Unconventional Recognition of Peptides by T Cells and the Implications for Autoimmunity

Nat Rev Immunol. 2012 Oct;12(10):721-8. doi: 10.1038/nri3294. Epub 2012 Sep 7.


The interaction of antigen-presenting cells with free peptides or a denatured protein can give rise to peptide-MHC class II complexes that are distinct from those generated after the processing of the whole protein. Such atypical peptide-MHC complexes can be recognized by unconventional 'type B' T cells that are not a component of the normal immune response to proteins. Importantly, these unconventional T cells can be found in the setting of autoimmunity. Here, we discuss unconventional peptide recognition by type B T cells and consider the implications for type 1 diabetes and other autoimmune diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antigen Presentation / immunology
  • Autoantigens / chemistry
  • Autoantigens / immunology
  • Autoimmunity*
  • CD4-Positive T-Lymphocytes / immunology
  • Epitopes, T-Lymphocyte / immunology
  • Epitopes, T-Lymphocyte / metabolism
  • Histocompatibility Antigens Class II / immunology
  • Histocompatibility Antigens Class II / metabolism
  • Humans
  • Peptides / immunology*
  • Peptides / metabolism
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocytes / immunology*


  • Autoantigens
  • Epitopes, T-Lymphocyte
  • Histocompatibility Antigens Class II
  • Peptides