title: Glycoprotein 2 (GP2): grabbing the FimH bacteria into M cells for mucosal immunity.
abstract: Membranous (M) cells are specialized epithelial antigen-transporting cells scattered in the follicle-associated epithelium covering the gut lymphoid follicles such as Peyer's patches. Although the importance of M cells as a main portal for luminal antigens has long been recognized, molecular mechanisms for M-cell antigen uptake has remained largely elusive. We have recently found that glycoprotein 2 (GP2) is exclusively expressed on M cells among intestinal epithelial cells and serves as an uptake receptor for a subset of commensal and pathogenic bacteria. GP2 interacts with FimH, a major component of the type 1 pilus on the outer membrane of a subset of gram-negative enterobacilli such as E. coli and Salmonella enterica. Furthermore, GP2-FimH interaction is necessary for efficient uptake of FimH(+) bacteria by M cells and subsequent bacteria-specific mucosal immune responses. Pancreatic GP2 may also be involved in innate immunity by 'opsonization' of FimH(+) bacteria to facilitate their egestion in feces as well as translocation across the intestinal epithelium.
authors.affiliation: Laboratory for Epithelial Immunobiology, Research Center for Allergy and Immunology, RIKEN, Yokohama, Kanagawa, Japan. ohno@rcai.riken.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohno
authors.forename: Koji
authors.initials: K
authors.lastname: Hase
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001422:Bacterial Adhesion; D004705:Endocytosis; D004755:Enterobacteriaceae / Q000276:immunology*; D004847:Epithelial Cells / Q000276:immunology*; D058851:GPI-Linked Proteins / Q000378:metabolism*; D006801:Humans; D018928:Immunity, Mucosal; D008221:Lymphoid Tissue / Q000276:immunology*; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D058851:GPI-Linked Proteins; D011956:Receptors, Cell Surface