transmission in developed countries, but most HIV-infected women live in developing countries where access to antiretrovirals is limited. In these cases, treatment of pregnant women (during pregnancy and delivery) and their newborn babies with a single dose of one antiretroviral drug, which can halve HIV transmission, is used, even though WHO/UNAIDS recommends simple antenatal, intrapartum, and postnatal antiretroviral regimens to achieve levels of less than 5% transmission in resource poor settings. These strategies will not have an impact on breastmilk transmission, which accounts for half the transmissions in these settings.
Why Was This Study Done?
One way to reduce breastmilk transmission of HIV might be by “passive immunization.” In this, newborn babies would be injected with HIV-specific antibodies—proteins that stick to molecules on the surface of HIV. Because the virus uses these molecules to invade the baby's immune cells, injected antibodies might stop HIV from the mother becoming established in her offspring. Four antibodies have been made in the laboratory—so-called human monoclonal antibodies—that bind to the surface of HIV subtype B, which is found mainly in Europe and North America, and stop HIV from killing human cells. However, most HIV isolated in Africa is subtype C, so in this study researchers have tested whether these antibodies prevent HIV subtype C killing cells grown in the laboratory. It is important, they argue, that antibodies should be shown to work outside the body before testing passive immunization in babies.
What Did the Researchers Do and Find?
The researchers isolated several subtype C viruses from babies born in Johannesburg, South Africa, and made artificial viruses (known as “pseudotyped” viruses) from them. These artificial viruses could then be used in tests to see whether the human monoclonal antibodies could prevent the viruses infecting human cells in a laboratory test, that is, whether the viruses were “sensitive” to the antibodies. All the viruses were insensitive to two of the antibodies (2G12 and 2F5), and the researchers show that this was because the viruses lacked the specific parts of the HIV surface molecules recognized by these antibodies. Four of the viruses were sensitive to an antibody called IgG1b12, and all were sensitive to antibody 4E10, albeit at high concentrations that might be difficult to achieve in people. Finally, the researchers report that the sensitivity of the viruses was not enhanced by using all four antibodies at the same time.
What Do These Findings Mean?
Given these results, the researchers warn against using 2G12 and 2F5 antibodies for passive immunization to prevent mother-to-child transmission, in particular postnatal transmission, in areas where most people are infected with HIV subtype C viruses. Furthermore, because animal studies have indicated that only combinations of at least three monoclonal antibodies with activity against HIV in laboratory tests provide complete protection against HIV infection, the researchers question whether any clinical trials on passive immunization should be started with currently available antibodies. Their doubts about such trials are heightened by observations that 4E10 and 2F5 react against antigens present on human cells, which might make them unsafe for use in people, although so far no adverse effects have been seen in adults treated with these antibodies. However, these experiments used an artificial laboratory-based assay and it's possible that these antibodies might kill HIV subtype C more effectively in people; other components of the immune system might help them deal with the virus. If clinical studies of these antibodies do go ahead, it is essential that the babies in these trials must be carefully monitored to ensure that the antibodies are safe, and they and their mothers should also be given access to optimal antiretroviral prophylaxis according to WHO/UNAIDS guidelines. In a related PLoS Medicine Perspective paper (http://dx.doi.org/10.1371/journal.pmed.0030259), Miroslaw Gorny1 and Susan Zolla-Pazner discuss the study further and stress the critical need to determine if passive immunization with such antibodies could decrease mother-to-child transmission of HIV, and if so what the best antibodies would be.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030255.
