Figure 1.

Effect of anti-β₂ integrin antibody on neutrophil migration and activation. (a) Effect of intact anti-β₂ integrin antibody on neutrophil migration across bare filters and T84 monolayers. Freshly isolated neutrophils were induced to migrate across bare filters or inverted T84 monolayers. Black bars: migration without added mAb, grey bars: migration in the presence of 30 µg/ml anti-β₂ antibody. Migration across T84 monolayers in the absence of chemoattractant was routinely less than 2%. The figure shows a representative of over five experiments across bare filters and over 20 experiments across T84 monolayers. Each bar is the mean of migration from three wells ± SD. Insert: Neutrophil migration across bare filters and T84 monolayers was assessed in the presence of binding isotype control anti-MHC class I antibody W6/32 (IgG2a). Black bars: migration without added mAb, grey bars: migration in the presence of W6/32 antibody. Each bar is the mean of migration from three wells ± SD. (b) Effect of intact anti-β₂ integrin antibody on neutrophil Mac-1 expression. Neutrophils were treated with anti-β₂integrin mAb or Fab′ fragments for 20 min at room temperature or left untreated. Bars indicate percentage increase in CD11b mean fluorescent intensity following intact antibody (n = 4) or Fab′ (n = 2) treatment of neutrophils relative to no anti-β₂ integrin mAb or Fab′ control. Bars represent the mean ± SD. Both IB4 and 60.3 anti-β₂ intact mAb were tested with similar results. (c) Effect of Fab′ fragments of anti-β₂ integrin mAb on neutrophil migration across bare filters and T84 monolayers. Migration was performed as in (a), except that Fab′ fragments were used instead of intact antibody. This experiment was repeated twice with similar results. Each bar is the mean of migration from three wells ± SD.