Mechanisms of HIV infection in resting CD4+ T cells stimulated by endothelial cells

About This Grant

Project Summary In most patients with HIV-1 infection, antiretroviral therapy (ART) successfully suppresses viral loads and restores CD4+ T cell numbers. However, lifelong therapy is required to maintain viral suppression, primarily due to a major latent reservoir in resting CD4+ T cells. The latent reservoir poses a great barrier to HIV cure and ensures viral persistence in patients. Knowledge about how such a latent reservoir is formed is limited. A more complete understanding of the mechanisms contributing to the establishment of the reservoir will impact the strategies in battling viral persistence. Microenvironment of the lymphoid tissue and cell-cell interactions in vivo played important roles in latency formation in resting CD4+ T cells. It was found that endothelial cells (ECs), which physiologically interact readily with T cells in the lymphoid tissues in vivo, promote both productive and latent HIV infection in resting CD4+ T cells and may play a significant role in latency formation in these cells in vivo. Having established the importance of ECs in HIV infection and latency formation, this study is to elucidate further the mechanisms involved in EC stimulation of T cells. The specific aims of the proposal are: 1. To investigate the roles of integrin on HIV infection of CD4+ T cells. 2. To examine the role of Bcl-3, Bcl-6, and SAMHD1 on HIV infection in EC-stimulated resting CD4+ T cells. 3. To identify T cell subtypes and signature molecules correlated with HIV infection in EC-stimulated CD4+ T cells. To achieve specific aim 1, blocking antibodies will be used to block integrins during EC stimulation of T cells. Chimeric antibodies will be used to stimulate integrins on T cells to see their effect on HIV infection, with or without IL-6. To achieve specific aim 2, intracellular staining will be used to determine whether there is correlation between expression of Bl-3, Bcl-6 and Phosphorylated SAMHD1 and HIV infection rates in EC stimulated resting CD4+ T cells. To achieve specific aim 3, intracellular staining for lineage-determining molecules will be used to identify potential subtypes of CD4+ T cells that have higher HIV infection rates upon EC stimulation. Single cell RNAseq method will also be used to identify novel subtypes and signature molecules that correlate with HIV infection in EC-stimulated resting T cells. The long-term objective of the study is to understand how endothelial cells impact HIV infection and latency formation in T helper cells. The knowledge gained from this study will significantly improve the understanding of HIV latent reservoir formation in a physiological context and will influence the strategies for battling viral persistence.