摘要
An alternative antigen receptor, named the variable lymphocyte receptor (VLR), was first identified in lampreys in 2004. Since then, the mechanism of VLR diversification via somatic gene assembly and the function of VLR-expressing lymphocytes have been the subject of much research. VLRs comprise leucine-rich repeat (LRR) motifs and are found only in the most phylogenetically distant vertebrates from mammals, lampreys, and hagfish. Previous reports showed that VLRA and VLRB are reciprocally expressed by lymphocytes that resemble T- and B cells; however, more recent reports show that another VLR, VLRC, is expressed on a third lymphocyte lineage, which may be equivalent to δ T cells. The existence of three major lymphocyte lineages – one B-cell-like and two T-cell-like – and their development in lampreys, parallels the mammalian adaptive immune system. This suggests that these three cell lineages were present in the common vertebrate ancestor approximately 500 million years ago.
摘要译文
一种替代抗原受体，命名为可变淋巴细胞受体（VLR）中，第一次确定了七鳃鳗2004此后，VLR多样化通过体细胞基因装配的机制和VLR表达淋巴细胞的功能已经很多研究的主题。的VLR包括富含亮氨酸重复序列（LRR）基序，并且发现，只有在来自哺乳动物，七鳃鳗和盲鳗最系统发育上遥远的脊椎动物。以前的报告显示，VLRA和VLRB往复通过类似于T细胞和B细胞淋巴细胞表达;然而，最近的报告显示，另一VLR，VLRC，表示在第三淋巴细胞谱系，这可能相当于
Natsuko Kishishita[1,2]; Fumikiyo Nagawa[3,*];. Evolution of adaptive immunity: Implications of a third lymphocyte lineage in lampreys[J]. BioEssays, 2014,36(3): 244-250