IFNA1 and infection: In order to determine whether exposure to IFN after virus infection would have a similar effect, cDCs were infected with PR8 virus at the 0 hour, and IFN-β (50 units/ml) was added at 0, 1.5, 3 and 6 hours post infection and left in the culture medium until the mRNA expression profile of the treated cDCs was analyzed 8 hours post infection.