Skip to main content
. 2006 Aug;80(16):7976–7983. doi: 10.1128/JVI.00415-06

FIG. 4.

FIG. 4.

Contribution of PB1-F2 to pathogenicity of a virus with an intermediate virulent phenotype (WPW). (A) Construction of a chimeric WSN-PR8 PB1 gene (WPW) and a WSN-PR8 PB1 gene knocked out for PB1-F2 (WP-WdelF2). The PB1-F2 protein was knocked out in a manner analogous to that described in the legend for Fig. 2. (B) Replication of WPW and WP-WdelF2 viruses in tissue culture. Cells were inoculated at the indicated MOIs, and infection supernatants were collected at 24, 48, and 72 h. (C) Pathogenesis of viruses in mice. Five mice per virus group were inoculated with 4 × 105 PFU of the indicated viruses, and mouse weights were assessed every day after infection. (D) Survival of mice infected with WPW and WP-WdelF2 viruses as described for panel C. (E) Mouse lung virus titers. Twenty-five mice per virus group were infected with 4 × 105 PFU of each virus. Five mice from each group were sacrificed on days 3, 5, 6, 7, and 9, and lung virus titers were assessed by infection of MDCK cell monolayers. Error bars represent standard errors of the means. (F) Viral pathogenesis in BALB/c mice. Five mice per group were inoculated with 2 × 105 PFU of the indicated viruses, and mouse weights were assessed every day after infection.