Transcriptional and methylation outcomes of didehydro-Cortistatin A use in HIV-1 infected CD4+T cells
Ongoing viral transcription from the reservoir of long-lived CD4+ T cells containing integrated HIV-1 DNA presents a barrier to cure and associates with poorer health outcomes for people living with HIV, including chronic immune activation and inflammation. We previously reported that didehydro-Cortistatin A (dCA), an HIV-1 Tat inhibitor, blocks HIV-1 transcription. We sought to extend this work and examine the impact of dCA on host immune CD4+ T cell transcriptional and epigenetic states. Here, we performed a comprehensive analysis of genome-wide transcriptomic and DNA methylation profiles upon long-term dCA-treatment of primary human memory CD4+ T cells. dCA prompted specific transcriptional and DNA methylation changes in cell cycle, histone, interferon-response and T cell lineage transcription factor genes, through inhibition of both HIV-1 and Mediator kinases. These alterations establish a tolerogenic Treg/Th2 phenotype, reducing viral gene expression and mitigating inflammation in primary CD4+T cells during HIV-1 infection. Additionally, dCA suppresses expression of lineage-defining transcription factors for Th17 and Th1 cells, critical HIV-1 targets and reservoirs. dCA's benefits thus extend beyond viral transcription inhibition, modulating immune cell landscape to limit HIV-1 acquisition and inflammatory environment linked to HIV-infection.  Overall design: A comparative RNA-seq analysis of primary memory CD4+ T cells treated with ART or ART + 50 nm didehydro-Cortistatin A for 5 weeks. Memory CD4+ T cells in the Kessing Study were isolated from people living with HIV and expanded and treated in vitro. Memory CD4+ T cells in the Mori study were isolated from people not living with HIV and expanded, treated and infected with HIV in vitro (or left uninfected). We compared cells treated with dCA versus those untreated and sought to distinguish the effects of dCA in HIV-infected cells versus the effects of dCA in uninfected cells.