In vitro antibody Fc–mediated complement activation is associated with in vivo TRALI induction. BALB/c WT mice, except for the naive group, were primed with LPS (0.1 mg/kg intraperitoneally) and CD4 T cells depleted with anti-CD4 (4.5 mg/kg; combined first hit) 16 hours before infusion of antibodies (4.5 mg/kg IV; second hit). (A) Rectal temperatures were monitored after TRALI induction. (B) Kaplan-Meier survival curve. (C) Representative images of the lungs of mice injected with C1.18.4 (left), SF1.1.10 (middle), and 34-1-2S (right). (D) Lung W/D weight ratios after 90 minutes of TRALI induction or at the time of death. (E) Protein levels in the BALF in mg/mL. Only significant differences of interest are shown; each dot represents 1 mouse; n = 5 to 6 mice per group. For panel B, 2 independent experiments were pooled; n = 11 to 12 mice per group. Data are shown as means ± standard deviation (SD). ∗P < .05; ∗∗∗P < .001; ∗∗∗∗P < .0001. Statistical analysis was performed with a one-way analysis of variance (ANOVA) with a Tukey post hoc test for panels A,D-E.