TCR--PEPTIDE--MHC INTERACTION IN T CELL CROSSREACTIVITY

本文的目的是在分子水平上阐明T细胞受体（TCR）的交叉反应。该独特的模型涉及免疫优势病毒肽与两个非常密切相关的I类MHC变体的交叉反应性TCR识别。待研究的TCRs具有相同的tcrβ链，但有些只看到其中一种复合物（单特异性识别），而另一些则看到两种复合物（交叉反应识别）。这表明tcrα链在交叉反应性中起决定性作用。TCR测序，单链TCR转基因（scTCRTg小鼠）的产生和分析，晶体结构测定和TCR诱变将用于解剖允许交叉反应的分子接触，这是同种异体反应性，耐受性诱导，移植排斥和自身免疫的现象。目标是：1。分析正常小鼠和scTCRTg小鼠的交叉反应性和单特异性CTL克隆的功能反应性和TCR序列，建立初步联系，确定密切相关TCR的交叉反应性和单特异性TCR：肽：MHC相互作用。2. 确定具有适当pep:MHC复合物的单特异性和交叉反应性tcr的x射线结构，并使用位点定向诱变明确解剖交叉反应性识别。

The aim of this proposal is to elucidate T cell receptor (TCR) crossreactivity at the molecular level. The unique model developed involves crossreactive TCR recognition of the immunodominant viral peptide coupled to two very closely related class I MHC variants. TCRs to be studied share the same TCRbeta chains, but some see only one of the complexes (monospecific recognition) while others see both (crossreactive recognition). This indicates that the TCRalpha chain must play a decisive role in crossreactivity. TCR sequencing, generation and analysis of single TCR chain transgenic (scTCRTg mice), Crystal structure determination and TCR mutagenesis will be used to dissect the molecular contacts that permit crossreactivity, a phenomenon underlying alloreactivity, tolerance induction, transplant rejection and autoimmunity. The aims are: 1. To analyze functional reactivity and TCR sequence of crossreactive and monospecific CTL clones from normal and scTCRTg mice and establish the preliminary contacts that define crossreactive and monospecific TCR:peptide:MHC interactions for closely related TCRs. 2. To determine the x-ray structures of the monospecific and crossreactive TCRs with the appropriate pep:MHC complexes, and use site-directed mutagenesis to definitively dissect crossreactive recognition.