ADHESIVENESS FOR EXTRACELLULAR MATRICES AND LYSOSOMAL-ENZYME RELEASE FROM NORMAL AND BETA(2) INTEGRIN-DEFICIENT BOVINE NEUTROPHILS

The adhesiveness of control and CD18-deficient bovine neutrophils on c ulture plates precoated with collagen I, collagen IV, fibronectin and laminin was measured to evaluate the possible factors for adherence to extracellular matrices. The release of N-acetyl-beta-D-glucosaminidas e (NAG(ase)) from control and CD18-deficient neutrophils stimulated wi th complement receptor type 3 (CR3) or Fc receptor dependent stimuli w as also evaluated. The adhesive activities of CD18-deficient neutrophi ls to collagen I, collagen IV and fibronectin were significantly dimin ished (P <0.05); however, similar adhesion to laminin was observed in CD18-deficient neutrophils and control neutrophils. The adhesive activ ity of control neutrophils on uncoated plates increased 2.5 times (P < 0.05) with the presence of PMA. The mean activities for NAG(ase) relea se from CD18-deficient neutrophils stimulated with opsonized zymosan a nd aggregated bovine immunoglobulin G (Agg-IgG) were 46.7 and 82.7% th at of the control neutrophils, respectively. The Agg-IgG-induced NAG(a se) release from control and CD18-deficient neutrophils was eliminated by H7, a protein kinase C inhibitor. These results support that an as sociation between CR3 and Fc receptors on neutrophils appears to play an essential role in neutrophil functions.