Advanced

Conformation-dependent GAD65 autoantibodies in diabetes

Luo, D; Gilliam, LK; Greenbaum, C; Bekris, L; Hampe, CS; Daniels, T; Richter, W; Marcovina, SM; Rolandsson, O and Landin-Olsson, Mona LU , et al. (2004) In Diabetologia 47(9). p.1581-1591
Abstract
Aims/hypothesis. Conformation-dependent autoantibodies directed against GAD65 are markers of Type 1 diabetes. In this study we aimed to determine whether the substitution of GAD65 with GAD67 amino acids would affect the binding of conformation-dependent GAD65 autoantibodies. Methods. We used PCR-based site-directed mutagenesis to generate a series of mutated GAD65 cDNA constructs in which specific GAD65 coding sequences for regions of the protein critical for autoantibody binding were replaced with GAD67 coding sequences. Results. The introduction of a point mutation at position 517, substituting glutamic acid with proline, markedly reduced the binding of disease-associated GAD65 antibodies. The binding of GAD65 antibodies to the E517P... (More)
Aims/hypothesis. Conformation-dependent autoantibodies directed against GAD65 are markers of Type 1 diabetes. In this study we aimed to determine whether the substitution of GAD65 with GAD67 amino acids would affect the binding of conformation-dependent GAD65 autoantibodies. Methods. We used PCR-based site-directed mutagenesis to generate a series of mutated GAD65 cDNA constructs in which specific GAD65 coding sequences for regions of the protein critical for autoantibody binding were replaced with GAD67 coding sequences. Results. The introduction of a point mutation at position 517, substituting glutamic acid with proline, markedly reduced the binding of disease-associated GAD65 antibodies. The binding of GAD65 antibodies to the E517P mutant was reduced in the sera of all newly diagnosed Type 1 diabetes patients (n=85) by a mean of 72% (p<0.0001) compared with binding to wild-type GAD65. Patients with latent autoimmune diabetes in adults (n=24) showed a similar reduction in binding (79% reduction, p<0.0001). First-degree relatives who subsequently progressed to Type 1 diabetes (n=12) showed a reduction in binding of 80% compared with a reduction of only 65% among relatives who had not progressed to disease (n=38; p=0.025). In healthy GAD65Ab-positive individuals who did not progress to diabetes during a 9-year follow-up period (n=51), binding to GAD65-E517P was reduced by only 28% compared with binding to wild-type GAD65. Conclusions/interpretation. Differences in autoantibody binding to wild-type GAD65 versus GAD65-E517P may provide predictive information about Type 1 diabetes risk beyond that provided by the presence or absence of GAD65 autoantibodies. Lack of binding to mutant GAD65-E517P defines GAD65-positive individuals who are at higher risk of developing diabetes. (Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Type 1 diabetes, Type 2 diabetes, in adults, latent autoimmune diabetes, GAD65, Epitope, autoantibody, autoimmunity
in
Diabetologia
volume
47
issue
9
pages
1581 - 1591
publisher
Springer Verlag
external identifiers
  • wos:000224584700015
  • pmid:15365614
  • scopus:5644244334
ISSN
1432-0428
DOI
10.1007/s00125-004-1495-3
language
English
LU publication?
yes
id
aeba87d0-4d89-4ab4-aa5b-75379bd25e2a (old id 264076)
date added to LUP
2007-10-24 21:24:45
date last changed
2017-01-01 04:49:42
@article{aeba87d0-4d89-4ab4-aa5b-75379bd25e2a,
  abstract     = {Aims/hypothesis. Conformation-dependent autoantibodies directed against GAD65 are markers of Type 1 diabetes. In this study we aimed to determine whether the substitution of GAD65 with GAD67 amino acids would affect the binding of conformation-dependent GAD65 autoantibodies. Methods. We used PCR-based site-directed mutagenesis to generate a series of mutated GAD65 cDNA constructs in which specific GAD65 coding sequences for regions of the protein critical for autoantibody binding were replaced with GAD67 coding sequences. Results. The introduction of a point mutation at position 517, substituting glutamic acid with proline, markedly reduced the binding of disease-associated GAD65 antibodies. The binding of GAD65 antibodies to the E517P mutant was reduced in the sera of all newly diagnosed Type 1 diabetes patients (n=85) by a mean of 72% (p&lt;0.0001) compared with binding to wild-type GAD65. Patients with latent autoimmune diabetes in adults (n=24) showed a similar reduction in binding (79% reduction, p&lt;0.0001). First-degree relatives who subsequently progressed to Type 1 diabetes (n=12) showed a reduction in binding of 80% compared with a reduction of only 65% among relatives who had not progressed to disease (n=38; p=0.025). In healthy GAD65Ab-positive individuals who did not progress to diabetes during a 9-year follow-up period (n=51), binding to GAD65-E517P was reduced by only 28% compared with binding to wild-type GAD65. Conclusions/interpretation. Differences in autoantibody binding to wild-type GAD65 versus GAD65-E517P may provide predictive information about Type 1 diabetes risk beyond that provided by the presence or absence of GAD65 autoantibodies. Lack of binding to mutant GAD65-E517P defines GAD65-positive individuals who are at higher risk of developing diabetes.},
  author       = {Luo, D and Gilliam, LK and Greenbaum, C and Bekris, L and Hampe, CS and Daniels, T and Richter, W and Marcovina, SM and Rolandsson, O and Landin-Olsson, Mona and Kockum, I and Lernmark, A},
  issn         = {1432-0428},
  keyword      = {Type 1 diabetes,Type 2 diabetes,in adults,latent autoimmune diabetes,GAD65,Epitope,autoantibody,autoimmunity},
  language     = {eng},
  number       = {9},
  pages        = {1581--1591},
  publisher    = {Springer Verlag},
  series       = {Diabetologia},
  title        = {Conformation-dependent GAD65 autoantibodies in diabetes},
  url          = {http://dx.doi.org/10.1007/s00125-004-1495-3},
  volume       = {47},
  year         = {2004},
}