Tails of wonder: endocytic-sorting motifs key for exogenous antigen presentation

Trends Immunol. 2005 Mar;26(3):141-9. doi: 10.1016/j.it.2005.01.005.


Antigen-presenting molecules, including MHC I, II and CD1, have central roles in the induction of T cell-mediated immunity against pathogens and tumors and also in the maintenance of tolerance towards self-antigens. The presentation of exogenously derived peptide and lipid antigens to specific T cells by professional antigen-presenting cells (pAPCs) is an essential part of both processes. Exogenous antigen loading takes place mostly within specialized endocytic and phagocytic compartments of pAPCs and targeting of antigen-presenting molecules to these intracellular compartments is mediated by highly conserved cytoplasmic sorting motifs. Recent data have revealed that the cytoplasmic tails of antigen-presenting molecules, by controlling the access of these molecules to exogenously derived antigens, have a crucially important and largely underappreciated role in the generation of tolerance and T-cell mediated immunity.

Publication types

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

MeSH terms

  • Amino Acid Motifs / immunology
  • Amino Acid Motifs / physiology
  • Animals
  • Antigen Presentation / immunology*
  • Antigens, CD1 / immunology
  • Endocytosis / immunology*
  • Histocompatibility Antigens Class I / immunology
  • Histocompatibility Antigens Class II / immunology
  • Humans
  • Models, Biological
  • T-Lymphocytes / immunology


  • Antigens, CD1
  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II