•  National Institute of Allergy and Infectious Diseases fact sheets on HIV infection and AIDS
•  US Department of Health and Human Services information on HIV/AIDS, including clinical guidelines and fact sheets on preventing transmission from mother to child
•  US Centers for Disease Control and Prevention information on HIV/AIDS, including pages on the prevention of mother-to-child transmission
•  MedlinePlus encyclopedia entry on HIV/AIDS
•  Preventing mother-to-child transmission of HIV Web page
Assessment of viruses from seven children with HIV-1 subtype C infection showed generally poor sensitivity to four monoclonal antibodies proposed for a trial of passive immunoprophylaxis to prevent mother-to-child transmission.
doi:10.1371/journal.pmed.0030255
PMCID: PMC1502151  PMID: 16834457
21.  Episodic Sexual Transmission of HIV Revealed by Molecular Phylodynamics 
PLoS Medicine  2008;5(3):e50.
Background
The structure of sexual contact networks plays a key role in the epidemiology of sexually transmitted infections, and their reconstruction from interview data has provided valuable insights into the spread of infection. For HIV, the long period of infectivity has made the interpretation of contact networks more difficult, and major discrepancies have been observed between the contact network and the transmission network revealed by viral phylogenetics. The high rate of HIV evolution in principle allows for detailed reconstruction of links between virus from different individuals, but often sampling has been too sparse to describe the structure of the transmission network. The aim of this study was to analyze a high-density sample of an HIV-infected population using recently developed techniques in phylogenetics to infer the short-term dynamics of the epidemic among men who have sex with men (MSM).
Methods and Findings
Sequences of the protease and reverse transcriptase coding regions from 2,126 patients, predominantly MSM, from London were compared: 402 of these showed a close match to at least one other subtype B sequence. Nine large clusters were identified on the basis of genetic distance; all were confirmed by Bayesian Monte Carlo Markov chain (MCMC) phylogenetic analysis. Overall, 25% of individuals with a close match with one sequence are linked to 10 or more others. Dated phylogenies of the clusters using a relaxed clock indicated that 65% of the transmissions within clusters took place between 1995 and 2000, and 25% occurred within 6 mo after infection. The likelihood that not all members of the clusters have been identified renders the latter observation conservative.
Conclusions
Reconstruction of the HIV transmission network using a dated phylogeny approach has revealed the HIV epidemic among MSM in London to have been episodic, with evidence of multiple clusters of transmissions dating to the late 1990s, a period when HIV prevalence is known to have doubled in this population. The quantitative description of the transmission dynamics among MSM will be important for parameterization of epidemiological models and in designing intervention strategies.
Using viral genotype data from HIV drug resistance testing at a London clinic, Andrew Leigh Brown and colleagues derive the structure of the transmission network through phylogenetic analysis.
Editors' Summary
Background.
Human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS), is mainly spread through unprotected sex with an infected partner. Like other sexually transmitted diseases, HIV/AIDS spreads through networks of sexual contacts. The characteristics of these complex networks (which include people who have serial sexual relationships with single partners and people who have concurrent sexual relationships with several partners) affect how quickly diseases spread in the short term and how common the disease is in the long term. For many sexually transmitted diseases, sexual contact networks can be reconstructed from interview data. The information gained in this way can be used for partner notification so that transmitters of the disease and people who may have been unknowingly infected can be identified, treated, and advised about disease prevention. It can also be used to develop effective community-based prevention strategies.
Why Was This Study Done?
Although sexual contact networks have provided valuable information about the spread of many sexually transmitted diseases, they cannot easily be used to understand HIV transmission patterns. This is because the period of infectivity with HIV is long and the risk of infection from a single sexual contact with an infected person is low. Another way to understand the spread of HIV is through phylogenetics, which examines the genetic relatedness of viruses obtained from different individuals. Frequent small changes in the genetic blueprint of HIV allow the virus to avoid the human immune response and to become resistant to antiretroviral drugs. In this study, the researchers use recently developed analytical methods, viral sequences from a large proportion of a specific HIV-infected population, and information on when each sample was taken, to learn about transmission of HIV/AIDS in London among men who have sex with men (MSM; a term that encompasses gay, bisexual, and transgendered men and heterosexual men who sometimes have sex with men). This new approach, which combines information on viral genetic variation and viral population dynamics, is called “molecular phylodynamics.”
What Did the Researchers Do and Find?
