FIG. 3.

Inhibition of CR3-mediated phagocytosis of zymosan and M. kansasii by anti-CR3 MAbs. (A) Schematic map of the regions of the human CD11b α chain recognized by the different MAbs used in this study (3, 8, 31). (B and C) CR3-transfected CHO cells were preincubated with the indicated nonrelevant IgG1 or IgG2 or with anti-CD11b MAbs for 30 min at 37°C before incubation with zymosan (B) or M. kansasii (C). The data are expressed as the percentage of phagocytosis compared to control values (100%, no antibody). The values are means + SEM of three to six separate experiments performed in duplicate. Statistical differences were measured for cells pretreated with MAbs compared to untreated cells. ∗, P < 0.05; ∗∗, P < 0.01; ∗∗∗, P < 0.005.