The persistence of latent HIV-1 reservoirs remains a major barrier to achieving a cure for HIV. While latency-reversing agents (LRAs) have been extensively studied, latency-promoting agents (LPAs) off Show more
The persistence of latent HIV-1 reservoirs remains a major barrier to achieving a cure for HIV. While latency-reversing agents (LRAs) have been extensively studied, latency-promoting agents (LPAs) offer a complementary strategy to silence viral transcription and prevent immune activation. Here, we propose that modulation of IRF7-driven transcription may represent a novel approach to control HIV-1 latency, by characterizing the role of the Janus kinase 2 inhibitor (JAK2i) pacritinib as a novel latency-promoting agent (LPA). The impact of JAK2i on HIV-1 reactivation, immune activation, and IRF7 expression were evaluated in lymphoid and myeloid HIV-1 latency models, as well as Pacritinib effectively suppressed HIV-1 latency reversal induced by LRAs without triggering immune activation. Mechanistically, pacritinib downregulated IRF7 expression at both transcript and protein levels, correlating with reduced HIV-1 transcription. Overexpression of IRF7 restored LTR transactivation, confirming its central role in HIV-1 transcription and latency. Co-immunoprecipitation assays revealed a direct interaction between IRF7 and the viral transactivator Tat. Furthermore, pacritinib selectively inhibited multiply spliced HIV-1 transcripts, suggesting a blockade at late transcriptional stages. Pacritinib acts as a potent LPA by silencing HIV-1 transcription through IRF7 downregulation, supporting a promising "block and lock" strategy for functional cure approaches. Targeting IRF7 may enable durable suppression of the viral reservoir without immune activation, supporting the development of "block and lock" therapies. Show less