The researchers compared the sequences of the genes encoding the HIV-1 protease and reverse transcriptase from more than 2,000 patients, mainly MSM, attending a large London HIV clinic between 1997 and 2003. 402 of these sequences closely matched at least one other subtype B sequence (the HIV/AIDS epidemic among MSM in the UK primarily involves HIV subtype B). Further analysis showed that the patients from whom this subset of sequences came formed six clusters of ten or more individuals, as well as many smaller clusters, based on the genetic relatedness of their HIV viruses. The researchers then used information on the date when each sample was collected and a “relaxed clock” approach (which accounts for the possibility that different sequences evolve at different rates) to determine dated phylogenies (patterns of genetic relatedness that indicate when gene sequences change) for the clusters. These phylogenies indicated that at least in one in four transmissions between the individuals in the large clusters occurred within 6 months of infection, and that most of the transmissions within each cluster occurred over periods of 3–4 years during the late 1990s.
What Do These Findings Mean?
This phylodynamic reconstruction of the HIV transmission network among MSM in a London clinic indicates that the HIV epidemic in this population has been episodic with multiple clusters of transmission occurring during the late 1990s, a time when the number of HIV infections in this population doubled. It also suggests that transmission of the virus during the early stages of HIV infection is likely to be an important driver of the epidemic. Whether these results apply more generally to the MSM population at risk for transmitting or acquiring HIV depends on whether the patients in this study are representative of that group. Additional studies are needed to determine this, but if the patterns revealed here are generalizable, then this quantitative description of HIV transmission dynamics should help in the design of strategies to strengthen HIV prevention among MSM.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050050.
Read a related PLoS Medicine Perspective article
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
HIV InSite has comprehensive information on all aspects of HIV/AIDS, including a list of organizations that provide information for gay men and MSM
The US Centers for Disease Control and Prevention provides information on HIV/AIDS and on HIV/AIDS among MSM (in English and Spanish)
Information is available from Avert, an international AIDS charity, on HIV, AIDS, and men who have sex with men
The Center for AIDS Prevention Studies (University of California, San Francisco) provides information on sexual networks and HIV prevention
The US National Center for Biotechnology Information provides a science primer on molecular phylogenetics
UK Collaborative Group on HIV Drug Resistance maintains a database of resistance tests
HIV i-Base offers HIV treatment information for health-care professionals and HIV-positive people
The NIH-funded HIV Sequence Database contains data on genetic sequences, resistance, immunology, and vaccine trials
doi:10.1371/journal.pmed.0050050
PMCID: PMC2267814  PMID: 18351795
22.  Cocaine Differentially Modulates Chemokine Production by Mononuclear Cells from Normal Donors and Human Immunodeficiency Virus Type 1-Infected Patients 
Earlier studies have supported a significant role for cocaine in the susceptibility to and the progression of human immunodeficiency virus type 1 (HIV-1) infection. Recently, several unique HIV-1 entry coreceptors (e.g., CCR5 and CCR3) and a trio of HIV-1-specific suppressor chemokines, namely, RANTES (regulated-upon-activation T expressed and secreted), macrophage inflammatory protein 1α (MIP-1α) and MIP-1β, were identified. Although cocaine has been linked to the immunopathogenesis of HIV-1 infection, the corresponding cellular and molecular mechanism(s) have not been well defined. We hypothesize that cocaine mediates these pathologic effects through the downregulation of HIV-1-suppressing chemokines and/or upregulating HIV-1 entry coreceptors in HIV-1-infected subjects, resulting in disease progression to AIDS. Our results show that cocaine selectively downregulates endogenous MIP-1β secretion by normal peripheral blood mononuclear cells (PBMC), while cocaine did not affect the MIP-1β production by PBMC from AIDS patients. Cocaine also selectively suppresses lipopolysaccharide-induced MIP-1β production by PBMC from HIV-infected patients. Further, cocaine significantly downregulates endogenous MIP-1β gene expression, while it upregulates HIV-1 entry coreceptor CCR5 by normal PBMC. These studies suggests a role for cocaine as a cofactor in the pathogenesis of HIV infection and support the premise that cocaine increases susceptibility to and progression of HIV-1 infection by inhibiting the synthesis of HIV-1 protective chemokines and/or upregulating the HIV-1 entry coreceptor, CCR5.
