Involvement of Ceramide in the Propagation of Japanese Encephalitis Virus
Involvement of Ceramide in the Propagation of Japanese Encephalitis Virus
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DOI：
10.1128/jvi.02499-09
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发表时间：
2010-03-01
影响因子：
5.4
通讯作者：
Matsuura, Yoshiharu
中科院分区：
文献类型：
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作者：
Tani, Hideki;Shiokawa, Mai;Matsuura, Yoshiharu
日本脑炎病毒（Japanese encephalitis virus，JEV）是一种蚊媒RNA病毒，是医学和兽医学领域最重要的黄病毒之一。虽然胆固醇已被证明参与JEV的进入和复制步骤，但感染机制，包括JEV的细胞受体，在很大程度上仍然未知。为了阐明JEV的感染机制，我们产生了携带JEV包膜蛋白的假型（JEVpv）和重组（JEVrv）水泡性口炎病毒。JEVpv和JEVrv对靶细胞都表现出高感染性，并且JEVrv能够像真实的JEV一样繁殖和形成病灶。抗JEV包膜抗体中和病毒感染。用液泡ATP酶和网格蛋白介导的内吞作用的抑制剂处理细胞降低了JEVpv的感染性，表明JEVpv通过pH和网格蛋白依赖性内吞途径进入细胞。尽管如先前报道的，用胆固醇处理JEVpv、JEVrv和JEV的颗粒显著降低了感染性，但是通过用甲基β-环糊精处理从颗粒中消耗胆固醇增强了感染性。此外，鞘磷脂酶（SMase），水解膜结合的鞘磷脂神经酰胺，细胞的治疗，大大增强了感染JEVpv和繁殖的JEVrv，这些增强被抑制与SMase抑制剂或C-6-神经酰胺治疗。这些结果表明，神经酰胺起着至关重要的作用，不仅在进入，但也外出的过程中的JEV，他们应该有助于澄清JEV的传播和开发新的治疗方法，对黄病毒感染引起的疾病。
Japanese encephalitis virus (JEV) is a mosquito-borne RNA virus and one of the most important flaviviruses in the medical and veterinary fields. Although cholesterol has been shown to participate in both the entry and replication steps of JEV, the mechanisms of infection, including the cellular receptors of JEV, remain largely unknown. To clarify the infection mechanisms of JEV, we generated pseudotype (JEVpv) and recombinant (JEVrv) vesicular stomatitis viruses bearing the JEV envelope protein. Both JEVpv and JEVrv exhibited high infectivity for the target cells, and JEVrv was able to propagate and form foci as did authentic JEV. Anti-JEV envelope antibodies neutralized infection of the viruses. Treatment of cells with inhibitors for vacuolar ATPase and clathrin-mediated endocytosis reduced the infectivity of JEVpv, suggesting that JEVpv enters cells via pH-and clathrin-dependent endocytic pathways. Although treatment of the particles of JEVpv, JEVrv, and JEV with cholesterol drastically reduced the infectivity as previously reported, depletion of cholesterol from the particles by treatment with methyl beta-cyclodextrin enhanced infectivity. Furthermore, treatment of cells with sphingomyelinase (SMase), which hydrolyzes membrane-bound sphingomyelin to ceramide, drastically enhanced infection with JEVpv and propagation of JEVrv, and these enhancements were inhibited by treatment with an SMase inhibitor or C-6-ceramide. These results suggest that ceramide plays crucial roles in not only entry but also egress processes of JEV, and they should assist in the clarification of JEV propagation and the development of novel therapeutics against diseases caused by infection with flaviviruses.