<i>Mycobacterium bovis</i> Mb3523c protein regulates host ferroptosis via chaperone-mediated autophagy

The occurrence of necrosis during <i>Mycobacterium bovis</i> (<i>M. bovis</i>) infection is regarded as harmful to the host because it promotes the spread of <i>M. bovis</i>. 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 <i>M. bovis</i> 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 <i>M. bovis</i> 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 <i>M. bovis</i> Mb3523c-host HSP90 interface represents a potential therapeutic strategy for tuberculosis (TB). <b>Abbreviations</b>: 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.