title: Identification of T-cell epitopes on U1A protein in MRL/lpr mice: double-negative T cells are the major responsive cells.
abstract: Systemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies such as anti-DNA, chromatin, histone, and ribonucleoprotein antibodies (Abs). Although the B-cell antigenic determinants have been well characterized, very limited data about the T-cell epitopes of self-antigen (Ag) have been reported. In the present study, we analysed auto-T-cell epitopes using bone marrow-derived dendritic cells (BM-DCs) pulsed with murine U1A (mU1A) protein capable of activating autoreactive T cells from unprimed MRL/lpr mice in vitro. The data suggested that there are at least four T-cell epitopes on the U1A protein, U1A31-50, U1A61-80, U1A201-220 and U1A271-287, and U1A31-50 had the most significant T-cell proliferative response. In addition, the main responsive T cells are the CD4- CD8- double-negative subgroup of T cells. Furthermore, we also demonstrated that the activation of double-negative T cells is major histocompatibility complex class II restricted. The study here provides information on T-cell epitope analysis of the U1A antigen using BM-DCs as the effective antigen-presenting cells.
authors.affiliation: Graduate Institute of Clinical Medicine Sciences, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Yang
authors.forename: Jau-Ling
authors.initials: JL
authors.lastname: Suen
authors.forename: Shiao-Lan
authors.initials: SL
authors.lastname: Li
authors.forename: Bor-Luen
authors.initials: BL
authors.lastname: Chiang
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D000974:Antibodies, Antinuclear / Q000096:biosynthesis; D001323:Autoantibodies / Q000096:biosynthesis; D001324:Autoantigens / Q000032:analysis; D001854:Bone Marrow Cells / Q000276:immunology; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology; D004195:Disease Models, Animal; D018984:Epitopes, T-Lymphocyte / Q000032:analysis*; D005260:Female; D005802:Genes, MHC Class II; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D019463:Mice, Inbred MRL lpr; D008815:Mice, Inbred Strains; D016601:RNA-Binding Proteins / Q000276:immunology*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D001324:Autoantigens; D015704:CD4 Antigens; D016827:CD8 Antigens; D018984:Epitopes, T-Lymphocyte; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; C075339:U1A protein