T CELL MATURATION AND LIGAND QUALITY

未能解决传染病，也未能抗击自身免疫 疾病往往是不适当的，而不是不充分的， 免疫反应。因此，疫苗设计的关键是能够 操纵引起的反应的类型。我们正在提议一项全面的 对有助于确定方向的参数进行分析 T细胞细胞因子分泌谱。我们将探讨如何 优势/加密性和可用性/亲和力影响决定因素 展示，以及抗原呈现模式的方式--在 什么菌株，什么细胞因子，通过什么途径--结合起来影响 Th1/Th2选择。免疫优势与Th1/Th2的关系 疾病的选择和诱导或保护？基于我们之前的 决定簇的MHC结合亲和力可以影响T细胞的证据 细胞细胞因子分泌谱，我们将重点介绍抗原的作用 它本身。我们将调节MHC与MHC结合的亲和力 缺乏抗原或主要利什曼原虫和髓鞘碱性蛋白(MBP)， 为了诱导Th1或Th2反应以保护小鼠免受主要乳杆菌的感染 感染或MBP诱导的实验性变态反应性脑脊髓炎(EAE)， 分别进行了分析。MHC结合亲和力、佐剂、 细胞因子环境(包括腺病毒介导的细胞因子基因传递)和 将评估小鼠的遗传背景。我们还将解决其影响 对T细胞谱系进行这样的操作。来自Vbeta单链 针对LACK多肽(161-173)的转基因T细胞，具有 不同的Valpha基因和完全不同的亲缘关系将被选择 并将制备3条新的表达这些TCR的转基因链。我们 将决定高亲和力和低亲和力T细胞是否都有 在高和低MHC存在的情况下影响Th1/Th2选择的能力 亲和配体。无论是高亲和力还是低亲和力，MHC配体的地址 使用免疫镜将确定不同的T细胞群 分析，这允许可视化的T细胞反应基于 不同的CDR3长度。T细胞对亚显性T细胞的作用 反应中的决定因素基于不同的CDR3长度。角色 MBP121-150中一个亚优势决定簇的特异性T细胞 区域，在决定簇传播的早期招募，将被研究。 这一区域由两个重叠的决定因素组成，它们具有 不同的MHC结合亲和力。我们将分析这些是否 决定因素诱导与T细胞具有重叠的共同特异性的T细胞 具有隐私或侧翼特异性的细胞。这项研究将使我们能够 确定MHC亲和力和TCR亲和力在引导 采取保护性而不是进攻性的应对方式。

The failure to resolve infectious diseases as well as to fight autoimmune diseases often results from inappropriate, rather than from insufficient, immune responses. Thus, it is critical for vaccine design to be able to manipulate the type of response induced. We are proposing a comprehensive analysis of parameters that contribute to determining the direction of the T cell cytokine secretion profile. We will explore how dominance/crypticity, and availability/affinity affect determinant display, as well as ways in which the mode of antigenic presentation--in what strain, with what cytokines, by what route--combine to influence Th1/Th2 choice. What is the relationship of immunodominance to Th1/Th2 choice and induction or protection from disease? Based on our previous evidence that MHC-binding affinity of the determinant can impact the T cell cytokine secretion profile, we will focus on the role of antigen itself. We will modulate the MHC-binding affinity of determinants of the LACK antigen or Leishmania major and of myelin basic protein (MBP), in order to induce a Th1 or Th2 response to protect mice from L. major infection or MBP-induced experimental allergic encephalomyelitis (EAE), respectively. The relative importance of MHC-binding affinity, adjuvant, cytokine milieu (including adenovirus-mediated cytokine gene delivery) and mouse genetic background will be assessed. We will also address the impact of such manipulations on the T cell repertoire. From Vbeta single chain transgenic T cells, specific for peptide (161-173) of LACK, T cells with different Valpha genes and of widely disparate affinities will be selected and 3 new transgenic chains will be prepared expressing these TCRs. We will determine whether both high avidity and low avidity T cells have the capacity to affect Th1/Th2 choice in the presence of high and low MHC- affinity ligands. Whether high and low affinity, MHC ligands address distinct populations of T cell swill be determined using immunoscope analysis, which allows visualization of the T cell response based on distinct CDR3 lengths. The role of T cells specific for a subdominant determinant within the responses based on distinct CDR3 lengths. The role of T cells specific for a subdominant determinant within the MBP121-150 region, recruited early during determinant spreading, will be studied. This region consists of two overlapping determinants that possess differential MHC-binding affinities. We will analyze whether these determinants induce T cells of overlapping common specificity versus T cells of private or flanking specificity. This study will allow us to define the relative roles of MHC affinity and TCR avidity in steering the response in a protective versus an aggressive direction.