Fig. 5.
Mobilization of specific granules by human and mouse PMNs.
(A) Human PMNs were incubated on IgA- or IgG-coated surfaces or on Ab-coated SK-BR-3 cells for 30 minutes. PMNs were detached from tumor cells by cytochalasin B, and supernatants were tested for presence of lactoferrin. In addition, PMNs were stimulated for 15 minutes with PMA or with FMLP in the presence of cytochalasin B. The different stimuli were tested in the absence (▪) or presence (░) of anti–Mac-1 mAb 44a. Results are expressed as mean ± SEM (n = 3). (B) Mouse PMNs (Tg Mac-1+/− and Tg Mac-1−/−, n = 3) were incubated on BSA- (control) or IgA-coated surfaces. Cells were detached after 30 minutes and homogenized. Sucrose gradient ultracentrifugation separated cytoplasm (C), plasma membrane (P), specific granule (S), and azurophilic granule (A) fractions. Translocation of p22 from specific granules to the plasma membrane was detected by Western blotting using α-mouse p22-phox antiserum. PMA-stimulated mouse PMNs served as positive control.