FIG 1 .
Increased serum HMGB1 levels in cotton rats infected with influenza B/Wisconsin virus. (A) Young male cotton rats were infected i.n. with 1 × 106 TCID50/rat of influenza B/Wisconsin virus (Live Influenza B). Another group of animals similarly inoculated with UV-inactivated influenza B/Wisconsin virus (UV Influenza B) (at a dose similar to that of live virus) were used as controls. Serum samples were obtained on the indicated days p.i., and HMGB1 levels were analyzed by ELISA. Results are expressed as geometric means ± standard errors of the means (SEMs) (error bars) of the quantity of HMGB1 (in nanograms per milliliter) at each indicated time. Values for the group inoculated with live influenza virus that were significantly different (P < 0.05) from the values for the group inoculated with UV-inactivated influenza B virus are indicated by an asterisk. There were five cotton rats in each group for each treatment and time point. (B) Age-matched male and female cotton rats were infected i.n. with 1 × 106 TCID50 of live influenza B virus per rat. Serum samples were obtained and analyzed for HMGB1 levels at the indicated days p.i. There were five cotton rats in each group at each time point. (C) Groups (five cotton rats in each group) were infected i.n. with either 1 × 105 or 1 × 106 TCID50 of live influenza B virus per rat, and serum HMGB1 levels were analyzed at the indicated days p.i. The values for rats infected with 1 × 106 TCID50 that were significantly different (P < 0.05) from the values for rats infected with 1 × 105 TCID50 are indicated by an asterisk.