de la Hera A, Müller U, Olsson C, Isaaz S, Tunnacliffe A
Basel Institute for Immunology, Switzerland.
J Exp Med. 1991 Jan 1;173(1):7-17. doi: 10.1084/jem.173.1.7.
Transgenic mice carrying and expressing the human CD3 epsilon gene incorporate the corresponding protein product into T cell receptor (TCR)/CD3 complexes on thymocyte and T cell surfaces. The chimeric antigen receptors allow normal T cell development and selection of repertoires in vivo and are able to transduce activation signals in vitro. We have exploited the ability to distinguish mouse (m) and human (h)CD3 epsilon chains to analyze the stoichiometry of CD3 epsilon in transgenic mouse TCRs. Immunoprecipitation and fluorescence resonance energy transfer experiments demonstrate that such TCRs can contain both h- and mCD3 epsilon chains, implying that more than one CD3 epsilon subunit occurs per TCR. Antigen comodulation studies are consistent with a stochastic use of h- or mCD3 epsilon during receptor assembly, and further suggest a structure for the TCR/CD3 complex with two CD3 epsilon chains. The determination of CD3 epsilon subunit stoichiometry, together with existing biochemical data, allows the generation of a minimal model for the structure of the TCR and illustrates the potential value of the transgenic approach to the analysis of complex receptors.
携带并表达人CD3ε基因的转基因小鼠将相应的蛋白质产物整合到胸腺细胞和T细胞表面的T细胞受体（TCR）/CD3复合物中。嵌合抗原受体在体内允许正常的T细胞发育和 repertoire 的选择，并且能够在体外转导激活信号。我们利用区分小鼠（m）和人（h）CD3ε链的能力来分析转基因小鼠TCR中CD3ε的化学计量。免疫沉淀和荧光共振能量转移实验表明，此类TCR可同时包含h-和mCD3ε链，这意味着每个TCR存在不止一个CD3ε亚基。抗原共调节研究与受体组装过程中随机使用h-或mCD3ε一致，并进一步提示了具有两条CD3ε链的TCR/CD3复合物的结构。CD3ε亚基化学计量的确定，连同现有的生化数据，使得能够生成TCR结构的最小模型，并说明了转基因方法在分析复杂受体方面的潜在价值。
