The Cytokine IL-22 Promotes Pathogen Colonization by Suppressing Related Commensal Bacteria
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Interleukin-22 (IL-22) is highly induced in response to infections with a variety of pathogens, and its main functions are considered to be tissue repair and host defense at mucosal surfaces. Here we showed that IL-22 has a unique role during infection in that its expression suppressed the intestinal microbiota and enhanced the colonization of a pathogen. IL-22 induced the expression of antimicrobial proteins, including lipocalin-2 and calprotectin, which sequester essential metal ions from microbes. Because Salmonella enterica ser. Typhimurium can overcome metal ion starvation mediated by lipocalin-2 and calprotectin via alternative pathways, IL-22 boosted its colonization of the inflamed intestine by suppressing commensal Enterobacteriaceae, which are susceptible to the antimicrobial proteins. Thus, IL-22 tipped the balance between pathogenic and commensal bacteria in favor of a pathogen. Taken together, IL-22 induction can be exploited by pathogens to suppress the growth of their closest competitors, thereby enhancing pathogen colonization of mucosal surfaces.
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Churchill M, Pandeya A, Bauer R, Christopher T, Krug S, Honodel R J Exp Med. 2025; 222(6).
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Mucosal immune response in biology, disease prevention and treatment.
Zhou X, Wu Y, Zhu Z, Lu C, Zhang C, Zeng L Signal Transduct Target Ther. 2025; 10(1):7.
PMID: 39774607 PMC: 11707400. DOI: 10.1038/s41392-024-02043-4.
Colonization resistance: the role of gut microbiota in preventing invasion and infection.
Deng L, Wang S Gut Microbes. 2024; 16(1):2424914.
PMID: 39514544 PMC: 11552263. DOI: 10.1080/19490976.2024.2424914.
Resta S, Guerra F, Tala A, Bucci C, Alifano P Cells. 2024; 13(21.
PMID: 39513865 PMC: 11545737. DOI: 10.3390/cells13211758.
Han X, Allaire J, Crowley S, Chan J, Lau K, Zhang C Gut Microbes. 2024; 16(1):2413372.
PMID: 39428744 PMC: 11497969. DOI: 10.1080/19490976.2024.2413372.