FIG 5.

Lack of IFN-I signaling reduces transmission of IAV and S. pneumoniae. (A) WT and Ifnar1^−/− index pups were infected i.n. with 10³ CFU S. pneumoniae at a ratio of 6 index to 20 contact in WT litters or 5 index to 18 contact in Ifnar1^−/− mice in three separate litters. The S. pneumoniae transmission rate and bacterial burden were higher in WT than Ifnar1^−/− contact mice. (B) WT and Ifnar1^−/− index pups were infected i.n. with 250 PFU IAV at a ratio of 12 index to 22 contact in WT litters or 10 index to 28 contact in Ifnar1^−/− mice in five separate litters. The IAV titer was higher in WT than Ifnar1^−/− contact mice. Colonization and titer data are for individual pups, with the line indicating the geometric mean. Each symbol represents the value from an individual pup on a single day. n ≥ 5 pups/group. *, P < 0.05; ***, P < 0.001 (Mann-Whitney test). The dotted line shows the limit of detection.