Viral distribution and cytokine production in respiratory tract of mice. A Six-week-old SPF BALB/c mice (three/group) were inoculated intranasally with 106 EID50 of RY6 and RY6-160T, and respiratory tract tissues were collected at 3, 6, 9, 12, 20, 24, 72 hpi for virus titration with RT-qPCR. Relative mRNA levels of HMGB1, IL10, and TNFα in the infected mouse turbinates B and lungs C. All values were normalized to Gapdh and are expressed as fold change compared with controls. Values represent means ± SD from three independent experiments. (*p < 0.05, **p < 0.01, ***p < 0.001).