Lymphocyte responses to DR4/1‐restricted peptides in rheumatoid arthritis. The immunodominant T cell epitope on the 19‐kdmycobacterium tuberculosisprotein

摘要

AbstractObjective.Peptides presented by DR4/1 may be involved in the pathogenesis of rheumatoid arthritis (RA). T cell responses to DR4/1‐restricted peptides unrelated to the causative antigen may be altered in RA. Thus, DR4/1‐restricted lymphocyte responses in healthy volunteers and patients with RA were determined.Methods.Peripheral blood lymphocytes (PBL) and synovial lymphocytes were cultured with synthetic peptides spanning the 19‐kdMycobacterium tuberculosis(MT) protein.Results.3H‐thymidine uptake by PBL from 5 of 7 healthy individuals and 5 of 7 RA patients increased in response to the N‐terminal peptide (residues 1–20). Eleven fresh synovial fluid and 4 fresh synovial tissue (ST) lymphocyte samples did not proliferate in response to any of the peptides. However, the same T cell epitope was identified by ST lymphocytes when these were precultured. The N‐terminal peptide was not a common antibody‐binding site, unlike several of the other peptides.Conclusion.Similar responses by RA and normal PBL to a DR4/1‐restricted immunodominant T cell epitope on the 19‐kd MT protein were observed. The responses were more readily detected in PBL than in synovial lymphocytes. These observations may be relevant for assessing unrelated synthetic peptides in the development of DR4/1‐restricted