CD4+CD38+ central memory T cells contribute to HIV persistence in HIV-infected individuals on long-term ART.

<bold>Background: </bold>Despite the effective antiretroviral treatment (ART) of HIV-infected individuals, HIV persists in a small pool. Central memory CD4+ T cells (Tcm) make a major contribution to HIV persistence. We found that unlike HLA-DR, CD38 is highly expressed on the Tcm of HIV-infected subjects receiving ART for > 5 years. It has been reported that the half-life of total and episomal HIV DNA in the CD4+CD38+ T cell subset, exhibits lower decay rates at 12 weeks of ART. Whether CD38 contributes to HIV latency in HIV-infected individuals receiving long-term ART is yet to be addressed.<bold>Methods: </bold>Peripheral blood mononuclear cells (PBMCs) were isolated from the whole blood of HIV-infected subjects receiving suppressive ART. The immunophenotyping, proliferation and apoptosis of CD4+ T cell subpopulations were detected by flow cytometry, and the level of CD38 mRNA and total HIV DNA were measured using real-time PCR and digital droplet PCR, respectively. A negative binomial regression model was used to determine the correlation between CD4+CD38+ Tcm and total HIV DNA in CD4+ T cells.<bold>Results: </bold>CD38 was highly expressed on CD4+ Tcm cells from HIV infected individuals on long-term ART. Comparing with HLA-DR-Tcm and CD4+HLA-DR+ T cells, CD4+CD38+ Tcm cells displayed lower levels of activation (CD25 and CD69) and higher levels of CD127 expression. The proportion of CD38+ Tcm, but not CD38- Tcm cells can predict the total HIV DNA in the CD4+ T cells and the CD38+ Tcm subset harbored higher total HIV DNA copy numbers than the CD38- Tcm subset. After transfected with CD38 si-RNA in CD4+ T cells, the proliferation of CD4+ T cells was inhibited.<bold>Conclusion: </bold>The current date indicates that CD4+CD38+ Tcm cells contribute to HIV persistence in HIV-infected individuals on long-term ART. Our study provides a potential target to resolve HIV persistence. [ABSTRACT FROM AUTHOR]