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- Chen, Lanlin, et al.
(författare)
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A nephritogenic peptide induces intermolecular epitope spreading on collagen IV in experimental autoimmune glomerulonephritis
- 2006
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673. ; 17:11, s. 3076-3081
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Tidskriftsartikel (refereegranskat)abstract
- This group previously identified a peptide p13 of alpha 3(IV)NC1 domain of type IV collagen that induces experimental autoimmune glomerulonephritis (EAG) in rats with generation of antibodies to sites on alpha 3(IV)NC1 external to the peptide as a result of intramolecular epitope spreading. It was hypothesized that intermolecular epitope spreading to other collagen IV chains also was induced. Rats were immunized with nephritogenic peptide that was derived from the amino terminal part of rat alpha 3(IV)NC1 domain, and serum and kidney eluate were examined for antibodies to both native and recombinant NC1 domains of collagen IV. Peptide induced EAG with proteinuria and decreased renal function and glomerular basement membrane IgG deposits. Sera from these rats were examined by ELISA, which revealed reactivity not only to immunizing peptide but also to human and rat alpha 3(IV)NC1 and to human alpha 4(IV)NC1 domains. Kidney eluate that was depleted of alpha 3(IV)NC1 antibodies still reacted to alpha 4(IV)NC1, and alpha 3(IV)NC1 column-bound antibody reacted with alpha 3(IV)NC1. There was minimal reactivity to other collagen chains. Eluate that was adsorbed to NC1 hexamer from rat glonterular basement membrane lost all reactivity to glomerular constituents, and the eluted antibodies reacted to alpha 3(IV)NC1 and alpha 4(IV)NC1 domains. These studies show that a T cell epitope of alpha 3(IV)NC1 induces EAG, intramolecular epitope spreading along alpha 3(IV)NC1, and intermolecular epitope spreading to alpha 4(IV)NC1 domain with minimal or no reactivity to other collagen chains or glomerular constituents. This is the first demonstration in EAG of intermolecular epitope spreading and identification of the spread epitopes.
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| 2. |
- Bolton, W Kline, et al.
(författare)
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Molecular mapping of the Goodpasture's epitope for glomerulonephritis
- 2005
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Ingår i: Transactions of the American Clinical and Climatological Association. - 0065-7778. ; 116, s. 229-238
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Tidskriftsartikel (refereegranskat)abstract
- Goodpasture's syndrome is an autoimmune disease characterized by pulmonary hemorrhage, glomerulonephritis, and antiglomerular basement membrane (GBM) antibodies. We have studied a rat model with chimeric proteins (CPs) consisting of portions of the nephritogenic non-collagenous domain of alpha3 type IV collagen (alpha3(IV)NC1) and non-nephritogenic alpha1(IV)NC1. CPs with aminoterminal alpha3 that contains the major epitope for Goodpasture antibody binding induced EAG. We next immunized with D3, an alpha1(IV)NC1 CP with 69AA of alpha3(IV)NC1 (binds Goodpasture sera), D4, the D3 construct shortened by 4 AA (nonbinding), P9 and P10, single AA mutants (nonbinding) and S2, an alpha1(IV)NC1 with nine AA of alpha3(IV)NC1 (binding). GBM, S2 and D3 induced EAG. GBM immunized rats had intense IgG deposits but S2 and D3 rats had minimal deposits. A 13 mer rat peptide encompassing the aminoterminal site induced EAG sans antibody, while peptides not encompassing the region failed to induce GN. Asparagine at position 19 rather than isoleucine was essential for disease induction. These studies define critical limited AA sequences of alpha3(IV)NC1 associated with glomerulonephritis without antibody, and demonstrate that this region contains a T-cell epitope responsible for induction of glomerulonephritis.
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