Enterohemorrhagic Escherichia coli Targets Annexin A6 and ATG16L1 to Inhibit Autophagy and Induce Inflammation

Autophagy is a critical host defense mechanism against pathogens; however, enterohemorrhagic Escherichia coli (EHEC) O157:H7 exploits it to establish infection. Here, we reveal how EHEC’s effector EspF collaborates with host Annexin A6 (ANXA6) to suppress autophagy and drive inflammation. CRISPR/Cas9-mediated ANXA6 knockout in intestinal epithelial cells reversed EHEC-induced autophagic inhibition, as evidenced by elevated LC3B-II levels and reduced p62 accumulation. Mechanistically, EspF stabilizes ANXA6 to disrupt PI3K/mTOR signaling and impair autophagosome formation, whereas ANXA6 suppresses the expression of ATG16L1, a key autophagy regulator. EHEC infection triggered IL-1β hypersecretion in macrophages, which was coupled with NF-κB pathway hyperactivation via IκBα/p65 phosphorylation. In vivo, EHEC infection upregulated intestinal ANXA6 expression, correlating with mucosal inflammation and barrier dysfunction. Crucially, ANXA6/ATG16L1 axis disruption created a self-reinforcing cycle of impaired autophagy, bacterial persistence, and inflammatory escalation. Our findings identify ANXA6 as a context-dependent autophagy modulator and ATG16L1 as a novel EHEC target, providing mechanistic insights into EHEC pathogenesis.