IGE CONTROL BY OVEREXPRESSION OF CD23

通过 CD23 过度表达来控制 IGE

基本信息

批准号：
2909174
负责人：
DANIEL H CONRAD
金额：
$ 25.11万
依托单位：
VIRGINIA COMMONWEALTH UNIVERSITY
依托单位国家：
美国
项目类别：
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/2909174
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

项目摘要

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，开发出一种新方法，通过抑制 CD23 诱导更高水平的 CD23 参与 CD23 分解的金属蛋白酶。拟议的研究将扩展这些发现。另外的 CD23 转基因动物已在其中CD23表达增加是在B细胞上；这些动物将继续评估其对抗原和寄生虫疗法的 IgE 反应，包括细胞外和细胞内寄生虫感染。细胞因子这些动物的概况将根据相对 Th1 与 Th1 来确定。 Th2 占优势。由于最初的发现表明膜的形式 CD23是活性剂，CD23上的初始蛋白水解位点已突变突变体 CD23 已被证明能以与 IgE 相同的亲和力结合亲本形式，但能抵抗从表面分裂。转基因携带突变型 CD23 的动物将按照与当前的 CD23 转基因。金属蛋白酶的作用机制将研究抑制剂对 IgE 合成的影响。体外实验将确定其他 Ig 类别是否受到相同水平的抑制以及是否 CD23 升高诱导转换细胞选择性凋亡。此外，将确定这些抑制剂在体内模型中的功效；这是对于确定这些药物是否具有潜力很重要作为抗过敏药物。第三个目标是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 CD23 转基因的 FDC 动物将被分离并与正常 B 细胞和 IgE 水平一起培养将获得的结果与用 FDC 培养的 B 细胞获得的结果进行比较正常控制。在第四个目标中，使用人类的类似共培养模型表达 CD23 的 CHO 细胞以及新开发的具有完整 IgE 的 sCD23 将再次使用体外人体 PBL 模型评估结合能力检查高 CD23 对 B 细胞增殖和 IgE 产生的影响最终目标是开发一个控制人类 IgE 的系统生产。