C-reactive Protein, Autoimmunity, and Inflammation in the Central Nervous System

描述(由申请人提供)：人类C反应蛋白是一种急性期蛋白，其血液浓度因炎症侮辱而急剧上升。虽然CRP主要起源于肝脏，但在中枢神经系统炎症期间，它也由神经元产生。C反应蛋白在中枢神经系统炎症中的作用以及神经性C反应蛋白的生物学重要性尚不清楚。我们实验室发表的工作表明，携带人CRP转基因(CRPtg)的小鼠可以免受髓鞘少突胶质细胞糖蛋白(MOG)多肽诱导的实验性自身免疫性脑脊髓炎(EAE)的保护，EAE是多发性硬化症(MS)的啮齿动物模型。通过转基因或注射方式表达的人CRP可以延缓EAE的发病并减轻其严重程度，这些作用依赖于Fc？RIIb的表达。我们发现转基因或注射人CRP不能改善Fc？RIIb-/-小鼠的EAE。对人类C反应蛋白有反应的表达Fc？RIIb的细胞仍不清楚。本研究的目的是(1)确定表达Fc？RIIb的细胞，CRP通过该细胞对EAE起保护作用；(2)确定CNS特异性表达的人CRP是否足以保护小鼠免受EAE的影响。我推测，CRP通过与树突状细胞(DC)上的Fc？RIIb结合来实现对EAE的改善，而局部中枢表达CRP就足以达到这一效果。利用纯化的人CRP，我将分析小鼠骨髓来源的DC对Fc？RIIb的充足或不足，以确定CRP是否改变了它们在病毒中的激活状态，以及是否有任何CRP驱动的作用依赖于Fc？RIIb。由于EAE/MS被认为是一种T细胞介导的疾病，我将研究CRP对DC刺激T细胞增殖和 DC的体外极化：以野生型和Fc？RIIb缺陷的DC为抗原提呈细胞的T细胞共培养。我还将在人源化小鼠(表达人CRP并在树突状细胞上表达人Fc？RIIb，但不表达人Fc？RIIb的小鼠)诱导EAE，以研究Fc？RIIb-&gt；DC轴是否足以用于CRP介导的EAE的改善。为了评估区议会的需求，我会在有选择地耗尽区议会的CRPtg中诱发EAE。最后，使用人类CRP表达仅限于神经元的小鼠，我将确定仅表达CNS的人CRP是否足以保护小鼠免受EAE的影响。我将在nCRPtg诱导EAE，并将他们的疾病与CRPtg和WT小鼠进行比较。成功地进行本文所述的工作将确定发挥保护作用的CRP的效应细胞 在EAE中，确认人CRP-&gt；人Fc？RIIb轴在体内工作，并阐明保护性CRP的来源。这将为新疗法的开发铺平道路，使大约350,000名患有多发性硬化症的美国公民受益。

DESCRIPTION (provided by applicant): Human C-reactive protein is an acute phase protein whose blood concentrations rise dramatically in response to inflammatory insults. Though CRP is primarily of hepatic origin, it is also produced by neurons during times of CNS inflammation. CRP's contribution to CNS inflammation and the biological importance of neuronal CRP are unknown. Published work from our lab shows that mice containing the human CRP transgene (CRPtg) are protected from myelin oligodendrocyte glycoprotein (MOG) peptide induced experimental autoimmune encephalomyelitis (EAE), a rodent model of Multiple Sclerosis (MS). Human CRP, expressed transgenically or administered by injection, delays onset and reduces severity of EAE, and these effects rely on expression of Fc?RIIB. We showed that transgenic or injected human CRP is unable to ameliorate EAE in Fc?RIIB-/- mice. The Fc?RIIB-expressing cell that responds to human CRP remains unknown. The goals of this research project are (1) to determine the Fc?RIIB expressing cell through which CRP exerts protection against EAE and (2) to determine if CNS specific expression of human CRP is sufficient to protect mice from EAE. I hypothesize that CRP mediated amelioration of EAE is manifest via CRP binding to Fc?RIIB on dendritic cells (DCs), and that local CNS expression of CRP is sufficient to achieve this benefit. Utilizing purified human CRP, I will analyze bone marrow derived DCs from mice either sufficient or deficient for Fc?RIIB to determine if CRP alters their activation status in viro and if any CRP driven effect depends upon Fc?RIIB. Since EAE/MS is considered to be a T cell mediated disease, I will examine CRP's effect on DCs' ability to stimulate T cell proliferation and polarization in vitro in DC:T cell co-cultures using wildtype versus Fc?RIIB deficient DCs as antigen (MOG) presenting cells. I will also induce EAE in humanized mice (mice that express human CRP and express human Fc?RIIB exclusively on DCs, but no mouse Fc?RIIB) to investigate if the Fc?RIIB->DC axis is sufficient for CRP mediated amelioration of EAE. To assess the requirement of DCs, I will induce EAE in CRPtg in which DCs have been selectively depleted. Finally, using mice wherein human CRP expression is limited to neurons I will determine if exclusively CNS expression of human CRP is sufficient to protect mice from EAE. I will induce EAE in nCRPtg and compare their disease to CRPtg and WT mice. Successful pursuit of the work described herein will identify the effector cell by which CRP exerts protection in EAE, confirm that a human CRP->human Fc?RIIB axis operates in vivo, and elucidate the source of protective CRP. This will pave the way for development of new therapies that will benefit the ~350,000 U.S. citizens with MS.