FIGURE 5.

Influenza A viruses up-regulates the expressions of TLR3 and TRIF mRNA and proteins. P815 cells were treated or infected as described in Figure 4B. (A) Total RNA was isolated at the designed times and examined with quantitative real-time PCR. The expression of TLR3and TRIF is shown. The data are presented as the relative fold change over mock treatment, and are pooled from three independent experiments. (B) P815 cells were collected at 2, 6, 12, and 24 h post-infection or treatment, and then analyzed by immunoblotting for expression of TLR3, TRIF, viral NS1 protein and β-actin. Data are representative of three separate experiments. (C) Endogenous interactions of TLR3 with TRIF. Whole cell extracts at 6 h (TLR3-TRIF) post-infection were immunoprecipitated with the indicated antibodies or isotype IgG controls and analyzed by western blot analysis.