T CELLS IN GRANULOMATOUS IMMUNE RESPONSES

对感染性病原体的早期免疫通常涉及对少数几个免疫优势表位的明确T细胞反应。然而，抗原特异性在慢性炎症部位T细胞聚集中的作用还知之甚少。这项应用的主要目的是了解抗原和T细胞受体特异性在慢性肉芽肿性炎症反应中的作用。由于追踪特定抗原的低频T细胞在技术上具有挑战性，目前还无法获得这一信息。T细胞受体转基因动物及其各自的抗原将被用来克服这一困难。这项技术将帮助我们表征T细胞的表型和功能，这些T细胞是由抗原或通过局部炎症部位内的替代激活途径特异性激活的。我们的模型将是由杜氏利什曼原虫(LCD)诱导的肉芽肿之一，其中T细胞对肉芽肿的形成至关重要。T细胞受体转基因小鼠的T细胞谱系只由两个不同的单特异性T细胞组成，它们将被表达只有一种T细胞识别的表位的重组LCD感染。这些细胞的定位和激活阶段将被测量。这两个转基因T细胞种群将被分类，它们控制寄生虫负载、形成肉芽肿和产生淋巴因子的能力将在过继转移研究中得到测试。这些实验将在野生型过继移植受者身上重复，以检查正常人群中单一特异性T细胞的功能。这些系统将被用来研究免疫对特异性和非特异性T细胞的细胞因子和效应功能的影响。我们的应用程序有三个具体目标。首先，我们将确定感染过程中肉芽肿和免疫外周中抗原特异性和非相关抗原限制性T细胞的比例。(目标1)。接下来，我们将研究这些确定的种群在整个寄生虫感染过程中的功能作用和特征(目标2)。最后，我们将使用疫苗接种来修饰由抗原或通过肉芽肿中的替代激活途径特异性激活的T细胞，以便为寄生虫疾病中的T细胞功能设计新的、精确的靶向疗法(目标3)。我们相信，该研究项目的成功完成将有助于加深对T细胞在肉芽肿性疾病中作用的了解，从而为控制肉芽肿性炎症性疾病(如利什曼病)的新的治疗方法奠定基础。

Early immunity to infectious agents generally involves a very well defined T cell response to a few immunodominant epitopes. However, the role of antigen specificity in T cell accumulation at chronic inflammatory sites is much less understood. The primary goal of this application is to understand the role of antigen and T cell receptor specificity in chronic granulomatous inflammatory reactions. This information is not presently available due to the technically challenging problem of tracing the low frequency T cells specific for a given antigen. T cell receptor transgenic animals and their respective antigens will be used to overcome this difficulty. This technology will help us to characterize the phenotype and function of T cells activated specifically by antigen or through alternative activation pathways within a localized inflammatory site. Our model will be one of granulomas induced by Leishmania chagasi donovani (LCD) where T cells are crucial for granuloma formation. T cell receptor transgenic mice with a T cell repertoire consisting only two different monospecific T cells will be infected with recombinant LCD expressing an epitope recognized by only one kind of the T cells. The localization and activation stages of these cells will be measured. The two transgenic T cell populations will be sorted and their capacity to control parasite load, form granulomas, and produce lymphokines will be tested in adoptive transfer studies. The experiments will be repeated in wild type adoptive transfer recipients to examine the function of the monospecific T cells within a normal population. These systems will be used to study the effects of immunization on cytokine and effector functions of specific and non-specific T cells. There are three Specific Aims for our application. First, we will determine the proportion of antigen-specific and unrelated antigen restricted T cells in granulomas and in the immune periphery during infection. (Aim 1). Next, we will study the functional role and characteristics of these defined populations throughout the parasitic infection (Aim 2). Finally, we will use vaccination to modify the T cells, activated specifically by antigen or through alternative activation pathways in the granulomas in order to design new, precisely targeted therapies for T cell functions in parasitic diseases (Aim 3). We believe that the successful completion of this research project will lead to an improved understanding of the role of T cells in granulomatous diseases and thus provide the foundation for new therapeutic methodologies for controlling granulomatous inflammatory diseases, such as leishmaniasis.