Unusual biochemical features and follicular dendritic cell expression of human Fcα/μ receptor
Unusual biochemical features and follicular dendritic cell expression of human Fcα/μ receptor
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DOI：
10.1002/eji.200737655
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发表时间：
2007-12-01
影响因子：
5.4
通讯作者：
Kubagawa, Hiromi
中科院分区：
文献类型：
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作者：
Kikuno, Kaoru;Kang, Dong-Won;Kubagawa, Hiromi
IgA和IgM的Fc受体（Fc α -/mu R）特别令人感兴趣，因为它可以结合IgM和IgA同型抗体，因此可能在全身和粘膜免疫中起关键作用。利用IgM和IgA配体和新生成的Fc α /mu R特异性单克隆抗体，我们确定了人Fc α /mu R的生化特征和细胞分布。重组和天然形式的人Fc α /mu R在细胞表面表达为非常稳定的同型二聚体跨膜糖蛋白，可以结合特异性聚合的IgM或IgA。唯一表达Fc α /mu R的人类B细胞，尽管水平非常低，存在于由IgD(+)/CD38（+）表型定义的生发前中心亚群中。因此，表达模式不同于小鼠，其中Fc α /mu R由循环和常驻B细胞群表达。值得注意的是，在人类中表达Fc α / mu R的主要细胞类型是生发中心的滤泡树突状细胞。因此，Fc α /mu R可能在生发中心反应中参与抗原呈递和B细胞选择。
The Fc receptor for IgA and IgM (Fc alpha-/mu R) is of particular interest because it can bind antibodies of both IgM and IgA isotypes and thus may play a pivotal role in systemic and mucosal immunity. Using IgM and IgA ligands and newly generated Fc alpha/mu R specific monoclonal antibodies we have defined biochemical features and cellular distribution of the human Fc alpha/mu R. Both recombinant and native forms of human Fc alpha/mu R are expressed on the cell surface as remarkably stable homodimeric transmembrane glycoproteins that can bind specifically polymeric IgM or IgA. The only human B cells to express Fc alpha/mu R, albeit at very low levels, are found in the pre-germinal center subpopulation defined by the IgD(+)/CD38(+) phenotype. Hence the expression pattern differs from that of the mouse wherein Fc alpha/mu R is expressed by both circulating and resident B cell populations. Significantly, the predominant cell type expressing the Fc alpha/ mu R in humans is the follicular dendritic cell of germinal centers. The Fc alpha/mu R may thus function in antigen presentation and B cell selection in the germinal center response.