| 1. |
- Bergman, Marie-Louise, et al.
(författare)
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CTLA-4-/- mice display T cell-apoptosis resistance resembling that ascribed to autoimmune-prone non-obese diabetic (NOD) mice
- 2001
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Ingår i: Journal of Autoimmunity. - : Elsevier. - 0896-8411 .- 1095-9157. ; 16:2, s. 105-113
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Tidskriftsartikel (refereegranskat)abstract
- The genes conferring susceptibility to autoimmune (insulin-dependent) diabetes mellitus (IDDM) are, in most cases, not defined. Among the loci so far identified as associated with murine IDDM (Idd1-19), only the nature of Idd1 has been assessed. Here we show that thymocytes and peripheral lymphocytes of the non-obese diabetic (NOD) mouse are relatively resistant to apoptosis induced by gamma-irradiation. By linkage analysis of F2 progeny mice, we map this trait to a locus on chromosome 1 containing the Idd5 diabetes susceptibility region. By the use of congenic mice, we confirm the linkage data and map this locus to a 6 cM region on proximal chromosome 1. Ctla4, being localized in this chromosomal region and mediating crucial functions in T cell biology, is a logical candidate gene in the Idd5 susceptibility region. In line with this, we demonstrate that T cells from Ctla4(-/-)deficient mice show a similar resistance to gamma-irradiation-induced apoptosis as observed in the NOD mice. This reinforces the notion that CTLA-4 contributes to the pathogenesis of autoimmune diabetes.
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| 2. |
- Bergman, Marie-Louise, et al.
(författare)
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Diabetes protection and restoration of thymocyte apoptosis in NOD Idd6 congenic strains
- 2003
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 52:7, s. 1677-1682
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes in the nonobese diabetic (NOD) mouse is a multifactorial and polygenic disease. The NOD-derived genetic factors that contribute to type 1 diabetes are named Idd (insulin-dependent diabetes) loci. To date, the biological functions of the majority of the Idd loci remain unknown. We have previously reported that resistance of NOD immature thymocytes to depletion by dexamethazone (Dxm) maps to the Idd6 locus. Herein, we refine this phenotype using a time-course experiment of apoptosis induction upon Dxm treatment. We confirm that the Idd6 region controls apoptosis resistance in immature thymocytes. Moreover, we establish reciprocal Idd6 congenic NOD and B6 strains to formally demonstrate that the Idd6 congenic region mediates restoration of the apoptosis resistance phenotype. Analysis of the Idd6 congenic strains indicates that a 3-cM chromosomal region located within the distal part of the Idd6 region controls apoptosis resistance in NOD immature thymocytes. Together, these data support the hypothesis that resistance to Dxm-induced apoptosis in NOD immature thymocytes is controlled by a genetic factor within the region that also contributes to type 1 diabetes pathogenesis. We propose that the diabetogenic effect of the Idd6 locus is exerted at the level of the thymic selection process.
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| 3. |
- Bergman, Marie-Louise, et al.
(författare)
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Low rate of proliferation in immature thymocytes of the non-obese diabetic mouse maps to the Idd6 diabetes susceptibility region
- 2001
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Ingår i: Diabetologia. - : Springer. - 0012-186X .- 1432-0428. ; 44:8, s. 1054-1061
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: The non-obese diabetic (NOD) mouse spontaneously develops T-cell-dependent autoimmune diabetes. This mouse strain has a number of immune dysfunctions related to T-cell development but so far there are no available data on the proliferation of NOD immature thymocytes. We therefore studied the thymocyte proliferation in the NOD mouse in discrete stages of T-cell development.Methods: We depleted thymocytes in vivo and analysed thymocyte proliferation during the thymus recovery from depletion. We used co-segregation analysis and quantitative loci trait analysis to investigate the genetic control of proliferation impairments in NOD thymocytes.Results: Immature thymocytes of female NOD mice proliferate with a relatively low rate compared to non-autoimmune C57Bl/6 mice. This aberrant proliferation was most pronounced in CD4– /loCD8+ cells differentiating from the CD4–CD8– to the CD4+CD8+ stage. A genetic mapping study using an F2 intercross between the NOD and the C57BL/6 strains showed that a major locus controlling this trait is linked to the insulin-dependent diabetes susceptibility locus Idd6.Conclusion/interpretation: Our results suggest that impairment of proliferation of immature thymocytes is one possible mechanism through which the Idd6 locus contributes to the pathogenesis of diabetes.
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| 4. |
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| 5. |
- Colucci, Francesco, et al.
