Role of SHP-1 in T cell activation and development

描述（由申请人提供）：SHP-1是一种主要在造血细胞中表达的蛋白酪氨酸磷酸酶，其与细胞因子、生长因子和抗原诱导的信号传导事件的负调节有关。小鼠SHP-1基因突变导致蛾化（me/me）表型。对于me等位基因纯合的小鼠，其导致不存在任何可检测的SHP-1蛋白，在所有造血谱系中显示出多种病症，导致出生后约两至三周死亡。这些小鼠提供了一个有价值的工具，结合联合收割机在体外生物化学测定与体内和离体生物学研究。我们的长期目标是了解SHP-1如何影响造血细胞的生长和分化。本提案将试图阐明SHP-1参与未成熟，成熟和调节T细胞的发育和功能，使用生物学和生物化学的方法相结合。我们已经表明，一个亚群的SHP-1定位于脂筏，这种定位是功能相关的TCR信号。然而，靶向SHP-1的模式尚不清楚。目的1的目标是确定驱动脂筏定位的SHP-1的分子机制和脂筏定位的功能意义：我们的初步研究表明，SHP-1缺陷小鼠的胸腺和脾脏中的CD 4 + CD 25+调节性T细胞的数量增加。在目的2中，我们提出检验SHP-1影响CD 4 + CD 25 + Treg细胞功能的假设。我们将使用体外和体内测定来检查SHP-1缺陷型Treg细胞的抑制潜力的强度和持续时间，以及SHP-1在Treg细胞的细胞内信号传导中的作用。在目标3中，我们将测试T细胞对SHP-1的内在需求，以及缺乏SHP-1活性的其他造血谱系对调节性T细胞群的产生/扩增的作用。我们将使用携带转基因的小鼠来诱导和组织特异性表达显性阴性SHP-1突变体来解决这些问题。总之，这里提出的研究应该让我们更好地了解SHP-1和TCR信号。此外，我们期望更好地了解影响CD 4 + CD 25 + Treg细胞发育和功能的因素，重点关注SHP-1在这些过程中的作用。

DESCRIPTION (provided by applicant): SHP-1 is a protein tyrosine phosphatase expressed predominantly in hematopoietic cells where it has been linked to negative regulation of signaling events induced by cytokines, growth factors and antigens. Mutations in the SHP-1 gene in mice cause the motheaten (me/me) phenotype. Mice homozygous for the me allele, which results in the absence of any detectable SHP-1 protein, display a variety of disorders in all hematopoietic lineages resulting in death about two to three weeks after birth. These mice provide a valuable tool to combine in vitro biochemical assays with in vivo and ex vivo biological studies. Our long term goal is to understand how SHP-1 influences the growth and differentiation of hematopoietic cells. This proposal will attempt to elucidate the involvement of SHP-1 in immature, mature and regulatory T cell development and function using a combination of biological and biochemical approaches. We have shown that a subpopulation of SHP-1 localizes to lipid rafts and that this localization is functionally relevant for TCR signaling. However, the mode of targeting SHP-1 is not known. The goal of Aim 1 is to determine the molecular mechanism driving lipid rafts localization of SHP-1 and the functional implications of lipid rafts localization: Our preliminary studies suggest that mice deficient in SHP-1 show increased numbers of CD4+CD25+ regulatory T cells in the thymus and spleen. In Aim 2, we propose to test the hypothesis that SHP-1 affects the function of CD4+CD25+ Treg cells. We will examine the strength and duration of the suppressive potential of SHP-1-deficient Treg cells using in vitro and in vivo assays, the role of SHP-1 in intracellular signaling of Treg cells. In Aim 3, we will test the T cell intrinsic requirement for SHP-1, and the role of other hematopoietic lineages deficient in SHP-1 activity on the generation/expansion of a regulatory T cell population. We will use mice carrying transgenes for inducible and tissue-specific expression of dominant negative SHP-1 mutants to address these questions. Taken together, the studies proposed here should give us a better understanding of the SHP-1 and TCR signaling. In addition, we expect to gain a better understanding of factors that influence the development and function of CD4+CD25+ Treg cells with a focus on the role of SHP-1 during these processes.