NSC95397 is a Novel HIV Latency Reversing Agent
The latent viral reservoir represents one of the major barriers of curing HIV. Focus on the “kick and kill” approach, in which virus expression is reactivated then cells producing virus are selectively depleted, has led to the discovery of many latency reversing agents (LRAs) that can reactivate latently integrated virus and further our understanding of the mechanisms driving HIV latency and latency reversal. Thus far, individual compounds have yet to be robust enough to work as a therapy, highlighting the importance of identifying new compounds that target novel pathways and synergize with known LRAs. In this study, we identified a promising LRA, NSC95397, from a screen of ~4250 compounds in J-Lat cell lines. We validated that NSC95397 reactivates latent viral transcription and protein expression from cells with unique integration events. Co-treating cells with NSC95397 and known LRAs demonstrated that NSC95397 has the potential to synergize with different drugs under both standard normoxic and physiological hypoxic conditions. We showed that NSC95397 does not globally increase open chromatin, and bulk RNA sequencing revealed that NSC95397 does not greatly change cellular transcription. Instead, NSC95397 downregulates many pathways key to metabolism, cell growth, and DNA repair – highlighting the potential of these pathways in regulating HIV latency. Overall, we identified NSC95397 as a novel LRA that does not alter global transcription, that shows potential for synergy with known LRAs, and that may act through novel pathways not previously recognized for their ability to modulate HIV latency. Overall design: To characterize differential genes expressed when latent HIV is reactivated by different latency reversing agents, 4x10^6 J-Lat 10.6 cells were cultured in RPMI media and were untreated or treated with 10.0 ng/mL PMA, 25.0 uM SAHA, or 5.0 uM NSC95397 for 24 hrs and then treated with TRIzol for RNA isolation. Experiment was done in quadruplicate.