Fig. 4.

H84T prevents influenza virus protein expression in MDCK cells. MDCK cells were pretreated for 1 h with H84T (0.1, 1, or 10 μM in A; 0.05, 0.1, or 1 μM in C), 10 μM D133G, or 40 μM of the fusion inhibitor ARB and infected with A/WSN/1933 (H1N1) (A) or A/Colorado/15/2014 (H3N2) (C) (MOI = 0.5) for 5 h at 37 °C. (A and C) Representative immunofluorescent micrographs of influenza A antigen staining (green) and nuclei (blue) 5 h postinfection. Data for A and C are representative of three and four independent experiments, respectively. Scale bars indicate 100 μm. (B and D) Quantitation of the number of cells with influenza protein-positive nuclei per field, as assessed by a trained observer in a blinded fashion. Statistical analyses were performed by t test. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, as compared to the infected, untreated group. Error bars denote the SEM.