Full-length clone and characterization of a human immunodeficiency virus type 1 subtype B' isolated from Hubei Province,China

There are two types of Human Immunodeficiency Virus （HIV）： HIV-1 and HIV-2. HIV-1 dominates epidemics in many different parts of the world, and HIV-2 is principally responsible for the epidemic in westem Africa. In China, Zeng et al have reported the first individual infected with HIV-1 in 1985. And in the 1990s, there was a severe epidemic involving the HIV-1 B＇ strain among people who sold blood and plasma in Henan, Hubei and adjacent provinces. To further study in HIV/AIDS vaccines and HIV-1 drug resistance for people in these regions, we need to construct an infectious HIV-1 B＇ molecular clone which is representative of the virus in these areas. To this end, we have isolated a HIV-1 B＇ virus from a child who was infected with HIV-1 from his mother in Hubei province, and have constructed a full-length clone from this genome.

Association between Nef-specific CD8 T-cell responses and disease progression in HIV-1 subtype B infection

Background The correlation between HIV-1 Nef-specific CD8 T-cell responses and markers of HIV-1 disease progression still remains unclear. This study analysed and compared the role of HIV-1 Nef-specific CD8 T-cell responses in patients with different disease status. Methods Two groups of patients with HIV-1 subtype B infection were selected according to CD4 count and clinical manifestations： long-term nonprogresssors （LTNPs, n = 20） and advanced progressors （APs, CD4 count 〈500 cells/pl, n = 34）. Nef-specific CD8 T-cell responses were studied by interferon- T ELISpot assay against 3 pools of HIV-Nef peptides. Results Nef-specific CD8 T-cell responses did not correlate with viral load or CD4 count in all patients and no significant differences were found in the magnitude of Nef-specific CD8 T-cell responses between groups LTNPs and APs （670 SFC/106 peripheral blood mononuclear cells vs 1107 SFC/106 peripheral blood mononuclear cells, P = 0.255）. Further comparisons showed that there were also no significant correlations observed in group LTNPs, but Nef-specific CD8 T cells correlated negatively with viral load （r = -0.397, P = 0.020） and positively with CD4 count （r = 0.364, P = 0.034） in group APs. Conclusion These data suggest that different correlation patterns between Nef-specific CD8 T-cell responses and disease progression exist in LTNPs and APs. Although a negative association was observed with concurrent plasma HIV RNA in APs, Nef-specific CD8 T-cell responses might fail to play a protective role in different stages of HIV- 1 infection.

HIV-Specific IL-2^+ and/or IFN-γ^+ CD8^+ T Cell Reponses during Chronic HIV-1 Infection in Former Blood Donors

Objective Conflicting data have been generated from previous studies to determine which kind of relationship exists between HIV-1 specific CD8 Tcell responses and HIV-1 viral load or CD4 count over the course of infection.In this study,153 HIV-1 infected LTNPs were enrolled to investigate the role of HIV-1 specific CD8 T-cell responses in chronic HIV-1 infection among HIV-1 infected former blood donors.Methods The patients were stratified into three groups according to CD4 count：CD4≥500 cells/μL;350 cells/μL≤CD4〈500 cells/μL;CD4〈350 cells/μL.PBMCs were isolated from the patients＇ anticoagulated blood samples.IL-2 and IFN-γ secretions of CD 8 T cells against 17 HIV-1 consensus B full peptide pools were analyzed by using ICS assay.Results An overall inverse correlation were observed between CD4 count and plasma viral load.Although no significant difference was observed during the comparisons of frequency/breadth of HIV-1 specific CD8 T cell responses,CD4 count stratification analysis showed that different correlation pattern existed in three strata：as for patients whose CD4 counts were less than 350 cells/μL,no significant correlations were identified between frequency/breadth of HIV-1 specific CD8 T cell responses and CD4 count/viral load;as for patients whose CD4 counts ranged from 350 cells /μL to 500 cells/μL,significant correlation was only observed between the response breadth of IL-2＋IFN-γ＋ CD8 T cells and CD4 count;however,as for patients whose CD4 counts were more than 500 cells/μL,direct correlations were identified between IL-2＋IFN-γ＋/IL-2＋/IFN-γ＋ CD8 T cells and viral load or CD4 count.Conclusions Universal consistent inverse correlation was only indentified between CD4 count and viral load.The relationship between HIV-1 specific CD8 T cell responses and CD4 count/viral load varied in different CD4 strata,which showed that better preserved CD4 T cells were correlated with better CD8 T cell functions.

R5 to X4 coreceptor switch of human immunodeficiency virus type 1B' and B'/C recombinant subtype isolates in China

The chemokine receptors CCR5 and CXCR4 play an important role as coreceptors for human immunodeficiency virus type 1 （HIV-1） entring into cells. HIV-1 isolates can be distinguished by the chemokine coreceptors. Nonsyncytium inducing （NSI）, macrophage tropic viruses utilizing CCR5, are called R5 viruses; syncytium inducing （SI） isolates use CXCR4 and known as X4 viruses. R5 viruses generally are associated with latent stage of infection and X4 viruses with later,