Fc receptor homolog 3 is a novel immunoregulatory marker of marginal zone and B1 B cells

Academic Article


  • Two members of the recently identified FcR homolog (FcRH) family in mice demonstrate preferential B cell expression. One of these, FcRH3, encodes a type I transmembrane protein with five extracellular Ig domains and a cytoplasmic tail with a consensus ITIM and a noncanonical ITAM. Analysis of full-length cDNAs from five different mouse strains defines two FcRH3 alleles. A panel of FcRH3-specific mAbs was generated to define its expression pattern and functional potential on B lineage cells. Although poorly detected on the majority of bone marrow or peripheral blood cells, FcRH3 was readily identified on splenic marginal zone (MZ) and MZ precursor B cells, but not on the bulk of newly formed B cells, follicular B cells, germinal center B cells, and plasma cells. In the peritoneal cavity, FcRH3 was found on B1 cells, and not on the majority of B2 cells. Consistent with its possession of an ITIM and ITAM-like sequence, FcRH3 was tyrosine phosphorylated following pervanadate treatment, and its coligation with the BCR inhibited calcium mobilization. These results suggest FcRH3 is a novel immunoregulatory marker of MZ and B1 B lineage cells. Copyright © 2006 by The American Association of Immunologists, Inc.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Won WJ; Foote JB; Odom MR; Pan J; Kearney JF; Davis RS
  • Start Page

  • 6815
  • End Page

  • 6823
  • Volume

  • 177
  • Issue

  • 10