Role of Blk in gamma delta T cell development and function

描述(申请人提供)：在所有携带抗原受体的淋巴细胞中，T细胞是最不被了解的。这种差异源于这样一个事实，即T细胞是通过克隆TCR和-基因而不是通过它们的功能特性而被发现的。自二十多年前发现以来，我们已经了解到T细胞识别与T细胞不同的一组抗原，并在免疫中发挥独特的作用，其介导伤口愈合和肿瘤监视的能力就是明证。然而，尽管在T细胞生物学领域取得了这些进展，但T细胞抗原受体(TCR)的结构和信号特性仍然知之甚少。最近，我们对TCR在体外T细胞上的亚单位组成和信号潜力进行了详细的分析。我们发现：(1)TCRs和TCRs的信号转导复合体的亚基组成有显著的不同，TCRs不同于TCRs，缺乏CD3二聚体；(2)从钙动员、ERK激活和细胞增殖的角度来看，TCRs在CD3交联后的信号转导比TCRs更强健。这种意想不到的信号和TCR信号潜力的差异导致了我们对T细胞发育和功能的理解的修订。在这个研究方案中，我们假设观察到的-和TCR信号转导的差异是由于连接到-和TCR的细胞内信号通路的不同。为了研究这一点，我们使用全球基因表达谱来识别在成熟细胞和T细胞群体中差异表达的信号分子。出乎意料的是，我们发现B淋巴样激酶(BLK)是一种通常在B系细胞中表达的Src家族蛋白酪氨酸激酶(PTK)，它在T细胞中表达，但在T细胞中不表达。这项研究计划的目的是确定BLK在T细胞中表达的生物学意义。具体地说，我们将1)表征BLK在系细胞中的表达模式、亚细胞定位和活性；2)分析BLK-/-小鼠系细胞的承诺、发育和效应功能。这项拟议的研究将增加我们对具体管理T细胞发育和功能的过程的了解。此外，这项研究的结果将为未来的研究提供基础，旨在测试Src PTK家族成员在And和T细胞中表达的这种质的差异是否有助于提高TCR的信号熟练程度。公共卫生相关性：预计这项研究将提供有关T细胞的重要信息。这些知识将有助于设计疫苗，旨在通过专门针对T细胞来提高对肿瘤细胞和病原体的抵抗力。

DESCRIPTION (provided by applicant): Of all the lymphocytes bearing antigen receptors, T cells are the least understood. This disparity stems from the fact that T cells were discovered by the cloning of the TCR and - genes and not by their functional properties. Since their discovery over two decades ago, we have learned that T cells recognize a different set of antigens than T cells and play unique roles in immunity, as evidenced by their ability to mediate wound healing and tumor surveillance. However, despite these advances in the area of T cell biology, the structure and signaling properties of the T cell antigen receptor (TCR) remain poorly understood. Recently, we performed a detailed analysis of the subunit composition and signaling potential of the TCR on ex vivo T cells. We found: (1) a striking difference in the subunit composition of the signal-transducing complexes of the - and TCRs, in that TCRs, unlike TCRs, lack CD3 dimers and (2) signal transduction by the TCR to be more robust than that of the TCR after CD3 crosslinking as measured by calcium mobilization, ERK activation and cellular proliferation. This unexpected difference in - and TCR signaling potential has resulted in a revision in our understanding of T cell development and function. In this research proposal, we hypothesize that the observed differences in - and TCR signal transduction are due to differences in the intracellular signaling pathways coupled to the - and TCRs. To investigate this, we employed global gene expression profiling to identify signaling molecules that are differentially expressed in mature and T cell populations. Unexpectedly, we found that B lymphoid kinase (Blk), a Src family protein tyrosine kinase (PTK) normally expressed in B lineage cells, is expressed in T cells but not in T cells. The goal of this research proposal is to determine the biological significance of Blk expression in T cells. Specifically, we will 1) characterize the expression pattern, subcellular localization, and activity of Blk in lineage cells and 2) analyze commitment, development and effector function of lineage cells in blk-/- mice. The proposed study will increase our knowledge of the processes that specifically govern the development and function of T cells. In addition, the results from this investigation will provide a foundation for future studies aimed at testing whether this qualitative difference in the expression of Src PTK family members in and T cells contributes to the enhanced signaling proficiency of the TCR. Public Health Relevance: It is expected that this study will provide important information about T cells. This knowledge will aid in the design of vaccines aimed at improving resistance to tumor cells and pathogens by specifically targeting T cells.