EV71感染所引起的CNS中免疫反应与神经内分泌系统相互作用在病毒致病过程中的机理研究

The recent clinical study of human hand-foot-mouth disease (HFMD) induced by EV71 infection indicated that the pathogenesis of HFMD severe/death cases induced by EV71 infection presented the brainstem-encephalitis of viral infection followed by pulmonary edema/cardiofailure. The pathophysiological role of later was confirmed as a chaotic process of neuroendocrine in central nerves system (CNS) induced by viral infection, which is related to hypothalamic-pituitary-adrenal axis. Our previous work suggested that the dynamic process of EV71 infection in CNS based on its proliferation in astrocytes, a key component to regulate neuron function and to perform immune response in CNS. In this case, this reasearch, based upon culture system and animal models of EV71 infection established in our lab, will investigate the biological role of astrocytes infected by EV71 and its impact through modified cytokine profile to neuroendocrine. The work in this study also focus on the interaction between immune response performed by infected astrocyte and neuroendocrine, and the biological effect of this interaction in CNS to hypothalamic-pituitary-adrenal axis. This work wish to trace a possible pathogenesis of EV71 infection in CNS and its followed pulmonary edema/cardiofailure presented in clinical process.

现有的临床研究表明，EV71感染所致的手足口病（HFMD）重症及死亡病例的病理特征是中枢神经系统（CNS）的炎症反应和由此引起神经源性肺水肿和/或心肺功能衰竭，而后者作为临床表症的病理生理机制是基于病毒感染而导致的神经内分泌系统失控，我们的前期工作提示，EV71进入CNS后的感染动力学过程很可能与星状胶质细胞这个联系神经系统功能和免疫反应的关键环节相关。因此，本研究拟利用EV71的体外组织培养系统及动物模型系统，主要探索EV71在感染CNS过程中，病毒在星状胶质细胞中增殖导致的星状胶质细胞生物学性状的变化的规律，及其所引起的，CNS中免疫反应与神经内分泌系统相互作用的生物学特征，并确定这一相互作用是否是导致CNS中下丘脑-垂体-肾上腺轴自主性神经系统（ANS）功能失控的病理机制，及其引起心肺系统出现相应功能紊乱临床表现的原因。

EV71 感染所致的手足口病（HFMD）重症及死亡病例的病理特征是中枢神经系统（CNS）的炎症反应和由此引起神经源性肺水肿和/或心肺功能衰竭，而后者作为临床表症的病理生理机制是基于病毒感染而导致的神经内分泌系统失控。本研究利用体外组织培养系统，完成恒河猴脑干、海马部位星状胶质细胞的体外分离及培养，并发现EV71病毒能够感染星状胶质细胞并在其中增殖，形成明显的S型病毒一步生长曲线，PCR检测到明显的病毒负链RNA合成，同时采用荧光显微镜和电镜均也可以观察到增多的绿色荧光病毒和晶格排列状的病毒颗粒。并且，EV71感染星状胶质细胞后会引起多种细胞因子变化，其中最显著的就是IL-6和IL-8水平上升；同时也可检测到肾上腺素和去甲肾上腺素显著变化，而多巴胺表达水平未出现显著改变。这些结果均与感染病毒恒河猴的脑组织匀浆液和外周血中相同物质的变化趋势一致。另外，我们针对IL-6、IL-8及肾上腺素对EV71感染小鼠的致病情况进行了深入研究，发现在EV71感染同时给予IL-6、IL-8处理的小鼠，可增大其血脑屏障的开放程度；IL-6和肾上腺素处理的小鼠更容易感染EV71病毒，并出现更大量的死亡。这些研究从丘脑-垂体-肾上腺轴自主性神经系统（ANS）功能失控的角度揭示了EV71的致病机制，对后续研究有启发作用。