PMCID: PMC95830  PMID: 10618285
23.  Association of chemokine receptor gene (CCR2-CCR5) haplotypes with acquisition and control of HIV-1 infection in Zambians 
Retrovirology  2011;8:22.
Background
Polymorphisms in chemokine (C-C motif) receptors 2 and 5 genes (CCR2 and CCR5) have been associated with HIV-1 infection and disease progression. We investigated the impact of CCR2-CCR5 haplotypes on HIV-1 viral load (VL) and heterosexual transmission in an African cohort. Between 1995 and 2006, cohabiting Zambian couples discordant for HIV-1 (index seropositive and HIV-1 exposed seronegative {HESN}) were monitored prospectively to determine the role of host genetic factors in HIV-1 control and heterosexual transmission. Genotyping for eight CCR2 and CCR5 variants resolved nine previously recognized haplotypes. By regression and survival analytic techniques, controlling for non-genetic factors, we estimated the effects of these haplotypic variants on a) index partner VL, b) seroconverter VL, c) HIV-1 transmission by index partners, d) HIV-1 acquisition by HESN partners.
Results
Among 567 couples, 240 virologically linked transmission events had occurred through 2006. HHF*2 homozygosity was associated with significantly lower VL in seroconverters (mean beta = -0.58, log10 P = 0.027) and the HHD/HHE diplotype was associated with significantly higher VL in the seroconverters (mean beta = 0.54, log10 P = 0.014) adjusted for age and gender in multivariable model. HHD/HHE was associated with more rapid acquisition of infection by the HESNs (HR = 2.0, 95% CI = 1.20-3.43, P = 0.008), after adjustments for index partner VL and the presence of genital ulcer or inflammation in either partner in Cox multivariable models. The HHD/HHE effect was stronger in exposed females (HR = 2.1, 95% CI = 1.14-3.95, P = 0.018).
Conclusions
Among Zambian discordant couples, HIV-1 coreceptor gene haplotypes and diplotypes appear to modulate HIV-1 VL in seroconverters and alter the rate of HIV-1 acquisition by HESNs. These associations replicate or resemble findings reported in other African and European populations.
doi:10.1186/1742-4690-8-22
PMCID: PMC3075214  PMID: 21429204
24.  Human immunodeficiency virus type 1 coreceptors participate in postentry stages in the virus replication cycle and function in simian immunodeficiency virus infection. 
Journal of Virology  1997;71(5):3932-3939.
Primate lentiviruses use chemokine coreceptors in addition to the CD4 receptor to initiate virus infection. Simian immunodeficiency virus (SIV) productively infects human cells expressing CD4 and the human allele of the chemokine coreceptor CCR-5 as efficiently as it infects macaque cells expressing human CD4, suggesting that SIV can function with either a simian or a human coreceptor in conjunction with human CD4. In the same macaque cells expressing human CD4, the replication of human immunodeficiency virus type 1 (HIV-1) is blocked at several stages of infection; some isolates are restricted prior to reverse transcription, while others, including some macrophage-tropic and primary isolates, are restricted at a step after reverse transcription but prior to migration of the preintegration complex to the nucleus. Both blocks in HIV-1 replication can be relieved by either expression of the appropriate human coreceptor (CCR-5 or CXCR-4) or expression of SIV gene products in cis with the HIV-1 envelope as a chimera between SIV and HIV-1 (SHIV). Thus, a virus with a SIV core and HIV-1 envelope can efficiently infect macaque cells expressing human CD4, presumably by interacting with the simian coreceptor, whereas a virus with an HIV-1 core and an HIV-1 envelope requires expression of the human allele of the coreceptor for productive infection of these cells. These studies suggest that there are interactions among the coreceptor, the viral envelope, and another viral gene product that govern postentry steps of virus replication. These data are consistent with the hypothesis that such interactions may be required for translocation of the virus core to the nucleus. Moreover, the differential abilities of SIV and HIV-1 to function in these processes with heterologous primate coreceptors may have implications for cross-species transmission.
