MHC class Ib molecules bridge innate and acquired immunity

Nat Rev Immunol. 2005 Jun;5(6):459-71. doi: 10.1038/nri1635.


Our understanding of the classical MHC class I molecules (MHC class Ia molecules) has long focused on their extreme polymorphism. These molecules present peptides to T cells and are central to discrimination between self and non-self. By contrast, the functions of the non-polymorphic MHC class I molecules (MHC class Ib molecules) have been elusive, but emerging evidence reveals that, in addition to antigen presentation, MHC class Ib molecules are involved in immunoregulation. As we discuss here, the subset of MHC class Ib molecules that presents peptides to T cells bridges innate and acquired immunity, and this provides insights into the origins of acquired immunity.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation
  • Autoimmunity
  • HLA Antigens / immunology
  • HLA-B Antigens / genetics
  • HLA-B Antigens / immunology*
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / immunology
  • Humans
  • Immunity, Innate
  • Immunologic Factors / genetics
  • Immunologic Factors / immunology*
  • Molecular Sequence Data
  • Peptides / genetics
  • Peptides / immunology
  • Phylogeny
  • Protein Sorting Signals / genetics


  • H2-M3 antigen
  • HLA Antigens
  • HLA-B Antigens
  • HLA-E antigen
  • Histocompatibility Antigens Class I
  • Immunologic Factors
  • Peptides
  • Protein Sorting Signals
  • Q surface antigens
  • Qdm protein, mouse