Mechanisms of passive sensitization. I. Presence of IgE and IgG molecules on human leukocytes.

Abstract

Immunoglobulins E and G were detected on human leukocytes by autoradiography. Evidence was obtained that specifically purified anti-human γE antibody combined with basophilic leukocytes from both normal and atopic individuals, and that anti-γG antibody bound with neutrophils and monocytes. Upon passive sensitization, E myeloma protein bound with basophils and normal γG bound with neutrophils and monocytes. The results show that basophils have receptor sites for γE, and that both neutrophils and monocytes have receptor sites for γG. Binding of the Fc fragments, but not the F(ab′) 2 fragments, of E myeloma protein with basophils indicated that γE combines with basophils through the Fc portion of the molecules. The binding of γE with basophils appears to be a process of passive sensitization for both antigen-induced and antibody-induced histamine release from leukocytes.