Structure/biology of short-lived MHC II-ligand complexes

在最后一个赠款周期，我们的特点是一个动力学的中间体结合抗原肽的MHC II类分子。这些中间复合物的特征在于低亲和力和快速缔合和解离速率;它们代表肽受体形式，并且在转化为稳定复合物之前需要发生构象变化。中间复合物可以通过流感HA 306-318肽的变体（改变为P1结合残基）和在P1口袋中突变的HLA-DR 1分子来模拟。在下一个周期，我们建议研究这些短暂的中间复合物的生物学，解决三个目标：1。体外T细胞对短寿命复合物的反应的表征，预期为无反应性诱导。2.鉴定负责无反应性诱导的APC 3a。比较DO-/-、DM-/-和WT胸腺基质细胞的肽库3b。产生表达参与短暂复合物的DR 1突变体（DRbG 86 Y）的小鼠并研究胸腺细胞选择。

During the last grant cycle, we have characterized a kinetic intermediate in the binding of antigenic peptides to MHC class II molecules. These intermediate complexes are characterized by low affinity and fast association and disassociation rates; they represent peptide-receptive forms, and require a conformational change to occur before converting to stable complexes. The intermediate complexes can be mimicked by variant of flu HA 306-318 peptide (changes to P1-binding residues) and by an HLA-DR1 molecule mutated in the P1 pocket. During the next cycle, we propose to study the biology of these short-lived intermediate complexes, addressing three aims: 1. Characterization of in vitro T cell responses to short-lived complexes, expected to be anergy induction. 2. Identify APCs responsible for anergy induction 3a. Compare peptide repertoires of DO-/-, DM-/- and WT thymic stromal cells 3b. Generate mice expressing a DR1 mutant (DRbG86Y) that participates in short-lived complexes and study thymocyte selection.