title: Genetic dissection of Iddm26 in the spontaneously diabetic BBDP rat.
abstract: The 40 Mb T1D susceptibility locus Iddm26 was mapped to chromosome 2 through linkage analysis of a conditioned cross-intercross between the diabetes-prone BBDP and the diabetes-resistant ACI.BBDP-Iddm1,Iddm2 (ACI.1u.Lyp). It is flanked by Iddm32 and Iddm33, which control the kinetics of disease progression. To fine-map Iddm26 and characterize immune phenotypes controlled by this locus, several congenic sublines were generated carrying smaller, overlapping intervals spanning Iddm26 and fragments of Iddm32 and 33. Analysis of disease susceptibility, age of disease onset, and immune phenotypes in these sublines identified subloci regulating these different parameters. Two ACI.1u.Lyp-derived subloci, Iddm26.1 and Iddm26.2, imparted significant protection from diabetes, decreasing the cumulative incidence by as much as 57% and 28%, respectively. Iddm26.2, which overlaps with the human PTPN22 locus, only affected disease susceptibility, whereas Iddm26.1 also significantly affected disease kinetics, delaying T1D onset by more than 10 days compared with the parental BBDP strain. These Iddm26 subloci also regulated various immune phenotypes, including the proportion of splenic macrophages by Iddm26.1, and the proportion of activated T-cells in secondary lymphoid organs by Iddm26.2. The analysis of Iddm26 congenic animals in two different SPF facilities demonstrated that the influence of this locus on T1D is environment-dependent.
authors.affiliation: 1] Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [2] Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sarmiento
authors.affiliation: Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: R H
authors.initials: RH
authors.lastname: Wallis
authors.affiliation: Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Ning
authors.affiliation: Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Marandi
authors.affiliation: 1] Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [2] Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: G Y C
authors.initials: GY
authors.lastname: Chao
authors.affiliation: 1] Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada [2] Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: A D
authors.initials: AD
authors.lastname: Paterson
authors.affiliation: 1] Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [2] Sunnybrook Research Institute, Biological Sciences Platform, Toronto, Ontario, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Poussier
mesh_terms: D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D033481:Chromosomes, Mammalian; D003433:Crosses, Genetic; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000235:genetics* / Q000276:immunology*; D005260:Female; D008040:Genetic Linkage; D056426:Genetic Loci / Q000235:genetics / Q000276:immunology; D020022:Genetic Predisposition to Disease / Q000235:genetics; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008264:Macrophages / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008297:Male; D051381:Rats; D011912:Rats, Inbred ACI; D011913:Rats, Inbred BB; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D060168:Thymocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D007073:Immunoglobulin E