IGE CONTROL BY OVEREXPRESSION OF CD23

通过 CD23 过度表达来控制 IGE

• 批准号: 6632160
• 负责人: DANIEL H CONRAD
• 金额: $ 26.22万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6632160
• 关键词: B lymphocyte; CD antigens; CHO cells; antibody formation; antibody receptor; dendritic cells; gene expression; genetically modified animals; immunoglobulin E; laboratory mouse; tissue inhibitor of metalloproteinases

DESCRIPTION (Adapted from Investigator's Abstract): Evidence is presented induces lower IgE production in an in vivo transgenic mouse model. In addition, a new method has been developed to induce higher levels of CD23 by inhibiting the metalloprotease involved in CD23 breakdown. The studies proposed will extend these findings. Additional CD23 transgenic animals have been prepared in which the increased CD23 expression is on B cells; these animals will continue to be evaluated for their IgE responses to antigen and parasite regimens, including both extra- and intracellular parasite infections. The cytokine profiles of these animals will be determined with respect to relative Th1 vs. Th2 predominance. Since the initial findings indicate that the membrane form of CD23 is the active agent, the initial proteolytic site on CD23 has been mutated and the mutant CD23 has been shown to bind IgE with the same affinity as the parental form, but is resistant to being cleaved from the surface. Transgenic animals bearing the mutant CD23 will be prepared and analyzed as with the current CD23 transgenics. The mechanism via which the metalloprotease inhibitors influence IgE synthesis will be studied. In vitro experiments will determine if other Ig classes are inhibited at the same level and whether the elevated CD23 induces selective apoptosis of switched cells. In addition, the efficacy of these inhibitors in in vivo models will be determined; this is important with respect to determination of whether these agents have potential as anti-allergic drugs. In the third aim, the influence of the follicular dendritic cells (FDC) on IgE production will be determined by using a modification of the in vitro model used in Aim 2. FDCs from CD23 transgenic animals will be isolated and cultured with normal B cells and the IgE levels obtained will be compared to that obtained with B cells cultured with FDCs from normal controls. In the fourth aim, an analogous co-culture model using human CD23 expressing CHO cells as well as a newly developed sCD23 with full IgE binding capacity will be evaluated using the in vitro human PBL model again examining the influence of high CD23 on B cell proliferation and IgE production with the eventual aim of developing a system for control of human IgE production.

描述（改编自研究者摘要）：提供证据 在体内转基因小鼠模型中诱导较低的IgE产生。此外，本发明还提供了一种方法， 已经开发了一种新的方法来诱导更高水平的CD 23， 参与CD 23分解的金属蛋白酶。拟议的研究将 扩展这些发现。已经制备了另外的CD 23转基因动物， 其中增加的CD 23表达在B细胞上;这些动物将继续 为了评估它们对抗原和寄生虫方案的IgE应答， 包括细胞外和细胞内寄生虫感染。细胞因子 将确定这些动物的相对Th 1与 Th 2优势。由于最初的研究结果表明， CD 23是活性剂，CD 23上的初始蛋白水解位点已经突变 并且突变的CD 23已经显示以与突变的CD 23相同的亲和力结合IgE。 亲本形式，但对从表面裂解具有抗性。转基因 将制备携带突变型CD 23的动物，并与 目前的CD 23转基因。金属蛋白酶 将研究抑制剂影响IgE合成。体外实验将 确定其他IG类是否在相同水平被抑制，以及 升高的CD 23诱导转换细胞的选择性凋亡。此外该 将测定这些抑制剂在体内模型中的功效;这是 对于确定这些试剂是否具有潜在 作为抗过敏药物。在第三个目标中，卵泡的影响 树突状细胞（FDC）对IgE产生的影响将通过使用 目标2中使用的体外模型的修改。来自CD 23转基因的FDC 将动物分离并与正常B细胞一起培养， 将获得的结果与用来自以下的FDC培养的B细胞获得的结果进行比较： 正常对照者在第四个目标中，使用人类的类似共文化模型， 表达CD 23的CHO细胞以及新开发的具有完整IgE的sCD 23 将再次使用体外人PBL模型评价结合能力 检测高CD 23对B细胞增殖和IgE产生的影响 其最终目的是开发一种用于控制人IgE的系统 生产