Capsid stabilization reprograms the nuclear fate of the HIV genome.

Capsid stabilization, induced by low-nanomolar concentrations of Lenacapavir (LEN)-a first-in-class capsid inhibitor-impedes HIV-1 replication in macrophages without disrupting reverse transcription or nuclear import. In LEN-treated cells, ultrastructural analyses reveal preserved conical capsids persisting within nuclear CPSF6-enriched puncta-HIV-1-induced membraneless organelles (HIV-1-MLOs)-which remain spatially segregated from canonical integration hubs near nuclear speckles (NSs). Rather than fusing with NSs, HIV-1-MLOs are rerouted to chromatin-associated promyelocytic leukemia nuclear bodies (PML-NBs), where molecular exchange occurs without condensate fusion. This nuclear redirection correlates with the sequestration of the viral genome within stabilized capsids, reducing the pool of viral DNA available for integration and redirecting the few accessible genomes to atypical integration sites near PML-NBs. These findings uncover a previously unrecognized mechanism of LEN action, whereby capsid stabilization reprograms the nuclear fate of the HIV-1 genome in macrophages, limiting integration and redirecting viral DNA toward more repressive nuclear environments, likely shaping the transcriptional potential of newly integrated viral DNA.