Sex and Age Impact CD4+ T Cell Susceptibility to HIV In Vitro Through Cell Activation Dynamics [scRNA-Seq]
Cellular composition and responsiveness of immune system evolve upon ageing and are influenced by biological sex. CD4+ T cells from women living with HIV exhibit decreased viral replication ex vivo compared to men. We thus hypothesized that these findings could be recapitulated in vitro, and infected primary CD4+ T cells with HIV-based vectors pseudotyped with VSV-G or HIV envelopes. We used cells isolated from twenty donors to interrogate the effect of sex and age on permissiveness over a six-day activation kinetics. Our data identified an increased permissiveness to HIV between 24 and 72h post-stimulation. Sex- and age-based analysis at these time points showed increased susceptibility to HIV of cells isolated from males and from donors over 50 years old, respectively. Parallel assessment of surface marker expression revealed higher frequencies of activation markers (CD69, CD25, HLA-DR) and immune check point inhibitors (PD-1 and CTLA-4 in cells from highly permissive donors. Furthermore, positive correlations were identified between CD69, PD-1 and CTLA-4 expression kinetics and HIV expression kinetics. Cell population heterogeneity was assessed by single-cell RNA-Seq analysis and no cell subtype enrichment was identified according to sex. Finally, transcriptomic analyses further highlighted the role of activation in those differences with enriched activation and cell cycle gene sets in men and in older women cells. Altogether, this study brought further evidence about individual features affecting HIV replication at the cellular level and should be considered in latency reactivation studies for HIV cure. Overall design: To investigate the differences in CD4+ T cell subpopulations between sexes, we stimulated (TCR-mediated) primary CD4+ T cells from 2 men and 2 women, then performed sc-RNA-Seq