Valproic acid and intensified antiretroviral therapy may deplete resting CD4+ T-cell HIV infection. We tested the ability of valproic acid to deplete resting CD4+ T-cell infection in patients receiving standard antiretroviral therapy.
Resting CD4+ T-cell infection was measured in 11 stably aviremic volunteers twice prior to, and twice after Depakote ER 1000 mg was added to standard antiretroviral therapy. Resting CD4+ T-cell infection frequency was measured by outgrowth assay. Low-level viremia was quantitated by single copy plasma HIV RNA assay.
A decrease in resting CD4+ T-cell infection was observed in only four of the 11 patients. Levels of immune activation and HIV-specific T-cell response were low and stable. Valproic acid levels ranged from 26 to 96 μg/ml when measured near trough. Single copy assay was performed in nine patients. In three patients with depletion of resting CD4+ T-cell infection following valproic acid, single copy assay ranged from less than 1–5 copies/ml. Continuous low-level viremia was observed in three patients with stable resting CD4+ T-cell infection (24–87, 8–87, and 1–7 copies/ml respectively) in whom multiple samples were analyzed.
The prospective addition of valproic acid to stable antiretroviral therapy reduced the frequency of resting CD4+ T-cell infection in a minority of volunteers. In patients in whom resting CD4+ T-cell infection depletion was observed, viremia was rarely detectable by single copy assay.
antiretroviral therapy; HIV; latency; resting CD4+ T cells; valproic acid
We examined serum lipids in association with carotid artery intima-media thickness (CIMT) in HIV-infected and HIV-uninfected women.
In 2003–4, among 1827 Women’s Interagency HIV Study participants, we measured CIMT and lipids (high-density lipoprotein cholesterol [HDL-c], low-density lipoprotein cholesterol [LDL-c], total cholesterol [TC], non-HDL-c). A subset of 520 treated HIV-infected women had pre-1997 lipid measures. We used multivariable linear regression to examine associations between lipids and CIMT.
In HIV-uninfected women, higher TC, LDL-c and non-HDL-c were associated with increased CIMT. Among HIV-infected women, associations of lipids with CIMT were observed in treated but not untreated women. Among the HIV-infected women treated in 2003–4, CIMT was associated both with lipids measured a decade earlier in infection, and with late lipid measurements.
Among HIV-infected women, hyperlipidemia is most strongly associated with subclinical atherosclerosis in treated women. Among treated women, the association appeared strongest early in the disease course.
cardiovascular diseases; carotid arteries; HAART; HIV; lipids
Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MoAbs) cetuximab and panitumumab have emerged as an effective targeted therapy in the treatment of cancer patients, but the overall incidence and risk of fatal adverse events (FAEs) associated with these agents is still unclear.
Databases from PubMed, Web of Science and abstracts presented at ASCO meeting up to May 31, 2013 were searched to identify relevant studies. Eligible studies included prospective randomized controlled trials evaluating MoAbs in cancer patients with adequate data on FAEs. Statistical analyses were conducted to calculate the summary incidence, odds ratio and 95% confidence intervals (CIs) by using either random effects or fixed effect models according to the heterogeneity of included studies.
A total of 14,776 patients with a variety of solid tumors from 21 clinical trials were included in our analysis. The overall incidence of MoAbs associated FAEs was 1.7% (95%CI: 1.1–2.5%), and the incidence of cetuximab-related FAEs was higher than that of panitumumab (2.0% versus 0.9%). Compared with the controls, the use of MoAbs was associated with a significantly increased risk of FAEs, with an OR of 1.37 (95%CI: 1.04–1.81, p=0.024). Subgroup analysis based on EGFR-MoAbs drugs, phase of trials and tumor types demonstrated a tendency to increase the risk of FAEs, but the risk did not increase in breast cancer, esophagus cancer and phase II trials.
With present evidence, the use of EGFR-MoAbs is associated with an increased risk of FAEs in patients with advanced solid tumors.
Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.
