Dendritic Cells Potently Purge Latent HIV-1 in TCR-Activated Cells via the PI3K-Akt-mTOR Pathway: Implications for Shock and Killl Strategies and Reservoir Analysis

The latent HIV-1 reservoir in treated patients primarily consists of resting memory CD4+ T cells. Stimulating the T-cell receptor (TCR), which facilitates transition of resting into effector T cells, is the most effective strategy to purge these latently infected cells. Here we demonstrate that TCR-stimulated effector T cells still frequently harbor latent HIV-1. Renewed TCR-stimulation or subsequent activation with latency reversing agents (LRAs) did not overcome latency. However, interaction of infected effector cells with dendritic cells (DCs) triggered further activation of latent HIV-1. When compared to TCR-stimulation only, CD4+ T cells from aviremic patients receiving TCR+DC-stimulation reversed latency more frequently. Such a “one-two punch” strategy seems ideal for purging the reservoir. We determined that DC contact activates the PI3K-Akt-mTOR pathway in CD4+ T cells. This insight could facilitate the development of a novel class of potent LRAs that purge latent HIV beyond levels reached by T-cell activation.