Tails of wonder: endocytic-sorting motifs key for exogenous antigen presentation.
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.
Lizée
Gregory
G
Biomedical Research Centre, The Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC, Canada, V6T 1Z3.
Basha
Genc
G
Jefferies
Wilfred A
WA
D020816:Amino Acid Motifs / Q000276:immunology / Q000502:physiology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D018949:Antigens, CD1 / Q000276:immunology; D004705:Endocytosis / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D008954:Models, Biological; D013601:T-Lymphocytes / Q000276:immunology
D018949:Antigens, CD1; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II