Immune regulation by Fcα/μ receptor (CD351) on marginal zone B cells and follicular dendritic cells.
Although both Fcα/μ receptor (Fcα/μR) and polymeric Ig receptor (poly-IgR) are Fc receptors for IgA and IgM and are functionally and genetically related, the expression profile of Fcα/μR is unique. Unlike poly-IgR, Fcα/μR is expressed on marginal zone (MZ) B cells and follicular dendritic cells, suggesting that Fcα/μR plays an important role in humoral immune responses. Fcα/μR mediates endocytosis of the IgM immune complex (IC). Recent research demonstrated that Fcα/μR downregulated retention of the IgM IC with a T-independent (TI) antigen on MZ B cells and follicular dendritic cells due to endocytosis of the IgM IC, suppressing germinal center formation, affinity maturation, and memory B-cell generation in response to TI antigen challenge. In addition, Fcα/μR physically associates with Toll-like receptor 4 (TLR4) and augments TLR4 oligomerization and signaling in MZ B cells upon lipopolysaccharide (LPS) challenge, leading to increased proinflammatory cytokine production by MZ B cells. Thus, Fcα/μR is a unique Fc receptor that is involved in humoral immune responses and inflammation.
Department of Immunology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.|Department of Immunology, Life Science Center of Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Ibaraki, Japan.|Department of Immunology, Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), University of Tsukuba, Ibaraki, Japan.
Akira
A
Shibuya
Department of Immunology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
Shin-ichiro
S
Honda
D000818:Animals; D000936:Antigen-Antibody Complex / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D020566:Dendritic Cells, Follicular / Q000276:immunology* / Q000378:metabolism*; D004705:Endocytosis; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015870:Gene Expression; D018858:Germinal Center / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D056724:Immunity, Humoral; D007070:Immunoglobulin A / Q000276:immunology / Q000378:metabolism; D007141:Immunoglobulin Fc Fragments / Q000276:immunology / Q000378:metabolism; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D056747:Immunomodulation; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005810:Multigene Family; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011961:Receptors, Fc / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D000936:Antigen-Antibody Complex; D018984:Epitopes, T-Lymphocyte; D007070:Immunoglobulin A; D007141:Immunoglobulin Fc Fragments; D007075:Immunoglobulin M; D011961:Receptors, Fc
Fc receptor; Fcα/μ receptor; IgA; IgM; follicular dendritic cells; marginal zone B cells