A novel Fc receptor for IgA and IgM is expressed on both hematopoietic and non-hematopoietic tissues.
By contrast to well-defined Fc gamma and Fc epsilon receptors, the structural and functional characteristics of Fc mu receptor are unclear. We have recently described a novel mouse Fc receptor, designated Fc alpha/mu receptor, and its human homologue, which bind both IgM and IgA. Here we show that the Fc alpha/mu receptor is expressed on mature, but not immature, B lymphocytes and acquires the ability to bind IgM and IgA antibodies after stimulation of B lymphocytes. Moreover, stimulation with phorbol 12-myristate 13-acetate increased endocytosis of IgM-coated microparticles mediated by the Fc alpha/mu receptor expressed on pro-B cell line Ba/F3 cells. We also show that the Fc alpha/mu receptor is expressed in secondary lymphoid organs, such as lymph node and appendix, kidney and intestine, suggesting an important role of the receptor for immunity in these organs.
Sakamoto
N
N
Department of Immunology, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Shibuya
K
K
Shimizu
Y
Y
Yotsumoto
K
K
Miyabayashi
T
T
Sakano
S
S
Tsuji
T
T
Nakayama
E
E
Nakauchi
H
H
Shibuya
A
A
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D004705:Endocytosis / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D051379:Mice; D008863:Microspheres; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011961:Receptors, Fc / Q000276:immunology* / Q000378:metabolism*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D007070:Immunoglobulin A; D007075:Immunoglobulin M; D012333:RNA, Messenger; D011961:Receptors, Fc; D013755:Tetradecanoylphorbol Acetate