Development of autoimmune diabetes in glutamic acid decarboxylase 65 (GAD65) knockout NOD mice

Abstract

Aims/hypothesis. Type 1 diabetes mellitus, a T-cellmediated autoimmune disease, results from the selective destruction of insulin-producing pancreatic beta cells. Autoantibodies against beta-cell components are used clinically as sensitive markers of this disease; however, their physiological role has not been clear. To investigate the role of glutamic acid decarboxylase 65 (GAD65) in the development of the Type 1 diabetes of non-obese diabetic (NOD) mice, we analysed and characterised NOD mice with targeted disruption of the GAD65 gene. Methods. GAD65-deficient mice were previously established. After backcrossing the knockout mutation onto the NOD genetic background for up to eight generations, female littermates of the three resulting genotypes were produced by intercrossing: GAD65 +/+ (n=23), GAD65 +/− (n=62), and GAD65 −/− (n=31).Results. The cumulative incidence of autoimmune diabetes showed no significant difference among the three groups in longitudinal studies using the KaplanMeier method. Islet morphology showed that the progression of islet infiltration did not differ significantly between the three groups. Conclusion/interpretation. The cumulative incidence of autoimmune diabetes was not influenced by the GAD65 deficiency. These data suggest that GAD65 is not a major regulatory target of beta-cell autoimmunity in NOD mice. [Diabetologia (2004) . It is, however, unclear whether the anti-GAD antibodies participate directly in betacell destruction or arise secondarily in response to the release of autoantigens from islets damaged by other components of the immune system. To investigate the role of GAD65 in the development of the autoimmune diabetes of NOD mice, we have generated GAD65 −/− NOD mice and analysed the onset and incidence of diabetes in these mice. Materials and methodsGeneration and genotyping of a GAD65 mutant mouse. We previously established 129/Ola-derived embryonic stem-cell clones carrying the GAD65 targeted mutation through homologous recombination [2]. GAD65 knockout embryonic stem cells were injected into C57BL/6 mouse blastocysts to make chimeras, and germ-line transmission was achieved. GAD65

Pathogenic Mechanisms in Type 1 Diabetes: The Islet is Both Target and Driver of Disease

“…Knockout of both Ins1 and Ins2, with restoration of hormonal function by transgenic expression of insulin, with an inactivated CD4 and CD8 epitope, completely prevents the development of antiinsulin antibodies, insulitis, and diabetes [44]. Knockouts of GAD65 or IA-2 expression does not alter diabetes onset in NOD mice [45,46]. These findings are consistent with the hypothesis that proinsulin is the primary antigen that initiates disease.…”

Acceleration of diabetes development in CXC chemokine receptor 3 (CXCR3)-deficient NOD mice

“…At the fifth generation (F5), mice were screened for polymorphic microsatellite markers to determine whether they had the NOD gene background and we confirmed that they had NOD type on all markers shown in the electronic supplementary material (ESM) Fig. 1 [17]. Cxcr3 homozygous knockout female NOD mice were generated by crossing F6 knockout male and heterozygous female mice (speed congenic method).…”

Altered Responses to Propofol, but Not Ketamine, in Mice Deficient in the 65-Kilodalton Isoform of Glutamate Decarboxylase

“…05-71) and were performed according to the Guide for Care and Use of Laboratory Animals (Institute of Laboratory Animal Resources, 1996). The generation of GAD65(Ϫ/Ϫ) mice has been described previously (Yanagawa et al, 1999;Yamamoto et al, 2004). These GAD65(Ϫ/Ϫ) mice were backcrossed to C57BL/6 mice more than 10 times, and then they were used for our experiments.…”