IN VIVO ROLE OF CRP IN TRANSGENIC MICE

CRP 在转基因小鼠体内的作用

• 批准号: 3161225
• 负责人: DAVID SAMOLS
• 金额: $ 16.76万
• 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/3161225
• 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）是人类肝脏来源的急性时相蛋白 其血浆浓度显着增加以响应多种 的炎症刺激。 CRP 是一种结合蛋白，当与一个 其配体，已被发现能够激活补体，并且 影响吞噬细胞的功能。 CRP还含有tuftsin样 CRP 肽和蛋白水解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（ 甚至在一些无脊椎动物中也发现），被解释为表明 CRP 具有调节炎症反应的功能。 与大多数脊椎动物相比，小鼠不合成 大量的 CRP 对炎症刺激作出反应。 我们有 利用这种进化的奇怪性并产生了转基因小鼠 能够表达兔 CRP，以确定其功能作用 体内 CRP。 这些动物将被用来评估 三种已建立的小鼠炎症模型中的兔 CRP。 我们将：1) 初步表征我们建立的转基因中 CRP 的特性 鼠标线。 2) 确定病理生理学和形态学效应 转基因CRP对内毒素休克、抗原诱导的急性关节炎和 乳酸杆菌在这些动物中诱发心脏炎。 3) 体内测试 CRP 的磷酸胆碱 (PC) 结合域的重要性，因为 PC 是 CRP 广泛结合的普遍存在的底物。 该域名将是 通过兔 CRP 基因的定点诱变而改变，之后 确认这些突变体无法结合 PC（表达后 在转染的细胞系中），将被用来产生额外的 转基因小鼠。 改变PC结合域的影响 CRP 的功能特性将在 1) 中概述的模型中进行测试 和 2) 以上。