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| 2. |
- Colucci, Francesco, et al.
(författare)
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Apoptosis resistance of nonobese diabetic peripheral lymphocytes linked to the Idd5 diabetes susceptibility region
- 1997
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 94:16, s. 8670-8674
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Tidskriftsartikel (refereegranskat)abstract
- Defects in lymphocyte apoptosis may lead to autoimmune disorders and contribute to the pathogenesis of type 1 diabetes. Lymphocytes of nonobese diabetic (NOD) mice, an animal model of autoimmune diabetes, have been found resistant to various apoptosis signals, including the alkylating drug cyclophosphamide. Using an F2 intercross between the apoptosis-resistant NOD mouse and the apoptosis-susceptible C57BL/6 mouse, we define a major locus controlling the apoptosis-resistance phenotype and demonstrate its linkage (logarithm of odds score = 3.9) to a group of medial markers on chromosome 1. The newly defined gene cannot be dissociated from Ctla4 and Cd28 and in fact marks a 20-centimorgan region encompassing Idd5, a previously postulated diabetes susceptibility locus. Interestingly, we find that the CTLA-4 (cytotoxic T lymphocyte-associated antigen 4) and the CD28 costimulatory molecules are defectively expressed in NOD mice, suggesting that one or both of these molecules may be involved in the control of apoptosis resistance and, in turn, in diabetes susceptibility.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Eriksson, Björn, et al.
(författare)
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Establishment and characterization of a mouse strain (TLL) that spontaneously develops T-cell lymphomas/leukemia
- 1999
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Ingår i: Experimental Hematology. - 0301-472X .- 1873-2399. ; 27:4, s. 682-688
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a mouse strain (TLL) that spontaneously develops T-cell lymphomas/leukemia with an early onset and high incidence was established and characterized. All tumors analyzed were found to express the alpha,beta T-cell receptor, and the majority of them had a mature, CD3+CD4+CD8- immunophenotype. In a few cases, tumors with a more immature CD3+CD4+CD8+ phenotype were isolated. Expanded phenotyping using a broad panel of lymphocyte differentiation markers confirmed the mature T-cell phenotype of the tumors. Histologic and cell cycle analysis of the tumors revealed an aggressive lymphoblastic malignancy with a very high proliferation rate and widespread engagement of bone marrow and lymphoid as well as nonlymphoid organs. Thus, the TLL mouse strain represents a unique model for the analysis of the oncogenesis and progression of mature T-cell tumors and for the development of therapeutic measures to combat such tumors.
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| 7. |
- Hillörn, Valter, et al.
(författare)
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Aberrant VHGene Utilization in Patients with Established Insulin-Dependent Diabetes Mellitus
- 1997
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Ingår i: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411 .- 1095-9157. ; 10:2, s. 157-163
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Tidskriftsartikel (refereegranskat)abstract
- We have compared the B-lymphocyte repertoire in seven IDDM patients with 12 healthy controls by examining the variable heavy (VH) gene expression. The VHgene representation in the pool of pokeweed mitogen (PWM) stimulated, immunocompetent B cells and in the pool of naturally activated plasma cells (actual repertoire) was analysed by RNA-RNA in situ hybridization. Differences between IDDM patients and normal controls in the relative expression of several VHgene families were observed. In IDDM patients, the VH3 was significantly underrepresented in the PWM stimulated repertoire. In the actual B cell repertoire the VH5 clones were underrepresented among diabetic patients. Moreover, the altered distribution of VHgene usage between the PWM stimulated repertoire and the actual repertoire observed in normal controls was found to be less pronounced in the IDDM patients. This observation suggests a defect in the V-gene directed cellular selection occurring between resting, immunocompetent B cells and naturally activated plasma cells. The possible implication of the observed aberrations in the B cell selection process for the pathogenesis of autoimmunity is discussed.
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| 8. |
- 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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| 9. |
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| 10. |
- Penha-Gonçalves, Carlos, et al.
(författare)
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Type 1 diabetes and the control of dexamethazone-induced apoptosis in mice maps to the same region on chromosome 6
- 1995
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Ingår i: Genomics. - : Elsevier. - 0888-7543 .- 1089-8646. ; 28:3, s. 398-404
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative trait loci mapping was used to identify the chromosomal location of genes that contribute to increase the resistance to apoptosis induced in immature CD4+8+ thymocytes. An F2 intercross of the nonobese diabetic (NOD) mouse (displaying an apoptosis-resistance phenotype) and the C57BL/6 mouse (displaying a nonresistance phenotype) was phenotypically analyzed and genotyped for 32 murine microsatellite polymorphisms. Maximum likelihood methods identified a region on the distal part of chromosome 6 that is linked to dexamethazone-induced apoptosis (lod score = 3.46) and accounts for 14% of the phenotypic variation. This chromosomal region contains the diabetes susceptibility locus Idd6, suggesting that the apoptosis-resistance phenotype constitutes a pathogenesis factor in IDDM of NOD mice.
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