VARIABLE GENE UTILIZATION IN SPECIFIC T CELL RESPONSES

我们已经描述了一个实验模型，在该模型中，变异肽是 在胎儿胸腺器官培养中引入以确定他们是否有 促进T细胞分化的能力 专一性。这类多肽家族的鉴定开启了 直接解决MHC之间关系的可能性- 选择胸腺中成熟T细胞的相关多肽和 诱导同一T细胞活化的特定异源多肽 在外围。一个被广泛讨论的模型表明，减少 T细胞受体与MHC相互作用的亲和力：自体肽 复杂可能导致正面而非负面的选择 胸腺。与大卫·马古利斯(免疫学实验室， NIAID，NIH)，我们将利用工程能力方面的最新进展 T细胞受体c DNA促进可溶性受体的分离 分子。然后我们将确定相对亲和力和动力学 纯化的TCR与可溶性H-2kb络合物的结合 未修饰的配体或与结构相关的肽类似物， 被用于阳性筛选表达该TCR的成熟T细胞。

We have described an experimental model in which variant peptides are introduced in fetal thymic organ culture to determine whether they have the ability to promote differentiation of T cells of a defined specificity. Identification of a family of such peptides opens the possibility of directly addressing the relationship between MHC- associated peptides that select a mature T cell in the thymus and the particular foreign peptide that induces activation of this same T cell in the periphery. One widely discussed model suggests that reduced affinity of interaction between T cell receptor and an MHC:self-peptide complex could result in positive rather than negative selection in the thymus. In collaboration with David Margulies (Laboratory of Immunology, NIAID, NIH), we will exploit recent advances in the ability to engineer T cell receptor cDNA to facilitate isolation of soluble receptor molecules. We will then determine the relative affinity and kinetics of binding of purified TCR for complexes of soluble H-2Kb with either unmodified ligands or with the structurally related peptide analogs that were employed to positively select mature T cells that express this TCR.