Promotion of neutrophil migration by laminin 8 and other laminin isoforms and participation of integrins. (A) Neutrophil migration through 3-μm pore filters precoated with phosphate-buffered saline (PBS), human serum albumin (HSA), mouse laminin 1 (mLN-1), recombinant human laminin 8 (rhLN-8), and recombinant human laminin 10 (rhLN-10). (B) Effect of mAbs to integrins on neutrophil migration through filters precoated with mLN-1, rhLN-8, and rhLN-10. mIgG (negative control), mAb IB4 (INTβ2, CD18), mAb 60.1 (INTαM, CD11b), and mAb 6S6 (INTβ1, CD29) were used. Transmigration was assessed microscopically after incubating the cells (250 × 103) for 1.5 hours at 37° C without chemoattractant or in the presence of either FMLP (10 nM) or IL-8 (11 nM). Filters were coated with proteins at 20 μg/mL and blocked with 2% polyvinylpyrrolidone (PVP). Adhesion-blocking mAbs were used at 20 μg/mL. Mean and SD are shown. P values (*P < .05; **P < .01; ***P < .001) compare laminin isoforms with HSA (A), and mAbs with mIgG (defined as 100% in all experiments) on each laminin isoform (B). Each substrate protein was tested 4 to 5 times.
