GP63 Alters the Macrophage Golgin160-Associated PIST Distribution by Reducing Caspase-3 Expression during Leishmania major Infection.

Leishmania major, an intracellular protozoan parasite, resides within parasitophorous vacuoles in host macrophages and relies on host-pathway manipulation for survival. Here, we uncover a novel role of the Leishmania surface metalloprotease GP63 in stabilizing the parasitophorous vacuoles through targeted subversion of host vesicular trafficking and apoptosis. We demonstrate that GP63 is essential for the selective recruitment of the Golgi-associated adaptor protein PIST to the parasitophorous vacuoles, a process that is impaired in GP63-deficient (LmGP63-/-) parasites. GP63 facilitates PIST-Golgin160 complex formation by suppressing caspase-3 activation, preventing Golgin160 cleavage. Caspase inhibition via Z-VAD-FMK further enhances this complex's recruitment. Moreover, GP63 selectively modulates autophagy by promoting PIST-Beclin1 colocalization while excluding LC3 from the parasitophorous vacuoles. These findings identify GP63 as a central effector that orchestrates host vesicular and apoptotic pathways to maintain parasitophorous vacuoles integrity and promote chronic infection, offering insights into potential therapeutic targets against Leishmaniasis.