title: Increased serum IgA in Fcα/μR-deficient mice on the (129 x C57BL/6) F1 genetic background.
abstract: Fcα/μR (CD351) is an Fc receptor for both IgA and IgM, which is abundantly expressed in the small intestine. However, the role of Fcα/μR in the intestinal tissue is largely unknown. Here, we found that Fcα/μR is highly expressed on follicular dendritic cells (FDCs) in Peyer's patches (PP) in the small intestine. Fcα/μR-deficient mice on the (129 x C57BL/6) F1 background showed increased serum, but not fecal, IgA level in response to gut-oriented antigens. IgA(+) B cells were increased in PP, but not in the lamina propria, of Fcα/μR-deficient mice, which was attenuated after reduction of commensal microbiota by oral treatment with antibiotics. Analyses of bone marrow chimeric mice, in which either FDCs or blood cells or both lack the expression of Fcα/μR, suggested that FDCs, but not blood cells, were responsible for the increased serum IgA concentration in Fcα/μR-deficient mice. Moreover, Fcα/μR-deficient mice showed enhanced germinal center formation against commensal microbiota in PP. Thus, serum IgA production against gut-oriented antigens is negatively regulated by Fcα/μR on FDCs in the F1 mice.
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kurita
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan. Electronic address: shonda@md.tsukuba.ac.jp.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Honda
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shibuya
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D003433:Crosses, Genetic; D020566:Dendritic Cells, Follicular / Q000378:metabolism; D005260:Female; D018858:Germinal Center / Q000378:metabolism; D007070:Immunoglobulin A / Q000097:blood*; D008297:Male; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D064307:Microbiota; D010581:Peyer's Patches / Q000378:metabolism; D011961:Receptors, Fc / Q000172:deficiency* / Q000378:metabolism
chemical_list: C526791:Fcalpha-mu protein, mouse; D007070:Immunoglobulin A; D011961:Receptors, Fc
keywords: FDC; Fcα/μR; Germinal center; IgA; Peyer's patches