Avidin attachment to biotinylated human neutrophils induces generation of superoxide anion

The influence of biotinylation and subsequent attachment of avidin on generation of superoxide anion by human neutrophils was studied. Biotinylation of human neutrophils with succinimide ester of biotin does not reduce superoxide generation in response to activation with phorbol myristate acetate (PMA) and formyl peptide (FMLP). Addition of avidin to biotinylated, but not native, leukocytes induces generation of superoxide anion. The kinetics and level of superoxide generation by biotinylated neutrophils in response to addition of avidin were quite similar to those in response to activation with FMLP. The avidin sugar moiety and charge were not involved in superoxide generation, since streptavidin was also active. Both avidin- and PMA-induced superoxide generation were independent of the extracellular calcium, while FMLP-induced superoxide generation was dependent on the presence of calcium in solution. Therefore, interaction of avidin with biotinylated components of the neutrophil membrane alters functional activity of this cell and might induce 'activation-like' reaction of leukocytes.