Publication Date:
2008-11-28
Description:
Major histocompatibility complex (MHC) class II alleles HLA-DQ8 and the mouse homologue I-A(g7) lacking a canonical aspartic acid residue at position beta57 are associated with coeliac disease and type I diabetes. However, the role of this single polymorphism in disease initiation and progression remains poorly understood. The lack of Asp 57 creates a positively charged P9 pocket, which confers a preference for negatively charged peptides. Gluten lacks such peptides, but tissue transglutaminase (TG2) introduces negatively charged residues at defined positions into gluten T-cell epitopes by deamidating specific glutamine residues on the basis of their spacing to proline residues. The commonly accepted model, proposing that HLA-DQ8 simply favours binding of negatively charged peptides, does not take into account the fact that TG2 requires inflammation for activation and that T-cell responses against native gluten peptides are found, particularly in children. Here we show that beta57 polymorphism promotes the recruitment of T-cell receptors bearing a negative signature charge in the complementary determining region 3beta (CDR3beta) during the response against native gluten peptides presented by HLA-DQ8 in coeliac disease. These T cells showed a crossreactive and heteroclitic (stronger) response to deamidated gluten peptides. Furthermore, gluten peptide deamidation extended the T-cell-receptor repertoire by relieving the requirement for a charged residue in CDR3beta. Thus, the lack of a negative charge at position beta57 in MHC class II was met by negatively charged residues in the T-cell receptor or in the peptide, the combination of which might explain the role of HLA-DQ8 in amplifying the T-cell response against dietary gluten.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784325/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3784325/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hovhannisyan, Zaruhi -- Weiss, Angela -- Martin, Alexandra -- Wiesner, Martina -- Tollefsen, Stig -- Yoshida, Kenji -- Ciszewski, Cezary -- Curran, Shane A -- Murray, Joseph A -- David, Chella S -- Sollid, Ludvig M -- Koning, Frits -- Teyton, Luc -- Jabri, Bana -- DK42086/DK/NIDDK NIH HHS/ -- DK55037/DK/NIDDK NIH HHS/ -- DK67180/DK/NIDDK NIH HHS/ -- R01 DK067180/DK/NIDDK NIH HHS/ -- R01 DK067180-04/DK/NIDDK NIH HHS/ -- England -- Nature. 2008 Nov 27;456(7221):534-8. doi: 10.1038/nature07524.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Pathology, Pediatrics and Committee of Immunology, University of Chicago, Chicago, Illinois 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19037317" target="_blank"〉PubMed〈/a〉
Keywords:
Amides/chemistry
;
Animals
;
CD4-Positive T-Lymphocytes/*immunology
;
Celiac Disease/*genetics/*immunology
;
Complementarity Determining Regions/chemistry/immunology
;
Cross Reactions
;
Epitopes, T-Lymphocyte/chemistry/immunology
;
Gliadin/chemistry/immunology
;
Glutens/chemistry/*immunology
;
HLA-DQ Antigens/chemistry/*genetics/immunology
;
Humans
;
Hybridomas/immunology
;
Mice
;
Mice, Transgenic
;
Polymorphism, Genetic/*genetics
;
Receptors, Antigen, T-Cell/chemistry/immunology
;
Static Electricity
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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