Circulation of HIV-1 subtype A within the subtype C HIV-1 epidemic in Tamil Nadu, India

The HIV‐1 epidemic in India is caused mainly by subtype C viruses that are transmitted sexually and by injecting drug use. The state of Tamil Nadu in Southern India has an HIV‐1 median prevalence of 16.8% among injecting drug users, 6.6% in men who have sex with men, and 4.6% in female sex workers. In the rural district of Namakkal, a prevalence >3% was detected among antenatal women. The goal of this study was to determine the HIV‐1 molecular epidemiology in Tamil Nadu. Blood samples were collected from 40 high‐risk HIV‐seropositive individuals from Chennai and Namakkal. HIV‐1 subtype was determined by envelope nucleotide sequencing. Among the samples studied, 85% were subtype C, however, a cluster of subtype A samples (12.5%) and one subtype E recombinant form CRF01_AE (close to the Thailand strains) were detected. The average genetic distance of subtype C samples from Chennai and Namakkal were 9.44 ± 0.77% and 11.8 ± 0.7%, respectively indicating an evolved epidemic. This pilot study confirmed that subtype C was predominant in these regions but an outbreak of subtype A was detected in Namakkal. These results stress the importance of periodic monitoring of circulating HIV‐1 subtypes in South India. J. Med. Virol. 84:1507–1513, 2012. © 2012 Wiley Periodicals, Inc.     

HIV-1 diversity among inmates of Italian prisons

In Italy, the prevalence of non-B HIV-1 subtypes ranges reportedly from 5.4% to 12.6%, yet there are no data on their circulation in prisons, where the prevalence of HIV infection is high. A retrospective study was conducted to evaluate the circulation of non-B subtypes and to characterize their determinants in five Italian prisons. To this end an aliquot of samples of blood was taken in the period 2001-2006 from all 262 HIV-positive inmates in whom antiretroviral treatment had failed. Complete HIV-1 PR and RT regions were sequenced for all samples and subjected to phylogenetic analysis; 250 (95.4%) sequences clustered with subtype B. The non-B subtype was found in 4% of Italian prison inmates and 16.7% of non-Italian prison inmates; the overall percentage increased from 1.8% for inmates infected in 1982-1990 to 4.4% in 1991-1999 and 21.9% in 2000-2006. Factors significantly associated with non-B subtypes were an exposure to other than injecting drug use and a first positive HIV test in 2000-2006. Non-B subtypes were distributed within five monophyletic clades. In all cases but one, it was possible to correlate the history of HIV-exposure to the origin of the clade, with high bootstrap values. In conclusion, although the sample may not be representative of the prison inmate population in Italy, the data suggest strongly that the circulation of non-B subtypes has apparently increased. Non-B subtypes were found to have been associated with heterosexual contact and time of the first HIV-positive test. Knowledge of the different subtypes circulating in prisons may be useful for tracking the epidemiology of HIV infection and for choosing antiretroviral therapy.     

Broad neutralizing antibody response and genetic variation in HIV-1 env genes in Koreans with primary HIV-1 infections

To determine the neutralization profiles induced by HIV-1 Korean clade B, which has a monophyletic lineage and relative limited genetic diversity, we investigated the ability of HIV variants to elicit neutralizing antibodies in the immune response to primary infection. We selected seven Korean drug-na?ve subjects with an HIV-1 primary infection and did pseudovirion-based neutralization assays using env genes of Korean HIV origin. The neutralizing antibody responses to the Korean clade B showed broad reactivity to subtype B but a highly subtype-specific pattern. The lengths of the amino acid sequences and the PNGS numbers in the V1-V5 region were positively correlated with neutralization. These results imply that the genetic characteristics of HIV-1 env may affect neutralizing antibody responses in HIV-1-infected individuals. This is the first report describing the relationship between neutralizing antibody responses and HIV-1 genetic characteristics in Korean subjects. It can be useful for developing AIDS vaccines against HIV-1 subtype B strains.     

