Combined noncanonical NF-κB agonism and targeted BET bromodomain inhibition reverse HIV latency ex vivo

• Published in: The Journal of clinical investigation Vol. 132; no. 8; pp. 1 - 14
• Main Authors: Falcinelli, Shane D, Peterson, Jackson J, Turner, Anne-Marie W, Irlbeck, David, Read, Jenna, Raines, Samuel Lm, James, Katherine S, Sutton, Cameron, Sanchez, Anthony, Emery, Ann, Sampey, Gavin, Ferris, Robert, Allard, Brigitte, Ghofrani, Simon, Kirchherr, Jennifer L, Baker, Caroline, Kuruc, JoAnn D, Gay, Cynthia L, James, Lindsey I, Wu, Guoxin, Zuck, Paul, Rioja, Inmaculada, Furze, Rebecca C, Prinjha, Rab K, Howell, Bonnie J, Swanstrom, Ronald, Browne, Edward P, Strahl, Brian D, Dunham, Richard M, Archin, Nancie M, Margolis, David M
• Format: Journal Article
• Language: English
• Published: United States American Society for Clinical Investigation 15-04-2022
• Subjects: AIDS/HIV; Animal models; Animals; Antagonists; Antiretroviral therapy; Apoptosis; Biomedical research; CD4 antigen; CD4-Positive T-Lymphocytes; Cell activation; CRISPR; Drug therapy; Gag protein; Gene expression; HIV; HIV Infections - drug therapy; HIV Infections - genetics; HIV-1 - physiology; Human immunodeficiency virus; Human Immunodeficiency Virus Proteins; IAP protein; Immunotoxicity; Infectious disease; Kinases; Latency; Lymphocytes; Lymphocytes T; NF-kappa B - genetics; NF-kappa B - metabolism; NF-κB protein; Nuclear Proteins - metabolism; Protein expression; Proteins; Ribonucleic acid; RNA; Tat protein; Transcription elongation; Transcription Factors - metabolism; Virus Activation; Virus Latency; Infectious disease; AIDS/HIV; Transcription; RNA processing; T cells
• ISSN: 1558-8238; 0021-9738; 1558-8238
• DOI: 10.1172/JCI157281

Latency reversal strategies for HIV cure using inhibitor of apoptosis protein (IAP) antagonists (IAPi) induce unprecedented levels of latent reservoir expression without immunotoxicity during suppressive antiretroviral therapy (ART). However, full targeting of the reservoir may require combinatorial approaches. A Jurkat latency model screen for IAPi combination partners demonstrated synergistic latency reversal with bromodomain (BD) and extraterminal domain protein inhibitors (BETi). Mechanistic investigations using CRISPR-CAS9 and single-cell RNA-Seq informed comprehensive ex vivo evaluations of IAPi plus pan-BET, bD-selective BET, or selective BET isoform targeting in CD4+ T cells from ART-suppressed donors. IAPi+BETi treatment resulted in striking induction of cell-associated HIV gag RNA, but lesser induction of fully elongated and tat-rev RNA compared with T cell activation-positive controls. IAPi+BETi resulted in HIV protein induction in bulk cultures of CD4+ T cells using an ultrasensitive p24 assay, but did not result in enhanced viral outgrowth frequency using a standard quantitative viral outgrowth assay. This study defines HIV transcriptional elongation and splicing as important barriers to latent HIV protein expression following latency reversal, delineates the roles of BET proteins and their BDs in HIV latency, and provides a rationale for exploration of IAPi+BETi in animal models of HIV latency.