A novel bromodomain inhibitor, CPI-203, serves as an HIV-1 latency-reversing agent by activating positive transcription elongation factor b.

The persistence of latent human immunodeficiency virus type 1 (HIV-1) reservoirs remains a major hurdle for HIV-1 eradication. The "shock and kill" strategy relies on the drug-mediated reversion of HIV-1 latency and the subsequent death of HIV-producing cells. Unfortunately, none of the agents currently in use possess a sufficient potency to reactivate latent virus or eliminate the latent HIV-1 reservoir in vivo. Here, we demonstrated that a promising specific bromodomain and extraterminal domain inhibitor, CPI-203, could potently reactivate latent HIV-1 in different latently infected cell lines with minimal cytotoxicity by activating the positive transcription elongation factor b signaling pathway. Notably, CPI-203 exhibited synergism in latent HIV-1 reactivation and alleviated the HIV-1-induced "cytokine storm" when used in combination with the protein kinase C (PKC) agonist prostratin. These findings highlight that CPI-203 shows promise as a novel, safe candidate for the design of targeted strategies to "shock and kill" HIV-1 and thus represents a potential functional cure.