A group of over 200 international scientists came together on April 15 in Sydney, Australia just before the 2012 International Microbicides Conference as a part of a workshop to address the basic concepts and factors that modulate HIV infection at the mucosal surface. The meeting focused on defining the interaction between virus, prevailing host physiology, microbiota, and innate and adaptive immune responses and how they combine to impact the outcome at the moment of potential viral transmission. Speakers examined the biology of HIV entry during transmission, innate and natural antiviral mechanisms at the mucosa, microbicide efficacy, pharmacokinetic, and pharmacodynamics, animal models, and opportunities for combining HIV prevention strategies. Other viral infection models both in vivo and in vitro were considered for the insights they provided into HIV transmission events. The workshop raised important questions that we need to answer to further our basic understanding of host and viral factors influencing HIV transmission to inform the development of novel prevention strategies.
HIV leads to CD4:CD8 ratio inversion as immune dysregulation progresses. We examined the predictors of CD4:CD8 normalization after combination antiretroviral therapy (cART) and determined whether normalization is associated with reduced progression to AIDS-defining illnesses (ADI) and death.
A Canadian cohort of HIV-positive adults with CD4:CD8<1.2 prior to starting cART from 2000–2010 were analyzed. Predictors of (1) reaching a CD4:CD8 ≥1.2 on two separate follow-up visits >30 days apart, and (2) ADI and death from all causes were assessed using adjusted proportional hazards models.
4206 patients were studied for a median of 2.77 years and 306 (7.2%) normalized their CD4:CD8 ratio. Factors associated with achieving a normal CD4:CD8 ratio were: baseline CD4+ T-cells >350 cells/mm3, baseline CD8+ T-cells <500 cells/mm3, time-updated HIV RNA suppression, and not reporting sex with other men as a risk factor. There were 213 ADIs and 214 deaths in 13476 person-years of follow-up. Achieving a normal CD4:CD8 ratio was not associated with time to ADI/death.
In our study, few individuals normalized their CD4:CD8 ratios within the first few years of initiating modern cART. This large study showed no additional short-term predictive value of the CD4:CD8 ratio for clinical outcomes after accounting for other risk factors including age and HIV RNA.
The contribution of immune activation to accelerated HIV-disease progression in older individuals has not been delineated.
Prospective multicenter cohort of older (≥45 years) and younger (18–30 years) HIV-infected adults initiating 192 weeks of antiretroviral therapy (ART). Longitudinal models of CD4 cell restoration examined associations with age-group, thymic volume, immune activation, and viral load.
Forty-five older and 45 younger adults (median age 50 and 26 years, respectively) were studied. Older patients had fewer naive CD4 cells (P <0.001) and higher HLA-DR/CD38 expression on CD4 (P = 0.05) and CD8 cells (P = 0.07) than younger patients at any time on ART. The rate of naive and total CD4 cell increase was similar between age groups, but older patients had a faster mean rate of B-cell increase (by +0.7 cells/week; P = 0.01), to higher counts than healthy controls after 192 weeks (P = 0.003). Naive CD4 increases from baseline were associated with immune activation reductions (as declines from baseline of %CD8 cells expressing HLA-DR/CD38; P <0.0001), but these increases were attenuated in older patients, or in those with small thymuses. A 15% reduction in activation was associated with naive gains of 29.9 and 6.2 cells/μl in younger, versus older patients, or with gains of 25.7, 23.4, and 2.1 cells/μl in patients with the largest, intermediate, and smallest thymuses, respectively (P <0.01 for interactions between activation reduction and age-group or thymic volume).
Older patients had significant B-cell expansion, higher levels of immune activation markers, and significantly attenuated naive CD4 cell gains associated with activation reduction.
aging; immune activation; immunosenescence; thymus
Pre-exposure chemoprophylaxis (PrECP) using antiretroviral agents is a promising strategy for the prevention of sexual HIV transmission in women. Molecular transporters in the human vaginal tract (VT) may play a pivotal role in determining drug disposition and, consequently, pharmacodynamic outcomes in these efforts. Little is known, however, on the expression of these transporters in vaginal tissues, representing a critical knowledge gap.
