HLA-B27-restricted T cells from patients with ankylosing spondylitis recognize peptides from B*2705 that are similar to bacteria-derived peptides.
Ankylosing spondylitis (AS) is an inflammatory systemic disease affecting the spine, sacroiliacal and peripheral joints. Although the aetiology of AS remains unknown, the strong association with the HLA-B27 allele might reflect directly a detrimental effect of the HLA-B27 molecule itself, resulting from its potential capability to present 'arthritogenic' peptides to CD8+ T cells. Because some forms of SpA are triggered by enterobacterial infection, such arthritogenic peptides might originate from autologous and/or bacterial proteins triggering cross-reactive CD8+ T cell clones. Intriguingly, two peptides from the second extracellular domain of HLA-B*2705 share sequence homologies with several enterobacterial antigens, exhibit the HLA-B27-binding-motif, and are presented by HLA-B*2705 itself. The objective of this study was to examine the clonal T cell reactivity against these peptides in patients with AS. To this end, we screened peripheral blood lymphocytes (PBL) of 26 patients with AS and 24 healthy donors for TNF-alpha-producing cells using ELISPOT assays. PBL and synovial fluid-derived lymphocytes (SFL) of peptide-responsive patients were then stimulated and cultured with the relevant peptide and control peptides in vitro. Antigen-specific T cell lines (TCL) were identified by standard chromium release assays. Clonal analysis was performed subsequently applying TCRB-CDR3 spectratyping. Among eight peptides tested, only the HLA-B27 168-176 peptide LRRYLENGK was recognized by PBL from B27+ AS patients but not from B27+ healthy controls (P=0.001). LRRYLENGK-specific T cell clones used preferentially the TCRBV5S1 and the BV14 segment. These results suggest that an HLA-B27-derived peptide with homology to bacterial peptides may play a role in AS.
Frauendorf
E
E
First Department of Medicine, Johannes Gutenberg-University Mainz, Germany. efrauend@mail.uni-mainz.de
von Goessel
H
H
May
E
E
Märker-Hermann
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D022801:Complementarity Determining Regions / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005260:Female; D015796:HLA-B27 Antigen / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D013167:Spondylitis, Ankylosing / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000942:Antigens, Bacterial; D001324:Autoantigens; D022801:Complementarity Determining Regions; D000939:Epitopes; D015796:HLA-B27 Antigen; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014409:Tumor Necrosis Factor-alpha