(författare)
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Diabetes induction in C57BL/6 mice reconstituted with lymphocytes of nonobese diabetic C57BL/6 mouse embryo aggregation chimeras
- 1998
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Ingår i: Scandinavian Journal of Immunology. - : Wiley-Blackwell. - 0300-9475 .- 1365-3083. ; 48:6, s. 571-576
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Tidskriftsartikel (refereegranskat)abstract
- To determine whether the genetic background of the insulin-producing beta cells of the pancreas contributes to autoimmune diabetes susceptibility, we have used a model of the disease based on transferring spleen cells from nonobese diabetic (NOD) <--> C57BL/6 (B6) embryo aggregation (EA) chimeras into B6 and NOD irradiated mice. Insulitis and diabetes could be induced into both B6 and NOD hosts, albeit with low incidence. Cyclophosphamide (CY) treatment, known to accelerate diabetes in prediabetic NOD mice, was found to increase diabetes incidence up to 50-60% in both B6 and NOD mice reconstituted with chimeric splenocytes, while diabetes did not occur in CY-treated B6 mice reconstituted with B6 splenocytes. We conclude that the genetic make-up of the target organ does not affect the final stage of the pathogenesis of insulin-dependent diabetes mellitus.
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| 6. |
- Colucci, Francesco, et al.
(författare)
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Induction of diabetes in NOD‹–›C57BL/6 embryo aggregation chimeras by cyclophosphamide through preferential depletion of C57BL/6 lymphocytes
- 1996
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Ingår i: Journal of Autoimmunity. - : Elsevier. - 0896-8411 .- 1095-9157. ; 9:4, s. 493-499
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Tidskriftsartikel (refereegranskat)abstract
- The majority of embryo aggregation (EA) mouse chimeras between non-obese diabetic (NOD) mice and C57BL/6 (B6) mice show clear signs of insulitis frequently accompanied by beta-cell destruction. Less than 5% of these chimeras, however, spontaneously progress to autoimmune diabetes, an incidence far lower than observed in NOD mice. The resistance in chimeras can be accounted for by the target organ chimerism and/or the immune system chimerism. To investigate the mechanism(s) controlling diabetes resistance in these mice, we studied a total of 92 NOD<-->B6 EA chimeras that showed overt lymphoid chimerism and treated 34 chimeras with cyclophosphamide (CY), a compound known to precipitate an acute form of insulin-dependent diabetes mellitus (IDDM) in pre-diabetic NOD mice, by interfering with regulatory mechanisms. We found that CY-treated EA chimeras displayed an increase in the NOD:B6 lymphocyte ratio and 32% of them developed diabetes that could be adoptively transferred to irradiated NOD or NOD-rag-2-/- mice. These findings suggest that lymphocyte chimerism rather than beta-cell chimerism accounts for diabetes resistance in NOD<-->B6 EA chimeras and that the susceptibility to CY-induced diabetes may be related to the proportion of NOD versus B6 lymphoid cells.
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| 7. |
- Colucci, Francesco, et al.
(författare)
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Programmed cell death in the pathogenesis of murine IDDM : resistance to apoptosis induced in lymphocytes by cyclophosphamide
- 1996
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Ingår i: Journal of Autoimmunity. - : Elsevier. - 0896-8411 .- 1095-9157. ; 9:2, s. 271-276
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Tidskriftsartikel (refereegranskat)abstract
- The non-obese diabetic (NOD) mouse displays several immune related defects, each of which could potentially contribute to the immunopathogenesis of diabetes that spontaneously develops in these mice. The reported resistance of NOD-lymphocytes to several apoptosis-inducing signals constitutes one such factor. Apoptosis plays a key role in the homeostasis of the immune system, as a means of selecting lymphocyte repertoires both in primary lymphoid organs and in the periphery; distortions in the apoptotic machinery may therefore be hypothesized to be implicated in the pathogenesis of autoimmune disorders. We now report that cyclophosphamide constitutes an apoptosis signal to peripheral lymphocytes and we provide evidence that NOD B cells as well as both CD4 and CD8 T cells display resistance to cyclophosphamide-induced apoptosis. These observations support the notion that apoptosis resistance in NOD mice exists at various levels, and suggest that the CY-sensitive lymphoid population, believed to play an important role in inhibiting the disease in diabetes resistant NOD mice (particularly males), may be controlled by mechanisms that are mediated by apoptosis.
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| 8. |
- Leijon, Kristina, 1967-, et al.
