Modulation of ADP-Ribosylation as a Target During HIV-1 Latency and Reactivation

PROJECT SUMMARY/ABSTRACT Human immunodeficiency virus 1 (HIV-1) is one of the most highly infectious pathogens of the modern age, characterized by a rapid loss in CD4+ T cells, which, if left untreated, results in acquired immunodeficiency syndrome and a high likelihood of death due to complications. Over the last forty years, scientists have worked

endlessly to stop the progression of HIV-1 through a plethora of chemical inhibitors. Although these drugs have been a boon to the affected communities, they only work prophylactically or to halt the spread post-infection. To date, there has not been an effective method for eradicating HIV-1. The most likely method of eliminating the

disease within a patient relies upon using latency reversing agents (LRAs) to activate dormant integrated HIV-1, thus allowing the immune system to target infected cells and clear the population. Unfortunately, most LRAs are only partially effective, and latent HIV-1 tends to become recalcitrant with time. The current LRAs that have

shown efficacy act either through NF-κB signaling or altered transcription dynamics. ADP-ribosylation (ADPr) is

a post-translational modification (PTMs) directly linked to transcriptional activity and NF-κB signaling. Still, it has never been looked at in the context of HIV-1 latency and reactivation. Thus, ADPr may serve as a novel therapeutic target to eliminate latent HIV-1 reservoirs. The long-term goal of this project is to enhance the

understanding of ADPr in HIV-1 biology through biochemical, proteomic, and cellular assays. Preliminary results in cell line models of HIV-1 latency show that ADPr preferentially targets proteins related to transcription and chromatin accessibility following reactivation with prostratin. The overall objective of this proposal is to identify

the role PARP specific interactions during HIV-1 reactivation. The objective will be achieved by testing the central hypothesis that ADPr-dependent signaling is altering transcriptional and immune signaling during HIV-1 reactivation. To test this hypothesis, the following three aims will be pursued. Aim 1: Identify global proteomic

changes to ADP-ribosylation during HIV-1 latency and reactivation. This aim will use mass spectrometry-based proteomics to compare the differences in ADPr and protein phosphorylation following administration of minimally overlapping LRAs to identify potential novel regulatory sites and interactors. Aim 2: Investigate PARP-HIV-1

Interactions in primary CD4+ T Cells using CRISPR-Cas9 knockouts. In this aim I will knockout PARP1, PARP11, and PARP14 in primary resting CD4+ T cells from healthy donors to assess the physiological changes following reactivation of replication-competent HIV-1. Aim 3: Systematically evaluate PARP1, PARP14 and Tat protein

interactions. In my final aim, I will identify PARP1, PARP14 and Tat-dependent protein-protein interactions during HIV-1 reactivation to assess the direct role of PARP1 and PARP14 in mediating latency and reactivation. Successful completion of the proposed research will significantly enhance our understanding of ADPr in HIV-1

and retrovirology. This will be a significant contribution as it will reveal novel therapeutic strategies to reactivate HIV-1 and help eliminate latent reservoirs in CD4+ T cells.