CD8+ CTL RECOGNITION OF MHC CLASS I

描述（改编自申请人摘要）：T细胞受体 (TCR)细胞毒性T淋巴细胞（CTL）利用其辅助受体CD 8 以识别病毒感染或恶性靶细胞。这样的靶细胞 表达具有结合的肽配体的I类MHC分子， 由TCR/CD 8复合物特异性识别。这里提出的工作 将研究TCR/CD 8分子相互作用的几个方面 I类/肽。最近已经确定， 肽在Ld-同种异体识别中是免疫显性的。这一观察将 扩展以确定这种免疫优势是否反映在 定量表达该肽，测定肽对 Ld，或TCR对Ld/肽复合物的亲和力。作为 在早期研究的基础上，该实验室开发了一种方法， 产生针对H-2Ld的肽特异性同种异体反应性CTL。使用此 方法，将产生肽特异性同种异体反应性CTL， 已知的内源性Ld配体，以确定它们是否在 同种异体反应，以及它们的表达是否在 不同的细胞类型我们还将测试同种异体CTL，特异性 对于内源性Ld配体，比内源性Ld配体更具有肽交叉反应性。 对病毒肽配体具有特异性同基因CTL。更好地了解 特异性TCR结构基序如何与I类或其结合物相互作用 配体，一个广泛的小组的位点特异性突变的I类将是 进行结构功能分析。这些研究还将 包括几个受相同I类限制但特异性 对于不同的肽以及受类似类别限制的CTL克隆， I分子和特异性肽相同。的延伸 早期的研究绘制了CD 8识别位点，一个I类α-3 不被CD 8识别的突变体将在体内和体外进行表征 为了更好地确定CD 8在诱导CTL应答中的作用， 在CTL的I类识别中。总之，所提出的实验 将利用独特的资源和方法来定义各种 控制TCR/CD 8分子的功能性相互作用的参数 对CTL与靶细胞上的I类/肽分子的作用。

DESCRIPTION (Adapted from the Applicant's abstract): The T-cell receptor (TCR) and its coreceptor CD8 are used by cytotoxic T lymphocytes (CTL) to identify virus-infected or malignant target cells. Such target cells express class I MHC molecules with bound peptide ligands that are specifically recognized by the TCR/CD8 complex. The work proposed here will investigate several aspects of the molecular interaction of TCR/CD8 with class I/peptide. It has been recently determined that a single peptide is immunodominant in Ld- allorecognition. This observation will be extended to determine if this immunodominance is reflected in the quantitative expression of this peptide, the affinity of the peptide for Ld, or the affinity of the TCR for the Ld/peptide complex. As an extension of earlier studies, this laboratory has developed a method to generate peptide-specific alloreactive CTL to H-2Ld. Using this methodology, peptide-specific alloreactive CTL will be generated to known endogenous Ld ligands to determine whether they function in allogeneic responses and whether their expression is ubiquitous on different cell types. We will also test whether allogeneic CTL, specific for endogenous Ld ligands, are more peptide cross-reactive than syngeneic CTL specific for viral peptide ligands. To better understand how specific TCR structural motifs interact with class I or its bound ligand, an extensive panel of site-specific mutants of class I will be subjected to structure-function analyses. These studies will also include several CTL clones restricted by the same class I but specific for different peptides as well as CTL clones restricted by similar class I molecules and specific for the same peptide. As an extension of earlier studies mapping the CD8 recognition site, a class I alpha-3 mutant not recognized by CD8, will be characterized in vivo and in vitro to better define the role of CD8 in the induction of CTL responses and in class I recognition by CTL. In summary, the proposed experiments will exploit unique resources and approaches to define various parameters governing functional interactions of the TCR/CD8 molecules on CTL with class I/peptide molecules on target cells.