Yagi J, Uchiyama T, Janeway C A
Department of Microbiology and Immunology, Tokyo Women's Medical College, Japan.
J Immunol. 1994 Feb 1;152(3):1154-62.
Responses to the superantigen Mls are characterized by proliferation of a significant percentage of T cells expressing receptors encoded by one or a few V beta gene segments. Apparently similar responses are elicited by the staphylococcal enterotoxins (SEs) and other bacterial superantigens. We have observed that T cells can be stimulated by the bacterial superantigen SEs presented by either spleen cells or fibroblasts transfected with the appropriate MHC class II genes. However, the results in this study showed that T cells required more than 100-fold higher concentrations of SEA in the presence of L cell transfectants than spleen APC, although T cell responses to SEB and several other toxins presented by the two types of APC were equivalent. Thus, L cell transfectants have a selective defect in presenting SEA. These data suggest that fibroblasts lack a component required by SEA to stimulate certain T cells, and lead us to propose an alternative model for bacterial superantigen mitogenesis in which the superantigen binds to and modifies the behavior of an endogenous co-ligand.
对超抗原Mls的反应特征是，相当比例的表达由一个或几个Vβ基因片段编码的受体的T细胞发生增殖。葡萄球菌肠毒素（SEs）和其他细菌超抗原显然会引发类似的反应。我们观察到，细菌超抗原SEs可被转染了适当MHC II类基因的脾细胞或成纤维细胞呈递从而刺激T细胞。然而，本研究结果表明，在L细胞转染子存在的情况下，T细胞对SEA的浓度要求比脾抗原呈递细胞（APC）高出100倍以上，尽管T细胞对两种APC呈递的SEB和其他几种毒素的反应是相同的。因此，L细胞转染子在呈递SEA方面存在选择性缺陷。这些数据表明，成纤维细胞缺乏SEA刺激某些T细胞所需的一种成分，并促使我们提出一种细菌超抗原促细胞分裂的替代模型，即超抗原结合并改变内源性共配体的行为。
