| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom; and
Department of Pharmacology, Merck Research Laboratories, Rahway, NJ 07065
Two loci, Idd5.1 and Idd5.2, that determine susceptibility to type 1 diabetes (T1D) in the NOD mouse are on chromosome 1. Idd5.1 is likely accounted for by a synonymous single nucleotide polymorphism in exon 2 of Ctla4: the B10-derived T1D-resistant allele increases the expression of the ligand-independent isoform of CTLA-4 (liCTLA-4), a molecule that mediates negative signaling in T cells. Idd5.2 is probably Nramp1 (Slc11a1), which encodes a phagosomal membrane protein that is a metal efflux pump and is important for host defense and Ag presentation. In this study, two additional loci, Idd5.3 and Idd5.4, have been defined to 3.553 and 78 Mb regions, respectively, on linked regions of chromosome 1. The most striking findings, however, concern the evidence we have obtained for strong interactions between these four disease loci that help explain the association of human CTLA4 with T1D. In the presence of a susceptibility allele at Idd5.4, the CTLA-4 resistance allele causes an 80% reduction in T1D, whereas in the presence of a protective allele at Idd5.4, the effects of the resistance allele at Ctla4 are modest or, as in the case in which resistance alleles at Idd5.2 and Idd5.3 are present, completely masked. This masking of CTLA-4 alleles by different genetic backgrounds provides an explanation for our observation that the human CTLA-4 gene is only associated with T1D in the subgroup of human T1D patients with anti-thyroid autoimmunity.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This study was supported by National Institutes of Health Grant NIH P01 AI039671. The availability of NOD congenic mice through the Taconic Farms Emerging Models Program was supported by grants from the Merck Genome Research Institute, National Institute of Allergy and Infectious Diseases, and the Juvenile Diabetes Research Foundation. L.S.W. and J.A.T. were supported by grants from the Juvenile Diabetes Research Foundation and the Wellcome Trust, and L.S.W. was a Juvenile Diabetes Research Foundation/Wellcome Trust Principal Research Fellow.
2 Address correspondence and reprint requests to Dr. Linda S. Wicker, Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Addenbrooke’s Hospital, Cambridge, U.K. E-mail address: linda.wicker{at}cimr.cam.ac.uk
3 Abbreviations used in this paper: Idd, insulin dependent diabetes; T1D, type 1 diabetes; liCTLA-4, "ligand-independent" splice form of CTLA-4; SNP, single nucleotide polymorphism; AITD, autoimmune thyroid disease.
This article has been cited by other articles:
|
|
 |
|
  J. Irie, B. Reck, Y. Wu, L. S. Wicker, S. Howlett, D. Rainbow, E. Feingold, and W. M. Ridgway Genome-Wide Microarray Expression Analysis of CD4+ T Cells from Nonobese Diabetic Congenic Mice Identifies Cd55 (Daf1) and Acadl as Candidate Genes for Type 1 Diabetes J. Immunol., January 15, 2008; 180(2): 1071 - 1079. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
