CELL BIOLOGY OF IMMUNE INTERACTIONS

超出提供的空间。抗原(Ag)特异性T细胞和抗原提呈细胞(APC)之间的相互作用可以启动产生免疫反应，但这种相互作用也可以导致相互作用的细胞失活或诱导耐受。这些研究的长期目标是揭示多种细胞和分子机制的复杂整合，这些机制决定了相互作用细胞的命运，并导致了这些不同的生物结果。利用新的T-APC结合物的三维数字成像显示，信号和黏附受体和细胞内蛋白被招募到细胞接触并形成空间分离的超分子激活簇(SMAC)，构成免疫突触(IS)。SMAC的功能作用尚不清楚。一些TCR介导的信号甚至在SMAC形成之前就已经产生了。然而，TCR信号随后定位在c-SMAC内，Smac的形成似乎是产生T细胞激活所必需的。这一应用重点是测试一种新的T细胞激活的综合模型。该模型提出，T细胞的成功激活需要TCR信号的有序进行，TCR信号在SMAC形成之前启动，经历了SMAC中几个在空间和时间上不同的阶段。这种连续的空间信号的任何干扰都会导致T细胞失活。该模型将使用活的和固定的T-APC偶联物的新型多维成像进行测试，并结合遗传、生化和功能研究。这些研究将识别和定位在T细胞激活的不同阶段发生的信号事件。最先进的成像工具包括单分子示踪、FRET和激活特异性生化试剂将被用来跟踪T细胞激活不同阶段的关键酪氨酸激酶Lck和Zap-70，并将研究这些激酶与CD3/TCR、CD4、CD28和适配蛋白的相互作用。药理抑制剂和基因操作将被用来干扰和定位激活过程的选择性时空阶段，并将确定结构和功能后果。这些新颖的研究可能会更好地理解调节T细胞激活的分子事件，并可能对未来更好的免疫监测方案、免疫抑制药物和新疫苗的设计有用。表演网站========================================Section End===========================================

EXCEED THE SPACE PROVIDED. The interactions between antigen (Ag)-specific T cells and antigen-presenting cells (APCs) initiate productive immune responses, but such interactions can also result in the inactivation or induction of tolerance in the interacting cells. Uncovering the complex integration of the multiple cellular and molecular mechanisms that determine the fates of the interacting cells and cause these diverse biologic outcomes is the long term goal of these studies. Using novel 3-D digital imaging of T-APC conjugates it was shown that signaling and adhesion receptors and intracellular proteins are recruited to the cell contacts and form spatially segregated Supra-Molecular Activation Clusters (SMACs), which constitute the Immunological Synapse (IS). The functional role of the SMACs is unclear. Some TCR mediated signals are generated even before the formation of SMACs. However, TCR signals are subsequently located within the c-SMACs and SMAC formation appears to be required for productive T cell activation. This application focuses on testing a novel integrative model of T cell activation. The model proposes that successful T cell activation requires the ordered progression of TCR signals, which are initiated before the formation of SMACs, through several spatially and temporally distinct stages in the SMACs. Any disruption of this sequential spatial signaling would result in T cell inactivation. The model will be tested using novel multi-dimensional imaging of live and fixed T-APC conjugates, coupled with genetic, biochemical and functional studies. The studies would identify and localize the signaling events that take place at the different stages of T cells activation. State of the art imaging tools including Single Molecule Tracking, FRET and activation-specific biochemical reagents would be used to follow the key tyrosine kinases Lck and Zap-70 during the different stages of T cell activation and would study the interactions of these kinases with CD3/TCR, CD4, CD28 and adapter proteins. Pharmacological inhibitors and genetic manipulation would be used to disrupt and localize selective spatial-temporal stages of the activation processes and the structural and functional consequences would be determined. These novel studies are likely to achieve better understanding of the molecular events that regulate T cell activation and may be useful in future designs of better immune surveillance protocols, immunosuppression drugs and new vaccines. PERFORMANCE SITE ========================================Section End===========================================