RNase L inhibitor (RLI) antisense constructions block partially the down regulation of the 2-5A/RNase L pathway in encephalomyocarditis-virus-(EMCV)-infected cells
RNase L inhibitor (RLI) antisense constructions block partially the down regulation of the 2-5A/RNase L pathway in encephalomyocarditis-virus-(EMCV)-infected cells
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DOI：
10.1046/j.1432-1327.1998.2540248.x
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发表时间：
1998-06-01
期刊：
影响因子：
--
通讯作者：
Bisbal, C
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文献类型：
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作者：
Martinand, C;Salehzada, T;Bisbal, C
干扰素（IFN）诱导的2 '，5'-寡腺苷酸（2-5A）/核糖核酸内切酶L（RNase L）途径在IFN的抗病毒和抗增殖作用中起主要作用。2-5A/RNase L途径似乎受到细胞生长状态或病毒感染的调节。病毒，特别是小核糖核酸病毒，已经进化出逃避2-5A/RNase L途径相关抗病毒活性的策略，我们最近克隆了编码RNase-L特异性蛋白抑制剂RLI的cDNA。通过病毒感染调控2-5A/RNase L的表达，为调控2-5A/RNase L通路提供了新的策略。由于RNase L已被证明是下调后，脑心肌炎（EMCV）感染，我们稳定转染HeLa细胞与RLI反义cDNA表达载体。分析了命名为VAS 1、VAS 2、VAS 3和VAS 4的四个独立克隆以及作为对照的用空载体（VV）转染的一个克隆。VAS 1、VAS 2、VAS 3和VAS 4的RLI水平分别降低了20%、25%、75%和50%。与对照HeLa细胞相比，在EMCV感染期间观察到的RNA酶L的失活在这些克隆中减少。在这里，结果在四个克隆之间也不同。在对照细胞和VAS 1中观察到RNA酶L的最大抑制（90%），而在VAS 3中观察到48%的抑制，在VAS 3中观察到25%的抑制。因此，RNase L抑制的逆转密切反映了所得的RLI水平，这与RLI在EMCV诱导的RNase L的2- 5A结合活性下调中的主要作用一致。此外，表达低水平RLI（VAS 3和VAS 4）的细胞对EMCV感染具有部分抗性。
The interferon-(IFN)-inducible 2',5'-oligoadenylate (2-5A)/endoribonuclease L (RNase L) pathway plays a major role in the antiviral and antiproliferative effects of IFN. The 2-5A/RNase L pathway appears to be regulated by the cell-growth status or viral infection. Viruses, and picornaviruses in particular, have evolved strategies to escape the 2-5A/RNase L-pathway-associated antiviral activity.We have recently cloned a cDNA coding for RLI, a RNase-L-specific protein inhibitor. Its regulated expression by viral infection could provide a new strategy to modulate the 2-5A/RNase L pathway. Since RNase L had been shown to be down regulated upon encephalomyocarditis (EMCV) infection, we stably transfected HeLa cells with a RLI antisense cDNA expressing vector. Four independant clones named VAS1, VAS2, VAS3 and VAS4 and one clone transfected with the empty vector (VV) as control, were analyzed. The level of RLI was decreased by 20% for VAS1, 25% for VAS2, 75% for VAS3 and 50% for VAS4. The inactivation of RNase L observed during EMCV infection was decreased in these clones as compared to control HeLa cells. Here again the results vary between the four clones. The maximum inhibition of RNase L (90%) was observed in control cells and in VAS1 while 48% inhibition was observed in VAS3 and 25 % in VAS3. The reversal in RNase L inhibition thus reflects closely the resulting RLI level, in keeping with a major role of RLI in EMCV-induced down regulation of 2-5A-binding activity of RNase L. Moreover, cells expressing a low level of RLI (VAS3 and VAS 4) are partially resistant to EMCV infection.