Ruiz M C, Abad M J, Charpilienne A, Cohen J, Michelangeli F
Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
J Gen Virol. 1997 Nov;78 ( Pt 11):2883-93. doi: 10.1099/0022-1317-78-11-2883.
It has previously been shown that trypsinized triple-layered particles of rotavirus induce destabilization of liposomes and membrane vesicles in the absence of Ca2+, a condition which leads to solubilization of the outer capsid proteins of the virus. In this work, we have studied the relationship between outer capsid solubilization and permeabilization of membrane vesicles, monitoring particle and vesicle size simultaneously by changes in light scattering. Permeabilization of intact cells induced by solubilized outer capsid proteins was monitored by following the rate of entry of ethidium bromide into the cells. Solubilized outer capsid proteins separated from double-layered particles induced vesicle permeabilization. Solubilization of the outer capsid preceded and was required for vesicle or cell permeabilization. Membrane damage induced by rotaviral outer proteins was not repaired upon addition of 1 mM Ca2+ to the medium. Rotavirus infection and cell permeabilization were correlated in six different cell lines tested. This phenomenon might be related to the mechanism of virus entry into the cell. We propose a new model for rotavirus internalization based on the permeabilizing ability of outer capsid proteins and the cycling of trapped calcium in the endosomal compartment.
先前的研究表明，在没有Ca2+的情况下，经胰蛋白酶处理的三层轮状病毒颗粒会导致脂质体和膜囊泡不稳定，这种情况会导致病毒外衣壳蛋白溶解。在这项工作中，我们研究了外衣壳溶解与膜囊泡通透性之间的关系，通过光散射的变化同时监测颗粒和囊泡的大小。通过跟踪溴化乙锭进入细胞的速率，监测溶解的外衣壳蛋白诱导的完整细胞的通透性。从双层颗粒中分离出的溶解的外衣壳蛋白诱导囊泡通透性。外衣壳的溶解先于囊泡或细胞通透性，并且是其必需条件。向培养基中添加1 mM Ca2+后，轮状病毒外蛋白诱导的膜损伤并未修复。在测试的六种不同细胞系中，轮状病毒感染与细胞通透性相关。这种现象可能与病毒进入细胞的机制有关。我们基于外衣壳蛋白的通透能力和内体区室中捕获的钙的循环，提出了一种轮状病毒内化的新模型。
