PTPN2 regulates bacterial clearance in a mouse model of enteropathogenic and enterohemorrhagic E. coli infection
Marianne R. Spalinger, Vinicius Canale, Anica Becerra, Ali Shawki, Meli’sa Crawford, Alina N. Santos, Pritha Chatterjee, Jiang Li, Meera G. Nair, Declan F. McCole
Marianne R. Spalinger, Vinicius Canale, Anica Becerra, Ali Shawki, Meli’sa Crawford, Alina N. Santos, Pritha Chatterjee, Jiang Li, Meera G. Nair, Declan F. McCole
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Research Article Gastroenterology Inflammation

PTPN2 regulates bacterial clearance in a mouse model of enteropathogenic and enterohemorrhagic E. coli infection

Abstract

Macrophages intimately interact with intestinal epithelial cells, but the consequences of defective macrophage–epithelial cell interactions for protection against enteric pathogens are poorly understood. Here, we show that in mice with a deletion in protein tyrosine phosphatase nonreceptor type 2 (PTPN2) in macrophages, infection with Citrobacter rodentium, a model of enteropathogenic and enterohemorrhagic E. coli infection in humans, promoted a strong type 1/IL-22–driven immune response, culminating in accelerated disease but also faster clearance of the pathogen. In contrast, deletion of PTPN2 specifically in epithelial cells rendered the epithelium unable to upregulate antimicrobial peptides and consequently resulted in a failure to eliminate the infection. The ability of PTPN2-deficient macrophages to induce faster recovery from C. rodentium was dependent on macrophage-intrinsic IL-22 production, which was highly increased in macrophages deficient in PTPN2. Our findings demonstrate the importance of macrophage-mediated factors, and especially macrophage-derived IL-22, for the induction of protective immune responses in the intestinal epithelium, and show that normal PTPN2 expression in the epithelium is crucial to allow for protection against enterohemorrhagic E. coli and other intestinal pathogens.

Authors

Marianne R. Spalinger, Vinicius Canale, Anica Becerra, Ali Shawki, Meli’sa Crawford, Alina N. Santos, Pritha Chatterjee, Jiang Li, Meera G. Nair, Declan F. McCole

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Figure 3

Ptpn2-deficient macrophages promote Reg3g expression in an IL-22–dependent manner.

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Ptpn2-deficient macrophages promote Reg3g expression in an IL-22–depend...
(A) T cells (live, CD45+, CD3+ cells); granulocytes (granulo) (live, CD45+, Ly6G+ cells); monocytes (mono) (live, Cd45+, CD11bhi, Ly6C+, MHCII– cells); NK cells (live, CD45+, NK1.1+, CD3– cells); lineage-negative, CD45+ (lin–CD45+) cells (live, CD3-B220–, NK1.1–, CD11b–, CD11c–, Ly6C–, Ly6G–, F4/80–, CD64– cells); and macrophages (macro) (live, CD45+, Cd11b+, CD64+, F4/80+ cells) were sorted from the spleen of Ptpn2fl/fl and Ptpn2-LysM-Cre mice and analyzed for Il22 mRNA expression. (B) Small intestinal explants from WT mice or (C) small intestinal organoids from WT mice were cultured for 24 hours with bone marrow macrophages from Ptpn2fl/fl mice (WT) and Ptpn2-LysM-Cre littermates (KO) in presence of an isotype control (negative) or an anti–IL-22 (+) neutralizing Ab. (D) Small intestinal explants from Ptpn2ΔIEC/ERT (ΔIEC/ERT) or Ptpn2fl/fl littermates (fl/fl) were cultured for 24 hours with bone marrow macrophages from Ptpn2fl/fl mice (WT) and Ptpn2-LysM-Cre littermates (KO). (E) Organoids derived from the small intestine of naive Ptpn2ΔIEC/ERT (ΔIEC/ERT) or Ptpn2fl/fl littermates (WT) were exposed to 4-hydroxytamoxifen for 48 hours to induce recombination. Tamoxifen was removed and organoids subcultured for 3 additional days before coculture with bone marrow macrophages from Ptpn2fl/fl mice (WT) and Ptpn2-LysM-Cre littermates (KO) for 24 hours. *P < 0.05, **P < 0.01, ***P < 0.001; #P < 0.05 compared with WT ileum with WT macrophages, ##P < 0.01 compared with WT ileum with KO macrophages; 2-sided t test (A) or 1-way ANOVA (B–E). Each dot represents an independent biological replicate, n = 5 (A) or n = 4 (B–E). Δ, change in; Mφ, macrophage.