Char D, Sanchez P, Chen C L, Bucy R P, Cooper M D
Department of Microbiology, University of Alabama, Birmingham 35294.
J Immunol. 1990 Dec 1;145(11):3547-55.
Avian homologues of mammalian gamma delta and alpha beta TCR, termed TCR1 and TCR2, have been identified in the chicken with specific mAb. A third TCR, dubbed TCR3, has been identified on a subpopulation of T cells that lack the TCR1 or TCR2 epitopes. We have now produced a mAb that identifies this TCR3 molecule. The anti-TCR3 antibody immunoprecipitates a CD3-associated heterodimer with a relative Mr of 88,000, composed of 48,000 and 40,000 disulfide-linked chains. The Mr 40,000 chains of TCR3 and TCR2 exhibited the same isoelectric points of 5.6 to 6.5 and had core proteins of 34,000. Although the Mr 48,000 chain of TCR3 and the Mr 50,000 chain of TCR2 had the same basic isoelectric point of 6.2 to 7.6, their core proteins were different in size, 31,000 vs 29,000. Immunofluorescence analysis reveals that the TCR3 was present on all of the CD3+ T cells not identified by antibodies specific for TCR1 or TCR2. Thymocytes that expressed the surface CD3/TCR3 complex at relatively low levels were predominantly CD4+ and CD8+, whereas those with higher levels of surface CD3/TCR3 were predominantly CD4+ and CD8+ singles. Mature TCR3+ cells in the periphery were also either CD4+ (80%) or CD8+ (20%). The TCR1+, TCR2+, and TCR3+ subsets of T cells were generated sequentially in the thymus and seeded to the periphery in the same order. Intrathymic development of the TCR3+ cells was selectively inhibited by embryonic treatment with the anti-TCR3 mAb. The pattern of histologic localization of TCR3+ cells in the periphery was similar to the TCR2 subset of cells except that the TCR3+ cells were rarely seen in the intestine. Cross-reactivity patterns of the anti-chicken TCR antibodies suggested that other gallinaceous species share the three types of TCR. We conclude that TCR2 and TCR3 in gallinaceous birds may represent alpha beta subfamilies of TCR that are sequentially expressed on developmentally discrete sublines of T cells.
利用特异性单克隆抗体在鸡体内已鉴定出哺乳动物γδ和αβTCR的禽类同源物，分别称为TCR1和TCR2。在缺乏TCR1或TCR2表位的T细胞亚群上已鉴定出第三种TCR，称为TCR3。我们现已制备出一种可识别该TCR3分子的单克隆抗体。抗TCR3抗体免疫沉淀出一种与CD3相关的异二聚体，其相对分子质量为88,000，由48,000和40,000的二硫键连接链组成。TCR3和TCR2的40,000相对分子质量链表现出相同的5.6至6.5的等电点，核心蛋白为34,000。虽然TCR3的48,000相对分子质量链和TCR2的50,000相对分子质量链具有相同的6.2至7.6的碱性等电点，但它们的核心蛋白大小不同，分别为31,000和29,000。免疫荧光分析显示，TCR3存在于所有未被TCR1或TCR2特异性抗体识别的CD3+T细胞上。表面CD3/TCR3复合物表达水平相对较低的胸腺细胞主要是CD4+和CD8+双阳性细胞，而表面CD3/TCR3水平较高的细胞主要是CD4+和CD8+单阳性细胞。外周成熟的TCR3+细胞也主要是CD4+(80%)或CD8+(20%)。T细胞的TCR1+、TCR2+和TCR3+亚群在胸腺中依次产生，并以相同顺序播种到外周。用抗TCR3单克隆抗体对胚胎进行处理可选择性抑制TCR3+细胞在胸腺内的发育。外周TCR3+细胞的组织学定位模式与TCR2细胞亚群相似，只是在肠道中很少见到TCR3+细胞。抗鸡TCR抗体的交叉反应模式表明，其他鸡形目物种也有这三种类型的TCR。我们得出结论，鸡形目鸟类中的TCR2和TCR3可能代表TCR的αβ亚家族，它们在发育上不同的T细胞亚系上依次表达。
