Figure 1: NK cell depletion leads to enhanced mortality late after sepsis induction.

A) Experimental Design: The frequency of NK cells (CD3⁻CD122⁺CD49b⁺) in the PBL of mice every other day for 10 days. Mice were administered either control IgG or αNK1.1 depleting antibody on days 0 and 2 (after monitoring PBL). The frequency of NK cells in the spleen was assessed at D10. (B) Representative Gating: Gate of CD122⁺CD49b⁺ cells in the PBL 10 days after the initial depletion. Prior gating is on CD3⁻ lymphocytes. Frequencies are of total lymphocytes. (C) Frequency of NK cells in the PBL throughout the following administration of control IgG or αNK1.1 antibody. (D) Frequency of NK cells in the spleen 10 days after the initial depletion. Data are representative from at least 3 independent experiments with 3–5 mice per group. E) Experimental Design: 2 days prior to surgery mice were administered either control IgG or αNK1.1 depleting antibody. On the day of surgery mice underwent either Sham (no ligation or puncture), CLP₂₀ (ligation and 1 puncture), or CLP₅₀ (ligation and 2 punctures) and received a second antibody injection. (F,G) Sham, (H,I) CLP₂₀, and (J,K) CLP₅₀ were monitored for (F,H,J) weight loss and (G,I,K) mortality daily for 8 days. Morbidity and mortality data are cumulative from 3 independent experiments with 9–32 mice per group. Mortality data is displayed as Kaplan-Meier curves. Error bars represent standard error of the mean.