(författare)
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Analysis of VH gene utilisation in the non-obese diabetic mouse
- 1993
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Ingår i: Autoimmunity. - : Harwood Academic. - 0891-6934 .- 1607-842X. ; 15:1, s. 11-18
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Tidskriftsartikel (refereegranskat)abstract
- The immunoglobulin (Ig) heavy chain variable (VH) gene complexity and the VH gene utilisation pattern of the non-obese diabetic (NOD) mouse were investigated. We found that the NOD mouse displays a VH gene complexity which appears to be identical to that of the C57BL/6 mouse. Thus, Southern hybridisation using probes specific for 9 of the murine VH gene families revealed identical restriction fragment length polymorphism (RFLP) patterns in both mouse strains. As indicated by immunofluorescence analysis using allotype specific monoclonal antibodies the NOD mice were also found to carry the IgCH-1b allele. Collectively, these data suggest that the NOD mice carry an IgVH locus identical to that carried by C57BL/6. In contrast to the apparent identity at the level of germline VH gene repertoires, the pattern of VH gene utilisation differed considerably between these two mouse strains. Thus, in NOD mice the neonatal preference of D-proximal VH genes was found to be more pronounced than in C57BL/6 mice. Moreover, in contrast to adult C57BL/6 mice a D-proximal bias was evident also in adult NOD mice. On the basis of these findings we discuss the possibility that the distorted development of B cell repertoires in the NOD mouse could be directly or indirectly related to the T cell mediated, autoimmune process in the NOD mouse.
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| 9. |
- Leijon, Kristina, 1967-, et al.
(författare)
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Non-obese diabetic (NOD) mice display enhanced immune responses and prolonged survival of lymphoid cells
- 1994
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Ingår i: International Immunology. - Oxford : Oxford University Press. - 0953-8178 .- 1460-2377. ; 6:2, s. 339-345
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Tidskriftsartikel (refereegranskat)abstract
- We report that lymphoid cells originating from the non-obese diabetic (NOD) autoimmune prone mouse strain are resistant to several signals known to induce programmed cell death. In vitro culturing of lymphoid cells of splenic or lymph node origin showed that B cells and T cells of both CD4+ and CD8+ phenotypes from NOD mice display extended survival in vitro. By cytofluorimetric analysis, immature CD4+ CD8+ NOD thymocytes were shown to partially resist in vivo treatment with corticosteroids. Finally, immunization with protein antigens induced enhanced and prolonged immune responses in NOD mice compared with normal C57BL/6, BALB/c, and C3H/Tif control mice. We conclude that the NOD mouse displays a defect in the mechanism(s) mediating programmed cell death in T and B lymphocytes. These findings provide a novel explanation for the B cell aberrations observed in the NOD mouse and may have implications for the understanding of the autoimmune pathogenesis in this mouse strain.
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| 10. |
- Leijon, Kristina, 1967-, et al.
(författare)
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Specific destruction of islet transplants in NOD‹–›C57BL/6 and NOD‹–›C3H/Tif embryo aggregation chimeras irrespective of allelic differences in beta-cell antigens
- 1995
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Ingår i: Journal of Autoimmunity. - : Elsevier. - 0896-8411 .- 1095-9157. ; 8:3, s. 347-356
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Tidskriftsartikel (refereegranskat)abstract
- We have tested the hypothesis that allelic differences in the antigens expressed by the beta-cells of the islets of Langerhans influence the development of insulitis in the non-obese diabetic (NOD) mouse. Islets of Langerhans from NOD, C57BL/6 and C3H/Tif mice were transplanted under the kidney capsule of NOD<-->C57BL/6 and NOD<-->C3H/Tif embryo aggregation (EA) chimeras and the infiltration was scored 5-7 weeks later. Mononuclear cell infiltration of pancreatic islets was observed in 60% of the NOD<-->C57BL/6 and in 55% of the NOD<-->C3H/Tif EA chimeras. All transplanted EA chimeras that developed insulitis also displayed mononuclear cell infiltrates in the transplants, irrespective of the origin of the transplanted islets. In contrast, no infiltration of transplants was detected in EA chimeras scoring negative for insulitis. These results demonstrate that the specific destruction of islet transplants does not require the expression of NOD specific antigens by the islets. Moreover, the beta-cell destruction appears not to be restricted to NOD-MHC. The correlation between insulitis and transplant beta-cell destruction suggests the possibility that the development of insulitis is a prerequisite for transplant specific destruction. MHC restricted destruction may, therefore, precede the beta-cell destruction of transplanted islets. The chimerism among the mononuclear cells infiltrating the islet transplants was found to correlate with the overall haematopoetic chimerism in each of the individual EA chimeras. This observation suggests that NOD bone marrow, as well as non-NOD bone marrow, generates cells contributing to the beta-cell destruction process.
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