Figure 4.
CHIPS specifically inhibits fMLP- and C5a-induced calcium mobilization in neutrophils. The effect of CHIPS on intracellular-free calcium release induced by 10−9 M fMLP, 10−10 M C5a, and 10−10 M IL-8 in neutrophils was determined using Fluo-3–labeled cells and flow cytometry. After preincubating neutrophils with 1 μg/ml CHIPS (gray lines) or buffer (black lines), the basal fluorescence level was measured for each sample before fMLP (A), C5a (C), or IL-8 (B and D) was added (indicated by first arrow). To show receptor specificity, cells were rechallenged with a second stimulus of fMLP (B), C5a (D), or IL-8 (A and C) after 5 min (indicated by second arrow).