AIM: To investigate whether Programmed death-1 (PD-1) expression on peripheral CD4~+CD25~(nt/hi)CD127~(lo) regulatory T cells (Treg) was associated with disease progression in HIV-1-infected patients. METHODS: Peripheral blood from 108 HIV-1-infected patients in distinct disease progression statuses and 27 healthy individuals were collected in the present investigation. PBMCs were isolated by centrifugation on Ficoll-Hypaque, followed by staining with anti-CD4-PerCP, anti-CD25-FITC, anti-CD127-PE and anti-PD-1-APC. PD-1 expression on Treg was analyzed by four-color staining flow cytometry. CD4~+T cell absolute counts were determined using Multitest CD3/CD4/CD8/CD45 kit and plasma viral loads were detected on NucliSens EasyQ. All data were analyzed using SPSS14.0 software. RESULTS: In peripheral blood of healthy individuals, Treg expressed PD-1 at very low levels (1.72%±0.65%). In contrast, Treg from HIV-1-infected patients showed a significantly increased PD-1 expression (5.33%±2.24%, P<0.01). Moreover, AIDS patients exhibited statistically higher PD-1 expression on Treg (7.87%±2.23%) than newly HIV-1 infected patients (3.22%±1.01%, P<0.05) and patients in progression to AIDS(5.21%±1.72%, P<0.05). PD-1 up-regulation on Treg was closely correlated with reduced CD4~+T cell absolute counts but elevated plasma viral load. CONCLUSION: Overall, we found that PD-1 expression on peripheral Treg was up-regulated and correlated with disease progression in HIV-1-infected patients for the first time. These findings not only extend our understanding of how Treg functions in HIV-1-infected patients but also support the notion that blocking PD-1/PD-L1 interactions may represent a potential therapeutic strategy for HIV-1-infected patients.

Objective To measure the levels of cross-reactive neutralizing antibodies responding to various subtypes of HIV-1 strains in people with HIV-1 infection in Chongqing and to analyze their character-istics.Methods Two hundred and thirty-six plasma samples were collected from patients with chronic HIV-1 infection in Chongqing city.The single-round-infection assay in TZM-bl cells were performed to screen the plasma samples with cross-reactive neutralizing antibodies against various subtypes of HIV-1 strains by using HIV-1 pseudovirus strains and to measure the 50%inhibitory dose ( ID50 ) .Results Eight-een out of 236 (7.63%) plasma samples were able to neutralize various B subtypes and/or C subtypes of HIV-1 pseudovirus strains, among which 15 plasma samples showed the great ability to neutralize pseudovir-us strains of different subtypes.Conclusion The cross-reactive neutralizing antibodies against various sub-types of HIV-1 strains existed in plasma samples collected from people with chronic HIV-1 infection in Chongqing city.

Objective To investigate the molecular epidemiology of human immunodefieiency viruses (HIV)-1 infected individuals in Honghe district,Yunnan Province and provide the evidence of molecular biology features of HIV-1 infection.Methods HIV-1 pol gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR).Then sequencing and phylogenetic tree analysis were employed tO determine HIV-I subgenotype.The sequence alignment was performed in the database of international drug resistance tO identify resistance-associated mutations.Results The samples from 60 HIV-1 infected individuals were investigated:39 were male,21 were female,with average age 35.5 years old.Thirty-four cases were infected with HIV-I through intravenous drug abuse,12 by sexual contacts,2 were contaminated blood/blood products transfusion and 12 with unknown transmission routes.Phylogenetic analysis revealed that 53 cases (88.3%) were subtype 08-BC,6 (10.0%) were subtype 07-BC and 1 (1.7%) was subtype 01_AE.The total rate of drug resistance associated mutations was 33.3%.The major mutations in protease (PR) and reverse transcriptase (RT) regions accounted for 5.0% and 3 1.7%,respectively.The major mutations in PR region were I541M,V82VFIL,M46MI,which were found in 1 case,respectively.The mutations in RT region were as follows:4 cases were T69D,6 were A62V,1 was D67DE,1 was E44D,3 were V179D,1 was V179E.1 was K238KN,1 was L234T+P236S and 1 was V106E.Conclusions The major transmission route of HIV-I infection in Honghe district,Yunnan Province is through drug injection.The major HIV-1 subtype of HIV-infeeted individuals is 08_BC.PR inhibitor and RT inhibitor drug resistance associated mutations in HlV-1 gene have already existed.

Objective:To investigate the impact of the CD4+CD25nt/hiCD127lo regulatory T cell subset frequency on the immune status and disease progression of Chinese HIV-1 infected individuals.Methods:83 untreated HIV-infected individuals and 312 healthy control individuals of four distinct age groups were enrolled in the research. The CD4+ T cell absolute counts, phenotypes and frequency determination of CD4+CD25nt/hiCD127lo Regulatory T cell subsets was performed on freshly obtained whole blood samples by 3-color immune staining flow cytometry. The HIV-1 specific cellular immune function was test at single cell level by ELISpot. The corresponding plasma viral load was determined by NASBA.Results:The frequency of peripheral CD4+CD25nt/hiCD127lo regulatory T cells of HIV infected individuals in distinct disease progression status was dissimilar in China , and significantly increased in contrast to the healthy controls(P