Mycobacterium bovis Mb3523c protein regulates host ferroptosis via chaperone-mediated autophagy

The occurrence of necrosis during Mycobacterium bovis (M. bovis) infection is regarded as harmful to the host because it promotes the spread of M. bovis. Ferroptosis is a controlled type of cell death that occurs when there is an excessive buildup of both free iron and harmful lipid peroxides. Here, we demonstrate that the mammalian cell entry (Mce) 4 family protein Mb3523c triggers ferroptosis to promote M. bovis pathogenicity and dissemination. Mechanistically, Mb3523c, through its Y237 and G241 site, interacts with host HSP90 protein to stabilize the LAMP2A on the lysosome to promote the chaperone-mediated autophagy (CMA) pathway. Then, GPX4 is delivered to lysosomes for destruction via the CMA pathway, eventually inducing ferroptosis to promote M. bovis transmission. In summary, our findings offer novel insights into the molecular mechanisms of pathogen-induced ferroptosis, demonstrating that targeting the GPX4-dependent ferroptosis through blocking the M. bovis Mb3523c-host HSP90 interface represents a potential therapeutic strategy for tuberculosis (TB).Abbreviations: CFU: colony-forming units; CMA: chaperone-mediated autophagy; Co-IP: co-immunoprecipitation; Fer-1: ferrostatin-1; GPX4: glutathione peroxidase 4; HSP90: heat shock protein 90; LDH: lactate dehydrogenase; Mce: mammalian cell entry; MOI: multiplicity of infection; Nec-1: necrostatin-1; PI: propidium iodide; RCD: regulated cell death.