Memory CD4+ T cell subsets show differential responses to HIV latency reversing agents [LRA stimulated]

HIV-1 persists in individuals on ART in infected central (CM), transitional (TM) and effector memory (EM) CD4+ T cells. We developed LARA (latency and reversion assay), which facilitates the examination of HIV latency reversal in CM, TM and EM subsets in a single assay. Studies with latency reversing agents (LRAs) revealed responses specific to each subset, including compounds that significantly reversed latency in all subsets but with a range of efficiency (bryostatin) to those that demonstrated subset specificity (IL-15). Significantly, LARA has allowed the demonstration that EM cells display a more activated profile compared to CM, which translated to enhanced efficiency in responsiveness to multiple LRAs and allowed the identification of mechanisms associated with the compounds that reactivate latent HIV in all subsets. Understanding the responsiveness of memory CD4+ T cells subsets to LRAs will accelerate the development of anti-latency therapy to interfering with viral persistence in vivo. Overall design: CD4 T cells were isolated from a cohort of Florida HIV-infected subjects that have been on successful ART for >36 months with a viral load =50 copies/mL. Three subjects in this cohort have previously been characterized according to their reservoir size (pDNA copies/million CD4) and relative distribution of the reservoir in memory CD4 T cell subsets namely central memory (TCM), transitional memory (TTM) and effector memory (TEM) CD4 T cells (R. Fromentin & N. Chomont unpublished data). We compared different classes of agents including PKC activators (Bryostatin), gamma-c cytokines (IL-15) and PMA+Ionomycin in their ability to induce viral transcription in the sorted memory CD4 T cell subsets. RNA from the sorted and 24h-stimulated subsets were purified. Unstimulated sorted cells from the same donors were included as pre-reactivation baseline controls.