T CELL ACTIVATION AND ANERGY INDUCTION BY ANTI-CD3

Blustone博士的实验室已经开发出一种新型的基于抗CD3的免疫抑制剂，这种药物可以有效地抑制免疫反应，而不会出现与使用传统的抗CD3单抗疗法相关的严重副作用。新的抗CD3单抗似乎通过对抗致病的Th1细胞而诱导免疫耐受，并促进相反的Th2反应。生化分析显示，两个T细胞亚群的早期TCR信号模式相同，类似于用改变的多肽配体处理的T细胞。据推测，信号不平衡是导致T细胞活性差异的原因，可能是体内调节T细胞活化和分化的共同机制。这项拟议的研究的目标是定义调节这些过程的信号机制。本研究的第一个目的是用常规的生化方法进一步研究新型抗CD3单抗处理的T细胞的信号异常。待分析的分子包括Ick、Fyn、TCR zetu、JNK和p38激酶。第二个目标是利用遗传方法确定无能诱导和Th分化的最小信号需求。上述信号分子的改变形式将在体外被引入T细胞，以阻断或增强个别信号通路，并将分析这种操纵对无能诱导或Th分化的影响。一种新开发的逆转录病毒基因转导系统将被用于将这些基因导入幼稚或克隆的T细胞。这些实验的结果将提供关于差异TCR信号的功能结果的信息，这是使用转化的T细胞株无法获得的。随着这类新的抗CD-3单抗进入临床试验，迫切需要了解其体内作用的分子基础。这些信息在设计新的更安全、更具体的治疗途径以防止移植排斥反应和治疗自身免疫性疾病方面将是非常宝贵的。

Dr. Bluestone's laboratory has developed a novel class of anti-CD3-based immunosuppressant that was effective at suppressing immune response without the severe side effects associated with the use of conventional anti-CD3 mAb therapy. The novel anti-CD3 mAbs appear to induce immune tolerance by anergizing the pathogenic Th1 cells, and promote the opposing Th2 response. Biochemical analysis showed identical early TCR signaling patterns in both subsets of T cells similar to that observed in T cells treated with altered peptide ligands. It is hypothesized that imbalanced signal is responsible for the differential activity and may be a common mechanism to regulate T cell activation and differentiation in vivo. The goal of this proposed study is to is to define the signaling mechanisms that regulate these processes. The first aim of this study is to further map signaling abnormality in T cells treated with the novel anti-CD3 mAb using conventional biochemical approaches. The molecules to be analyzed include Ick, fyn, TCR zetu, JNK, and p38 kinase. The second aim is focused on defining the minimal signaling requirements for anergy induction and Th differentiation using genetic approaches. Altered forms of the above signaling molecules will be introduced into T cells in vitro to either block or enhance individual signaling pathways and effects of such manipulation on anergy induction or Th differentiation will be analyzed. A newly developed retroviral gene transduction system will be used to introduce these genes into either naive or cloned T cells. The results from these experiments will provide information on the functional outcome of differential TCR signaling, which cannot be obtained using transformed T cell lines. As this novel class of anti-CD-3 mAb moves into clinical trials, there is an urgent need to understand the molecular basis of its in vivo effect. The information will be invaluable in designing new safer and more specific therapeutic avenues for preventing transplant rejection and treating autoimmune disorders.