Fig. 2. IFNγ signaling plays an essential role in preventing transmission of respiratory viruses.

(a) PCA plot of sorted virus-specific CD8 T_RM and T_EM from BAL, lung and spleen of influenza primed mice at resting memory (d30, n=3 per group) and 3 days post challenge (d30+3, n=3 per group), pooled over 3 independent experiments. (b) Heat map of RNA transcript expression for the listed differentially expressed genes. (c) Schematic of experiment to investigate the importance of IFNγR or perforin for limiting transmission to naïve contact mice. (d) Bioluminescence of WT (n=11), Prf^−/− (n=10), and Ifngr^−/− (n=6) index mice following direct infection with Sendai-Luc. (e) AUC of bioluminescence in index mice. (f) Bioluminescence in B6 contact mice (WT, n=40 contacts; Prf^−/−, n=32 contacts; Ifngr^−/−, n=22 contacts) following co-housing with infected index mice on day 3 post infection. (g) AUC of bioluminescence in contact mice that become infected following co-housing with an infected index mouse. (h) Probability of transmission to naïve contact mice for each genotype of immunized index mouse, calculated as the proportion of contact mice that became infected. Error bars represent 95% binomial confidence interval. Data are combined from 3 independent experiments (d-h). For bioluminescence curves (d, f), solid dark lines represent means, solid pale lines represent individual mice, dashed grey line represents background bioluminescence, and dashed red line represents the limit of infection. Solid lines (e, g, h) and error bars (d-g) represent mean with 95% confidence interval. Statistical significance was determined using two-sided Mann Whitney test. * p<0.05, *** p<0.001, **** p<0.0001, ns: non-significant.