PMCID: PMC191545  PMID: 9094670
25.  Male Circumcision at Different Ages in Rwanda: A Cost-Effectiveness Study 
PLoS Medicine  2010;7(1):e1000211.
Agnes Binagwaho and colleagues predict that circumcision of newborn boys would be effective and cost-saving as a long-term strategy to prevent HIV in Rwanda.
Background
There is strong evidence showing that male circumcision (MC) reduces HIV infection and other sexually transmitted infections (STIs). In Rwanda, where adult HIV prevalence is 3%, MC is not a traditional practice. The Rwanda National AIDS Commission modelled cost and effects of MC at different ages to inform policy and programmatic decisions in relation to introducing MC. This study was necessary because the MC debate in Southern Africa has focused primarily on MC for adults. Further, this is the first time, to our knowledge, that a cost-effectiveness study on MC has been carried out in a country where HIV prevalence is below 5%.
Methods and Findings
A cost-effectiveness model was developed and applied to three hypothetical cohorts in Rwanda: newborns, adolescents, and adult men. Effectiveness was defined as the number of HIV infections averted, and was calculated as the product of the number of people susceptible to HIV infection in the cohort, the HIV incidence rate at different ages, and the protective effect of MC; discounted back to the year of circumcision and summed over the life expectancy of the circumcised person. Direct costs were based on interviews with experienced health care providers to determine inputs involved in the procedure (from consumables to staff time) and related prices. Other costs included training, patient counselling, treatment of adverse events, and promotion campaigns, and they were adjusted for the averted lifetime cost of health care (antiretroviral therapy [ART], opportunistic infection [OI], laboratory tests). One-way sensitivity analysis was performed by varying the main inputs of the model, and thresholds were calculated at which each intervention is no longer cost-saving and at which an intervention costs more than one gross domestic product (GDP) per capita per life-year gained. Results: Neonatal MC is less expensive than adolescent and adult MC (US$15 instead of US$59 per procedure) and is cost-saving (the cost-effectiveness ratio is negative), even though savings from infant circumcision will be realized later in time. The cost per infection averted is US$3,932 for adolescent MC and US$4,949 for adult MC. Results for infant MC appear robust. Infant MC remains highly cost-effective across a reasonable range of variation in the base case scenario. Adolescent MC is highly cost-effective for the base case scenario but this high cost-effectiveness is not robust to small changes in the input variables. Adult MC is neither cost-saving nor highly cost-effective when considering only the direct benefit for the circumcised man.
Conclusions
The study suggests that Rwanda should be simultaneously scaling up circumcision across a broad range of age groups, with high priority to the very young. Infant MC can be integrated into existing health services (i.e., neonatal visits and vaccination sessions) and over time has better potential than adolescent and adult circumcision to achieve the very high coverage of the population required for maximal reduction of HIV incidence. In the presence of infant MC, adolescent and adult MC would evolve into a “catch-up” campaign that would be needed at the start of the program but would eventually become superfluous.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Acquired immunodeficiency syndrome (AIDS) has killed more than 25 million people since 1981 and more than 31 million people (22 million in sub-Saharan Africa alone) are now infected with the human immunodeficiency virus (HIV), which causes AIDS. There is no cure for HIV/AIDS and no vaccine against HIV infection. Consequently, prevention of HIV transmission is extremely important. HIV is most often spread through unprotected sex with an infected partner. Individuals can reduce their risk of HIV infection, therefore, by abstaining from sex, by having one or a few sexual partners, and by always using a male or female condom. In addition, male circumcision—the removal of the foreskin, the loose fold of skin that covers the head of penis—can halve HIV transmission rates to men resulting from sex with women. Thus, as part of its HIV prevention strategy, the World Health Organization (WHO) recommends that male circumcision programs be scaled up in countries where there is a generalized HIV epidemic and where few men are circumcised.