Our study analyzed the genome-wide transcriptome in 44 vaginal tissue samples from 6 reproductive-age women undergoing gynecologic surgeries. The analysis revealed that, unexpectedly, a large number (43%) of gene isoforms corresponding to membrane transporters were over-expressed (above the median expression level) in all samples. A subset of 12 highly expressed membrane transporters was identified and contained 10 members (83%) of the solute carrier superfamily. The largest difference in membrane transporter gene expression was observed across subjects, but more subtle differential expression also was found along the anterior-posterior axis of the VT. Cross-validation of the microarray analyses with measurements RT-qPCR demonstrated high concordance between these data sets. Immunofluorescence labeling of membrane transporter proteins in vaginal tissues was highly dependent on tissue/cell types.
Antiretroviral PrECP drugs currently under evaluation are substrates for molecular transporters that were commonly expressed, but fell into both over- or under-expressed categories in all samples, suggesting a complex role for carrier-mediated processes in determining the disposition of these xenobiotics in vaginal tissues. These findings hold important implications for the successful development of products, either oral or intravaginal, for female-controlled HIV PrECP.
HIV Gag-specific CD4+ and CD8+ T-cell responses are important for HIV immune control. Pulsing overlapping Gag peptides on autologous lymphocytes (OPAL) has proven immunogenic and effective in reducing viral loads in multiple pigtail macaque studies, warranting clinical evaluation.
We performed a phase I, single centre, placebo-controlled, double-blinded and dose-escalating study to evaluate the safety and preliminary immunogenicity of a novel therapeutic vaccine approach ‘OPAL-HIV-Gag(c)’. This vaccine is comprised of 120 15mer peptides, overlapping by 11 amino acids, spanning the HIV Gag C clade sequence proteome, pulsed on white blood cells enriched from whole blood using a closed system, followed by intravenous reinfusion. Patients with undetectable HIV viral loads (<50 copies/ml plasma) on HAART received four administrations at week 0, 4, 8 and 12, and were followed up for 12 weeks post-treatment. Twenty-three people were enrolled in four groups: 12 mg (n = 6), 24 mg (n = 7), 48 mg (n = 2) or matching placebo (n = 8) with 18 immunologically evaluable. T-cell immunogenicity was assessed by IFNγ ELIspot and intracellular cytokine staining (ICS).
The OPAL-HIV-Gag(c) peptides were antigenic in vitro in 17/17 subjects. After vaccination with OPAL-HIV-Gag(c), 1/6 subjects at 12 mg and 1/6 subjects at 24 mg dose groups had a 2- and 3-fold increase in ELIspot magnitudes from baseline, respectively, of Gag-specific CD8+ T-cells at week 14, compared to 0/6 subjects in the placebo group. No Gag-specific CD4+ T-cell responses or overall change in Rev, Nef, Tat and CMV specific responses were detected. Marked, transient and self-limiting lymphopenia was observed immediately post-vaccination (4 hours) in OPAL-HIV-Gag(c) but not in placebo recipients, with median fall from 1.72 to 0.67 million lymphocytes/mL for active groups (P<0.001), compared to post-placebo from 1.70 to 1.56 lymphocytes/ml (P = 0.16).
Despite strong immunogenicity observed in several Macaca nemestrina studies using this approach, OPAL-HIV-Gag(c) was not significantly immunogenic in humans and improved methods of generating high-frequency Gag-specific T-cell responses are required.
Name of Registry
ClinicalTrials.gov, Registry number: NCT01123915, URL trial registry database: http://www.clinicaltrials.gov/ct2/results?term=OPAL-HIV-1001&Search=Search
Bacterial vaginosis (BV) and Trichomonas vaginalis (TV) infection are both very common and are associated with increased risk of sexual transmission of HIV. There are several mechanisms by which BV and TV could affect susceptibility including inducing pro-inflammatory cytokines and disrupting mucosal barrier function. This review highlights recent advances in our understanding of how these genital conditions lead to an increased risk of HIV infection in women.
