Fcgamma receptor regulation of Citrobacter rodentium infection.
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.
Masuda
Atsuhiro
A
Department of Gastroenterology, Kobe University School of Medicine, 7-5-1, Chu-o-ku, Kusunoki-Cho, Kobe, Hyogo 650-0017, Japan.
Yoshida
Masaru
M
Shiomi
Hideyuki
H
Ikezawa
Satoshi
S
Takagawa
Tetsuya
T
Tanaka
Hiroshi
H
Chinzei
Ryo
R
Ishida
Tsukasa
T
Morita
Yoshinori
Y
Kutsumi
Hiromu
H
Inokuchi
Hideto
H
Wang
Shuo
S
Kobayashi
Kanna
K
Mizuno
Shigeto
S
Nakamura
Akira
A
Takai
Toshiyuki
T
Blumberg
Richard S
RS
Azuma
Takeshi
T
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
D016207:Cytokines; D007074:Immunoglobulin G; D017452:Receptors, IgG