Enterohemorrhagic <i>Escherichia coli</i> targets Annexin A6 and ATG16L1 to inhibit autophagy and induce inflammation

Litai Xu; Min Gao; Yaoguo Wang; Bao Zhang; Wei Zhao; Weizhi Lu; Guanhua Cao; Chengsong Wan; Ying Hua; Litai Xu; Min Gao; Yaoguo Wang; Bao Zhang; Wei Zhao; Weizhi Lu; Guanhua Cao; Chengsong Wan; Ying Hua

doi:10.3934/microbiol.2025044

AIMS Microbiology

2025, Volume 11, Issue 4: 984-1006. doi: 10.3934/microbiol.2025044

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Research article

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

1.
Department of Microbiology; BSL-3 Laboratory (Guangdong), Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
2.
Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
3.
Guangzhou Center For Disease Control And Prevention (Guangzhou Health Supervision Institute), Guangzhou, China
4.
Department of clinical laboratory, Shaoxing Yuecheng People's Hospital, Shaoxing, China
These authors contributed equally to this work.

Received: 01 September 2025 Revised: 12 November 2025 Accepted: 02 December 2025 Published: 17 December 2025

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.
- enterohemorrhagic Escherichia coli,
- autophagy,
- EspF,
- Annexin A6,
- ATG16L1
Citation: Litai Xu, Min Gao, Yaoguo Wang, Bao Zhang, Wei Zhao, Weizhi Lu, Guanhua Cao, Chengsong Wan, Ying Hua. Enterohemorrhagic Escherichia coli targets Annexin A6 and ATG16L1 to inhibit autophagy and induce inflammation[J]. AIMS Microbiology, 2025, 11(4): 984-1006. doi: 10.3934/microbiol.2025044

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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.

Acknowledgments

We thank members of the BSL-3 Laboratory at Southern Medical University for support.

Author contributions

Litai Xu: Writing—original draft, Methodology, Conceptualization, Formal analysis, Data curation, Validation. Min Gao: Writing—original draft, Conceptualization, Methodology, Formal analysis, Data curation. Yaoguo Wang: Methodology, Conceptualization, Software. Bao Zhang and Wei Zhao: Methodology, Conceptualization, Resources. Weizhi Lu: Conceptualization, Software, Resources. Guanhua Cao: Methodology, Resources, Software. Chengsong Wan: Writing—review & editing, Supervision, Resources, Project administration. Ying Hua: Writing—original draft, review & editing, Supervision, Funding acquisition, Project administration, Conceptualization.

Funding

This work was supported by the National Natural Science Foundation of China under grant 32100143, the Outstanding Youths Development Scheme of Nanfang Hospital, Southern Medical University (2021J011), the Science and Technology Projects in Guangzhou under grant 2024A04J5215, Guangdong Basic Applied Basic Research Foundation under grant 2021A1515011240, and the Zhejiang Province Traditional Chinese Medicine Science and Technology Plan under grant 2023ZL735. All funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethics approval

All animal study was reviewed and approved by the Southern Medical University Experiment Animal Ethics Committee (SMUL202409021).

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