Abstract

REVISED ABSTRACT: Type 1 diabetes (T1D) mellitus is a predictable disease and autoantibodies (Ab) against GAD65, IA-2 or insulin (IAA) are effective markers. During the current funding period we have made considerable progress towards the identification of GAD65Ab epitopes associated with T1D. We also established that GAD65Ab were associated with HLA DR3-DQ2 while DR4-DQ8 was associated with IA-2Ab or IAA. IAA were associated with INS VNTR on chromosome 11. We now aim to uncover the mechanisms by which these autoantibody disease markers are triggered and mature in relation to progression towards T1D.
The specific aims test these hypotheses:1) Islet autoimmunity is established by the shift towards specific isotype and subtype autoantibodies;2) Progression to T1D is associated with maturation towards specific GAD65Ab epitopes;3) Maturation towards specific autoantibody epitopes is associated with HLA alone, or modulated by non-HLA genetic factors such as INS VNTR for IAA and Oligoadenylate synthetase (OAS) for GAD65Ab. These hypotheses will be tested in prospective studies of large populations of newborns, healthy subjects and studies of school children and first-degree relatives. We will dissect early autoantibody responses including IgM, IgA, and IgE compared to persistent GAD65-lgG using novel high throughput assays with recombinant biotinylated GAD65 and GAD65-specific Fab for epitope mapping. We will a) detect individuals with very early autoantibody response to GAD65, and b) identify isotype switches and maturation to disease-associated epitopes. We will correlate the maturation towards specific autoantibody epitopes with HLA, non-HLA genetic factors, alone or in combination. We will also clarify why some epitope-restricted autoantibodies are associated islet autoimmunity alone and others with progression towards T1D.
This research aims to uncover the mechanisms of the early immune response to GAD65 and the relationship between the autoantibody response maturation and progression to clinical onset of T1D.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK026190-23
Application #
7778205
Study Section
Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section (HAI)
Program Officer
Spain, Lisa M
Project Start
1980-01-01
Project End
2012-02-29
Budget Start
2010-03-01
Budget End
2012-02-29
Support Year
23
Fiscal Year
2010
Total Cost
$301,272
Indirect Cost

  Institution

Name
University of Washington
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195

  Publications

Mulukutla, Surya N; Hsu, Jean W; Gaba, Ruchi et al. (2018) Arginine Metabolism Is Altered in Adults with A-? + Ketosis-Prone Diabetes. J Nutr 148:185-193
Liimatainen, Suvi; Honnorat, Jerome; Pittock, Sean J et al. (2018) GAD65 autoantibody characteristics in patients with co-occurring type 1 diabetes and epilepsy may help identify underlying epilepsy etiologies. Orphanet J Rare Dis 13:55
Hampe, C S; Radtke, J R; Wester, A et al. (2018) Reduced display of conformational epitopes in the N-terminal truncated GAD65 isoform: relevance for people with stiff person syndrome or DQ8/8-positive Type 1 diabetes mellitus. Diabet Med :
Manto, Mario; Hampe, Christiane S (2018) Endocrine disorders and the cerebellum: from neurodevelopmental injury to late-onset ataxia. Handb Clin Neurol 155:353-368
Mulukutla, Surya N; Tersey, Sarah A; Hampe, Christiane S et al. (2018) Elevated unmethylated and methylated insulin DNA are unique markers of A+?+ ketosis prone diabetes. J Diabetes Complications 32:193-195
Mitoma, Hiroshi; Manto, Mario; Hampe, Christiane S (2018) Time Is Cerebellum. Cerebellum 17:387-391
Mitoma, Hiroshi; Manto, Mario; Hampe, Christiane S (2018) Immune-mediated cerebellar ataxias: Practical guidelines and therapeutic challenges. Curr Neuropharmacol :
Mitoma, Hiroshi; Manto, Mario; Hampe, Christiane S (2017) Immune-mediated cerebellar ataxias: from bench to bedside. Cerebellum Ataxias 4:16
Bansal, N; Hampe, C S; Rodriguez, L et al. (2017) DPD epitope-specific glutamic acid decarboxylase (GAD)65 autoantibodies in children with Type 1 diabetes. Diabet Med 34:641-646
Mitoma, Hiroshi; Manto, Mario; Hampe, Christiane S (2017) Pathogenic Roles of Glutamic Acid Decarboxylase 65 Autoantibodies in Cerebellar Ataxias. J Immunol Res 2017:2913297

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