Attaching-and-Effacing Pathogens Exploit Junction Regulatory Activities of N-WASP and SNX9 to Disrupt the Intestinal Barrier.

Autor:	Garber JJ; Gastrointestinal Unit, Massachusetts General Hospital, Boston, Massachusetts.; Division of Gastroenterology/Nutrition and Center for Inflammatory Bowel Disease Treatment and Research, Boston Children's Hospital, Boston, Massachusetts.; Department of Medicine, Harvard Medical School, Boston, Massachusetts., Mallick EM; Department of Medicine Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts., Scanlon KM; Department of Medicine and Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland., Turner JR; Department of Medicine, Harvard Medical School, Boston, Massachusetts.; Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts., Donnenberg MS; Department of Medicine and Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland., Leong JM; Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts., Snapper SB; Division of Gastroenterology/Nutrition and Center for Inflammatory Bowel Disease Treatment and Research, Boston Children's Hospital, Boston, Massachusetts.; Department of Medicine, Harvard Medical School, Boston, Massachusetts.; Division of Gastroenterology and Hepatology, Brigham and Women's Hospital, Boston, Massachusetts.
Jazyk:	angličtina
Zdroj:	Cellular and molecular gastroenterology and hepatology [Cell Mol Gastroenterol Hepatol] 2017 Dec 15; Vol. 5 (3), pp. 273-288. Date of Electronic Publication: 2017 Dec 15 (Print Publication: 2018).
DOI:	10.1016/j.jcmgh.2017.11.015
Abstrakt:	Background & Aims: Neural Wiskott-Aldrich Syndrome protein (N-WASP) is a key regulator of the actin cytoskeleton in epithelial tissues and is poised to mediate cytoskeletal-dependent aspects of apical junction complex (AJC) homeostasis. Attaching-and-effacing (AE) pathogens disrupt this homeostasis through translocation of the effector molecule early secreted antigenic target-6 (ESX)-1 secretion-associated protein F (EspF). Although the mechanisms underlying AJC disruption by EspF are unknown, EspF contains putative binding sites for N-WASP and the endocytic regulator sorting nexin 9 (SNX9). We hypothesized that N-WASP regulates AJC integrity and AE pathogens use EspF to induce junction disassembly through an N-WASP- and SNX9-dependent pathway. Methods: We analyzed mice with intestine-specific N-WASP deletion and generated cell lines with N-WASP and SNX9 depletion for dynamic functional assays. We generated EPEC and Citrobacter rodentium strains complemented with EspF bearing point mutations abolishing N-WASP and SNX9 binding to investigate the requirement for these interactions. Results: Mice lacking N-WASP in the intestinal epithelium showed spontaneously increased permeability, abnormal AJC morphology, and mislocalization of occludin. N-WASP depletion in epithelial cell lines led to impaired assembly and disassembly of tight junctions in response to changes in extracellular calcium. Cells lacking N-WASP or SNX9 supported actin pedestals and type III secretion, but were resistant to EPEC-induced AJC disassembly and loss of transepithelial resistance. We found that during in vivo infection with AE pathogens, EspF must bind both N-WASP and SNX9 to disrupt AJCs and induce intestinal barrier dysfunction. Conclusions: Overall, these studies show that N-WASP critically regulates AJC homeostasis, and the AE pathogen effector EspF specifically exploits both N-WASP and SNX9 to disrupt intestinal barrier integrity during infection.
Databáze:	MEDLINE
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