Comparative performance of the Amplicor HIV-1 Monitor Assay versus NucliSens EasyQ in HIV subtype C-infected patients

In facing global programs for treating HIV-infected patients in the developing countries, there is a real need for viral load assays that are accurate for the local subtypes. The present study was designed to evaluate viral load measurements using the newer version of the NASBA assay in subtype C-infected patients. The performances of this new version, a real-time nucleic acid sequence-based amplification HIV-1 assay (NucliSens EasyQ), were compared to Amplicor HIV-1 Monitor Assay version 1.5 in 79 samples of subtype C-infected patients originating from Ethiopia. Twenty HIV-1 subtype B-infected patients served as a control group. Blood samples from patients in both groups were tested by both assays. The results were compared by a paired, two-tailed Student's t-test. The disparity between the results of the two viral load assays was highly significant in subtype C samples (P = 0.005), such that in the vast majority, higher values of viral load were obtained by the Amplicor assay. However, no differences between the two assays were found in subtype B samples (P = 0.77). CD4 measurements were available for 78 samples of subtype C-infected patients. Of these, a CD4-to-viral load discrepancy (CD4 相似文献   

Correlation of T-lymphocyte subpopulations with immunological markers in HIV-1-infected Indian patients

Progressive HIV disease is characterized by CD4 T cell decline and activation of the immune system. We aimed to study the quantitative alterations in the naive (CD45RA+CD62L+), memory/effector (CD45RO+) and activated (HLA-DR+CD38+) T-lymphocyte subpopulations in antiretroviral treatment naive, HIV-1 infected Indian patients by three-color multi-parametric flow cytometry. The association of different CD4+ and CD8+ T cell subsets with the immunological markers- CD4+ and CD8+ T cell percentages was examined by calculating the partial correlation coefficients. We also observed significant differences in the expression of different CD4+ and CD8+ T-cell subsets among the two groups of patients formed using the median CD4+ T cell percentage value (15%) of the study population. The correlations of different CD4+ and CD8+ T cell subsets reflected the quantitative alterations in the T-lymphocyte subpopulations and activation of the immune system during HIV-infection. The study outcome also emphasizes the significance of the CD38+CD8+ T-lymphocyte subset as a prognostic marker for HIV management and ART monitoring in resource-limited settings of developing countries like India.     

Impact of HIV-1 genetic diversity in China on the measurement of viral load

In this study, 190 HIV-positive samples were collected from different regions of China. The HIV clades of 153 samples were determined successfully based on env sequencing. Specifically, 48, 5, 87, and 13 isolates belonged to clades B', B, BC, and AE, respectively. The viral loads in all samples were measured using three commercial assays, Amplicor HIV-1 monitor v1.5, Nuclisens HIV-1 QT and NucliSens EasyQ HIV-1 assays. The differences and linear correlations for individual assays were compared, with expected 1:1 relationships. Significant differences were found for the following viral loads: clade BC measured by any two assays (P < 0.001); clade AE between Amplicor 1.5 and Easy Q (P = 0.005); clade B' between Amplicor 1.5 and Nuclisens QT (P = 0.002); clade AE between Amplicor 1.5 and Nuclisens QT (P = 0.025); and clade B' between Amplicor 1.5 and EasyQ (P = 0.04). The largest mean difference in the log(10) values was 0.9518, which was found between Amplicor 1.5 and Nuclisens QT. However, the viral loads for clades AE and B' measured by EasyQ and Nuclisens QT, and those for clade B measured by any two assays did not differ significantly. The degrees of correlation for clades B and B' between any two assays (R > 0.8) were higher that those for clades AE and BC between any two assays (R < 0.7), except for clade AE between Amplicor 1.5 and Easy Q. Thus, the clade types, especially clades BC and AE, are most likely to impact on the quantitation of viral load using differentassays.     

