FIG 2.

Influenza A viruses encoding Belzig-NP escape MxA restriction in MxA-overexpressing cells. (A and B) MDCKII cells were infected at an MOI of 0.001 with wild-type or mutant H7N7 (A) or rBelzig (B) viruses and were incubated at 37°C. Viral titers were determined at 12, 24, 36, and 48 h postinfection via plaque assay. Error bars indicate the standard errors of the means from at least three independent experiments. (C and D) MDCK-SIAT1 cells stably expressing either MxA (filled bars) or the antivirally inactive MxA-T103A mutant (open bars) were infected at an MOI of 0.001 with wild-type or mutant H7N7 (C) or rBelzig (D) viruses and were incubated at 37°C. The H5N1 and pH1N1 viruses were used as controls for MxA-sensitive and -resistant viruses, respectively. Viral titers were determined 24 h postinfection via plaque assay. Error bars indicate the standard errors of the means from at least three independent experiments. Student’s t test was performed to determine the P value. *, P < 0.05; **, P < 0.01; ***, P < 0.001.