title: Ultrastructural localization of IgE in peripheral blood monocytes from atopics.
abstract: Monocyte-enriched preparations derived from peripheral blood leukocytes of atopics were probed via a cocktail comprising peroxidase-conjugated (Fab1)2 fragments of two monoclonal antibodies against human IgE. Reaction product indicative of intracellular IgE was identified by electron microscopy in both large and small vacuoles, and at high magnification exhibited a characteristic granular deposition pattern consistent with highly concentrated (perhaps insolublized) material. IgE-containing vacuoles were observed with comparable frequency to those containing IgG, despite the greater than 10,000-fold relative excess of the latter in serum suggesting highly selective uptake of IgE by the monocytes. These results are similar to those reported recently for IgA in human milk macrophages.
authors.affiliation: Clinical Immunology Research Unit, Princess Margaret Hospital, Subiaco, Australia.
authors.forename: K J
authors.initials: KJ
authors.lastname: Turner
authors.forename: A
authors.initials: A
authors.lastname: Marzo
authors.forename: B J
authors.initials: BJ
authors.lastname: Holt
authors.forename: A
authors.initials: A
authors.lastname: Wharton
authors.forename: J M
authors.initials: JM
authors.lastname: Papadimitriou
authors.forename: K J
authors.initials: KJ
authors.lastname: Cameron
authors.forename: N P
authors.initials: NP
authors.lastname: Siemensma
authors.forename: P G
authors.initials: PG
authors.lastname: Holt
mesh_terms: D000911:Antibodies, Monoclonal; D003593:Cytoplasm / Q000276:immunology / Q000648:ultrastructure; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007073:Immunoglobulin E / Q000032:analysis*; D009000:Monocytes / Q000032:analysis / Q000648:ultrastructure*
chemical_list: D000911:Antibodies, Monoclonal; D007073:Immunoglobulin E