Characterization of HIV-1 Gag-specific T cell responses in chronically infected Indian population

India is at the epicentre of the global HIV/AIDS epidemic in South-east Asia, predominated by subtype C infections. It is important to characterize HIV-1-specific T cell responses in this particular population with the aim of identifying protective correlates of immunity to control HIV-1 infection. In this study, we performed a comprehensive analysis of the breadth and magnitude of T cell responses directed at HIV-1 subtype C Gag, one of the most conserved HIV-1 proteins. The study population consisted of antiretroviral naive, chronic HIV-1 subtype C-infected individuals at various stages of infection. We used recent advanced techniques such as enzyme-linked immunospot (ELISPOT) assay and intracellular cytokine staining to quantify the total CD4(+) and CD8(+) T cell response to HIV-1 gag at single peptide level, regardless of HLA haplotype of the infected individual. The p24-Gag was identified as the most frequently recognized subunit protein with the greatest magnitude of CD4(+) and CD8(+) T cell responses. Stronger and broader CD8 T cell responses were recognized, contrasting with the weaker and narrower CD4 T cell responses with regard to Gag protein subunits. The magnitude of the HIV-specific interferon (IFN)-gamma responses was observed to be higher than the corresponding interleukin (IL)-2 response, indicating the persistence of antigenic load in chronically infected Indian population due to the probable dysfunction of HIV-specific, IFN-gamma-secreting CD8 T cells in absence of IL-2 help.     

Molecular epidemiology of HIV-1 subtypes and drug resistant strains in Taiwan

The Taiwanese government has provided free highly active antiretroviral therapy since April 1997. Previously, we have reported on the molecular epidemiology of HIV‐1 in Taiwan from 1988 to 1998. In addition, an outbreak of circulating recombinant form (CRF) 07_BC among intravenous drug users was noted in 2004. Therefore, the purposes of this study were to elucidate the distribution of HIV‐1 subtypes among different high‐risk groups in Taiwan from 1999 to 2000 and to conduct surveillance on drug resistance among treatment naïve patients from 1997 to 2000. Blood samples from 239 HIV‐1/AIDS patients and their subtypes were examined using DNA sequencing and phylogenetic analysis. The results showed that among 226 male patients, 213 (94.2%) had subtype B, 11 (4.9%) had CRF01_AE, 1 had unique recombinant strain related to both CRF07_BC and CRF08_BC (strain T12‐99TW) and 1 had CRF08_BC (strain L9312‐00TW). The patients infected with T12‐99TW and L9312‐00TW were intravenous drug users and had needle‐sharing experiences in Yunnan Province, China. Of the 13 HIV‐1‐infected females, 7 (53.8%) had subtype B, 5 (38.5%) had CRF01_AE, and 1 (7.7%) had subtype C. Phylogenetic analysis demonstrated that the neither strain T12‐99TW nor L9312‐00TW clustered with CRF07_BC strains isolated from Taiwanese intravenous drug users in 2004. In addition, 126 treatment naïve patients were selected for genotypic DR analysis and the results showed that 4.3% (2/47) homosexual males had M184V mutations. This is the first report on the identification of CRF08_BC and a unique recombinant strain related to both CRF07_BC and CRF08_BC in Taiwan. J. Med. Virol. 80:183–191, 2008. © 2007 Wiley‐Liss, Inc.     

Correlation of immune activation with HIV-1 RNA levels assayed by real-time RT-PCR in HIV-1 subtype C infected patients in Northern India

BACKGROUND: Assays with specificity and cost effectiveness are needed for the measurement of HIV-1 burden to monitor disease progression or response to anti-retroviral therapy (ART) in HIV-1 subtype C infected patients. OBJECTIVES: The objective of this study was to develop and validate an affordable one step real-time RT-PCR assay with high specificity and sensitivity to measure plasma HIV-1 loads in HIV-1 subtype C infected patients. RESULTS: We developed an RT-PCR assay to detect and quantitate plasma HIV-1 levels in HIV-1 subtype C infected patients. An inverse correlation between plasma viral loads (PVL) and CD4+ T-cell numbers was detected at all CDC stages. Significant correlations were found between CD8+ T-cell activation and PVL, as well as with the clinical and immunological status of the patients. CONCLUSIONS: This RT-PCR assay provides a sensitive method to measure PVL in HIV-1 subtype C infected patients. Viral loads correlated with immune activation and can be used to monitor HIV care in India.     

