Although antiretroviral therapy (ART) is effective in suppressing viral replication, it does not cure HIV-1 infection due to the presence of the viral latent reservoir. Rather than reactivating the latent viruses, the "block and lock" strategy aims to shift the viral reservoir to a deeper state of transcriptional silencing, thus preventing viral rebound after ART interruption. Although some latency-promoting agents (LPAs) have been reported, none of them have been approved for clinical application due to cytotoxicity and limited efficacy; therefore, it is important to search for novel and effective LPAs. Here, we report an FDA-approved drug, ponatinib, that can broadly repress latent HIV-1 reactivation in different cell models of HIV-1 latency and in primary CD4+ T cells from ART-suppressed individuals ex vivo. Ponatinib does not change the expression of activation or exhaustion markers on primary CD4+ T cells and does not induce severe cytotoxicity and cell dysfunction. Mechanistically, ponatinib suppresses proviral HIV-1 transcription by inhibiting the activation of the AKT-mTOR pathway, which subsequently blocks the interaction between key transcriptional factors and the HIV-1 long terminal repeat (LTR). In summary, we discovered a novel latency-promoting agent, ponatinib, which could have promising significance for future applications of HIV-1 functional cure.
Keywords: HIV-1; block and lock; latency; ponatinib.