CD46、Nectin-4在麻疹病毒感染人肺泡上皮细胞中的作用

摘要

目的:探讨CD46、Nectin-4在麻疹病毒感染人肺泡上皮细胞中的作用.以及CD46和Nectin-4之间的相互作用.方法:分为麻疹病毒感染前处理组和感染后2 h组,均用抗CD46抗体、抗Nectin-4抗体处理人肺泡上皮细胞,并设对照组.检测细胞内病毒滴度的变化,采用Western blot和Real-time PCR检测NP蛋白的表达水平,并运用免疫共沉淀检测CD46与Nectin-4的相互作用.结果:与对照组相比,麻疹病毒感染前用抗CD46抗体、抗Nectin-4抗体处理的人肺泡上皮细胞内麻疹病毒滴度显著降低,分别为对照组的48.03%和49.53%,同时用抗CD46抗体、抗Nectin-4抗体处理使病毒滴度下降为27.15%,差异均有统计学意义(P<0.01).然而,在麻疹病毒感染2 h后用抗CD46抗体、抗Nectin-4抗体处理,人肺泡上皮细胞内麻疹病毒滴度和NP蛋白量未见显著减少.Western blot和Real-time PCR结果与上述结果一致;免疫共沉淀实验显示,CD46与Nectin-4存在相互作用.结论:CD46、Nectin-4在麻疹病毒感染肺泡上皮细胞中起到介导作用,CD46与 Nectin-4可能存在协同作用,该作用对麻疹病毒的感染起到了增强效果.%Objective:To investigate the role of CD46 and Nectin-4 on Measles virus (MV) infecting human pulmonary alveolar epithelial cells (HPAEpiC),and the interaction between CD46 and Nectin-4.Methods: Measles virus was divided into pre-infection group and 2 h-infection group,HPAEpiCs treatment with anti-CD46 antibody and/or anti-Nectin-4 antibody as experimental groups,and untreated HPAEpiCs as a control.The variation of viral replication level was detected.A Co-immunoprecipitation assay (Co-IP) was used to explore whether CD46 and Nectin-4 had interactive relationship in MV infection.Results: Compared with the control group,MV titers were reduced in HPAEpiCs of the pre-infection group treated with anti-CD46 and anti-Nectin-4 respectively (48.03% and 49.53%).Furthermore,virus titers showed a more reduction in which treated with anti-CD46 and anti-Nectin-4 antibodies (27.15%,P<0.01).Western blot and Real-time PCR showed that anti-CD46 antibody and anti-Nectin-4 antibodies decreased the rate of MV infection.In the 2 h-infection group,however,the treatment with anti-CD46 and anti-Nectin-4 could significantly reduce the MV titer and NP protein in HPAEpiCs.The Co-IP assay showed that there were interaction between CD46 and Nectin-4.Conclusion: CD46 and Nectin-4 mediated MV infecting HPAEpiCs.Moreover,CD46 and Nectin-4 may play a synergetic role in MV infection,which could enhance the infection effect.