Topical gel formulation of broadly neutralizing anti-HIV-1 monoclonal antibody VRC01 confers protection against HIV-1 vaginal challenge in a humanized mouse model

The new generation broadly neutralizing antibody VRC01 against HIV-1 shows great potential as a topically administered microbicide to prevent sexual transmission. We evaluated its efficacy in a RAG-hu humanized mouse model of vaginal HIV-1 transmission. Mice were challenged vaginally with R5 tropic HIV-1 BaL an hour after intravaginal application of the VRC01 (1 mg/ml concentration) gel. A combination of four first generation bNAbs, namely b12, 2F5, 4E10 and 2G12, was used as a positive efficacy control whereas a non-specific dengue MAb 4G2 was used as negative control. Our results showed that seven out of nine VRC01 antibody administered mice and all of the mice receiving the four bNAb antibody combination were protected against HIV-1 challenge. These findings demonstrate the efficacy of the new bNAb VRC01 as a topical microbicide to protect against HIV-1 vaginal transmission and highlight the use of the RAG-hu mouse model for testing HIV prevention strategies.     

Inverse relationship between HIV-1 p24 antigenemia, anti-p24 antibody and neutralizing antibody response in all stages of HIV-1 infection

A double blind cohort study was conducted on 149 homosexual males and 36 patients with AIDS to investigate the relationship between HIV-1 antigenemia, the presence of neutralizing antibody (NA) activity and specific anti-viral core protein (p24) antibody (Ab) in the sera of HIV infected individuals during their progression to AIDS. All AIDS patients and 68% (101/149) of the homosexual males were HIV seropositive upon entering the study. Of those 48 (32%) homosexuals who were HIV negative at the onset, three seroconverted during the two year observation period. Retrospective studies of the HIV(-) subjects' sequentially stored serum samples demonstrated an early transient appearance of gag encoded p24 antigen (Ag) which preceded their production of NA and specific anti-p24 Ab. Following their seroconversion, no more circulating p24 Ag could be detected. Among the 101 HIV positive homosexuals, 16% rapidly progressed to AIDS and seven of these 16 (44%) subjects eventually died during the two year observation period. In this group of individuals with poor prognosis, presence of NA and anti-p24 Ab commenced at the onset reaching peak levels just prior to developing AIDS and began to decline as the clinical course worsened. Their circulating level of p24 Ag remained undetectable as long as there was quantifiable NA and anti-p24 Ab in their sera. Reappearance of circulatory p24 Ag, on the other hand, was associated with high risk for progression to AIDS.2+hus, while only 11     

艾滋病痴呆综合征患者HIV-1 nef基因多样性分析

目的 研究艾滋病痴呆综合征(ADC)患者体内HIV-1 nef基因变异规律,为ADC发病机制的研究提供依据.方法 提取1例ADC病例尸检标本的外周(脾)和中枢神经系统(基底核、额叶灰质、脑膜、颞叶)共5个部位组织中的基因组DNA,PCR扩增HIV-1 nef基因,与pMD19-T克隆载体连接后,蓝白斑筛选挑取阳性菌落测序,序列经BLAST分析后,每个部位取5个序列,利用Bioedit、MEGA4等生物学软件进行基因距离、系统进化树以及同义/非同义替换值(ds/dn)等分析.结果 该ADC患者感染的是HIV-1 B亚型,与标准序列HXB2比较,该病例的HIV-1 nef基因存在变异,且外周组织与中枢神经系统各组织间以及中枢神经组织不同部位的基因变异不同,相同组织来源的nef序列基因距离较小,外周和中枢的nef基因距离差异较大,该病例H IV-1 nef基因在外周和中枢神经系统变异时均受到负向选择压力.结论 ADC患者体内HIV-1 nef基因存在多样性,且不同组织部位的基因变异不同,其导致的Nef蛋白某些氨基酸位点的改变对其生物学活性的影响有待进一步研究.     

