title: Detection of Fc receptors for IgA on rat alveolar and peritoneal macrophages.
abstract: The presence of Fc receptors for IgA on alveolar macrophages was determined by rosette assay and immunogold labeling. IgA-mediated phagocytosis by alveolar macrophages was observed. Results of these assays were compared between rats receiving no treatment and those receiving long-term cortisone administration. Sheep erythrocytes coated with dextran and an IgA monoclonal antibody specific for the alpha 1,3 linkages of dextran bound to 16% of alveolar macrophages. However, peritoneal macrophages did not form rosettes with dextran-IgA-coated erythrocytes. Immunogold labeling by transmission electron microscopy revealed that most Fc receptors for IgA were found on the membrane of pseudopodia of activated alveolar macrophages. Long-term cortisone administration diminished the phagocytosis and phagocytic index of alveolar macrophages, thereby contributing to decreased host resistance to infection (e.g., Pneumocystis carinii pneumonia).
authors.affiliation: Department of Microbiology, California State University, Long Beach 90840.
authors.forename: E
authors.initials: E
authors.lastname: Park
authors.forename: C A
authors.initials: CA
authors.lastname: Itatani
mesh_terms: D000818:Animals; D006854:Hydrocortisone / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000276:immunology*; D008297:Male; D010529:Peritoneal Cavity / Q000166:cytology; D010587:Phagocytosis / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011961:Receptors, Fc / Q000032:analysis*; D011971:Receptors, Immunologic / Q000032:analysis*; D012397:Rosette Formation
chemical_list: C045281:IgA receptor; D011961:Receptors, Fc; D011971:Receptors, Immunologic; D006854:Hydrocortisone