Fig. 1.

A: hematoxylin and eosin staining of lung sections. Mice were injected intraperitoneally with LPS or saline. Eight hours later the animals received anti-KC:KC immune complexes (ICs) [acute lung injury (ALI) group] or saline (Saline group). ALI/Neutrophils siRNA FcγRIII mice were injected with vinblastin to deplete neutrophils and then neutrophils were replenished with cells deficient in FcγRIII receptors (ALI/Neutrophils siRNA FcγRIII group). B: expression of FcγRIII receptors (green) in lung neutrophils of mice treated with LPS and anti-KC:KC ICs (ALI group) and ALI/Neutrophils siRNA FcγRIII mice. Lung neutrophils were visualized with anti-neutrophil antibody Ly6G1A8 (Gr-1; white). Three animals per group were analyzed, and typical findings are presented. Knockdown efficiency was 92%. C: hematoxylin and eosin staining of lung sections of mice that were immunized with KC to develop anti-KC autoantibodies and then either received Saline (Saline) or KC (Anti-KC:KC IC ALI), or were treated with vinblastine (anti-KC:KC IC ALI/vinblastine), or were treated with vinblastine and received neutrophils transfected with siRNA specific for FcγRIII (Anti-KC:KC IC ALI/Neutrophils siRNA FcγRIII). D: expression of FcγRIII receptors (green) in lung neutrophils of mice (anti-KC:KC IC ALI) and (anti-KC:KC IC ALI/Neutrophils siRNA FcγRIII mice). Lung neutrophils were visualized with anti-neutrophil antibody Ly6G1A8 (Gr-1; white). Three animals per group were analyzed, and typical findings are presented. Knockdown efficiency was 93%. E: efficiency of transfection of bone marrow neutrophils (neutrophil marker Gr-1, magenta; control siRNA/FITC, green). Approximately 300 cells were analyzed and typical findings are presented. Cont, control. In A–D samples were collected at 14 h after anti-KC:KC IC administration.