Fig. 6

SOCS1 is a target of miR-155. a A549 cells were pre-treated with luteolin for 24 h before infected with RSV. At 12 or 24 h post infection, cells were collected for RT-qPCR to detect the miR-155 expression. b Putative miR-155 binding sites in the SOCS1 3′-UTR. The sites targeted by mutagenesis are indicated. c Dual luciferase reporter assay was performed in A549 cells that co-transfected with pcDNA-Luc Wt SOCS1 or pcDNA-Luc Mut SOCS1 and miR-155 mimic or miR-155 negative control to detect the luciferase activity at 48 h after transfection. Renilla luciferase activities normalized for firefly luciferase are presented. A549 cells were transfected with miR-155 mimc or miR-155 inhibitor for 24 h, d The mRNA expression of miR-155 was detected by RT-qPCR. e Cells were treated with luteolin for 24 h before infected with RSV and proteins were extracted at the indicated hours post infection to detect the SOCS1 expression by Western Blotting. f At the indicated hours post infection, virus titer or RSV-F mRNA expression were determined by plaque assay or RT-qPCR, respectively. g At the indicated hours post infection, cells were collected for RNA extraction and RT-qPCR was performed to detect the MX1, OAS1 and ISG15 expressions. Data shown are means ± SEM. Statistical significance was examined by Students’ t-test. P < 0.05 was considered statistically significant. *P < 0.05, **P < 0.01, ***P < 0.001. SOCS suppressor of cytokine, RSV respiratory syncytial virus, MOI multiplicity of infection, STAT1 signal transducers and activators of transcription 1, JAK Janus-activated kinase