Intermolecular Interactions in the Immunological Synapse

描述（由申请人提供）：FRET显微镜是一种非常有效的手段来研究蛋白质：活细胞中的蛋白质相互作用。本项目使用FRET显微镜来研究抗原识别过程中TCR和共受体之间诱导的相互作用。FRET显微镜将用于分析CD8a（3和aa在抗原识别过程中作为辅助受体和被招募到免疫突触的不同能力，以及确定内源性肽如何增强T细胞识别，包括增强TCR：辅助受体相互作用）。在抗原识别过程中，Lck和Fyn的运动和相互作用将通过荧光嵌合体和FRET生物传感器进行分析。在发育中的胸腺细胞和活化的T细胞中发现了CD8的不同唾液化。唾液化在突触募集CD8、链配对、TCR:CD8和CD8:Lck相互作用中的作用将被研究。表达CD3？-CFP和CD8 ？-YFP将用于成像不同选择条件下发育中的胸腺细胞和基质细胞之间的细胞偶联物中的TCR：共受体相互作用，以了解TCR：共受体相互作用的速度和强度如何在正选择和负选择中被调节。这些因素也将分析幼稚，效应和记忆T细胞。t细胞抗原受体、辅助受体（如CD4）和信号蛋白之间的相互作用对免疫反应至关重要。了解这些相互作用是如何发生的将有助于提高对病毒或癌症的免疫反应，并减少自身免疫反应。

DESCRIPTION (provided by applicant): FRET microscopy is a very effective means to investigate protein:protein interactions in living cells. This project uses FRET microscopy to investigate the induced interactions between TCR and co-receptors that occur during antigen recognition. FRET microscopy will be used to analyze the different abilities of CD8a (3 and aa to act as coreceptors and to be recruited to the immunological synapse during antigen recognition, as well as to determine how endogenous peptides enhance T cell recognition, including enhancing the TCR:coreceptor interaction). The movement and interactions of Lck and Fyn during antigen recognition will be analyzed with fluorescent chimeras, and with a FRET biosensor. Differential sialylation of CD8 has been found in developing thymocytes and in activated T cells. The role of sialylation in recruitment of CD8 to the synapse, chain pairing, TCR:CD8 and CD8:Lck interactions will be investigated. Transgenic mice expressing CD3?-CFP and CD8 ?-YFP will be used to image TCR:coreceptor interactions in cell conjugates between developing thymocytes and stromal cells, under different selecting conditions, to understand how the speed and intensity of the TCR:coreceptor interactions are modulated in positive and negative selection. These factors will also be analyzed for naive, effector and memory T cells. The interactions between the T-cell antigen receptor, coreceptors such as CD4, and signaling proteins, are crucial to the immune response. Understanding how these interactions take place will aid in improving the immune response to viruses or cancer, and in reducing autoimmune reactions.