FIG. 4.

IL-1R1^−/− mice exhibit normal cytotoxic T-cell effector responses. Mice were infected with 100 PFU influenza virus PR8 and analyzed on day 10 postinfection. (A) To determine primary CTL responses at the site of virus infection, pools of BAL cells from groups of mice (n = 4/group) were serially diluted threefold in microtiter plates starting with 1 × 10⁶ cells before addition of ⁵¹Cr-labeled NP68 peptide-pulsed EL-4 target cells (1 × 10⁴ per well) and incubated for 5 h before measurement of ⁵¹Cr release. (B) Mediastinal lymph node cells were restimulated in vitro with specific peptide for 5 days. Effector cells were mixed with EL-4 target cells at the ratios indicated. Values show percent lysis. Nonspecific lysis of target cells not pulsed with peptide was below 2% (not shown).