[Interaction of fibronectin with polymorphonuclear leukocytes normally and in anaphylaxis]

Fibronectin is known as an opsonic glycoprotein possessing a wide range of specificity. Fibronectin interaction with neutrophils (normal ones and those obtained at peak of anaphylactic shock) was studied. Neutrophils were brought in contact with purified homologous fibronectin previously bound to gelatin-Sepharose granules. The presence of fibronectin-binding proteins on the surface of human and rabbit neutrophils was demonstrated, the binding being strongly dependent on Ca2+ and especially Mg2+ ions. "Anaphylactic" neutrophils, in contrast to normal ones, did not interact with fibronectin, which may be important for the pathogenesis of the immediate type hypersensitivity reactions.