Biochemical nature and cellular distribution of the paired immunoglobulin-like receptors, PIR-A and PIR-B

J Exp Med. 1999 Jan 18;189(2):309-18. doi: 10.1084/jem.189.2.309.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies / immunology
  • Base Sequence
  • Cells, Cultured
  • Dendritic Cells / immunology
  • Flow Cytometry
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Receptors, Cell Surface / immunology
  • Receptors, Fc / immunology
  • Receptors, Immunologic / immunology*
  • Recombinant Proteins / immunology
  • Spleen / immunology
  • Transfection / genetics


  • Antibodies
  • Pira1 protein, mouse
  • Pirb protein, mouse
  • Receptors, Cell Surface
  • Receptors, Fc
  • Receptors, Immunologic
  • Recombinant Proteins