Bacterial vaginosis; HIV; Inflammation; Trichomonas vaginalis
Vaginal bacterial communities play an important role in human health and have been shown to influence HIV infection. Pigtailed macaques (Macaca nemestrina) are used as an animal model of HIV vaginal infection of women. Since the bacterial microbiota could influence retrovirus infection of pigtailed macaques, the genital microbiota in 10 cycling macaques was determined by pyrosequencing. The microbiota of all macaques was polymicrobial with a median of 13 distinct genera. Strikingly, the genera Sneathia and Fusobacterium, both in the phylum Fusobacteria, accounted for 18.9% and 13.3% of sequences while the next most frequent were Prevotella (5.6%), Porphyromonas (4.1%), Atopobium (3.6%), and Parvimonas (2.6%). Sequences corresponding to Lactobacillus comprised only 2.2% of sequences on average and were essentially all L. amylovorus. Longitudinal sampling of the 10 macaques over an 8-week period, which spanned at least one full ovulatory cycle, showed a generally stable presence of the major types of bacteria with some exceptions. These studies show that the microbiota of the pigtailed macaques is substantially dissimilar to that found in most healthy humans, where the genital microbiota is usually dominated by Lactobacillus sp. The polymicrobial makeup of the macaque bacterial populations, the paucity of lactobacilli, and the specific types of bacteria present suggest that the pigtailed macaque microbiota could influence vaginal retrovirus infection.
Three models for promoting male circumcision (MC) as a preventative intervention against HIV infection were compared among migrant worker populations in western China.
A cohort study was performed after an initial cross-sectional survey among migrant workers in three provincial level districts with high HIV prevalence in western China. A total of 1,670 HIV seronegative male migrants were cluster-randomized into three intervention models, in which the dissemination of promotional materials and expert- and volunteer-led discussions are conducted in one, two, and three stage interventions. Changes in knowledge of MC, acceptability of MC, MC surgery uptake, and the costs of implementation were analyzed at 6-month and 9-month follow-up visits.
All three models significantly increased the participants’ knowledge about MC. The three-stage model significantly increased the acceptability of MC among participants and led to greatest increase in MC uptake. At the end of follow-up, 9.2% (153/1,670) of participants underwent MC surgery; uptake among the one-, two-, and three-stage models were 4.9%, 9.3%, and 14.6%, respectively. Multivariable Cox regression analysis showed that three-stage model was the most effective method to scale up MC, with RR = 2.0 (95% CI, 1.3-3.1, P=0.002) compared to the on-site session model. The two-stage intervention model showed no significant difference with either the on-site session model (RR=1.5, 95% CI, 0.92-2.4, P=0.12) or three-stage model (P=0.10).
A three-stage intervention with gradual introduction of knowledge led to the significantly increase in MC uptake among migrant workers in western China, and was also the most cost-effective method among the three models.
Preclinical studies of overlapping 15mer peptides, spanning SIV, SHIV or HIV, pulsed on autologous PBMC ex vivo have demonstrated high level, virus-specific T cell responses and viral suppression in non-human primates (NHP). Opal-HIV-Gag(c) consists of 120 synthetic 15mer peptides spanning Clade C, consensus Gag, manufactured to current good manufacturing practice; having been evaluated in a good laboratory practice toxicology study in Macaca mulatta. We evaluated the safety and preliminary immunogenicity of such peptides administered intravenously after short-duration ex vivo incubation, to HIV-positive adults on suppressive antiretroviral therapy.
Methods and Findings
A first-in-human, placebo-controlled, double-blind, dose escalation study was conducted. Twenty-three patients with virus suppressed by antiretroviral therapy were enrolled in four groups 12 mg (n = 6), 24 mg (n = 6), 48 mg (n = 2) or matching placebo (n = 8). Treatment was administered intravenously after bedside enrichment of 120 mL whole blood for white cells using a closed system (Sepax S-100 device), with ex vivo peptide admixture (or diluent alone) and 37°C incubation for one hour prior to reinfusion. Patients received 4 administrations at monthly intervals followed by a 12-week observation post-treatment. Opal-HIV-Gag(c) was reasonably tolerated at doses of 12 and 24 mg. There was an increased incidence of temporally associated pyrexia, chills, and transient/self-limiting lymphopenia in Opal-HIV-Gag(c) recipients compared to placebo. The study was terminated early, after two patients were recruited to the 48 mg cohort; a serious adverse event of hypotension, tachycardia secondary to diarrhoea occurred following a single product administration. An infectious cause for the event could not be identified, leaving the possibility of immunologically mediated product reaction.
A serious, potentially life-threatening event of hypotension led to early, precautionary termination of the study. In the absence of a clearly defined mechanism or ability to predict such occurrence, further development of Opal-HIV-Gag(c) will not be undertaken in the current form.