Analysis of the neutralizing antibody response elicited in rabbits by repeated inoculation with trimeric HIV-1 envelope glycoproteins

The elicitation of broadly neutralizing antibodies directed against the human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins, gp120 and gp41, remains a major challenge. Attempts to utilize monomeric gp120 as an immunogen to elicit high titers of neutralizing antibodies have been disappointing. Envelope glycoprotein constructs that better reflect the trimeric structure of the functional envelope spike have exhibited improved immunogenicity compared with monomeric gp120. We have described soluble gp140 ectodomain constructs with a heterologous trimerization motif; these have previously been shown to elicit antibodies in mice that were able to neutralize a number of HIV-1 isolates, among them primary isolate viruses. Recently, solid-phase proteoliposomes retaining the envelope glycoproteins as trimeric spikes in a physiologic membrane setting have been described. Here, we compare the immunogenic properties of these two trimeric envelope glycoprotein formulations and monomeric gp120 in rabbits. Both trimeric envelope glycoprotein preparations generated neutralizing antibodies more effectively than gp120. In contrast to monomeric gp120, the trimeric envelope glycoproteins elicited neutralizing antibodies with some breadth of neutralization. Furthermore, repeated boosting with the soluble trimeric formulations resulted in an increase in potency that allowed neutralization of a subset of neutralization-resistant HIV-1 primary isolates. We demonstrate that the neutralization is concentration-dependent, is mediated by serum IgG and that the major portion of the neutralizing activity is not directed against the gp120 V3 loop. Thus, mimics of the trimeric envelope glycoprotein spike described here elicit HIV-1-neutralizing antibodies that could contribute to a protective immune response and provide platforms for further modifications to improve the efficiency of this process.     

A clustering phenomenon among HCV-1a strains among patients coinfected with HIV from Buenos Aires, Argentina

The human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes which lead to high coinfection rates. Among HIV‐infected individuals such rates reached 21% in Argentina, being HCV‐1a the most predominant subtype. In this work, 25 HCV subtype 1a (HCV‐1a) strains from Argentinean patients coinfected with HIV were studied based on E2 and NS5A sequences. Phylogenetic analyses indicated that 12 strains were highly related to each other, constituting a highly supported (posterior probability = 0.95) monophyletic group that we called “M.” The remaining HCV strains (group dispersed or “D”) were interspersed along the phylogenetic trees. When comparing both groups of HCV‐1a, 10 amino acid differences were located in functional domains of E2 and NS5A proteins that appeared to affect eventually the peptides binding to MHC‐I molecules thus favoring immune escape and contributing to the divergence of HCV genotypes. Bayesian coalescent analyses for HCV‐1a cluster M isolates indicated that the time to the most recent common ancestor (tMRCA) overlaps with the age estimated recently for the HIV‐BF epidemic in Argentina. Furthermore, the genomic characterization based on pol gene analysis from HIV viremic patients showed that most HIV isolates from patients coinfected with HCV‐1a cluster M were BF recombinants with identical recombination patterns. In conclusion, these results suggest the presence of an HCV‐1a monophyletic cluster with a potential HIV co‐transmission by phylogenetic analyses. J. Med. Virol. 84:570–581, 2012. © 2011 Wiley Periodicals, Inc.     

