EOSINOPHIL CHEMOTACTIC FACTOR (ECF) .2. RELEASE FROM HUMAN POLYMORPHONUCLEAR LEUKOCYTES DURING PHAGOCYTOSIS

Abstract

Phagocytosis stimulates ECF release from neutrophils (PMN [polymorphonuclear leukocytes]). Human PMN (> 98%) were exposed to zymosan (Z), zymosan-coated with complement (Z(x)), or zymosan in the presence of serum (Z(s)). The release of ECF was time- and dose-dependent. Like ionophore-induced ECF, phagocytosis-derived ECF preferentially attracted and deactivated eosinophils. Chromatography on Sephadex G-25 revealed an elution pattern similar to the antigen-induced, basophil-derived and to the ionophore-induced PMN-derived ECF. The addition of complement as Z(x) or Z(s) accelerated the release of ECF. With both stimuli, the initial kinetics of ECF paralleled the release of .beta.-glucuronidase and NBT reduction. With Z alone, .beta.-glucuronidase release and NBT [nitroblue tetrazolium] reduction were negligible, whereas the amount of ECF released was similar to that induced by Z(x). In the presence of serum Z(s), decreased activity was noted. Supernatants of phagocytosis at late time periods showed less activity than early supernatants, suggesting that ECF might be inactivated. Phagocytosis apparently causes the release of an ECF, which appears to be similar to the IgE [immunoglobulin E]-induced ECF-A.