IN VIVO ROLE OF CRP IN TRANSGENIC MICE

CRP 在转基因小鼠体内的作用

• 批准号: 3161223
• 负责人: DAVID SAMOLS
• 金额: $ 15.5万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3161223
• 关键词: acute phase protein; allergic arthritis; amyloid proteins; bacterial endocarditis; binding proteins; biological models; chemical binding; complement pathway; enzyme linked immunosorbent assay; gene expression; genetically modified animals; histochemistry /cytochemistry; inflammation; laboratory mouse; molecular site; phosphorylcholine; protein structure function; site directed mutagenesis; tissue /cell culture; transfection

C-reactive protein (CRP) is an acute phase protein of hepatic origin in man whose plasma concentration increases markedly in response to a wide variety of inflammatory stimuli. CRP is a binding protein which, when bound to one of its ligands, has been found capable of activating complement, and affecting the function of phagocytic cells. CRP also contains tuftsin-like peptides and proteolytic fragments of CRP can stimulate inflammatory cells. These properties along with evolutionary conservation of the protein (which is even found in some invertebrates), have been interpreted as indicating that CRP functions to modulate the inflammatory response. The mouse, in contrast to most vertebrates, does not synthesize a significant quantity of CRP in response to inflammatory stimuli. We have taken advantage of this evolutionary oddity and produced transgenic mice capable of expressing rabbit CRP in order to define the functional role of CRP in vivo. These animals will be employed to assess the effects of rabbit CRP in three established mouse models of inflammation. We will: 1) Initially characterize the properties of CRP in our established transgenic mouse lines. 2) Determine the pathophysiologic and morphologic effects of transgenic CRP on endotoxic shock, antigen-induced acute arthritis and Lactobacillus induced carditis in these animals. 3) Test the in vivo importance of the phosphorylcholine (PC) binding domain of CRP since PC is a ubiquitous substrate to which CRP binds avidly. This domain will be altered by site directed mutagenesis of the rabbit CRP gene and, after confirmation that these mutants are unable to bind PC (following expression in transfected cell lines), will be employed to produce additional transgenic mice. The effects of altering the PC binding domain on the functional properties of CRP will be tested in the models outlined in 1) and 2) above.

C-反应蛋白(Crp)是人类肝脏来源的一种急性时相蛋白。 其血浆浓度显著升高，以应对广泛的变化 炎性刺激。C反应蛋白是一种结合蛋白，当结合到一个 在其配体中，已发现能够激活补体，以及 影响吞噬细胞功能的。C反应蛋白还含有类Tuftsin C反应蛋白的多肽和蛋白水解物片段可以刺激炎症细胞。 这些特性以及蛋白质的进化保守性(即 甚至在一些无脊椎动物中发现)，被解释为表明 C反应蛋白起调节炎症反应的作用。 与大多数脊椎动物不同的是，老鼠不会合成 炎症刺激反应中大量的C反应蛋白。我们有 利用这一进化上的奇特之处，产生了转基因小鼠 能够表达兔C反应蛋白以确定其功能作用 体内的C反应蛋白。这些动物将被用来评估 兔C反应蛋白在三种已建立的小鼠炎症模型中。我们将：1) 我们已建立的转基因技术中C反应蛋白特性的初步表征 老鼠线。2)确定细胞的病理生理和形态效应 转基因CRP对内毒素休克、抗原性急性关节炎的治疗作用 乳酸菌在这些动物中引起了心脏炎。3)体内测试 C反应蛋白的磷酰胆碱(PC)结合域的重要性因为PC是 一种无处不在的底物，CRP强烈地与其结合。这个域名将是 通过兔CRP基因的定点突变而改变，并在 确认这些突变体不能结合PC(如下表达式 在转基因细胞系中)，将被用来生产额外的 转基因小鼠。改变PC结合域对细胞周期的影响 将在1)中概述的模型中测试CRP的功能属性 和2)以上。