Immune Regulation of Neuronal Injury and Repair

这是一个基于我们发现的abenefal的项目的修订后的竞争续订申请 外周免疫系统在小鼠面部运动神经元(FMN)修复过程中的作用。在 最初的资助期，确定了所涉及的免疫细胞和分子成分：CD4 Th2效应细胞是面神经损伤后FMN存活所必需的，通过抗原依赖的过程 需要外周激活和中枢再激活。脑源性神经营养因子(BDNF)是一种 基本分子。重要的是，对切除轴突的小鼠的淋巴结细胞进行的FACS分析表明 Th1/Th2细胞因子分泌细胞是在周围神经损伤时产生的。功能性 在免疫缺陷小鼠中，挤压伤引起的面瘫的恢复受到损害，但可以 恢复为野生型(WT)并进行免疫重建。据推测，CD4效应性T细胞 在运动神经元修复过程中扮演不同的角色，Tha细胞介导FMN 中枢BDNF依赖的生存过程和Thi细胞介导的功能 通过参与病变部位的促炎反应恢复。4个AIMS将测试这一点 假设。目标1是确定CD4效应器T细胞定位的机制 面神经损伤后的面神经运动核。实验将利用重组的免疫缺陷小鼠 用GFP表达的CD4T细胞，与THI/Th2细胞因子核探针进行SIFU杂交，趋化因子RT- 聚合酶链式反应、趋化因子中和抗体/基因敲除小鼠。目标2是确定机制 面神经损伤后潜在的CD4T细胞介导的FMN存活，并将使用WT和嵌合体 BDNF阴性小鼠检测CD4T细胞来源的BDNF在FMN救援中的作用。目标3是确定 免疫细胞介导的脑运动神经元(FMN)从轴突切断诱导的细胞死亡中的拯救 概括为脊髓型MN。WT、免疫缺陷和重组免疫缺陷小鼠将用于 确定免疫系统对坐骨神经损伤后坐骨神经存活的影响。目标4是 确定THI效应细胞是否参与周围神经损伤后的功能恢复 瘫痪。STAT4、T-bet和STAT6缺陷小鼠将用于选择性重建实验 确定Th1/Th.2效应细胞在运动功能恢复中的作用，通过行为测试进行评估 面部或坐骨神经挤压伤后。免疫系统既有保护性也有破坏性 对神经疾病(如肌萎缩侧索硬化症，一种致命的锰疾病)和/或创伤(如 脊髓损伤)，但这种相互矛盾的行为的监管性质尚未确定。 了解免疫系统如何使受损的神经系统受益，这在 制定有效的治疗策略，以抵消疾病或伤害的进展，减少残疾。

This is a revised competitive renewal application of a project based on our discovery of abeneficial role for the peripheral immune system in mouse facial motoneuron (FMN)reparative processes. In the initial funding period, the immune cellular and molecular components involved were identified:the CD4+ effector Th2 cell is necessary for FMN survival after facial nerve injury, via an antigen-dependent process requiring peripheral activation and central re-activation. & brain-derived neurotrophic factor (BDNF) is an essential molecule. Importantly, FACS analysis of lymph node cells taken from axotomized mice indicates that Thi/Th2 cytokine-secreting cells are generated in response to peripheral nerve injury. Functional recovery from facial paralysis induced by crush injury is impaired in immunodeficient mice, but can be restored to wildtype (WT) with immune reconstitution. It is hypothesizedthat CD4+effector T cells play distinct roles in motoneuron reparative processes, with the Tha cell mediating FMN survival through a central BDNF-dependent process and the Thi cell mediating functional recovery byparticipation in the lesion site pro-inflammatory response. 4 aims will test this hypothesis. Aim #1 is to determine the mechanism underlying CD4+ effector T cell localization within the facial motor nucleus after facial nerve injury. Experiments will utilize immunodeficient mice reconstituted with GFP-expressing CD4+Tcells, in sifu hybridization with Thi/Th2 cytokine riboprobes, chemokine RT- PCR, and chemokine neutralization antibodies/knockout mice. Aim #2.is to determine the mechanism underlying CD4+ T cell-mediated FMNsurvival after facial nerve injury, and will use WT and chimeric BDNF-negative mice to test the role of CD4+T cell-derived BDNF in FMNrescue. Aim #3 is to determineif immune cell-mediated rescue of cranial motoneurons (FMN)from axotomy-induced cell death can be generalized to a spinal MN. WT,immunodeficient,and reconstituted immunodeficientmicewill be used to determine the impact ofthe immune system on sciatic MNviability after sciatic nerve injury. Aim #4 is to determine if the Thi effector cell mediates functionalrecoveryfrom peripheral nerveinjury-induced paralysis. STAT4,T-bet, and STAT6deficient mice will be used with selective reconstitution experiments to determine the role of Thi/Th.2 effector cells in recovery of motor function, assessed with behavioral tests, after a facial or sciatic nerve crush injury. The immune system can have both protective and destructive effects in neural disease (such as amyotrophic lateral sclerosis, a fatal MNdisease) and/or trauma (such as spinal cord injury), but the regulatory nature ofsuch contradictory actions has yet to be determined. Understanding how the immune system benefits the injured nervous system holds great promise in the development of effective treatment strategies to offset disease or injury progression, and reduce disability.