Role of Blk in gamma delta T cell development and function

描述（由申请人提供）：在所有携带抗原受体的淋巴细胞中，T细胞是了解最少的。这种差异源于这样一个事实，即T细胞是通过克隆TCR和-基因而不是通过其功能特性发现的。自从二十多年前发现它们以来，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，正如它们介导伤口愈合和肿瘤监视的能力所证明的那样。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）的结构和信号传导特性仍然知之甚少。最近，我们进行了一个详细的分析的亚基组成和信号转导潜力的TCR离体T细胞。我们发现：（1）TCR和TCR的信号转导复合物的亚基组成的显著差异，因为TCR与TCR不同，缺乏CD 3二聚体，和（2）如通过钙动员、ERK活化和细胞增殖测量的，在CD 3交联后，TCR的信号转导比TCR的信号转导更稳健。这种意想不到的差异-和TCR信号转导潜力导致了我们的T细胞发育和功能的理解修订。在这项研究建议中，我们假设所观察到的差异和TCR信号转导是由于细胞内信号通路的差异耦合到的和TCR。为了研究这一点，我们采用了全球基因表达谱来鉴定在成熟和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），一种通常在B谱系细胞中表达的Src家族蛋白酪氨酸激酶（PTK），在T细胞中表达，但在T细胞中不表达。本研究的目的是确定Blk在T细胞中表达的生物学意义。具体而言，我们将1）表征Blk在谱系细胞中的表达模式、亚细胞定位和活性，以及2）分析blk-/-小鼠中谱系细胞的定型、发育和效应子功能。这项拟议的研究将增加我们对专门控制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T细胞中表达的这种定性差异是否有助于增强TCR的信号传导能力。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，旨在通过特异性靶向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.