Figure 7.

A β2 integrin, CD11b, expressed by eosinophils is involved in the cells’ response to β-glucan. A, Freshly isolated human eosinophils or neutrophils were stained with anti-CD11b mAbs (clone 2LPM19c and clone M1/70). Cells were stained with PE-conjugated secondary antibody and analyzed by flow cytometry. Representative histograms from two independent experiments are shown. B, Neutrophils or eosinophils were pre-incubated with medium alone, control mouse IgGs (mIgG1 or mIgG2b), or anti-CD11b mAbs (clone 2LPM19c or clone M1/70) (10 μg/ml) for 30 minutes at RT and then incubated with medium alone or purified β-glucan particles (100 μg/ml) for 18 h. After incubation, cell-free supernatants were collected and analyzed for MPO (neutrophils) and EDN (eosinophils). Data were normalized to the values with appropriate control mouse IgGs plus β-glucan particles as 100%. Spontaneous levels of MPO and EDN release without β-glucan particles were an average of 38% and 31%, respectively, of the values with control mouse IgGs plus β-glucan particles, and these values were subtracted before normalization. Results show means±SEM from 3 independent experiments. **; p<0.01 compared to values with control IgGs.