Cellular distribution, regulation, and biochemical nature of an Fcα receptor in humans

• Type of Material: Article
• Authors: Renato C. Monteiro, University of Alabama at Birmingham; Hiromi Kubagawa, University of Alabama at Birmingham; Max Cooper, Emory University
• Language: English
• Date: 1990-03-01
• Publisher: Rockefeller University Press
• Publication Version: Final Published Version
• Copyright Statement: © Rockefeller University Press.
• Final Published Version (URL): http://dx.doi.org/10.1084/jem.171.3.597
• Title of Journal or Parent Work: Journal of Experimental Medicine
• ISSN: 0022-1007
• Volume: 171
• Issue: 3
• Start Page: 597
• End Page: 613
• Grant/Funding Information: This work was supported by grants CA-16673, CA-13148, and AI-18745 from the National Institutes of Health. M. D. Cooper is a Howard Hughes Medical Institute investigator.
• Keywords: Life Sciences & Biomedicine; Research & Experimental Medicine; Science & Technology; Immunology

Abstract

In these studies, we characterize an Fc receptor (FcR) for IgA that is present on human granulocytes, monocyte/macrophages, and their corresponding cell lines. Receptor expression appears to be constitutive but can be selectively upregulated on monocyte cell lines by stimulation with a phorbol ester and polymeric IgA. Both the induction requirements and ligand specificity of the IgA receptor differ from the IgG receptors, Fcγ R I, II, and III, that are also expressed on monocytes and granulocytes. IgA binding to the cell surface receptor is mediated via the Fcα region. The Fcα R is a heterogenously charged, approximately 60-kD molecule with an isoelectric point of 4.5-5.6 that binds monomeric or polymeric IgA1 and IgA2 molecules. This transmembrane glycoprotein appears to be composed of 32- and 36-kD protein cores with multiple N-linked carbohydrate moieties. We conclude that this Fcα R represents a novel member of the FcR family that may have a distinctive role in host defense.