A Reassessment of IgM Memory Subsets in Humans.
A Reassessment of IgM Memory Subsets in Humans.
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DOI：
10.4049/jimmunol.1500753
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发表时间：
2015-10-15
期刊：
影响因子：
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通讯作者：
Reynaud CA
中科院分区：
文献类型：
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作者：
Bagnara D;Squillario M;Kipling D;Mora T;Walczak AM;Da Silva L;Weller S;Dunn-Walters DK;Weill JC;Reynaud CA
从三名成年供体的配对血液和脾脏样本中，我们对由IgD和CD 27表达定义的人B细胞亚群进行了高通量V-h测序：IgD+ CD 27+（“MZ”），IgD− CD 27+（“记忆”，包括IgM（“仅IgM”），IgG和伊加）和IgD− CD 27 −细胞（“双阴性”，包括IgM，IgG和伊加）。91，294个独特的序列聚集在42，670个克隆中，揭示了这些子集中每个子集的主要克隆扩增。在这些克隆中，我们进一步分析了来自不同子集或组织的那些共享序列的Vh基因突变、H-CDR 3长度和Vh/Jh使用，将这些不同特征与来自其来源子集的所有序列进行比较，这些参数构成了不同的特征。仅IgM的库谱与MZ B细胞的库谱显著不同，突变频率更高，Vh 4基因使用率更低，Jh 6基因使用率更高。引人注目的是，来自MZ和记忆IgG/伊加区室之间共享的克隆的IgM序列显示出仅IgM而非MZ B细胞的突变和库概况。同样，所有IgM克隆关系（MZ、仅IgM和双阴性区室之间）均涉及具有仅IgM B细胞特征的序列。最后，组织间的克隆关系表明MZ和转换的B细胞之间具有不同的再循环特征。因此，“仅IgM”亚组（包括具有其库特征但IgD较高或CD 27表达水平较低的细胞）似乎是显示与CD 27+转换的记忆B细胞的受体-产物关系的唯一亚组，表明它们代表生发中心来源的IgM记忆B细胞，并且IgM记忆和MZ B细胞构成两种不同的实体。
From paired blood and spleen samples from three adult donors we performed high-throughput V-h sequencing of human B-cell subsets defined by IgD and CD27 expression: IgD+CD27+ (“MZ”), IgD−CD27+(“memory”, including IgM (“IgM-only”), IgG and IgA) and IgD−CD27− cells (“double-negative”, including IgM, IgG and IgA). 91,294 unique sequences clustered in 42,670 clones, revealing major clonal expansions in each of these subsets. Among these clones, we further analyzed those shared sequences from different subsets or tissues for Vh-gene mutation, H-CDR3-length, and Vh/Jh usage, comparing these different characteristics with all sequences from their subset of origin, for which these parameters constitute a distinct signature. The IgM-only repertoire profile differed notably from that of MZ B cells by a higher mutation frequency, and lower Vh4 and higher Jh6 gene usage. Strikingly, IgM sequences from clones shared between the MZ and the memory IgG/IgA compartments showed a mutation and repertoire profile of IgM-only and not of MZ B cells. Similarly, all IgM clonal relationships (between MZ, IgM-only, and double-negative compartments) involved sequences with the characteristics of IgM-only B cells. Finally, clonal relationships between tissues suggested distinct recirculation characteristics between MZ and switched B cells. The “IgM-only” subset (including cells with its repertoire signature but higher IgD or lower CD27 expression levels) thus appear as the only subset showing precursor-product relationships with CD27+ switched memory B cells, indicating that they represent germinal center-derived IgM memory B cells, and that IgM memory and MZ B cells constitute two distinct entities.