Variable lymphocyte receptors play a key role in neutralization and opsonization in the lamprey.
Variable lymphocyte receptors play a key role in neutralization and opsonization in the lamprey.
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DOI：
10.1093/abbs/gmy029
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发表时间：
2018-05
影响因子：
3.7
通讯作者：
Hongyang Wen;Yanjiao Dong;Xiong Pan;Zhao Tai;Ying Zhou;Qingwei Li;Y. Pang
中科院分区：
文献类型：
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作者：
Hongyang Wen;Yanjiao Dong;Xiong Pan;Zhao Tai;Ying Zhou;Qingwei Li;Y. Pang
七鳃鳗具有替代的适应性免疫系统，其使用可变淋巴细胞受体（VLR）来结合抗原，而不是有颌脊椎动物使用的基于免疫球蛋白（IG）的抗原受体[1，2]。可变淋巴细胞受体B（VLRB）通过识别表面糖蛋白（HA）球状头部结构域中的主要抗原位点对甲型流感病毒（IAV）作出反应[3]。此外，VLRB通过形成识别优势H-三糖抗原的VLR-抗原复合物对人O型红细胞产生应答[4]。VLRs（VLRB.平均绩点。23)最近显示可识别聚糖，如肿瘤相关的Al-Friedenreich抗原（TFα; Gal 1 -3GalNAc），其作为O-聚糖与丝氨酸或苏氨酸连接[5，6]。以往的研究已经证明了VLRB的抗原识别能力，但很少有研究集中在其其他免疫功能。本研究首次从大肠杆菌刺激的白细胞cDNA文库中鉴定出一个新的VLRB基因。该813-bp开放阅读框（ORF）编码270个氨基酸的蛋白质，通过ExPASy的ProtParam程序（http：//www. expasy。ch/tools/protparam。html）。用SMART软件预测VLRB的结构域，VLRB有5个功能域：LRR NT、LRR、LRR TYP、LRR TYP和LRR TYP。
Lampreys possess an alternative adaptive immune system that uses variable lymphocyte receptors (VLRs) to bind to antigens rather than the immunoglobulin (Ig)-based antigen receptors used by jawed vertebrates [1, 2]. Variable lymphocyte receptor B (VLRB) responds to influenza A virus (IAV) by recognizing the major antigenic sites in a surface glycoprotein (HA) globular head domain [3]. Additionally, VLRB responds to human blood type O erythrocytes by forming a VLR-antigen complex that recognizes the dominant H-trisaccharide antigen [4]. VLRs (VLRB. aGPA. 23) were recently shown to recognize glycans, such as the tumor-associated Thomsen-Friedenreich antigen (TFα; Gal1-3GalNAc), which are linked to serine or threonine as O-glycans [5, 6]. Previous studies have demonstrated the antigen recognition capacity of VLRB; however, less research has focused on its other immune functions. In this study, a novel VLRB gene was first identified from a cDNA library of leukocytes stimulated by Escherichia coli. The 813-bp open reading frame (ORF) encodes a protein of 270 amino acids with an estimated molecular mass of 29,274 Da and a theoretical isoelectric point of 8.44 (Supplementary Fig. S1A) predicted by ProtParam program of ExPASy (http://www. expasy. ch/tools/protparam. html). SMART software was used to predict the domains of VLRB, which has five functional domains: LRR NT, LRR, LRR TYP, LRR TYP, and