Ectopic ATP synthase facilitates transfer of HIV-1 from antigen-presenting cells to CD4+ target cells

Antigen-presenting cells (APCs) act as vehicles that transfer HIV to their target CD4+ cells through an intercellular junction, termed the virologic synapse. The molecules that are involved in this process remain largely unidentified. In this study, we used photoaffinity labeling and a proteomic approach to identify new proteins that facilitate HIV-1 transfer. We identified ectopic mitochondrial ATP synthase as a factor that mediates HIV-1 transfer between APCs and CD4+ target cells. Monoclonal antibodies against the β-subunit of ATP synthase inhibited APC-mediated transfer of multiple strains HIV-1 to CD4+ target cells. Likewise, the specific inhibitors of ATPase, citreoviridin and IF1, completely blocked APC-mediated transfer of HIV-1 at the APC-target cell interaction step. Confocal fluorescent microscopy showed localization of extracellular ATP synthase at junctions between APC and CD4+ target cells. We conclude that ectopicATP synthase could be an accessible molecular target for inhibiting HIV-1 proliferation in vivo.