title: Fcgamma receptor regulation of Citrobacter rodentium infection.
abstract: Citrobacter rodentium, a murine model pathogen for enteropathogenic Escherichia coli, colonizes the colon utilizing attaching and effacing lesions to adhere specifically to the surfaces of intestinal epithelial cells and cause mucosal inflammation. CD4+ T cells, B cells, and immunoglobulin G (IgG), but not secretory IgA or IgM, play a critical role in eradicating this pathogen. Consistent with the importance of IgG in C. rodentium eradication, IgG transport by the neonatal Fc receptor for IgG within the intestinal epithelium also has a critical role in the regulation of C. rodentium infection. It remains to be determined, however, whether Fcgamma receptors (FcgammaRs), the receptors for the Fc portion of IgG, regulate this bacterial infection within mucosal tissues. Therefore, we investigated the roles of FcgammaRs during C. rodentium infection. Fc receptor common gamma chain (FcRgamma)-deficient mice were more susceptible to C. rodentium-induced colitis. This occurred through decreased efficiency of FcR-mediated endocytosis and maturation of dendritic cells and consequently T-cell activation of antigen-specific T cells. Moreover, in the absence of FcgammaRs, phagocytosis by macrophages was significantly diminished. Therefore, activating FcgammaRs play an important role in defending against C. rodentium infection, indicating that the critical role played by IgG in this infection is not mediated by IgG alone but is dependent upon this class of receptors.
authors.affiliation: Department of Gastroenterology, Kobe University School of Medicine, 7-5-1, Chu-o-ku, Kusunoki-Cho, Kobe, Hyogo 650-0017, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Masuda
authors.forename: Masaru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shiomi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikezawa
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Ryo
authors.initials: R
authors.lastname: Chinzei
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ishida
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Morita
authors.forename: Hiromu
authors.initials: H
authors.lastname: Kutsumi
authors.forename: Hideto
authors.initials: H
authors.lastname: Inokuchi
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.forename: Kanna
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Shigeto
authors.initials: S
authors.lastname: Mizuno
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takai
authors.forename: Richard S
authors.initials: RS
authors.lastname: Blumberg
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
mesh_terms: D000818:Animals; D044082:Citrobacter rodentium / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology; D004198:Disease Susceptibility; D004756:Enterobacteriaceae Infections / Q000276:immunology* / Q000382:microbiology*; D005786:Gene Expression Regulation; D007074:Immunoglobulin G / Q000276:immunology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D051379:Mice; D010587:Phagocytosis; D017452:Receptors, IgG / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D016207:Cytokines; D007074:Immunoglobulin G; D017452:Receptors, IgG