TLR2 and infection: To clarify how the XJ49-NS1mut virus affects host innate immune responses in vitro, A549 cells were infected with the indicated viruses, and expression of mRNA encoding key innate immune molecules (IL-28, IL-29, TLR-2, TLR-3, RIG-I, TRIM22, and TRIM25) was measured by qPCR (Figure 4C) after 24 h of infection.