Mutations in the E2 glycoprotein of Venezuelan equine encephalitis virus confer heparan sulfate interaction, low morbidity, and rapid clearance from blood of mice
Mutations in the E2 glycoprotein of Venezuelan equine encephalitis virus confer heparan sulfate interaction, low morbidity, and rapid clearance from blood of mice
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DOI：
10.1006/viro.2000.0546
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发表时间：
2000-10-10
期刊：
影响因子：
3.7
通讯作者：
Johnston, RE
中科院分区：
文献类型：
--
作者：
Bernard, KA;Klimstra, WB;Johnston, RE
虫媒病毒，即委内瑞拉马脑炎病毒（VEE），会在定期爆发期间引起人类和马的疾病。小鼠模型非常模仿该疾病的脑炎形式，用于研究减毒机制。使用分子克隆的 VEE 病毒：一种强毒、流行的亲本病毒和源自亲本病毒的八种位点特异性糖蛋白突变体。在体外选择其中四个突变体进行快速结合和渗透，导致 E2 糖蛋白中的正电荷从谷氨酸或苏氨酸变为赖氨酸（N.L.Davis、N.Powell、G.F.Greenwald、L.V.Willis、B.J.Johnson、J.F.Smith 和 R.E.Johnston，Virology 183, 20-31, 1991）。组织培养适应还选择了结合硫酸乙酰肝素的能力，如肝素抑制噬菌斑形成、降低缺乏硫酸乙酰肝素的 CHO 细胞的感染性以及与肝素-aga 玫瑰珠紧密结合所证明的。相反，亲代病毒和其他三个突变体不使用硫酸乙酰肝素作为受体。皮下接种后，所有八个突变体在成年小鼠的死亡率方面均部分或完全减弱，并且在体外与硫酸乙酰肝素相互作用的五个突变体具有较低的发病率（0-50%）。这五种突变体在静脉注射后迅速从血液中清除。相比之下，亲本病毒和其他三种突变体被清除得非常缓慢。总之，含有组织培养选择突变的五种 VEE 病毒与细胞表面硫酸乙酰肝素相互作用，这种相互作用与低发病率和从血液中快速清除相关。我们提出一种减毒机制是由于病毒与普遍存在的硫酸乙酰肝素结合而在体内快速清除病毒，(C) 2000 学术出版社。
The arbovirus, Venezuelan equine encephalitis virus (VEE), causes disease in humans and equines during periodic outbreaks. A murine model, which closely mimics the encephalitic form of the disease, was used to study mechanisms of attenuation. Molecularly cloned VEE viruses were used: a virulent, epizootic, parental virus and eight site-specific glycoprotein mutants derived from the parental virus. Four of these mutants were selected in vitro for rapid binding and penetration, resulting in positive charge changes in the E2 glycoprotein from glutamic acid or threonine to lysine (N. L. Davis, N. Powell, G. F. Greenwald, L. V. Willis, B. J. Johnson, J. F. Smith, and R. E. Johnston, Virology 183, 20-31, 1991). Tissue culture adaptation also selected for the ability to bind heparan sulfate as evidenced by inhibition of plaque formation by heparin, decreased infectivity for CHO cells deficient for heparan sulfate, and tight binding to hepa rin-aga rose beads. In contrast, the parental virus and three other mutants did not use heparan sulfate as a receptor. All eight mutants were partially or completely attenuated with respect to mortality in adult mice after a subcutaneous inoculation, and the five mutants that interacted with heparan sulfate in vitro had low morbidity (0-50%). These same five mutants were cleared rapidly from the blood after an intravenous inoculation. In contrast the parental Virus and the other three mutants were cleared Very slowly. In summary, the five VEE viruses that contain tissue-culture-selected mutations interacted with cell surface heparan sulfate, and this interaction correlated with low morbidity and rapid clearance from the blood. We propose that one mechanism of attenuation is rapid viral clearance in vivo due to binding of the virus to ubiquitous heparan sulfate, (C) 2000 Academic Press.