Mechanisms for HIV containment in CD4 T cells under homeostatic proliferation

The main obstacle in curing an established HIV-1 infection is the long-lived reservoir of latently infected CD4+ T cells. This reservoir is maintained by T cell expansion that can be activated by several mechanisms including antigen-driven proliferation and homeostatic proliferation (HSP). Antigen-driven proliferation triggered by T cell receptor (TCR) signaling is a strong physiological inducer of CD4+ T cell expansion. This also reactivates latent HIV-1 and thus, can be the source of viral rebound. Unlike antigen-driven proliferation, HSP allows the expansion of HIV-1-infected CD4+ T cells without activating HIV-1 expression. While this condition strongly activates STAT5 signaling, the mechanisms for HIV-1 containment are unknown. Our previous work using HIV-infected primarily CD4+ T cells maintained under HSP conditions suggested a post-transcriptional block as a cause of the containment (Tsunetsugu-Yokota et al. 2016 Front Microbiol). To decipher the mechanisms that contribute to the HIV-1 refractory state in homeostatic proliferating CD4+ T cells, we analyzed differentially expressed genes in primary CD4 + cells that were cultured either under HSP conditions (culture with IL-7 and IL-15) or after TCR-stimulation (culture with IL-2 after anti-CD3/CD28 activation). Overall design: RNA-seq of total RNAs from naive CD4+ T cells cultured under four different conditions