Cytophilic antibodies in mice contact-sensitized with oxazolone. Immunochemical characterization and preferential binding to a trypsin-sensitive macrophage receptor.

Abstract

Oxazolone-specific cytophilic antibodies in the sera of non-immune CBA mice and mice contact-sensitized with oxazolone, were studied with a rosette test employing peritoneal exudate macrophages and oxazolone-coupled sheep erythrocytes. Macrophage rosettes, produced by direct or indirect cytophilic antibodies, were found to depend on optimally hapten-coupled erythrocytes. Sera obtained 1 week after contact sensitization with oxazolone contained principally 7S IgG2a cytophilic antibodies. Monomeric 7S IgM antibodies cytophilic for macrophages may have been present as well. Primary contact sensitization and boosting was found uniquely to lead to high titres of hyperimmune oxazolone cytophilic antibodies predominantly binding to trypsin-sensitive macrophage receptors.