Mentored Scientist Award

Despite its effectiveness in suppressing HIV replication, Antiretroviral therapy (ART) does not eliminate the long-lived pool of HIV reservoir cells. These infected cells are a main barrier to curing HIV, and it is currently unknown how reservoir cells producing viral RNA and viral proteins can persist and avoid recognition and elimination by the immune system. The gut- associated lymphoid tissue (GALT), is a preferential site for the persistence of the HIV reservoir during ART. Evidence shows that HIV infection shifts the immune populations of the gut to a more regulatory state. In this proposal, I postulate that the GALT microenvironment provides a favorable environment for persistence of the HIV reservoir. I will test the hypothesis that HIV reservoir cells in the GALT express genes that promote their survival (Aim 1), and surround themselves within a regulatory immune microenvironment that allows their

persistence (Aim 2). For both aims, I will investigate ileum (small intestine) and sigmoid rectal (colon) paired samples from 6 ART-suppressed people with HIV (PWH), taking advantage of two novel techniques I have developed for the study of the HIV reservoir: i) HIV-1 Protein and scRNA-seq EXploration (HIV-prex), a scRNAseq method that allows HIV RNA detection, transcriptional profiling, HIV intracellular protein detection and proteomic phenotyping, and ii) HIV protein and RNAscope analysis by Multiplexed Ion Beam Imaging by Time Of Flight (HIV-TOF), an imaging technique that allows simultaneous detection of up to 40 surface and intracellular markers. With these techniques, I expect to find new biomarkers for the gut associated reservoir, and to determine the specific regulatory populations in contact with the HIV+ cells that could be targeted in future HIV cure therapies. I have already generated preliminary data demonstrating that I can apply these two techniques for the study of the reservoir, as detailed in this proposal.