title: Biochemical nature and cellular distribution of the paired immunoglobulin-like receptors, PIR-A and PIR-B.
abstract: PIR-A and PIR-B, paired immunoglobulin-like receptors encoded, respectively, by multiple Pira genes and a single Pirb gene in mice, are relatives of the human natural killer (NK) and Fc receptors. Monoclonal and polyclonal antibodies produced against a recombinant PIR protein identified cell surface glycoproteins of approximately 85 and approximately 120 kD on B cells, granulocytes, and macrophages. A disulfide-linked homodimer associated with the cell surface PIR molecules was identified as the Fc receptor common gamma (FcRgammac) chain. Whereas PIR-B fibroblast transfectants expressed cell surface molecules of approximately 120 kD, PIR-A transfectants expressed the approximately 85-kD molecules exclusively intracellularly; PIR-A and FcRgammac cotransfectants expressed the PIR-A/ FcRgammac complex on their cell surface. Correspondingly, PIR-B was normally expressed on the cell surface of splenocytes from FcRgammac-/- mice whereas PIR-A was not. Cell surface levels of PIR molecules on myeloid and B lineage cells increased with cellular differentiation and activation. Dendritic cells, monocytes/macrophages, and mast cells expressed the PIR molecules in varying levels, but T cells and NK cells did not. These experiments define the coordinate cellular expression of PIR-B, an inhibitory receptor, and PIR-A, an activating receptor; demonstrate the requirement of FcRgammac chain association for cell surface PIR-A expression; and suggest that the level of FcRgammac chain expression could differentially affect the PIR-A/PIR-B equilibrium in different cell lineages.
authors.affiliation: Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, 35294, USA.
authors.forename: H
authors.initials: H
authors.lastname: Kubagawa
authors.forename: C C
authors.initials: CC
authors.lastname: Chen
authors.forename: L H
authors.initials: LH
authors.lastname: Ho
authors.forename: T S
authors.initials: TS
authors.lastname: Shimada
authors.forename: L
authors.initials: L
authors.lastname: Gartland
authors.forename: C
authors.initials: C
authors.lastname: Mashburn
authors.forename: T
authors.initials: T
authors.lastname: Uehara
authors.forename: J V
authors.initials: JV
authors.lastname: Ravetch
authors.forename: M D
authors.initials: MD
authors.lastname: Cooper
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D001483:Base Sequence; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology; D005434:Flow Cytometry; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000276:immunology; D011961:Receptors, Fc / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013154:Spleen / Q000276:immunology; D014162:Transfection / Q000235:genetics
chemical_list: D000906:Antibodies; C105948:Pira1 protein, mouse; C105949:Pirb protein, mouse; D011956:Receptors, Cell Surface; D011961:Receptors, Fc; D011971:Receptors, Immunologic; D011994:Recombinant Proteins