Balk S P, Polischuk J E, Probert C, Stevens C, Ebert E, She J, Terhorst C, Blumberg R S
Hematology/Oncology Division, Beth Israel Hospital, Harvard Medical School, Boston, MA 02215, USA.
Int Immunol. 1995 Aug;7(8):1237-41. doi: 10.1093/intimm/7.8.1237.
Human intestinal intraepithelial lymphocytes (iIEL) are a unique population of predominantly CD8 alpha beta+, TCR alpha beta+ lymphocytes and, to a lesser extent, TCP gamma delta+ lymphocytes that proliferate poorly to anti-CD3 mitogenic signals but display significant cytolytic activity. Studies in mouse model systems have shown that the gamma chain of the high-affinity receptor for IgE (Fc epsilon RI gamma) may substitute for the zeta chain in the TCR-CD3 complex of iIEL. This has suggested that the functional properties of these cells may be associated with an altered composition of the TCR-CD3 complex. We therefore analyzed the TCR-CD3 complex of normal human iIEL. One- and two-dimensional non-reducing/reducing SDS-PAGE analysis of CD3 gamma, CD3 delta, CD3 epsilon, zeta and Fc epsilon RI gamma chain immunoprecipitates of cell surface radiolabeled proteins with subunit-specific antibodies revealed a TCR-CD3 complex without associated Fc epsilon RI gamma chains. Thus, normal human iIEL contain a TCR-CD3 complex that consists predominantly of zeta homodimers in association with the alpha beta TCR and CD3 gamma, delta and epsilon, similar to the majority of peripheral lymphocytes. This indicates that the distinct properties of human iIEL are not associated with substitutions of the Fc epsilon RI gamma chain in the TCR-CD3 complex.
人肠道上皮内淋巴细胞（iIEL）是一群独特的淋巴细胞，主要为CD8αβ⁺、TCRαβ⁺淋巴细胞，少量为TCRγδ⁺淋巴细胞，它们对抗CD3促有丝分裂信号的增殖能力较差，但具有显著的细胞溶解活性。在小鼠模型系统中的研究表明，IgE高亲和力受体（FcεRIγ）的γ链可能替代iIEL的TCR-CD3复合物中的ζ链。这表明这些细胞的功能特性可能与TCR-CD3复合物组成的改变有关。因此，我们分析了正常人iIEL的TCR-CD3复合物。用亚基特异性抗体对细胞表面放射性标记蛋白的CD3γ、CD3δ、CD3ε、ζ和FcεRIγ链免疫沉淀物进行一维和二维非还原/还原SDS-PAGE分析，结果显示TCR-CD3复合物中没有相关的FcεRIγ链。因此，正常人iIEL含有一种TCR-CD3复合物，其主要由ζ同二聚体与αβTCR以及CD3γ、δ和ε组成，这与大多数外周淋巴细胞相似。这表明人iIEL的独特特性与TCR-CD3复合物中FcεRIγ链的替代无关。
