Figure 4.

(A and B) Normal neutrophils were tested for C3aR and C5aR expression by FACS. A representative example is shown. The gray line depicts the matching isotype control. (C) TNF-α–primed neutrophils were stimulated with a mAb to PR3 for 45 min. Supernatants of these were incubated for 15 min with normal serum (NS), C3-depleted serum, or C5-depleted serum. These different conditioned sera were used in different neutrophils for priming (45 min at 37°C), after which cells were activated with a mAb to PR3. ROS production was measured after 45 min of stimulation with αPR3, and data are means ± SEM (given as MFI; five independent experiments performed in duplicate). (D) Neutrophils were preincubated with a blocking antibody to C5aR or a C3aR blocker, afterward primed with conditioned serum for 45 min and subsequently activated with a mAb to PR3. ROS production was measured after 45 min of stimulation with αPR3, and data are means ± SEM (given as MFI; data from three independent experiments performed in duplicate). **P < 0.01.