Complement protection and anaphylatoxins in neuroinflammation

描述(申请人提供)：中枢神经系统的炎症通常伴随着补体激活，补体系统与多种疾病有关，如阿尔茨海默病、肌萎缩侧索硬化症和多发性硬化症。我们利用了铜试剂的脱髓鞘-再髓鞘模型，表明补体在脱髓鞘过程中是一个负面因素，然而，缺乏完整的补体系统会显著延迟再髓鞘形成。在脱髓鞘过程中，保护性的Crry蛋白表达减少，而中枢神经系统特异性的可溶性Crry蛋白完全抑制脱髓鞘。这些结果表明，即使在没有抗体参与的中枢神经系统疾病中，补体也是活跃的(就像在Cuprizone模型中一样)。为了进一步阐明补体在神经炎症中的作用，我们建议检验以下假设：(1)过敏性毒素蛋白的产生通过增加小胶质细胞的激活在脱髓鞘过程中发挥关键作用，但这些炎性蛋白是小胶质细胞激活髓鞘所必需的。C3a和C5a都是在补体激活过程中产生的，但无论是单独还是联合分析这些蛋白质的作用是非常困难的。我们已经为中枢神经系统的传递产生了新的病毒结构(腺病毒和慢病毒)，我们有了这些蛋白质受体的基因缺失的小鼠，我们可以用来检验我们的假设。(2)Crry基因表达缺失，在老茧体内创造了促进补体激活的环境，但补体激活减少会导致髓鞘清除丧失和再髓鞘形成延迟。我们的初步数据显示，在铜酮治疗的小鼠中，Cry蛋白显著丢失，中枢神经系统产生一种可溶的Crry蛋白，可防止脱髓鞘。令人惊讶的是，当从饮食中移除铜草酮时，sCrry转基因小鼠在应该重新髓鞘形成的时候发生了脱髓鞘。这些数据表明，原发性脱髓鞘是可以预防的，但补体阻断会对再髓鞘形成产生不利影响。我们将使用病毒传递的可溶性Crry蛋白来测试该蛋白在这个系统中改变局部脱髓鞘和重新髓鞘形成的能力。我们的研究将开始揭示不同的补体蛋白如何在中枢神经系统中相互作用，以调节不同的效应器功能，这些信息对于理解补体如何以及何时可能成为疾病的候选治疗靶点至关重要。有许多疾病的特点是中枢神经系统中的补体激活，包括阿尔茨海默病、肌萎缩侧索硬化症和多发性硬化症。我们正在使用小鼠脱髓鞘和重新髓鞘形成的模型来研究免疫补体在疾病效应阶段的作用。我们独特的模型还允许我们研究人类髓鞘生物学最关键的方面，即重新髓鞘形成过程。

DESCRIPTION (provided by applicant): Inflammation in the central nervous system is often accompanied by complement activation and the complement system has been implicated in diverse disorders such as Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. We have utilized the cuprizone model of demyelination-remyelination and show that complement is a negative factor during demyelination, however lack of an intact complement system significantly delays remyelination. There is decreased expression of the protective Crry protein during demyelination and a CNS specific soluble Crry protein completely inhibits demyelination. These results indicate that complement is active even in CNS diseases without antibody involvement (as is the case in the cuprizone model). In order to further delineate the role of complement in neuroinflammation we propose to test the following hypotheses: (1) The production of anaphylatoxin proteins plays a key role in demyelination through increased microglial activation, but these inflammatory proteins are required for microglial activation required for myelin clearance. Both C3a and C5a are produced during complement activation, yet it is very difficult to dissect the roles these proteins, either alone or in combination. We have generated novel viral constructs (adenoviral and lentiviral) for CNS delivery and we have mice with genetic deletions in the receptors for these proteins that we can use to test our hypothesis. (2) Loss of Crry expression creates an environment in the corpus callosum that facilitates complement activation; yet decreased complement activation leads to loss of myelin clearance and remyelination delay. Our preliminary data have shown significant loss of Crry protein in cuprizone-treated mice and CNS production of a soluble Crry protein prevents demyelination. Surprisingly, when cuprizone is removed from the diet sCrry transgenic mice undergo demyelination when they should be remyelinating. These data show that primary demyelination can be prevented, but there is an adverse affect on remyelination with complement blockade. We will use virally delivered soluble Crry protein to test the ability of the protein to alter local demyelination and remyelination in this system. Our studies will begin to uncover how disparate complement proteins interact in the CNS to mediate different effector functions, information that will be critical for understanding how and when complement might be a candidate therapeutic target in disease. There are a number of diseases that are characterized by complement activation in the CNS including Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. We are using a mouse model of demyelination and remyelination to study the role of immune complement in the effector stage of disease. Our unique model also allows us to study the most critical aspect of myelin biology in the human, namely the remyelination process.