Human immunoglobulin (Ig)M+IgD+ peripheral blood B cells expressing the CD27 cell surface antigen carry somatically mutated variable region genes: CD27 as a general marker for somatically mutated (memory) B cells.
Human immunoglobulin (Ig)M+IgD+ peripheral blood B cells expressing the CD27 cell surface antigen carry somatically mutated variable region genes: CD27 as a general marker for somatically mutated (memory) B cells.
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DOI：
10.1084/jem.188.9.1679
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发表时间：
1998-11-02
期刊：
影响因子：
--
通讯作者：
Küppers R
中科院分区：
文献类型：
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作者：
Klein U;Rajewsky K;Küppers R
免疫球蛋白（IG）M+IgD+ B细胞通常被认为代表无抗原经验、表达无体细胞突变的可变（V）区基因的初始B细胞。我们在这里报告，人IgM+IgD+外周血（PB）B细胞表达的CD 27细胞表面抗原携带突变的V基因，与CD 27阴性IgM+IgD+ B细胞。IgM+IgD+ CD 27 + B细胞在细胞表型方面类似于类别转换和仅IgM记忆细胞，并且在健康成人中占PB B淋巴细胞的约15%。此外，检测到非常小的高度突变的仅有IgD的B细胞群体（<1%的PB B细胞），其可能代表仅有IgD的扁桃体生发中心和浆细胞的PB对应物。总体而言，成人PB中的B细胞池由约40%的突变记忆B细胞和60%的未突变、初始IgD+ CD 27 − B细胞（包括CD 5 + B细胞）组成。在体细胞突变的B细胞中，VH区基因携带的体细胞突变负荷比重排的Vκ基因高2 - 3倍。这可能是由于κ轻链基因的突变率本质上低于重链基因和/或GC B细胞中κ轻链基因重排所致。体细胞突变的B细胞亚群的共同特征是表达CD 27细胞表面抗原，因此其可代表人类记忆B细胞的一般标记。
Immunoglobulin (Ig)M+IgD+ B cells are generally assumed to represent antigen-inexperienced, naive B cells expressing variable (V) region genes without somatic mutations. We report here that human IgM+IgD+ peripheral blood (PB) B cells expressing the CD27 cell surface antigen carry mutated V genes, in contrast to CD27-negative IgM+IgD+ B cells. IgM+IgD+CD27+ B cells resemble class-switched and IgM-only memory cells in terms of cell phenotype, and comprise ∼15% of PB B lymphocytes in healthy adults. Moreover, a very small population (<1% of PB B cells) of highly mutated IgD-only B cells was detected, which likely represent the PB counterpart of IgD-only tonsillar germinal center and plasma cells. Overall, the B cell pool in the PB of adults consists of ∼40% mutated memory B cells and 60% unmutated, naive IgD+CD27− B cells (including CD5+ B cells). In the somatically mutated B cells, VH region genes carry a two- to threefold higher load of somatic mutation than rearranged Vκ genes. This might be due to an intrinsically lower mutation rate in κ light chain genes compared with heavy chain genes and/or result from κ light chain gene rearrangements in GC B cells. A common feature of the somatically mutated B cell subsets is the expression of the CD27 cell surface antigen which therefore may represent a general marker for memory B cells in humans.