T CELL ACTIVATION AND FUNCTIONAL AVIDITY

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 CD 8 + T细胞对于控制和清除许多微生物和寄生虫感染至关重要，并且是许多潜在疫苗接种策略成功的关键。尽管T细胞介导的免疫具有广泛的临床意义，并且对该主题进行了深入的研究，但引发有效T细胞应答的潜在机制仍有待完全确定。为了开始解决这个问题，我们已经使用肽/MHC四聚体和测量细胞溶解活性和细胞因子产生的功能测定法直接离体分析了抗原特异性T细胞。 急性病毒感染后，我们发现，T细胞的反应性（称为功能性亲和力）肽抗原显着增加，在正常和T细胞受体（TcR）转基因小鼠，即使TcR的亲和力几乎保持不变。Lck表达和功能的初步分析表明，TcR信号转导机制的预组装可能是降低抗原特异性CD 8 + T细胞活化阈值的重要机制。 本提案的重点是更彻底地表征急性病毒感染过程中显性和亚显性CD 8 + T细胞群体的功能性亲合力成熟过程，并确定抗原敏感性增加是否与Lck表达增加、定位和/或其活化状态有关。这些研究的结果对于改进疫苗设计以及进一步了解抗病毒T细胞免疫学非常重要。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. CD8+ T cells are critical for the control and clearance of many microbial and parasitic infections, and are key to the success of many potential vaccination strategies. Despite the broad clinical relevance of T cell-mediated immunity and the intense investigation of this subject, the underlying mechanisms involved with eliciting effective T cell responses still remain to be fully determined. To begin to address this issue, we have analyzed antigen-specific T cells directly ex vivo using peptide/MHC-tetramers and functional assays that measure cytolytic activity and cytokine production. Following acute viral infection, we have found that T cell responsiveness (termed functional avidity) to peptide antigen increased significantly in both normal and T cell receptor (TcR) transgenic mice, even though TcR avidity remained virtually unaltered. Preliminary analysis of Lck expression and function indicates that pre-assembly of the TcR signal transduction machinery may serve as an important mechanism for decreasing the threshold of activation in antigen-specific CD8+ T cells. The focus of this proposal is to more thoroughly characterize the process of functional avidity maturation by dominant and subdominant CD8+ T cell populations during the course of acute viral infection, and to determine if increased antigen sensitivity is related to increased Lck expression, localization, and/or its state of activation. The results of these studies will be important for improving vaccine design as well as furthering our knowledge of antiviral T cell immunology.