Search tips
Search criteria

Results 1-8 (8)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Absence of reproducibly detectable low-level HIV viremia in highly exposed seronegative men and women. 
AIDS (London, England)  2011;25(5):619-623.
Transient HIV infections have been invoked to account for the cellular immune responses detected in highly virus-exposed individuals who have remained HIV seronegative. We tested for very low levels of HIV RNA in 524 seronegative plasma samples from 311 highly exposed women and men from 3 longitudinal HIV cohorts.
2073 transcription mediated amplification (TMA) HIV RNA tests were performed for an average of 3.95 TMA assays per plasma sample. Quadruplicate TMA assays, analyzing a total of 2 ml of plasma, provided an estimated sensitivity of 3.5 HIV RNA copies/ml.
Four samples from subjects who did not sero-convert within the following six months were positive for HIV RNA. For one sample, human polymorphism DNA analysis indicated a sample mix up. Borderline HIV RNA detection signals were detected for the other three positive samples and further replicate TMA testing yielded no positive results. Nested PCR assays (n=254) for HIV proviral DNA on PBMC from these 3 subjects were negative.
Transient viremia was not reproducibly detected in highly HIV exposed seronegative men and women. If transient infections do occur, plasma HIV RNA levels may remain below the detection limits of the sensitive assay used here, be of very short duration, or viral replication may be restricted to mucosal surfaces or their draining lymphoid tissues.
PMCID: PMC3458706  PMID: 21297421
2.  Comparison of Techniques for HIV-1 RNA Detection and Quantitation in Cervicovaginal Secretions 
HIV-1 in female genital secretions has been measured using swabs, Sno Strips (Akorn, Inc., Buffalo Grove, IL), and cervicovaginal lavage (CVL), but little is known regarding the comparability of these collection techniques.
We compared HIV-1 RNA detection and quantity in specimens obtained from HIV-1–seropositive women in Kenya using three sample collection techniques and three storage techniques and evaluated reproducibility in samples collected 5 days apart. Specimens were stored in no medium, freezing medium, or TRI Reagent (Molecular Research Center, Cincinnati, OH) for 2 to 15 months.
HIV-1 RNA assays were conducted on 640 specimens from 20 antiretroviral naive women. Storage in TRI Reagent significantly enhanced detection of genital HIV-1 and yielded significantly higher mean log10 RNA levels than specimens collected in either no or freezing medium. The prevalence of HIV-1 RNA detection in TRI Reagent ranged from 50% to 80% depending on collection method and was highest in cervical swabs. Mean log10 HIV-1 RNA levels were 3.1 log10 copies/cervical swab, 2.6 log10 copies/cervical Sno Strip, 2.5 log10 copies/vaginal swab, 2.4 log10 copies/vaginal Sno Strip, 2.9 log10 copies/ml for cervicovaginal lavage (CVL) cell pellet, and 2.1 log10 copies/ml in CVL supernatant. Comparing specimens from days 1 and 6, there was significant concordance of HIV-1 RNA detection and correlation of HIV-1 RNA levels for cervical swabs, vaginal swabs, vaginal Sno Strips, and CVL cell pellets (κ, 0.5–0.9; r, 0.5–0.9), but not for cervical Sno Strips or CVL supernatants.
Cervical or vaginal swab, vaginal Sno Strip, and CVL collection led to reproducible measurement of genital HIV-1 RNA, despite storage for several months and international transport. Collection using swabs was simpler than Sno Strips or cervicovaginal lavage, and yielded the highest prevalence of HIV-1 RNA detection and reproducibility.
PMCID: PMC3372416  PMID: 11242185
Cervical; Vaginal; Female; Genital; HIV-1 RNA; Detection
3.  Sequential Turnover of Human Immunodeficiency Virus Type 1 env throughout the Course of Infection▿ †  
Journal of Virology  2006;80(21):10591-10599.
We examined the rates of variant population turnover of the V1-V2 and V4-V5 hypervariable domains of the human immunodeficiency virus type 1 (HIV-1) gp120 molecule in longitudinal plasma samples from 14 men with chronic HIV-1 infection using heteroduplex tracking assays (HTA). Six men had high rates of CD4+ T-cell loss, and eight men had low rates of CD4+ T-cell loss over 2.5 to 8 years of infection. We found that V1-V2 and V4-V5 env populations changed dramatically over time in all 14 subjects; the changes in these regions were significantly correlated with each another over time. The subjects with rapid CD4 loss had significantly less change in their env populations than the subjects with slow CD4 loss. The two subjects with rapid CD4 loss and sustained low CD4 counts (<150/μl for at least 2 years) showed stabilization of their V1-V2 and V4-V5 populations as reflected by low levels of total change in HTA pattern and low HTA indices (a novel measure of the emergence of new bands and band distribution); this stabilization was not observed in other subjects. The stabilization of env variant populations at low CD4 counts following periods of rapid viral evolution suggests that selective pressure on env, likely from new immune responses, is minimal when CD4 counts drop dramatically and remain low for extended periods of time.
PMCID: PMC1641766  PMID: 16956948
5.  Rate and Incidence Estimates of Recent Human Immunodeficiency Virus Type 1 Infections among Pregnant Women in São Paulo, Brazil, from 1991 to 2002 
Journal of Clinical Microbiology  2005;43(3):1439-1442.