ClinicalTrials.gov NCT01123915; EudraCT: 2008-005142-23
Disease progression of human immunodeficiency virus type 1 (HIV-1) is associated with immune activation. Activation indices are higher during coinfection of hepatitis C virus (HCV) and HIV. The effect of immune activation on interferon α (IFN-α) therapy response is unknown. We evaluated soluble CD14 (sCD14) and natural killer (NK)–cell subsets at baseline, and during pegIFN-α2a/ribavirin therapy in HCV-HIV coinfection. The sCD14 level increased during therapy. Baseline sCD14 positively correlated with baseline HCV level and CD16+56− NK-cell frequency, and both sCD14 and CD16+56− NK cells correlated negatively with magnitude of HCV decline. IL28B genotype was associated with therapy response but not sCD14 or CD16+56− NK frequency. Markers of innate immune activation predict poor host response to IFN-α–based HCV therapy during HCV-HIV coinfection.
Background.Inflammation persists in treated human immunodeficiency virus (HIV) infection and may contribute to an increased risk for non–AIDS-related pathologies. We investigated the correlation of cytokine responses with changes in CD4 T-cell levels and coinfection with hepatitis C virus (HCV) during highly active antiretroviral treatment (HAART).
Methods.A total of 383 participants in the Women's Interagency HIV Study (212 with HIV monoinfection, 56 with HCV monoinfection, and 115 with HIV/HCV coinfection) were studied. HIV-infected women had <1000 HIV RNA copies/mL, 99.7% had >200 CD4 T cells/μL; 98% were receiving HAART at baseline. Changes in CD4 T-cell count between baseline and 2–4 years later were calculated. Peripheral blood mononuclear cells (PBMCs) obtained at baseline were used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 12 (IL-12), and tumor necrosis factor α (TNF-α) responses to Toll-like receptor (TLR) 3 and TLR4 stimulation.
Results.Undetectable HIV RNA (<80 copies/mL) at baseline and secretion of IL-10 by PBMCs were positively associated with gains in CD4 T-cell counts at follow-up. Inflammatory cytokines (IL-1β, IL-6, IL-12, and TNF-α) were also produced in TLR-stimulated cultures, but only IL-10 was significantly associated with sustained increases in CD4 T-cell levels. This association was significant only in women with HIV monoinfection, indicating that HCV coinfection is an important factor limiting gains in CD4 T-cell counts, possibly by contributing to unbalanced persistent inflammation.
Conclusions.Secreted IL-10 from PBMCs may balance the inflammatory environment of HIV, resulting in CD4 T-cell stability.
High-sensitive real-time PCR assays are routinely used to monitor HIV-1 infected subjects. Inter-assay discrepancies have been described at the low viral load (VL) end, where clinical decisions regarding possible virological rebound are based.
A retrospective study was performed to analyze frequencies of viral blips after transition to the COBAS Ampliprep/COBAS TaqMan v2.0 HIV-1 assay (Taqman v2.0) in patients with prior undetectable VLs as measured with the Roche Cobas Ampliprep Amplicor HIV-1 Monitor Test, v1.5 (Amplicor) and was evaluated in comparison to a group of patients monitored with the Abbott Real-time HIV-1 assay (Abbott RT) during the same period of time.
85 of 373 patients with VLs below the limit of quantification with Amplicor had VLs >50 copies/mL after transition to the TaqMan v2.0 assay. Among these 74.1% had VLs ranging from 50–499 copies/mL, 22.9% had VLs >500 copies/mL. From 22 patients with initial Taqman v2.0 based VLs exceeding 500 copies/mL, 6 patients had VLs <20 copies/mL after novel VL measurement on a next visit. In our control group with VL quantification using the Abbott RT assay, only 1 patient became detectable and showed a VL of <40 copies/mL after new measurement.
Transition to the Taqman v2.0 assay was accompanied by an increase of quantifiable HIV-1 VLs in patients with long term viral suppression under antiretroviral therapy that might be attributed to technical shortcomings of the Taqman v2.0 assay. A high test variability at the low VL end but also beyond was observed, making meaningful clinical interpretation of viral blips derived from different assays difficult.
