Intestinal Epithelial Expression of MHCII Determines Severity of Chemical, T-Cell-Induced, and Infectious Colitis in Mice.

Autor:	Jamwal DR; Department of Pediatrics, University of Arizona, Tucson, Arizona., Laubitz D; Department of Pediatrics, University of Arizona, Tucson, Arizona., Harrison CA; Department of Pediatrics, University of Arizona, Tucson, Arizona., Figliuolo da Paz V; Department of Pediatrics, University of Arizona, Tucson, Arizona., Cox CM; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona., Wong R; Department of Immunobiology, University of Arizona, Tucson, Arizona., Midura-Kiela M; Department of Pediatrics, University of Arizona, Tucson, Arizona., Gurney MA; Department of Pediatrics, University of Arizona, Tucson, Arizona., Besselsen DG; University Animal Care, University of Arizona, Tucson, Arizona., Setty P; Department of Pediatrics, University of Arizona, Tucson, Arizona., Lybarger L; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona., Bhattacharya D; Department of Immunobiology, University of Arizona, Tucson, Arizona., Wilson JM; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona., Ghishan FK; Department of Pediatrics, University of Arizona, Tucson, Arizona., Kiela PR; Department of Pediatrics, University of Arizona, Tucson, Arizona; Department of Immunobiology, University of Arizona, Tucson, Arizona. Electronic address: pkiela@peds.arizona.edu.
Jazyk:	angličtina
Zdroj:	Gastroenterology [Gastroenterology] 2020 Oct; Vol. 159 (4), pp. 1342-1356.e6. Date of Electronic Publication: 2020 Jun 23.
DOI:	10.1053/j.gastro.2020.06.049
Abstrakt:	Background & Aims: Intestinal epithelial cells (IECs) provide a barrier that separates the mucosal immune system from the luminal microbiota. IECs constitutively express low levels of major histocompatibility complex (MHC) class II proteins, which are upregulated upon exposure to interferon gamma. We investigated the effects of deleting MHCII proteins specifically in mice with infectious, dextran sodium sulfate (DSS)-, and T-cell-induced colitis. Methods: We disrupted the histocompatibility 2, class II antigen A, beta 1 gene (H2-Ab1) in IECs of C57BL/6 mice (I-Ab ΔIEC ) or Rag1 -/- mice (Rag1 -/- I-Ab ΔIEC ); we used I-Ab WT mice as controls. Colitis was induced by administration of DSS, transfer of CD4 + CD45RB hi T cells, or infection with Citrobacter rodentium. Colon tissues were collected and analyzed by histology, immunofluorescence, xMAP, and reverse-transcription polymerase chain reaction and organoids were generated. Microbiota (total and immunoglobulin [Ig]A-coated) in intestinal samples were analyzed by16S amplicon profiling. IgA + CD138 + plasma cells from Peyer's patches and lamina propria were analyzed by flow cytometry and IgA repertoire was determined by next-generation sequencing. Results: Mice with IEC-specific loss of MHCII (I-Ab ΔIEC mice) developed less severe DSS- or T-cell transfer-induced colitis than control mice. Intestinal tissues from I-Ab ΔIEC mice had a lower proportion of IgA-coated bacteria compared with control mice, and a reduced luminal concentration of secretory IgA (SIgA) following infection with C rodentium. There was no significant difference in the mucosal IgA repertoire of I-Ab ΔIEC vs control mice, but opsonization of cultured C rodentium by SIgA isolated from I-Ab ΔIEC mice was 50% lower than that of SIgA from mAb WT mice. Fifty percent of I-Ab ΔIEC mice died after infection with C rodentium, compared with none of the control mice. We observed a transient but significant expansion of the pathogen in the feces of I-Ab ΔIEC mice compared with I-Ab WT mice. Conclusions: In mice with DSS or T-cell-induced colitis, loss of MHCII from IECs reduces but does not eliminate mucosal inflammation. However, in mice with C rodentium-induced colitis, loss of MHCII reduces bacterial clearance by decreasing binding of IgA to commensal and pathogenic bacteria. (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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