Gujuluva C N, Kundu A, Murti K G, Nayak D P
Department of Microbiology and Immunology, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, School of Medicine 90024-1747.
Virology. 1994 Nov 1;204(2):491-505. doi: 10.1006/viro.1994.1563.
Since influenza A virus replication is defective in HeLa229 cells but productive in Madin-Darby canine kidney (MDCK) cells, we have investigated the steps in the infectious cycle of A/WSN/33 virus defective in HeLa229 cells. We find that both the entry and exit processes of the infectious cycle were defective in HeLa229 cells. During entry, viral adsorption was apparently normal in HeLa229 cells but a subsequent step(s) involving one or more processes namely the fusion/uncoating and nuclear transport of viral ribonucleoprotein was inefficient and slow compared to those in MDCK cells. Fewer HeLa229 cells were infected at the same multiplicities of infection, resistance to ammonium chloride developed much more slowly and degradation of the incoming virus proteins was delayed when compared to those in MDCK cells. Subsequent to the entry process, there was no significant difference in either the synthesis of viral proteins or the transport, maturation, and membrane insertion of viral glycoproteins although the glycosylation pattern of hemagglutinin was different and the peak protein synthesis was albeit delayed in HeLa229 cells compared to that in MDCK cells. However, there was a major defect in the budding and release of viral particles. In HeLa229 cells, viral bud formation occurred but viral particles remained attached to the plasma membrane and were not released into the medium. This defect in virus release was not due to lack of neuraminidase activity but could be, at least partly, overcome by cytochalasin B treatment, suggesting a possible involvement of microfilaments in virus release. These results indicate that the abortive replication of influenza virus A/WSN/33 in HeLa229 cells appears to be due to multiple defects involving both the entry and release of viral particles and that host cell membrane and microfilaments may be important contributing factors in these processes.
由于甲型流感病毒在HeLa229细胞中复制存在缺陷，但在犬肾传代细胞（MDCK）中能够有效复制，我们研究了A/WSN/33病毒在HeLa229细胞中感染周期的各个步骤。我们发现，HeLa229细胞中感染周期的进入和释放过程均存在缺陷。在进入过程中，HeLa229细胞中的病毒吸附明显正常，但与MDCK细胞相比，随后涉及病毒核糖核蛋白的融合/脱壳和核转运等一个或多个过程效率低下且缓慢。在相同感染复数下，HeLa229细胞被感染的数量较少，对氯化铵的抗性发展更为缓慢，与MDCK细胞相比，进入的病毒蛋白降解延迟。进入过程之后，病毒蛋白的合成以及病毒糖蛋白的转运、成熟和膜插入均无显著差异，尽管血凝素的糖基化模式不同，且与MDCK细胞相比，HeLa229细胞中的蛋白质合成高峰有所延迟。然而，病毒颗粒的出芽和释放存在重大缺陷。在HeLa229细胞中，病毒芽形成，但病毒颗粒仍附着在质膜上，未释放到培养基中。病毒释放的这种缺陷并非由于缺乏神经氨酸酶活性，但至少部分可通过细胞松弛素B处理克服，这表明微丝可能参与病毒释放。这些结果表明，甲型流感病毒A/WSN/33在HeLa229细胞中的流产性复制似乎是由于病毒颗粒进入和释放的多重缺陷所致，宿主细胞膜和微丝可能是这些过程中的重要促成因素。