Background. Despite viral suppression, antiretroviral therapy (ART) does not restore CD4+ T-cell counts in many patients infected with human immunodeficiency virus type 1 (HIV-1).
Methods. In a single-arm pilot trial involving ART recipients with suppressed plasma levels of HIV-1 RNA for at least 48 weeks and stable suboptimal CD4+ T-cell recovery, subjects added maraviroc, a CCR5 antagonist, to their existing ART for 24 weeks. After stopping maraviroc, they were followed for an additional 24 weeks. A Wilcoxon signed-rank test was used to evaluate whether maraviroc was associated with an increase of at least 20 cells/µL in the CD4+ T-cell count.
Results. A total of 34 subjects were enrolled. The median age was 50 years, and the median baseline CD4+ T-cell count was 153 cells/µL. The median increase in CD4+ T-cell count from baseline to week 22/24 was 12 cells/µL (90% confidence interval, 1–22). A CD4+ T-cell count increase of at least 20 cells/µL was not detected (P = .97). Markers of immune activation and apoptosis decreased during maraviroc intensification; this decline partially reversed after discontinuing maraviroc.
Conclusions. Adding maraviroc to suppressive ART for 24 weeks was not associated with an increase in CD4+ T-cell counts of at least 20 cells/µL. Further studies of CCR5 antagonists in the dampening of immune activation associated with HIV infection are warranted.
Clinical Trials Registration. NCT 00709111.
Depletion of thymus derived naive T-cells is a feature of HIV infection. Here the impact of HIV infection on the compartmentalization of recent thymic emigrants of (RTE) and naive T-cells was examined.
Peripheral blood mononuclear cells (PBMC) and lymphoid tissue (LT) from 43 HIV-infected patients and 12 controls were examined for RTE distribution by measuring coding joint T-cell receptor excisional circles (cjTREC) by PCR and naive and memory T-cell subsets and adhesion molecules (L-selection, LFA-1) by flow cytometry.
In HIV-infected patients, the RTE as quantified by cjTRECs in CD4 LT cells were significantly higher than in PBMC. Their values, however, were less than in control subjects, in both the LT and PBMC compartments. This was associated with an increase in L-selectin and LFA-1 expression on LT derived T cells. In PBMC, a significant positive relationship between TREC and naive CD4 cells and an inverse relationship between TREC and cellular viral load (CVL) was observed. Whereas in LT, there was a positive relationship between cjTREC and both naive CD4 cell percentage and CVL.
Collectively, the data suggests that LT is a significant reservoir for RTE. The RTE appeared to be entrapped in LT from HIV-infected subjects. Such entrapment is probably a response to the high viral load in these tissues. These observations may partially explain the decline in RTE observed in the peripheral blood of HIV-infected patients, and the delay in recovery of naive cells in blood after initiation of HAART.
Naive T cells; recent thymic emigrants; TRECs; HIV; AIDS
Non-AIDS–defining comorbidities that occur despite viral suppression and immune reconstitution using antiretroviral therapy depict early aging process in HIV-infected individuals. During aging, a reduction in T-cell renewal, together with a progressive enrichment of terminally differentiated T cells, translates into a general decline of the immune system, gradually leading to immunosenescence. Inflammation is a hallmark of age-associated comorbidities, and immune activation is a hallmark of HIV disease. Constant stimulation of the immune system by HIV or due to co-infections activates the innate and adaptive immune system, resulting in release of mediators of inflammation. Immune activation coupled with lack of anti-inflammatory responses likely results in accelerated aging in HIV disease. Dysfunctional thymic output, along with HIV-mediated disruption of the gastrointestinal barrier leading to microbial translocation, contributes to the circulating antigenic load driving early senescence in HIV disease.
Inflammation and hemostasis perturbation may be involved in vascular complications of HIV infection. We examined atherogenic biomarkers and subclinical atherosclerosis in HIV-infected adults before and after beginning highly-active antiretroviral therapy (HAART).
In the Women's Interagency HIV Study (WIHS), 127 HIV-infected women studied pre- and post-HAART were matched to HIV-uninfected controls. Six semi-annual measurements of soluble CD14, tumor necrosis factor (TNF)-alpha, soluble interleukin (IL)-2 receptor, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, D-dimer, and fibrinogen were obtained. Carotid artery intima-media thickness (CIMT) was measured by B-mode ultrasound.
