BINDING OF PEPTIDES TO MHC MOLECULES

这项工作的目标一直是了解 自体和外源多肽与MHC分子相互作用的研究 通过体外结合法和T细胞活化试验。 随着这个项目的发展，我们开发了一个系统，在这个系统中 抗原肽与MHC-I类分子H-2LD的结合 在其中我们可以并行地测量 MHC/多肽与T细胞受体的复合体。目前的实验已经 研究了辅受体分子CD8对血管内皮细胞生长的影响 MHC/TCR相互作用及早期信号事件的性质 它们是由多肽/MHC刺激T细胞而引起的 复合体和含有变异肽的复合体。 人们的注意力集中在一个矛盾的结果上：身份识别 与小鼠MHC I类分子复合的单肽变异体 分子H-2LD，作为一种有效的致敏肽，但失败了 形成一种络合物，在其中我们可以检测到表面等离子激元的结合 共鸣。这种变异肽似乎形成了一种复合体，可以激活 T细胞对细胞的溶解、淋巴因子的产生，或现在，如由 M.Jelonek博士与I.Stefan ova博士合作 磷酸化事件。因为已经有了这样的差异 变异肽/H-2LD复合体与TCR的体外结合能力 值得注意的是，T细胞的反应似乎只表现出轻微的 早期磷酸化模式的动力学和定量差异。 试图评估CD8(由澳大利亚人制作)的贡献 合作者Brendan Classon和Peter Hudson)与结合反应 H-2LD/肽复合体与同源TCR的相互作用 CD8到H-2LD分子无肽。这表明，一个 CD8蛋白氨基末端的H-2LD多肽基序 通过MHC的多肽结合介导与MHC分子的结合 最佳状态。各种直接结合和竞争实验已经 证实了H-2LD可以进行这种模式的成熟结合 CD8。

The objective of this work has been to understand the details of the interaction of self and foreign peptides with MHC molecules, as studied both by in vitro binding methods and by assays of T cell activation. As this project has developed, we have developed a system in which the binding of the antigenic peptide to the MHC class I molecule H-2Ld is measured and in which we can in parallel measure the interaction of the MHC/peptide complex with the T cell receptor. Current experiments have investigated the influence of the coreceptor molecule, CD8, on the MHC/TCR interaction as well as the nature of the early signaling events that are elicited by the stimulation of the T cell with peptide/MHC complexes and those containing variant peptides. Attention has been focused on a paradoxical result: the identification of a single peptide variant that complexes with the mouse MHC class I molecule H-2Ld, serves as an effective sensitizing peptide, but fails to form a complex in which we can detect binding by surface plasmon resonance. The variant peptide seems to form a complex that activates the T cells to cytolysis, lymphokine production, or now, as studied by Dr. M. Jelonek in collaboration with Dr. I. Stefanova by early phosphorylation events. Since there has been such a discrepancy in the ability of the variant peptide/H-2Ld complex to bind the TCR in vitro it is remarkable that the T cell response seems to show only minor kinetic and quantitative differences in early phosphorylation patterns. Attempts to evaluate the contribution of CD8 (produced by Australian collaborators Brendan Classon and Peter Hudson) to the binding reaction of H-2Ld/peptide complexes with the cognate TCR revealed interaction of the CD8 to H-2Ld molecules devoid of peptide. This suggested that an H-2Ld peptide motif in the amino terminal region of the CD8 protein was mediating binding to the MHC molecule through the MHC's peptide binding groove. A variety of direct binding and competition experiments have confirmed that H-2Ld can carry out this mode of binding to the mature CD8.