CD43 REGULATION OF IMMUNE RESPONSES

CD43无疑是T细胞表面最丰富的蛋白质之一。然而，关于这种分子的功能，文献中充满了看似矛盾的发现。特别是，CD43被认为既可以作为共刺激分子又可以作为负调节分子。这些相互矛盾的假设是基于观察到交联CD43和CD43缺乏具有相同的净效应。在这两种情况下，T细胞对刺激的反应都增强了。其次，我们发现当T细胞与APC相互作用时，CD43自然被排除在接触部位之外。总之，这些数据支持这样一种假设，即由于CD43的丰度和高度糖基化的性质，它可以作为T细胞相互作用的屏障。我们发现CD43与至少7个磷酸化蛋白相关，其中一个在TCR信号转导中起关键作用。我们相信，了解1)CD43调节的机制，2)由于与CD43调节的细胞质尾部相关而移出相互作用位点的蛋白质，2)由于与CD43调节的细胞质尾部相关而移出相互作用位点的蛋白质，以及3)CD43调节的功能后果，将导致阐明该蛋白在免疫调节中的作用。因此，该建议的中心假设是CD43离开T细胞APC相互作用位点的独特能力是CD43调节T细胞功能的机制。因此，这项拨款的目标是确定分子相互作用的T细胞免疫反应。为了实现这些目标，我们提出以下具体目标：(1)确定CD43的移动是否通过细胞质与细胞骨架的相互作用发生。我们假设一个内/外信号从转染到CD43-/- T细胞，以确定高电荷的细胞外区域CD43和细胞内区域在T细胞- apc相互作用位点CD43的调节中的作用。(2)阐明T细胞- apc相互作用位点参与CD43调控的信号转导通路。我们假设T细胞受体信号通过细胞内蛋白中间体的关联导致CD43的磷酸化和调节。为了验证这一假设，CD43通过调节远离T细胞：APC相互作用位点来影响T细胞反应，并且在此过程中，CD43调节共轭物的形成并特异性地从激活位点移除TCR信号转导分子。为了验证这一假设，我们将通过比较野生型、CD43-/-型和CD43-/-型细胞的功能能力来测试CD43调节对T细胞功能的影响，这些细胞已经被改变了调节能力的突变CD43分子重组。

CD43 is unarguably one of the most abundant proteins on the T cell surface. However, the literature is full of seemingly contradictory findings on the function of this molecule. In particular, CD43 has been proposed to function as both a co-stimulatory molecule and a negative regulating molecule. These contradictory hypotheses are based on the observation that cross-linking CD43 and CD43-deficiency have the same net effect. in both situations the T cells have augmented responses to stimulus. Second, we find that when T cells interact with APC, CD43 is naturally excluded from the contact site. Together, these data support the hypothesis that, due its abundance and highly glycosylated nature, CD43 acts as a barrier to T cell interactions. We have found that CD43 associates at least 7 phosphorylated proteins, one of which is a key player in the TCR signal transduction. We believe that understanding 1) the mechanism of CD43 modulation, 2) the proteins that move out of the interaction site due to their association with the cytoplasmic tail of CD43 modulation, 2) the proteins that move out of the interaction site due to their association with the cytoplasmic tail of CD43, and 3) the functional consequences of CD43 modulation, will lead to the elucidation of the role this protein plays in immune regulation. Thus, the central hypothesis of this proposal is that the unique ability of CD43 to move away from the T cell: APC interaction site is the mechanism by which CD43 regulates T cell function. Therefore, the goal of this grant is to identify the molecular interactions T cell immune responses. To achieve these goals, we propose the following specific aims: (1) Determine whether CD43 movement occurs through cytoplasmic interactions with the cytoskeleton. We hypothesize that an inside/out signal from the transfected into a CD43-/- T cells to determine the role of highly charged extra-cellular region of CD43 and the intracellular region in the modulation of CD43 from the T cell-APC interaction site. (2) To elucidate the signal transduction pathways involved in CD43 modulation from the T cell-APC interaction site. We hypothesize that T cell receptor signaling leads to the phosphorylation and modulation of CD43 via the association of intracellular protein intermediates. To test this hypothesize that CD43 influences T cell responses by modulating away from the T cell: APC interaction site and that in dong so, CD43 regulates conjugate formation and specifically removes TCR signal transduction molecules from the site of activation. To test this hypothesis, the effect of CD43 modulation on T cell function will be tested by comparing the functional capacity of wild type, CD43-/-, and CD43-/- cells that have been reconstituted with mutant CD43 molecules that have altered modulating abilities.