RESUMEN
To investigate whether influenza virus (IFZ) could up-regulate the expression of mucin 1 (MUC1) which exists in epithelial cells of upper respiratory track to restrict the inflammation, as respiratory syncytial virus (RSV) does. Quantitative RT-PCR and Western Blot were performed to detect the expression level of MUC1 induced by two single-strand RNA viruses in A549 cell lines. HEp-2 and MDCK cells were used respectively to culture RSV and IFZ. At 24h post A549 cells infection with the same titer of RSV or IFZ, the total RNA was harvest, qRT-PCR was then performed to observe the expression level of MUC1 mRNA. Meanwhile, at 24 h and 48 h post A549 cells infection with the same titer of RSV or IFZ, the total protein and supernatant were collected respectively after cell lysis, Western Blot was then used to detect the expression level of MUC1. Results showed that RSV could up-regulate the expression of MUC1 in airway epithelial cells with a significant dose-effect correlation, whereas IFZ could not. This study firstly investigated the differences of the regulation on the expression of MUC1 induced by two single-strand RNA viruses, and demonstrated initially that the mechanism of IFZ self-limiting differed from RSV, which attributed to up-regulation of the expression level of MUC1.