The v-erbB oncogene confers enhanced cellular susceptibility to reovirus infection
The v-erbB oncogene confers enhanced cellular susceptibility to reovirus infection
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DOI：
10.1128/jvi.70.1.612-616.1996
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发表时间：
1996-01
影响因子：
5.4
通讯作者：
J. Strong;Patrick Lee
中科院分区：
文献类型：
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作者：
J. Strong;Patrick Lee
我们先前已经证明，两种不易被呼肠孤病毒感染的小鼠细胞系在用编码表皮生长因子受体（EGFR）的基因转染后变得高度易感（J.E.斯特朗，D. Tang和P.W. K. Lee，Virology 197：405-411，1993）。这种感染效率的增强需要功能性EGFR，因为在表达突变（激酶失活）EGFR的细胞中没有观察到这种增强。呼肠孤病毒能够直接结合EGFR的N-末端胞外域的额外发现（D. Tang，J.E. Strong和P.W. K. Lee，Virology 197：412-414，1993）使我们质疑这种相互作用是否是激活信号级联所必需的，该信号级联以某种方式增强随后的感染过程。在本研究中，我们解决了这个问题，使用细胞转染的v-erbB癌基因，它编码的蛋白质结构相关的EGFR，但缺乏大部分的N-末端配体结合域。v-erbB蛋白还具有配体非依赖性、组成型酪氨酸激酶活性。测定了对呼肠孤病毒（血清型3，Dearing株）感染性差的对照NIH 3 T3细胞和用v-erbB癌基因（THC-11）转染的NIH 3 T3细胞对呼肠孤病毒感染的敏感性。通过病毒蛋白的免疫荧光检测、放射性标记细胞的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析和空斑滴定来测定免疫活性。所有三种测定都证明了THC-11细胞系对感染的高度敏感性。这种增强的敏感性被发现被废除的细胞与染料木素，酪氨酸蛋白激酶的抑制剂，但只有部分通过与大豆黄酮，染料木素的非活性类似物治疗。我们提出，增强感染效率的机制，赋予EGFR和v-erbB是通过机会性利用病毒的一个已经激活的信号转导途径。
We have previously demonstrated that two mouse cell lines that are poorly infectible by reovirus become highly susceptible upon transfection with the gene encoding the epidermal growth factor receptor (EGFR) (J. E. Strong, D. Tang, and P. W. K. Lee, Virology 197:405-411, 1993). This enhancement of infection efficiency requires a functional EGFR, since such an enhancement is not observed in cells expressing a mutated (kinase-inactive) EGFR. The additional finding that reovirus is capable of directly binding to the N-terminal ectodomain of the EGFR (D. Tang, J. E. Strong, and P. W. K. Lee, Virology 197:412-414, 1993) has led us to question whether this interaction is required for the activation of a signalling cascade that somehow augments the ensuing infection process. In the present study, we address this question, using cells transfected with the v-erbB oncogene, which encodes a protein structurally related to the EGFR but lacking a large portion of the N-terminal ligand-binding domain. The v-erbB protein also possesses ligand-independent, constitutive tyrosine kinase activity. Control NIH 3T3 cells, which are poorly infectible by reovirus (serotype 3, strain Dearing), and NIH 3T3 cells transfected with the v-erbB oncogene (THC-11) were assayed for their susceptibilities to reovirus infection. Infectivity was determined by immunofluorescent detection of viral proteins, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of radiolabeled cells, and plaque titration. All three assays demonstrated a drastically higher degree of susceptibility to infection in the THC-11 cell line. This enhanced susceptibility was found to be abrogated by treatment of the cells with genistein, an inhibitor of tyrosine protein kinases, but only partially by treatment with daidzein, an inactive analog of genistein. We propose that the mechanism of enhancement of infection efficiency conferred by EGFR and v-erbB is through the opportunistic utilization by the virus of an already activated signal transduction pathway.