title: A distinct immunogenic region of glutamic acid decarboxylase 65 is naturally processed and presented by human islet cells to cytotoxic CD8 T cells.
abstract: CD8 T cells specific for islet autoantigens are major effectors of β cell damage in type 1 diabetes, and measurement of their number and functional characteristics in blood represent potentially important disease biomarkers. CD8 T cell reactivity against glutamic acid decarboxylase 65 (GAD65) in HLA-A*0201 subjects has been reported to focus on an immunogenic region 114-123 (VMNILLQYVV), with studies demonstrating both 114-123 and 114-122 epitopes being targeted. However, the fine specificity of this response is unclear and the key question as to which epitope(s) β cells naturally process and present and, therefore, the pathogenic potential of CD8 T cells with different specificities within this region has not been addressed. We generated human leucocyte antigen (HLA)-A*0201-restricted CD8 T cell clones recognizing either 114-122 alone or both 114-122 and 114-123. Both clone types show potent and comparable effector functions (cytokine and chemokine secretion) and killing of indicator target cells externally pulsed with cognate peptide. However, only clones recognizing 114-123 kill target cells transfected with HLA-A*0201 and GAD2 and HLA-A*0201(+) human islet cells. We conclude that the endogenous pathway of antigen processing by HLA-A*0201-expressing cells generates GAD65114-123 as the predominant epitope in this region. These studies highlight the importance of understanding β cell epitope presentation in the design of immune monitoring for potentially pathogenic CD8 T cells.
authors.affiliation: Department of Immunobiology, King's College London, London, UK.
authors.forename: R R
authors.initials: RR
authors.lastname: Knight
authors.forename: G
authors.initials: G
authors.lastname: Dolton
authors.forename: D
authors.initials: D
authors.lastname: Kronenberg-Versteeg
authors.forename: M
authors.initials: M
authors.lastname: Eichmann
authors.forename: M
authors.initials: M
authors.lastname: Zhao
authors.forename: G C
authors.initials: GC
authors.lastname: Huang
authors.forename: K
authors.initials: K
authors.lastname: Beck
authors.forename: D K
authors.initials: DK
authors.lastname: Cole
authors.forename: A K
authors.initials: AK
authors.lastname: Sewell
authors.forename: A
authors.initials: A
authors.lastname: Skowera
authors.forename: M
authors.initials: M
authors.lastname: Peakman
mesh_terms: D017951:Antigen Presentation / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D002460:Cell Line; D002999:Clone Cells; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005968:Glutamate Decarboxylase / Q000737:chemistry / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D001324:Autoantigens; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2
keywords: CD8 T cell clones; GAD65; autoimmunity; peptide-processing; type 1 diabetes
references.citation: Transplantation. 2004 Jan 15;77(1):143-5
references.pmid: 14724452
references.citation: Diabetologia. 2012 Jul;55(7):2026-31
references.pmid: 22526607
references.citation: Nature. 2007 Dec 6;450(7171):887-92
references.pmid: 18004301
references.citation: J Immunol. 2013 Jul 15;191(2):583-93
references.pmid: 23776170
references.citation: Blood. 2013 Feb 14;121(7):1112-23
references.pmid: 23255554
references.citation: Clin Exp Immunol. 2014 Sep;177(3):571-85
references.pmid: 24773525
references.citation: Diabetes. 2013 Jan;62(1):205-13
references.pmid: 22936177
references.citation: Immunogenetics. 1999 Nov;50(3-4):213-9
references.pmid: 10602881
references.citation: Clin Exp Immunol. 2014 May;176(2):199-206
references.pmid: 24387268
references.citation: J Exp Med. 1995 May 1;181(5):1923-7
references.pmid: 7722468
references.citation: Curr Opin Immunol. 2011 Dec;23(6):746-53
references.pmid: 22051340
references.citation: Anal Biochem. 1993 Oct;214(1):17-24
references.pmid: 8250221
references.citation: Sci Transl Med. 2013 Jun 26;5(191):191ra82
references.pmid: 23803704
references.citation: J Clin Invest. 2008 May;118(5):1806-14
references.pmid: 18431516
references.citation: J Exp Med. 2012 Jan 16;209(1):51-60
references.pmid: 22213807
references.citation: Diabetes. 2010 Jul;59(7):1721-30
references.pmid: 20357361
references.citation: J Clin Invest. 2008 Oct;118(10):3390-402
references.pmid: 18802479
references.citation: Immunology. 2009 Feb;126(2):147-64
references.pmid: 19125886
references.citation: Diabetes. 2012 Jul;61(7):1752-9
references.pmid: 22522618
references.citation: Clin Exp Immunol. 2007 Apr;148(1):1-16
references.pmid: 17349009
references.citation: Nucleic Acids Res. 2010 Jan;38(Database issue):D854-62
references.pmid: 19906713
references.citation: Vaccine. 2013 Mar 15;31(12):1610-5
references.pmid: 23246542
references.citation: Diabetes Metab Res Rev. 2011 Nov;27(8):720-6
references.pmid: 22069251
references.citation: Clin Exp Immunol. 2009 Feb;155(2):173-81
references.pmid: 19128359
references.citation: Clin Exp Immunol. 2014 Jul;177(1):47-63
references.pmid: 24673376
references.citation: Clin Exp Immunol. 2013 May;172(2):186-202
references.pmid: 23574316
references.citation: J Immunol. 2007 Nov 1;179(9):5785-92
references.pmid: 17947651
references.citation: J Biomed Biotechnol. 2009;2009:576219
references.pmid: 20029631
references.citation: Immunogenetics. 2011 Jan;63(1):43-55
references.pmid: 21079948
references.citation: Nucleic Acids Res. 2011 Jan;39(Database issue):D913-9
references.pmid: 21062830
references.citation: Protein Sci. 1995 Nov;4(11):2411-23
references.pmid: 8563639
references.citation: Methods Enzymol. 2004;383:282-317
references.pmid: 15063655