title: T cell epitopes of type II collagen in HLA-DRB1*0101 or DRB1*0405-positive Japanese patients with rheumatoid arthritis.
abstract: Rheumatoid arthritis (RA) is a T cell-mediated autoimmune disease, but target antigens (autoantigens) responsible for T cell activation remain unclear. Type II collagen (CII) is a candidate autoantigen that is largely confined to the articular cartilage. To investigate whether CII is an important antigen in patients with RA, we examined peripheral blood T cell reactivity to CII in HLA-DRB1*0101 and DRB1*0405-positive RA patients. Reactivities to candidate T cell epitopes of CII were also examined. Peripheral blood T cell reactivity to CII and CII peptides (256-271, 429-442, 593-610, 1064-1081) were detected by measurement of IL-2, IFN-gamma, and IL-4 in culture supernatant of PBMC after in vitro antigen stimulation. Cytokine concentration was measured by ELISA. In DRB1*0101-positive patients, T cell reactivity to CII as detected by measurement of IL-2 production in culture supernatant, was present in 4 out of 9 patients. IL-2 production upon stimulation with CII 256-271 peptide was found in all of these 4 patients. In DRB1*0405-positive patients, high frequency of positive T cell response to CII was detected in 9 out of 11 patients. IFN-gamma production was also detected in 4 out of 6 patients producing IL-2 by stimulation with CII. T cell response to CII 256-271 and/or CII 1064-1081 was detected in these patients. In DRB1*0101-positive RA patients, CII 256-271 peptide might function as a T cell epitope, whereas either CII 256-271 or CII 1064-1081 peptide may be a major T cell epitope in DRB1*0405-positive RA patients. In DRB1*0405-positive RA patients, CII reactive T cells might play a crucial role in the development of RA through IFN-gamma production.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba City, Ibaraki 305-8575, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: Akito
authors.initials: A
authors.lastname: Tsutsumi
authors.forename: Tateo
authors.initials: T
authors.lastname: Sakamaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sumida
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000473:pathology; D024043:Collagen Type II / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000032:analysis*; D006684:HLA-DR Antigens / Q000276:immunology*; D059811:HLA-DRB1 Chains; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D007376:Interleukin-2 / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D007564:Japan; D010446:Peptide Fragments / Q000494:pharmacology
chemical_list: D024043:Collagen Type II; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007376:Interleukin-2; D010446:Peptide Fragments; D015847:Interleukin-4; D007371:Interferon-gamma