Regueiro J R, Timón M, Pérez-Aciego P, Corell A, Martín-Vílla J M, Rodríguez-Gallego C, Góngora R, Arnaiz-Villena A
Scand J Immunol. 1992 Sep;36(3):363-9. doi: 10.1111/j.1365-3083.1992.tb02950.x.
The recent description of a selective human CD3 gamma deficiency and other T-cell receptor (TCR)/CD3 structural and functional defects, together with previous biochemical data on the structure and interactions of the TCR/CD3 complex, may aid in elucidating the physiology of this multi-subunit membrane ensemble. CD3 gamma seemed to be required for the commitment and thymic maturation of an important fraction of T lymphocytes to the CD8 (but not CD4) lineage, perhaps by participating with the CD8 co-receptor in the instructive signal delivered through the alpha beta TCR during intrathymic positive selection by HLA class I molecules. The homologous CD3 delta component would, in contrast, be necessary for the selection of CD4 lymphocytes by HLA class II molecules. The interaction of CD4 and CD8 with the TCR/CD3 complex during antigen recognition may thus be asymmetrical, taking place through CD3 delta and gamma, respectively. Also, the existence of in vivo functional TCR/CD3 hemireceptors (lacking either CD3 gamma or CD3 delta) is suggested, and defects in their relative amount on the T-cell surface may disrupt unresponsiveness to self antigens and generate autoimmunity.
最近对选择性人类CD3γ缺陷以及其他T细胞受体（TCR）/CD3结构和功能缺陷的描述，连同先前关于TCR/CD3复合物结构和相互作用的生化数据，可能有助于阐明这种多亚基膜组件的生理学。CD3γ似乎是T淋巴细胞中很大一部分向CD8（而非CD4）谱系定向分化和胸腺成熟所必需的，可能是通过在HLA I类分子进行胸腺内阳性选择期间，与CD8共受体一起参与通过αβ TCR传递的指导性信号。相比之下，同源的CD3δ成分对于HLA II类分子选择CD4淋巴细胞是必需的。因此，在抗原识别过程中，CD4和CD8与TCR/CD3复合物的相互作用可能是不对称的，分别通过CD3δ和γ发生。此外，提示存在体内功能性TCR/CD3半受体（缺乏CD3γ或CD3δ），并且它们在T细胞表面的相对数量缺陷可能会破坏对自身抗原的无反应性并产生自身免疫。
