T CELL ACTIVATION AND ANERGY INDUCTION BY ANTI-CD3

Bluestone博士的实验室已经开发出一种新型的基于抗CD 3的免疫抑制剂，这种免疫抑制剂可以有效抑制免疫反应，而不会产生与使用常规抗CD 3 mAb治疗相关的严重副作用。新型抗CD 3单克隆抗体似乎通过使致病性Th 1细胞失去活力而诱导免疫耐受，并促进相反的Th 2应答。 生化分析显示，在两个T细胞亚群中的早期TCR信号模式相同，与用改变的肽配体处理的T细胞中观察到的模式相似。 推测失衡的信号是导致T细胞活性差异的原因，并且可能是体内调节T细胞活化和分化的共同机制。 这项研究的目的是确定调节这些过程的信号传导机制。 本研究的第一个目的是使用常规生物化学方法进一步绘制用新型抗CD 3 mAb处理的T细胞中的信号传导异常。待分析的分子包括Ick、fyn、TCR zetu、JNK和p38激酶。 第二个目标是集中在定义的最低信号要求无反应性诱导和Th分化使用遗传学方法。 将上述信号分子的改变形式引入体外T细胞中以阻断或增强个体信号传导途径，并分析这种操作对无反应性诱导或Th分化的影响。 一个新开发的逆转录病毒基因转导系统将被用来将这些基因导入幼稚或克隆的T细胞。 来自这些实验的结果将提供关于差异TCR信号传导的功能结果的信息，这不能使用转化的T细胞系获得。 随着这种新型抗CD-3 mAb进入临床试验，迫切需要了解其体内作用的分子基础。 这些信息对于设计新的更安全和更具体的治疗途径来预防移植排斥和治疗自身免疫性疾病将是非常宝贵的。

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.