重症手足口病中Calreticulin介导EV71损伤脑干神经元的机制研究

肠病毒71型（Enterovirus 71, EV71）是引发重症手足口病的最主要病毒。通过病理研究，我们发现EV71感染病例死亡原因为脑干神经元被胶质细胞吞噬而导致的脑干功能衰竭。在原代培养的脑干神经元中，我们已经证实EV71壳蛋白VP1级联激活脑干神经元内质网应激-细胞自噬，引起钙网蛋白（calreticulin, CRT）从神经元内质网转位到细胞膜，增强神经细胞的免疫原性。糖皮质激素可以直接抑制VP1引起的内质网应激从而阻断CRT的转位。据此，我们提出假设：EV71上调细胞表面CRT引起胶质细胞吞噬脑干神经元。本项目将进一步证实EV71感染导致中枢神经系统免疫原性上调的普遍性，获得VP1诱导脑干神经元免疫原性增强的直接证据，并在动物体内验证糖皮质激素保护神经元的机制，为使用糖皮质激素来治疗重症手足口病提供理论依据。

Enterovirus 71 (EV71) is the leading cause of severe hand-foot-and-mouth disease (HFMD). We confirmed that EV71 caused neuronophagia and brain stem failure in the dead cases of severe HFMD. In cultured brainstem neurons, EV71 capsid protein VP1 induced the activation of endoplasmic reticulum stress and autophagy, and following promoted the endoplasmic reticulum-cell membrane translocation of calreticulin (CRT). The cell membrane localized CRT enhanced the immunogenicity of neural cells. Furthermore, we found Glucocorticoids can inhibit VP1 induced endoplasmic reticulum stress and block the translocation of CRT. Based on this, we propose that EV71 increases the cell membrane localized CRT and induces neuronophagia of brainstem neuron. This project will further confirm the prevalence of EV71 infection induced immunogenicity upregulation of the central nervous system, gain the direct evidence of VP1 increases the immunogenicity of brainstem neurons, and validate neuroprotective mechanism of glucocorticoids in vivo, and provide a theoretical basis for the use of glucocorticoids to treat severe HFMD.