Gascoigne N R, Ames K T
Department of Immunology, Research Institute of Scripps Clinic, La Jolla 92037.
Proc Natl Acad Sci U S A. 1991 Jan 15;88(2):613-6. doi: 10.1073/pnas.88.2.613.
The interaction of the T-cell receptor (TCR) with peptide antigen plus major histocompatibility complex (MHC) protein requires both alpha and beta chains of the TCR. The "superantigens" are a group of molecules that are recognized in association with MHC class II but that do not appear to conform to this pattern. Superantigens are defined as such because they cause the activation or thymic deletion of many or all T cells bearing specific TCR beta-chain variable region (V beta) elements. The strong association of particular V beta S with T-cell responses to superantigens suggests that their interaction with the TCR is fundamentally different from that of most antigens. We have directly investigated the involvement of the beta chain in recognition of a superantigen by using a secreted, truncated TCR beta chain and the bacterial superantigen staphylococcal enterotoxin A complexed to cell-surface MHC class II. We demonstrate that this interaction is specific for the enterotoxin and is dependent on MHC class II expression by the cell. The reaction can be inhibited by antibodies against the three components of the reaction: V beta, enterotoxin, and class II. This shows that the TCR beta chain is sufficient to mediate the interaction with a superantigen-class II complex. The TCR alpha chain and co-receptors such as CD4 are not required.
T细胞受体（TCR）与肽抗原加上主要组织相容性复合体（MHC）蛋白的相互作用需要TCR的α链和β链。“超抗原”是一类与MHC II类分子相关联而被识别的分子，但它们似乎并不符合这种模式。超抗原之所以这样定义，是因为它们能导致许多或所有带有特定TCRβ链可变区（Vβ）元件的T细胞被激活或在胸腺中被清除。特定的Vβ与T细胞对超抗原的反应之间的强烈关联表明，它们与TCR的相互作用与大多数抗原的相互作用有着根本的不同。我们通过使用一种分泌型、截短的TCRβ链以及与细胞表面MHC II类分子复合的细菌超抗原葡萄球菌肠毒素A，直接研究了β链在超抗原识别中的作用。我们证明这种相互作用对肠毒素具有特异性，并且依赖于细胞表达的MHC II类分子。该反应可被针对反应的三个组分的抗体抑制：Vβ、肠毒素和II类分子。这表明TCRβ链足以介导与超抗原 - II类复合体的相互作用。不需要TCRα链和诸如CD4之类的共受体。
