Figure 7.
Extracellular HMGB1 compromises the leukocyte function of phagocytosis. The experiment with antibody treatment was performed as described in Figure 1. Airway leukocytes were isolated from BAL samples. RAW 264.7 cells were exposed to 95% O2 and incubated with fluorescent latex beads. Phagocytosis by leukocytes (ex vivo) (A) and phagocytosis by RAW cells (in vitro) (C) were expressed as beads/cell. At least 100 cells/slide were counted. HMGB1 concentrations in the BAL (B) and cell culture media (D) were measured by Western blot analysis. Data represent the means ± SEMs from three independent experiments (n = 4–6 mice per group). *P < 0.05, compared with mice receiving control mAb. **P < 0.01, compared with cells remaining at 21% O2 control level.