The long elusive IgM Fc receptor, FcμR

J Clin Immunol. 2014 Jul;34 Suppl 1(0 1):S35-45. doi: 10.1007/s10875-014-0022-7. Epub 2014 May 3.


IgM exists as both a monomer on the surface of B cells and a pentamer secreted by plasma cells. Both pre-immune "natural" and antigen-induced "immune" IgM antibodies are important for protective immunity and for immune regulation of autoimmune processes by recognizing pathogens and self-antigens. Effector proteins interacting with the Fc portion of IgM, such as complement and complement receptors, have thus far been proposed but fail to fully account for the IgM-mediated protection and regulation. A major reason for this deficit in our understanding of IgM function seems to be lack of data on a long elusive Fc receptor for IgM (FcμR). We have recently identified a bona fide FcμR in both humans and mice. In this article we briefly review what we have learned so far about FcμR.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Autoantigens / immunology
  • B-Lymphocytes / immunology*
  • Humans
  • Immunoglobulin M / immunology*
  • Immunomodulation
  • Mice
  • Receptors, Fc / immunology*
  • Receptors, Fc / isolation & purification


  • Autoantigens
  • Immunoglobulin M
  • Receptors, Fc
  • immunoglobulin M receptor