Fig. 1

Influenza infection of mice and cotton rats induces GRP in lungs and serum. a WT C57BL/6J mice were infected with mouse-adapted influenza strain PR8 (LD₉₀; ~7500 TCID₅₀). Mice were euthanized on days 0, 2, 4, 6, and 8 post-infection (3–5 mice/group; *p < 0.001; **p < 0.0002). Lungs were homogenized and processed for GRP levels by EIA according to the manufacturer’s protocol. b Cotton rats were infected i.n. with 1 × 10⁶ TCID₅₀ of either California pH1N1, and Wuhan H3N2, or 1 × 10⁵ TCID₅₀ of Victoria H3N2, and serum GRP levels were analyzed at the indicated days p.i. *p < 0.05 and p < 0.01 for comparison between day 0 GRP (N = 23) vs. each time p.i. for each of the different influenza A strains