Why Was This Study Done?
One such country is Rwanda. Here, 3% of the adult population is infected with HIV but only 15% of men are circumcised—worldwide, about 30% of men are circumcised. Demand for circumcision is increasing in Rwanda but, before policy makers introduce a country-wide male circumcision program, they need to identify the most cost-effective way to increase circumcision rates. In particular, they need to decide the age at which circumcision should be offered. Circumcision soon after birth (neonatal circumcision) is quick and simple and rarely causes any complications. Circumcision of adolescents and adults is more complex and has a higher complication rate. Although several studies have investigated the cost-effectiveness (the balance between the clinical and financial costs of a medical intervention and its benefits) of circumcision in adult men, little is known about its cost-effectiveness in newborn boys. In this study, which is one of several studies on male circumcision being organized by the National AIDS Control Commission in Rwanda, the researchers model the cost-effectiveness of circumcision at different ages.
What Did the Researchers Do and Find?
The researchers developed a simple cost-effectiveness model and applied it to three hypothetical groups of Rwandans: newborn boys, adolescent boys, and adult men. For their model, the researchers calculated the effectiveness of male circumcision (the number of HIV infections averted) by estimating the reduction in the annual number of new HIV infections over time. They obtained estimates of the costs of circumcision (including the costs of consumables, staff time, and treatment of complications) from health care providers and adjusted these costs for the money saved through not needing to treat HIV in males in whom circumcision prevented infection. Using their model, the researchers estimate that each neonatal male circumcision would cost US$15 whereas each adolescent or adult male circumcision would cost US$59. Neonatal male circumcision, they report, would be cost-saving. That is, over a lifetime, neonatal male circumcision would save more money than it costs. Finally, using the WHO definition of cost-effectiveness (for a cost-effective intervention, the additional cost incurred to gain one year of life must be less than a country's per capita gross domestic product), the researchers estimate that, although adolescent circumcision would be highly cost-effective, circumcision of adult men would only be potentially cost-effective (but would likely prove cost-effective if the additional infections that would occur from men to their partners without a circumcision program were also taken into account).
What Do These Findings Mean?
As with all modeling studies, the accuracy of these findings depends on the many assumptions included in the model. However, the findings suggest that male circumcision for infants for the prevention of HIV infection later in life is highly cost-effective and likely to be cost-saving and that circumcision for adolescents is cost-effective. The researchers suggest, therefore, that policy makers in Rwanda and in countries with similar HIV infection and circumcision rates should scale up male circumcision programs across all age groups, with high priority being given to the very young. If infants are routinely circumcised, they suggest, circumcision of adolescent and adult males would become a “catch-up” campaign that would be needed at the start of the program but that would become superfluous over time. Such an approach would represent a switch from managing the HIV epidemic as an emergency towards focusing on sustainable, long-term solutions to this major public-health problem.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000211.
This study is further discussed in a PLoS Medicine Perspective by Seth Kalichman
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
Information is available from the Joint United Nations Programme on HIV/AIDS (UNAIDS) on HIV infection and AIDS and on male circumcision in relation to HIV and AIDS
HIV InSite has comprehensive information on all aspects of HIV/AIDS
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on HIV and AIDS in Africa, and on circumcision and HIV (some information in English and Spanish)
More information about male circumcision is available from the Clearinghouse on Male Circumcision
The National AIDS Control Commission of Rwanda provides detailed information about HIV/AIDS in Rwanda (in English and French)
doi:10.1371/journal.pmed.1000211
PMCID: PMC2808207  PMID: 20098721

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