The serological testing algorithm for recent human immunodeficiency virus (HIV) seroconversion (STARHS) was employed to estimate HIV incidence among pregnant women from São Paulo, Brazil. A cross-sectional study (1999 to 2002) showed an incidence of infection of 0.2 per 100 pregnant women per year (95% confidence interval, 0.041 to 0.608). Western blot profiles suggested an association between results of the STARHS analysis and gp41/gp31 bands.
PMCID: PMC1081217  PMID: 15750127
6.  Hierarchical Targeting of Subtype C Human Immunodeficiency Virus Type 1 Proteins by CD8+ T Cells: Correlation with Viral Load 
Journal of Virology  2004;78(7):3233-3243.
An understanding of the relationship between the breadth and magnitude of T-cell epitope responses and viral loads is important for the design of effective vaccines. For this study, we screened a cohort of 46 subtype C human immunodeficiency virus type 1 (HIV-1)-infected individuals for T-cell responses against a panel of peptides corresponding to the complete subtype C genome. We used a gamma interferon ELISPOT assay to explore the hypothesis that patterns of T-cell responses across the expressed HIV-1 genome correlate with viral control. The estimated median time from seroconversion to response for the cohort was 13 months, and the order of cumulative T-cell responses against HIV proteins was as follows: Nef > Gag > Pol > Env > Vif > Rev > Vpr > Tat > Vpu. Nef was the most intensely targeted protein, with 97.5% of the epitopes being clustered within 119 amino acids, constituting almost one-third of the responses across the expressed genome. The second most targeted region was p24, comprising 17% of the responses. There was no correlation between viral load and the breadth of responses, but there was a weak positive correlation (r = 0.297; P = 0.034) between viral load and the total magnitude of responses, implying that the magnitude of T-cell recognition did not contribute to viral control. When hierarchical patterns of recognition were correlated with the viral load, preferential targeting of Gag was significantly (r = 0.445; P = 0.0025) associated with viral control. These data suggest that preferential targeting of Gag epitopes, rather than the breadth or magnitude of the response across the genome, may be an important marker of immune efficacy. These data have significance for the design of vaccines and for interpretation of vaccine-induced responses.
PMCID: PMC371059  PMID: 15016844
7.  PCR-Based Assay To Quantify Human Immunodeficiency Virus Type 1 DNA in Peripheral Blood Mononuclear Cells 
Journal of Clinical Microbiology  2000;38(2):630-634.
An assay that quantifies the amount of human immunodeficiency virus type 1 (HIV-1) DNA in peripheral blood mononuclear cells has been developed. PCR amplification of the HIV-1 DNA is performed in the presence of an internal quantitation standard, and colorimetric detection of the amplified product is performed with microwell plates. The copies of HIV-1 DNA are normalized to total genomic DNA input. The assay has an analytical sensitivity of 10 input copies per amplification reaction and a three-log detection range. In an analysis of sequential samples from patients on combination therapy, HIV-1 DNA was quantifiable for all individuals tested, including those with undetectable plasma HIV-1 RNA. In a separate study, a comparison of HIV-1 DNA levels was made with a group of long-term survivors and progressors. The mean HIV-1 DNA levels were lower in the long-term survivors than in the progressors (P, 0.04). The mean HIV-1 RNA levels were also lower, but the difference was not statistically significant (P, 0.164). A quantitative DNA assay will provide an additional tool to gain insight into the natural history of infection and the continued efficacy of potent antiretroviral therapies.
PMCID: PMC86163  PMID: 10655358
8.  Full-Length Human Immunodeficiency Virus Type 1 Genomes from Subtype C-Infected Seroconverters in India, with Evidence of Intersubtype Recombination 
Journal of Virology  1999;73(1):152-160.
The development of an effective human immunodeficiency virus type 1 (HIV-1) vaccine is likely to depend on knowledge of circulating variants of genes other than the commonly sequenced gag and env genes. In addition, full-genome data are particularly limited for HIV-1 subtype C, currently the most commonly transmitted subtype in India and worldwide. Likewise, little is known about sequence variation of HIV-1 in India, the country facing the largest burden of HIV worldwide. Therefore, the objective of this study was to clone and characterize the complete genome of HIV-1 from seroconverters infected with subtype C variants in India. Cocultured HIV-1 isolates were obtained from six seroincident individuals from Pune, India, and virtually full-length HIV-1 genomes were amplified, cloned, and sequenced from each. Sequence analysis revealed that five of the six genomes were of subtype C, while one was a mosaic of subtypes A and C, with multiple breakpoints in env, nef, and the 3′ long terminal repeat as determined by both maximal χ2 analysis and phylogenetic bootstrapping. Sequences were compared for preservation of known cytotoxic T lymphocyte (CTL) epitopes. Compared with those of the HIV-1LAI sequence, 38% of well-defined CTL epitopes were identical. The proportion of nonconservative substitutions for Env, at 61%, was higher (P < 0.001) than those for Gag (24%), Pol (18%), and Nef (32%). Therefore, characterized CTL epitopes demonstrated substantial differences from subtype B laboratory strains, which were most pronounced in Env. Because these clones were obtained from Indian seroconverters, they are likely to facilitate vaccine-related efforts in India by providing potential antigens for vaccine candidates as well as for assays of vaccine responsiveness.
PMCID: PMC103818  PMID: 9847317

Results 1-8 (8)