title: The pathogenicity of T cell epitopes on human Goodpasture antigen and its critical amino acid motif.
abstract: Goodpasture antigen, the non-collagenous domain of α3 chain of type IV collagen [α3(IV)NC1], is the target antigen of anti-glomerular basement membrane (GBM) antibodies. The pathogenicity of T cell epitopes is not elucidated clearly. In this study, we aim to define the nephritogenic T cell epitopes and its critical amino acid residues. Twenty-four overlapping linear peptides were synthesized covering the whole sequence of human α3(IV)NC1. Wistar-Kyoto rats were immunized with linear peptides, and experimental autoimmune glomerulonephritis was evaluated. Critical amino acid was identified by the loss of nephritogenic function after each amino acid substitution by alanine. Of the 24 peptides, P14 (α3127-148) could induce 90.5% (19/21) of WKY rats developing anti-GBM glomerulonephritis with proteinuria, elevated serum urea and creatinine, IgG linear deposit on GBM and substantial (in average 82.4 ± 5.6%) crescent formation in glomeruli. Lymphocytes of immunized rats proliferated in response to α3127-148and α3(IV)NC1 in vitro. Sera of these rats recognized α3127-148and later on together with intact human α3(IV)NC1. Antibodies towards α3127-148and intact α3(IV)NC1 could also be detected from the kidney elutes. These antibodies showed no cross-reaction with each other, which implies intramolecular epitope spreading during disease progress. After sequential amino acid substitution, the α3127-148with substitution of tryptophan136, isoleucine137, leucine139or tryptophan140lost its nephritogenicity. Human α3127-148is a nephritogenic T cell epitope in WKY rats, with the critical amino acids as W136I137xL139W140. These findings might facilitate future investigation on microbial aetiology and potential specific immunotherapy of anti-GBM disease.
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.|Department of Nephrology, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Shui-Yi
authors.initials: SY
authors.lastname: Hu
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Qiu-Hua
authors.initials: QH
authors.lastname: Gu
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Jia
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Renal Division, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.|Peking-Tsinghua Center for Life Sciences, Beijing, China.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D019867:Anti-Glomerular Basement Membrane Disease / Q000097:blood / Q000276:immunology; D000906:Antibodies / Q000097:blood; D000917:Antibody Formation / Q000276:immunology; D001324:Autoantigens / Q000737:chemistry* / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology; D002417:Cattle; D024141:Collagen Type IV / Q000737:chemistry* / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology; D006801:Humans; D007114:Immunization; D007668:Kidney / Q000473:pathology; D010455:Peptides / Q000737:chemistry; D011921:Rats, Inbred WKY; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D001324:Autoantigens; D024141:Collagen Type IV; D018984:Epitopes, T-Lymphocyte; D010455:Peptides; C057112:type IV collagen alpha3 chain
keywords: Goodpasture antigen; T cell; anti-GBM disease; epitope; experimental autoimmune glomerulonephritis