# Enterohemorrhagic Escherichia coli targets Annexin A6 and ATG16L1 to inhibit autophagy and induce inflammation

## TL;DR

This study shows how a type of harmful E. coli uses host proteins to block cell cleanup and cause inflammation in the gut.

## Contribution

The study identifies Annexin A6 and ATG16L1 as novel targets of EHEC that disrupt autophagy and promote inflammation.

## Key findings

- EHEC's effector EspF stabilizes Annexin A6 to impair autophagy by disrupting PI3K/mTOR signaling.
- ANXA6 suppresses ATG16L1, a key autophagy regulator, and promotes inflammation via NF-κB pathway activation.
- Disruption of the ANXA6/ATG16L1 axis correlates with persistent infection and intestinal inflammation in vivo.

## Abstract

Autophagy is a critical host defense mechanism against pathogens; however, enterohemorrhagic Escherichia coli (EHEC) O157:H7 exploits it to establish infection. Here, we revealed how EHEC's effector EspF collaborates with host Annexin A6 (ANXA6) to suppress autophagy and drive inflammation. Our results showed that 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. In this study, EHEC infection triggered IL-1β hypersecretion in macrophages, which was coupled with NF-κB pathway hyperactivation via IκBα/p65 phosphorylation. In vivo, EHEC infection regulated 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 identified ANXA6 as a context-dependent autophagy modulator and ATG16L1 as a novel EHEC target, providing mechanistic insights into EHEC pathogenesis.