FIG. 3.

Increased infection of mTECs with recombinant HA mutant viruses. The cells were cultured under air-liquid interface conditions and infected with the indicated recombinant viruses at an MOI of 3 for 20 h. (A) Viral expression was detected by staining with anti-HK antibody (red). The nuclei were stained with DAPI (4′,6-diamidino-2-phenylindole) (blue). (B) Percentages of infected cells were counted for multiple microscopic fields (n = 4 to 8) from duplicate infections for each sample and are shown as averages ± standard deviations. All the mutants infected significantly more cells than the wt (P < 0.0001) (*).