Relative to HIV-uninfected controls, HAART-naïve HIV-infected women had elevated levels of soluble CD14 (1945 vs 1662 ng/mL, Wilcoxon signed rank P<0.0001), TNF-alpha (6.3 vs 3.4 pg/mL, P<0.0001), soluble IL-2 receptor (1587 vs 949 pg/mL, P<0.0001), IL-10 (3.3 vs 1.9 pg/mL, P<0.0001), MCP-1 (190 vs 163 pg/mL, P<0.0001) and D-dimer (0.43 vs 0.31 µg/mL, P<0.01). Elevated biomarker levels declined after HAART. While most biomarkers normalized to HIV-uninfected levels, in women on effective HAART, TNF-alpha levels remained elevated compared to HIV-uninfected women (+0.8 pg/mL, P=0.0002). Higher post-HAART levels of soluble IL-2 receptor (P=0.02), IL-6 (P=0.05), and D-dimer (P=0.03) were associated with increased CIMT.
Untreated HIV infection is associated with abnormal hemostasis (e.g., D-dimer), and pro-atherogenic (e.g., TNF-alpha) and anti-atherogenic (e.g., IL-10) inflammatory markers. HAART reduces most inflammatory mediators to HIV-uninfected levels. Increased inflammation and hemostasis are associated with subclinical atherosclerosis in recently treated women. These findings have potential implications for long-term risk of cardiovascular disease in HIV-infected patients, even with effective therapy.
antiretroviral therapy; cardiovascular diseases; cytokines; hemostasis; HIV; inflammation
Technically, HIV-1 tropism can be evaluated in plasma or peripheral blood mononuclear cells (PBMCs). However, only tropism testing of plasma HIV-1 has been validated as a tool to predict virological response to CCR5 antagonists in clinical trials. The preferable tropism testing strategy in subjects with undetectable HIV-1 viremia, in whom plasma tropism testing is not feasible, remains uncertain.
Methods & Results
We designed a proof-of-concept study including 30 chronically HIV-1-infected individuals who achieved HIV-1 RNA <50 copies/mL during at least 2 years after first-line ART initiation. First, we determined the diagnostic accuracy of 454 and population sequencing of gp120 V3-loops in plasma and PBMCs, as well as of MT-2 assays before ART initiation. The Enhanced Sensitivity Trofile Assay (ESTA) was used as the technical reference standard. 454 sequencing of plasma viruses provided the highest agreement with ESTA. The accuracy of 454 sequencing decreased in PBMCs due to reduced specificity. Population sequencing in plasma and PBMCs was slightly less accurate than plasma 454 sequencing, being less sensitive but more specific. MT-2 assays had low sensitivity but 100% specificity. Then, we used optimized 454 sequence data to investigate viral evolution in PBMCs during viremia suppression and only found evolution of R5 viruses in one subject. No de novo CXCR4-using HIV-1 production was observed over time. Finally, Slatkin-Maddison tests suggested that plasma and cell-associated V3 forms were sometimes compartmentalized.
The absence of tropism shifts during viremia suppression suggests that, when available, testing of stored plasma samples is generally safe and informative, provided that HIV-1 suppression is maintained. Tropism testing in PBMCs may not necessarily produce equivalent biological results to plasma, because the structure of viral populations and the diagnostic performance of tropism assays may sometimes vary between compartments. Thereby, proviral DNA tropism testing should be specifically validated in clinical trials before it can be applied to routine clinical decision-making.
Cell-associated receptor for urokinase plasminogen activator (uPAR) is released as both full-length soluble uPAR (suPAR) and cleaved (c-suPAR) form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART). However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1+ individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of inhibiting chemotaxis and inducing HIV-1 expression.
