title: T cell lines specific for a synthetic Heymann nephritis peptide derived from the receptor-associated protein.
abstract: Pathogenic antigens involved in the induction of Heymann nephritis (HN), an experimental rat model of human membranous nephritis, have been identified in megalin (gp330) and the receptor-associated protein (RAP) [1,2]. A pathogenic epitope has been identified in RAP (amino acid 1-86) that plays a significant role in the formation of immune deposits in glomeruli in HN. A synthetic peptide (P31-53) derived from RAP1-86 contains a pathogenic epitope recognized by antibodies eluted from glomerular immune deposits and includes two putative RT-1B1 MHC class II-binding motifs. We have investigated whether RAP P31-53 can be recognized by T cells. Five peptide-specific T cell lines were generated from regional lymph node (LN) T cells from Lewis rats immunized with P31-53. The T cell lines were characterized by using a T cell proliferation assay for their specificity, FACS and MHC restriction assay for the phenotype, reverse transcription-polymerase chain reaction for TCR Vbeta repertoire and cytokine expression, and cloning and sequencing for the analysis of the CDR3 sequence of TCR. The helper function of the T cell line was confirmed by autoantibody production in vitro. In this study, we clearly identify that the synthetic pathogenic peptide P31-53 contains a T cell epitope recognized by CD4+ Th2 cells in Lewis rats. This recognition was restricted by MHC class II RT1.B1. These CD4+ Th2 cells were able to promote B cells to produce specific antibodies and used a restricted set of TCR Vbeta genes with preferential usage of Vbeta18. A charged amino acid motif at the CDR3 region of predominant TCR Vbeta subfamilies may contribute to the specific ability of these cells to recognize the immunogenic T cell epitope within RAP peptide P31-53.
authors.affiliation: Centre for Kidney Research, Royal Alexandra Hospital for Children, Westmead, New South Wales, Australia. huilw@nch.edu.au
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: G Y
authors.initials: GY
authors.lastname: Zhang
authors.forename: J F
authors.initials: JF
authors.lastname: Knight
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D001324:Autoantigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D002455:Cell Division; D002460:Cell Line; D016207:Cytokines / Q000235:genetics; D005921:Glomerulonephritis / Q000276:immunology*; D026541:Heymann Nephritis Antigenic Complex; D006649:Histocompatibility Antigens / Q000276:immunology; D006801:Humans; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D016827:CD8 Antigens; D016207:Cytokines; D026541:Heymann Nephritis Antigenic Complex; D006649:Histocompatibility Antigens; D008562:Membrane Glycoproteins; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta; C038353:histocompatibility antigens RT, rat