T CELLS IN GRANULOMATOUS IMMUNE RESPONSES

对感染因子的早期免疫通常涉及对少数免疫显性表位的非常明确的T细胞应答。然而，抗原特异性在慢性炎症部位的T细胞积聚中的作用却知之甚少。 本申请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。 由于追踪对给定抗原特异的低频T细胞的技术挑战性问题，目前无法获得该信息。 T细胞受体转基因动物及其各自的抗原将被用于克服这一困难。 该技术将帮助我们表征由抗原特异性激活的T细胞的表型和功能，或通过局部炎症部位内的替代激活途径。 我们的模型将是一个肉芽肿诱导的恰加斯杜氏利什曼原虫（LCD），其中T细胞是至关重要的肉芽肿形成。具有仅由两种不同的单特异性T细胞组成的T细胞库的T细胞受体转基因小鼠将被表达仅由一种T细胞识别的表位的重组LCD感染。 将测量这些细胞的定位和活化阶段。 将对两种转基因T细胞群进行分选，并在过继转移研究中检测其控制寄生虫负荷、形成肉芽肿和产生淋巴因子的能力。 将在野生型过继转移受体中重复实验以检查正常群体内单特异性T细胞的功能。这些系统将用于研究免疫对特异性和非特异性T细胞的细胞因子和效应子功能的影响。我们的申请有三个具体目标。 首先，我们将确定抗原特异性和无关的抗原限制性T细胞在肉芽肿和感染过程中的免疫外周的比例。(Aim 1）。 接下来，我们将研究这些定义的人群在整个寄生虫感染过程中的功能作用和特征（目的2）。 最后，我们将使用疫苗接种来修饰T细胞，通过抗原特异性激活或通过肉芽肿中的替代激活途径来设计新的，精确靶向的寄生虫病T细胞功能疗法（目的3）。 我们相信，该研究项目的成功完成将导致更好地了解T细胞在肉芽肿性疾病中的作用，从而为控制肉芽肿性炎症性疾病（如利什曼病）的新治疗方法提供基础。

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.