Effect of mAbs to integrins (INT) and laminins (LN) on neutrophil migration through human serum albumin (HSA)–coated filters. Neutrophil transmigration assays were performed by using 3-μm pore insert filters precoated and blocked with HSA, and the number of transmigrated cells was determined microscopically. mIgG (negative control), mAb IB4 (INTβ2, CD18), mAb 60.1 (INTαM, CD11b), mAb 8C10 (LNα4), and mAb P3H9-2 (LNα3) were used. Starting with 250 × 10³ neutrophils in the upper chamber, migration to the lower chamber was assessed after incubating the cells for 1.5 hours at 37° C in the presence of FMLP (10 nM) as chemoattractant in the lower chamber. Mean and SD of 4 experiments are shown. P values (*P < .05; **P < .01) compare mAbs with mIgG.