Identification of a third variable lymphocyte receptor in the lamprey
Identification of a third variable lymphocyte receptor in the lamprey
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DOI：
10.1073/pnas.1001910107
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发表时间：
2010-08-10
影响因子：
11.1
通讯作者：
Kasahara, Masanori
中科院分区：
文献类型：
--
作者：
Kasamatsu, Jun;Sutoh, Yoichi;Kasahara, Masanori
无颌脊椎动物，如七鳃鳗和七鳃鳗，缺乏T细胞和B细胞受体；相反，它们有独特的抗原受体，称为可变淋巴细胞受体(VLR)。VLRs通过重组高度不同的富含亮氨酸的重复模块而产生多样性，并在淋巴样细胞(LLC)上克隆性表达。到目前为止，已经在七鳃鳗和七鳃鳗中鉴定出两种类型的受体，VLRA和VLRB。最近的证据表明，VLRA和VLRB分别表达在不同的LLCs群体上，它们分别类似于颌骨脊椎动物的T细胞和B细胞。在这里，我们在七鳃鳗中识别出了第三个VLR，命名为VLRC。经过测序的近100个VLRC克隆没有一个具有相同的序列，这表明VLRC可以产生足够的多样性来发挥抗原受体的功能。值得注意的是，VLRC的C-末端帽仅表现出有限的多样性，并且与VLRA和VLRB有重要的结构差异。单细胞聚合酶链式反应分析发现LLC重排了VLRC，但不能重排VLRA或VLRB，这表明存在一个仅表达VLRC的独特的LLC群体。
Jawless vertebrates such as lamprey and hagfish lack T-cell and B-cell receptors; instead, they have unique antigen receptors known as variable lymphocyte receptors (VLRs). VLRs generate diversity by recombining highly diverse leucine-rich repeat modules and are expressed clonally on lymphocyte-like cells (LLCs). Thus far, two types of receptors, VLRA and VLRB, have been identified in lampreys and hagfish. Recent evidence indicates that VLRA and VLRB are expressed on distinct populations of LLCs that resemble T cells and B cells of jawed vertebrates, respectively. Here we identified a third VLR, designated VLRC, in the lamprey. None of the approximate to 100 VLRC cDNA clones subjected to sequencing had an identical sequence, indicating that VLRC can generate sufficient diversity to function as antigen receptors. Notably, the C-terminal cap of VLRC exhibits only limited diversity and has important structural differences relative to VLRA and VLRB. Single-cell PCR analysis identified LLCs that rearranged VLRC but not VLRA or VLRB, suggesting the presence of a unique population of LLCs that express only VLRC.