Evaluation of Calypte AWARE HIV-1/2 OMT antibody test as a screening test in an Indian setting

Purpose: Integrated counselling and testing centres (ICTC) provide counselling and blood testing facilities for HIV diagnosis. Oral fluid tests provide an alternative for people whodo not want blood to be drawn. Also, it avoids the risk of occupational exposure. The goal of this study was to evaluate the utility of Calypte AWARE HIV-1/2 OMT antibody test as a screening test in an Indian setting. Materials and Methods: A cross-sectional study was carried out after ethics committee approval in 250 adult ICTC clients. Blood was collected and tested from these clients for HIV diagnosis as per routine policy and the results were considered as the gold standard. Also, after another written informed consent, oral fluid was collected from the clients and tested for the presence of HIV antibodies. Twenty five clients who had and 25 clients who had not completed their secondary school education (Group A and Group B, respectively) were also asked to perform and interpret the test on their own and their findings and experiences were noted. Result: The sensitivity, specificity, PPV and NPV of the oral fluid antibody test were 100%, 98.51%, 94.11% and 100%, respectively. Seventy six percent of clients preferred oral fluid testing. Group B found it difficult to perform the test as compared to Group A and this difference was statistically significant (P ≤ 0.05). Conclusion: Oral fluid testing can be used as a screening test for HIV diagnosis; however, confirmation of reactive results by blood-based tests is a must..     

High replication fitness and transmission efficiency of HIV-1 subtype C from India: Implications for subtype C predominance

HIV-1 subtype C has been the predominant subtype throughout the course of the HIV-1 epidemic in India regardless of the geographic region of the country. In an effort to understand the mechanism of subtype C predominance in this country, we have investigated the in vitro replication fitness and transmission efficiency of HIV-1 subtypes A and C from India. Using a dual infection growth competition assay, we found that primary HIV-1 subtype C isolates had higher overall relative fitness in PBMC than subtype A primary isolates. Moreover, in an ex vivo cervical tissue derived organ culture, subtype C isolates displayed higher transmission efficiency across cervical mucosa than subtype A isolates. We found that higher fitness of subtype C was not due to a trans effect exerted by subtype C infected PBMC. A half genome A/C recombinant clone in which the 3′ half of the viral genome of subtype A was replaced with the corresponding subtype C3′ half, had similar replicative fitness as the parental subtype A. These results suggest that the higher replication fitness and transmission efficiency of subtype C virus compared to subtype A virus from India is most probably not due to the envelope gene alone and may be due to genes present within the 5′ half of the viral genome or to a more complex interaction between the genes located within the two halves of the viral genome. These data provide a model to explain the asymmetric distribution of subtype C over other subtypes in India.     

Hantaan/Andes virus DNA vaccine elicits a broadly cross-reactive neutralizing antibody response in nonhuman primates

At least four hantavirus species cause disease with prominent renal involvement-hemorrhagic fever with renal syndrome (HFRS); and several hantavirus strains cause disease with significant pulmonary involvement-hantavirus pulmonary syndrome (HPS). The most prevalent and lethal hantaviruses associated with HFRS and HPS are Hantaan virus (HTNV) and Andes virus (ANDV), respectively. Here, we constructed a DNA vaccine plasmid (pWRG/HA-M) that contains both the HTNV and ANDV M gene segments. Rhesus macaques vaccinated with pWRG/HA-M produced antibodies that bound the M gene products (i.e., G1 and G2 glycoproteins), and neutralized both HTNV and ANDV. Neutralizing antibody titers elicited by the dual-immunogen pWRG/HA-M, or single-immunogen plasmids expressing only the HTNV or ANDV glycoproteins, increased rapidly to high levels after a booster vaccination administered 1-2 years after the initial vaccination series. Memory responses elicited by this long-range boost exhibited an increased breadth of cross-neutralizing activity relative to the primary response. This is the first time that hantavirus M gene-based DNA vaccines have been shown to elicit a potent memory response, and to elicit antibody responses that neutralize viruses that cause both HFRS and HPS.