King's College London

Research portal

A distinct immunogenic region of glutamic acid decarboxylase 65 is naturally processed and presented by human islet cells to cytotoxic CD8 T cells

Research output: Contribution to journalArticle

R. R. Knight, G. Dolton, D. Kronenberg-Versteeg, M. Eichmann, M. Zhao, G. C. Huang, K. Beck, D. K. Cole, A. K. Sewell, A. Skowera, M. Peakman

Original languageEnglish
Pages (from-to)100-107
Number of pages8
JournalClinical and Experimental Immunology
Volume179
Issue number1
Early online date26 Nov 2014
DOIs
Publication statusPublished - Jan 2015

King's Authors

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.

View graph of relations

© 2018 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454