Innate immune responses are reasoned to play an important role during both acute and chronic SIV infection and play a deterministic role during the acute stages on the rate of infection and disease progression. NK cells are an integral part of the innate immune system but their role in influencing the course of SIV infection has been a subject of debate. As a means to delineate the effect of NK cells on SIV infection, use was made of a Janus kinase 3 (JAK3) inhibitor that has previously been shown to be effective in the depletion of NK cells in vivo in nonhuman primates (NHP). Extensive safety and in vitro/in vivo PK studies were conducted and an optimal dose that depletes NK cells and NK cell function in vivo identified. Six chronically SIV infected rhesus macaques, 3 with undetectable/low plasma viral loads and 3 with high plasma viral loads were administered a daily oral dose of 10 mg/kg for 35 days. Data obtained showed that, at the dose tested, the major cell lineage affected both in the blood and the GI tissues were the NK cells. Such depletion appeared to be associated with a transient increase in plasma and GI tissue viral loads. Whereas the number of NK cells returned to baseline values in the blood, the GI tissues remained depleted of NK cells for a prolonged period of time. Recent findings show that the JAK3 inhibitor utilized in the studies reported herein has a broader activity than previously reported with dose dependent effects on both JAK2 and JAK1 suggests that it is likely that multiple pathways are affected with the administration of this drug that needs to be taken into account. The findings reported herein are the first studies on the use of a JAK3 inhibitor in lentivirus infected NHP.
The level of T cell activation in untreated HIV disease is strongly and independently associated with risk of immunologic and clinical progression. The factors that influence the level of activation, however, are not fully defined. Since endogenous glucocorticoids are important in regulating inflammation, we sought to determine whether less optimal diurnal cortisol patterns are associated with greater T cell activation.
We studied 128 HIV-infected adults who were not on treatment and had a CD4+ T cell count above 250 cells/µl. We assessed T cell activation by CD38 expression using flow cytometry, and diurnal cortisol was assessed with salivary measurements.
Lower waking cortisol levels correlated with greater T cell immune activation, measured by CD38 mean fluorescent intensity, on CD4+ T cells (r = −0.26, p = 0.006). Participants with lower waking cortisol also showed a trend toward greater activation on CD8+ T cells (r = −0.17, p = 0.08). A greater diurnal decline in cortisol, usually considered a healthy pattern, correlated with less CD4+ (r = 0.24, p = 0.018) and CD8+ (r = 0.24, p = 0.017) activation.
These data suggest that the hypothalamic-pituitary-adrenal (HPA) axis contributes to the regulation of T cell activation in HIV. This may represent an important pathway through which psychological states and the HPA axis influence progression of HIV.
South Africa’s national antiretroviral (ARV) treatment program expanded in 2010 to include the nucleoside reverse transcriptase (RT) inhibitors (NRTI) tenofovir (TDF) for adults and abacavir (ABC) for children. We investigated the associated changes in genotypic drug resistance patterns in patients with first-line ARV treatment failure since the introduction of these drugs, and protease inhibitor (PI) resistance patterns in patients who received ritonavir-boosted lopinavir (LPV/r)-containing therapy.
We analysed ARV treatment histories and HIV-1 RT and protease mutations in plasma samples submitted to the Tygerberg Academic Hospital National Health Service Laboratory.
Between 2006 and 2012, 1,667 plasma samples from 1,416 ARV-treated patients, including 588 children and infants, were submitted for genotypic resistance testing. Compared with 720 recipients of a d4T or AZT-containing first-line regimen, the 153 recipients of a TDF-containing first-line regimen were more likely to have the RT mutations K65R (46% vs 4.0%; p<0.001), Y115F (10% vs. 0.6%; p<0.001), L74VI (8.5% vs. 1.8%; p<0.001), and K70EGQ (7.8% vs. 0.4%) and recipients of an ABC-containing first-line regimen were more likely to have K65R (17% vs 4.0%; p<0.001), Y115F (30% vs 0.6%; p<0.001), and L74VI (56% vs 1.8%; p<0.001). Among the 490 LPV/r recipients, 55 (11%) had ≥1 LPV-resistance mutations including 45 (9.6%) with intermediate or high-level LPV resistance. Low (20 patients) and intermediate (3 patients) darunavir (DRV) cross resistance was present in 23 (4.6%) patients.
Among patients experiencing virological failure on a first-line regimen containing two NRTI plus one NNRTI, the use of TDF in adults and ABC in children was associated with an increase in four major non- thymidine analogue mutations. In a minority of patients, LPV/r-use was associated with intermediate or high-level LPV resistance with predominantly low-level DRV cross-resistance.