IGE CONTROL BY OVEREXPRESSION OF CD23

通过 CD23 过度表达来控制 IGE

• 批准号: 6511121
• 负责人: DANIEL H CONRAD
• 金额: $ 25.45万
• 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 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6511121
• 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《调查者摘要》)：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, 一种新的方法已经被开发出来，通过抑制抑制来诱导更高水平的CD23 金属蛋白酶参与了CD23的降解。建议的研究将 扩展这些发现。其他CD23转基因动物已在 CD23在B细胞上的表达增加；这些动物将继续 以评估他们对抗原和寄生虫方案的IgE反应， 包括胞外和胞内寄生虫感染。细胞因子 这些动物的概况将根据相对Th1和Th1确定。 Th2占优势。因为初步的发现表明，膜的形式 CD23是活性物质，CD23的起始蛋白水解点发生了突变 突变体CD23已被证明与IgE结合的亲和力与 亲本形式，但抵抗从表面分裂。转基因 携带突变CD23的动物将被制备和分析，就像 目前的CD23转基因。金属蛋白酶的作用机制 影响IgE合成的抑制剂将被研究。体外实验将会 确定是否在相同级别禁止其他Ig类，以及是否 CD23表达升高可诱导开关细胞选择性凋亡。此外， 这些抑制剂在体内模型中的有效性将被确定；这是 对于确定这些药剂是否具有潜力很重要 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 AIM体外模型的改进--2.CD23转基因FDC 动物将被隔离并与正常的B细胞和IgE水平一起培养 将获得的结果与B细胞与来自 正常对照组。在第四个目标中，建立了一个类似的人类共培养模型 表达CD23的CHO细胞及新研制的全长IgE的sCD23 结合能力将再次使用体外人外周血淋巴细胞模型进行评估 检测高CD23对B细胞增殖和IgE产生的影响 最终目标是开发一种控制人类IgE的系统 制作。