Figure 4. FMDV NCR transcripts trigger innate immunity in adult mice.

Groups of adult mice were i.p. inoculated with 200 µg of the IRES, the S fragment, poly (I:C), or PBS. Levels of IFN-αwere measured for each group of mice in pools of sera collected at 4, 8 or 24 h, by ELISA (A), cut-off 25 pg/ml, and the antiviral activity was determined (B) on L929 cells, starting from 1∶1 sera dilution, as described in Materials and Methods.