Cytophilic antibody: correlation of its distribution with activation of basophils and macrophages.

Abstract

AbstractImmunoglobulin determinants on the surface of guinea pig basopils were detected using mono‐ and divalent antiglobulin reagents conjugated with fluorscein isothiocyanate. The fluorescent pattern obtained with monovalent antiglobulin was always that of uniformly stained rings. Divalent antiglobulin agglutinated immunoglobulin determinates to form small fluorescent sports subsequently collected at one end of the cell (“cap” formation). The formation of caps is temperature‐dependent and is inhibited by sodiu azide and cytochalasin B.When basophils were incubated at 37 °C with divalent antiglobulin, morphological changes occurred, indicating that they had been activated. The same effect could be obtained with monovalent Fab́, but at least one hundred times more of it was required than the corresponding F(ab́)2.Cytophilic antiboidies on the surface of guinea pig peritoneal macrophages were also detected by immunofluorescence. In this case again, divalent antiglobulin reagents agglutinated the determinants to form small fluorescent sports. Cap formation was not observed and pinocytosis started as the first aggregates were formed. It was also found that cytophilic antibodies were not stable on the macrophages' surface and were easily eluted at 37 °C. A reaction with cross‐linking agents (divalent antiglobulin or antigen) stabilized the cytophilic antibody and pinocytosis was initiated.