KINETICS OF POLIOVIRUS UNCOATING IN HELA-CELLS IN A NONACIDIC ENVIRONMENT
KINETICS OF POLIOVIRUS UNCOATING IN HELA-CELLS IN A NONACIDIC ENVIRONMENT
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DOI：
10.1128/jvi.64.8.3590-3597.1990
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发表时间：
1990-08-01
影响因子：
5.4
通讯作者：
WETZ, K
中科院分区：
文献类型：
--
作者：
GROMEIER, M;WETZ, K
对感染脊髓灰质炎病毒的海拉细胞进行裂解，发现了完整的病毒、不含VP4但含有病毒RNA的135S颗粒以及80S空衣壳。在感染过程中，脊髓灰质炎病毒脱壳的动力学显示完整病毒持续减少，而135S颗粒和空壳的数量增加。感染1.5小时后，构象转变为改变的颗粒，导致完整病毒粒子完全消失。为了研究脊髓灰质炎病毒脱壳的机制（有人认为该机制依赖于细胞内体区室的低pH值），我们使用溶酶体促生胺来提高这些囊泡中的pH值。然而，在氯化铵存在的情况下，脱壳的动力学与未处理细胞相似，而在用甲胺、莫能菌素或氯喹处理的细胞中，脱壳仅仅延迟了约30分钟。这种效应可归因于用甲胺和莫能菌素处理后病毒进入细胞的延迟，而氯喹稳定了病毒衣壳本身。因此，内体pH值的升高并不影响病毒脱壳。因此，我们提出一种脊髓灰质炎病毒脱壳机制，该机制不依赖于低pH值。
Lysis of HeLa cells infected with poliovirus revealed intact virus; 135S particles, devoid of VP4 but containing the viral RNA; and 80S empty capsids. During infection the kinetics of poliovirus uncoating showed a continuous decrease of intact virus, while the number of 135S particles and empty shells increased. After 1.5 h of infection conformational transition to altered particles resulted in complete disappearance of intact virions. To investigate the mechanism of poliovirus uncoating, which has been suggested to depend on low pH in endosomal compartments of cells, we used lysosomotrophic amines to raise the pH in these vesicles. In the presence of ammonium chloride, however, the kinetics of uncoating were similar to those for untreated cells, whereas in cells treated with methylamine, monensin, or chloroquine, uncoating was merely delayed by about 30 min. This effect could be attributed to a delay of virus entry into cells after treatment with methylamine and monensin, whereas chloroquine stabilized the viral capsid itself. Thus, elevation of endosomal pH did not affect virus uncoating. We therefore propose a mechanism of poliovirus uncoating which is independent of low pH.