Novel phorbol-12-O-octoate derivatives exert a dual effect by inhibiting de novo HIV-1 infection and reactivating latent virus.

Viral reservoirs represent the primary obstacle to achieving a cure for HIV-1 infection, as viral replication rebounds after interruption of antiretroviral therapy (ART). To identify promising dual-effect phorbol-12-O-octoate derivatives capable of both effectively inhibiting viral replication in acute HIV-1 infection and reactivating latent HIV-1, we designed, synthesized, and evaluated a new series of phorbol esters and explored their underlying mechanisms. HPB-5073 was identified as a promising candidate that inhibits HIV-1 replication at nanomolar concentrations. Further analysis revealed that HPB-5073 reduces the expression of the HIV-1 entry receptor CD4 and co-receptor CXCR4 and impairs the formation of the early reverse transcription intermediate, -ssDNA, indicating that it targets early steps of the HIV-1 life cycle, including viral entry and early post-entry replication. Meanwhile, HPB-5073 effectively reversed HIV-1 latency in both latently infected cell lines and PBMCs from people living with HIV-1 (PLWH) on ART, with minimal cytotoxicity. Mechanistically, HPB-5073 induced the initiation and elongation of HIV-1 LTR transactivation, thereby reactivating latent HIV-1 transcription by modulating the interaction of EGR1 and Tat with the HIV-1 LTR.