| 1. |
- Kuric, Enida, et al.
(författare)
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Demonstration of Tissue Resident Memory CD8 T Cells in Insulitic Lesions in Adult Patients with Recent-Onset Type 1 Diabetes
- 2017
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Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 187:3, s. 581-588
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Tidskriftsartikel (refereegranskat)abstract
- Subtypes of CD8(+) T cells in insulitic lesions in biopsy specimens from six subjects with recent-onset type 1 diabetes (T1D) and six nondiabetic matched controls were analyzed using simultaneous multicolor immunofluorescence. Also, insulitic islets based on accumulation of CD3(+) T cells were microdissected with laser-capture microscopy, and gene transcripts associated with inflammation and autoimmunity were analyzed. We found a substantial proportion, 43%, of the CD8(+) T cells in the insulitic lesions to display a tissue resident memory T cell (TRM) (CD8(+)CD69(+)CD103(+)) phenotype in T1D subjects. Most TRM cells were located in the insulitic lesion in the endocrine-exocrine interface. TRM cells were also sporadically found in islets of control subjects. Moreover, gene expression analysis showed a lack of active transcription of genes associated with acute inflammatory or cytotoxic T-cell responses. We present evidence that a substantial proportion of T cells in insulitic lesions of recent-onset T1D patients are TRM cells and not classic cytotoxic CD8(+) T cells. Our findings highlight the need for further analysis of the T cells involved in insulitis to elucidate their role in the etiology of T1D.
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| 2. |
- Lundberg, Marcus, et al.
(författare)
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Insulitis in human diabetes : a histological evaluation of donor pancreases
- 2017
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 60:2, s. 346-353
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis According to the consensus criteria developed for type 1 diabetes, an individual can be diagnosed with insulitis when >= 15 CD45(+) cells are found within the parenchyma or in the islet-exocrine interface in >= 3 islets. The aim of this study was to determine the frequency of individuals with type 2 diabetes fulfilling these criteria with reference to non-diabetic and type 1 diabetic individuals. Methods Insulitis was determined by examining CD45(+) cells in the pancreases of 50, 13 and 44 organ donors with type 2 diabetes, type 1 diabetes and no diabetes, respectively. CD3(+) cells (T cells) infiltrating the islets were evaluated in insulitic donors. In insulitic donors with type 2 diabetes, the pancreases were characterised according to the presence of CD68 (macrophages), myeloperoxidase (MPO; neutrophils), CD3, CD20 (B cells) and HLA class I hyperstained islets. In all type 2 diabetic donors, potential correlations of insulitis with dynamic glucose-stimulated insulin secretion in vitro or age, BMI, HbA(1c) or autoantibody positivity were examined. Results Overall, 28% of the type 2 diabetic donors fulfilled the consensus criteria for insulitis developed for type 1 diabetes. Of the type 1 diabetic donors, 31% fulfilled the criteria. None of the non-diabetic donors met the criteria. Only type 1 diabetic donors had >= 15 CD3(+) cells in >= 3 islets. Type 2 diabetic donors with insulitis also had a substantial number of CD45(+) cells in the exocrine parenchyma. Macrophages constituted the largest fraction of CD45(+) cells, followed by neutrophils and T cells. Of type 2 diabetic pancreases with insulitis, 36% contained islets that hyperstained for HLA class I. Isolated islets from type 2 diabetic donors secreted less insulin than controls, although with preserved dynamics. Insulitis in the type 2 diabetic donors did not correlate with glucose-stimulated insulin secretion, the presence of autoantibodies, BMI or HbA(1c). Conclusions/interpretation The current definition of insulitis cannot be used to distinguish pancreases retrieved from individuals with type 1 diabetes from those with type 2 diabetes. On the basis of our findings, we propose a revised definition of insulitis, with a positive diagnosis when >= 15 CD3(+) cells, not CD45(+) cells, are found in >= 3 islets.
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| 3. |
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| 4. |
- Seiron, Peter, et al.
(författare)
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Characterisation of the endocrine pancreas in type 1 diabetes : islet size is maintained but islet number is markedly reduced
- 2019
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Ingår i: The journal of pathology. Clinical research. - : Wiley. - 2056-4538. ; 5:4, s. 248-255
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Tidskriftsartikel (refereegranskat)abstract
- Insulin deficiency in type 1 diabetes (T1D) is generally considered a consequence of immune-mediated specific beta-cell loss. Since healthy pancreatic islets consist of similar to 65% beta cells, this would lead to reduced islet size, while the number of islets per pancreas volume (islet density) would not be affected. In this study, we compared the islet density, size, and size distribution in biopsies from subjects with recent-onset or long-standing T1D, with that in matched non-diabetic subjects. The results presented show preserved islet size and islet size distribution, but a marked reduction in islet density in subjects with recent onset T1D compared with non-diabetic subjects. No further reduction in islet density occurred with increased disease duration. Insulin-negative islets in T1D subjects were dominated by glucagon-positive cells that often had lost the alpha-cell transcription factor ARX while instead expressing PDX1, normally only expressed in beta cells within the islets. Based on our findings, we propose that failure to establish a sufficient islet number to reach the beta-cell mass needed to cope with episodes of increased insulin demand contributes to T1D susceptibility. Exhaustion induced by relative lack of beta cells could then potentially drive beta-cell dedifferentiation to alpha-cells, explaining the preserved islet size observed in T1D compared to controls.
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| 5. |
- Seiron, Peter, 1990-
(författare)
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Studies of the Pancreas: Implications for Type 1 Diabetes Aetiology
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D) is a disease of severe insulin deficiency through loss of β cells in the endocrine pancreas. The T1D dogma maintains that a precipitating event unleashes autoimmunity in at-risk individuals, often measured through autoantibodies against β cell antigens. This is followed by the death of β cells at the hands of autoreactive cytotoxic T cells. However, several findings have not found their place within this dogma; first, the immune cell infiltrate in islets is usually located outside the islets, and second, there is a pronounced impact on the exocrine pancreas with lower pancreatic weight and fibrosis surrounding the ducts. In this thesis, pancreata from human subjects without diabetes (ND) as well as with T1D or type 2 diabetes (T2D) have been examined in an attempt to clarify the aetiology of T1D.The consensus definition of insulitis (≥15 CD45+ cells per islet in ≥3 islets) was validated against ND pancreata. In paper I we show that this definition cannot sufficiently discriminate between the findings in T1D and T2D pancreata, due to an increase in exocrine infiltration in T2D, predominantly made up by macrophages. As exocrine infiltration is also a common finding in T1D, we propose a new definition. In paper II we found tissue resident memory T (TRM) cells in association to islets in both ND and T1D pancreata, and they made up a significant proportion of the insulitic lesion in T1D. Islets contain on average 60% β cells. In paper III we found that despite the seeming loss of this predominant cell type in the T1D islets, islet size remained the same. Instead, islet density was markedly reduced. The islets contained mainly α cells, some of which expressed PDX1, a transcription factor marker of β cells. In paper IV we examined pancreata from ND organ donors aged 1-81 years. For the first time, the islet transcriptome was analysed without prior enzymatic digestion of the tissue. We corroborate earlier findings of reduced cell cycle activity and increased senescence with increasing age, as well as present a hypothesis of how islet age might affect T1D.The findings in this thesis sprout an alternative hypothesis that disturbed establishment of β cells in early life, due to lower islet density and lower pancreatic weight, would lead to β cell stress as insulin demand increases with physical growth. However, as islets do not decrease in size, we suggest that the disappearance of β cells could be explained by transdifferentiation into glucagon-producing cells.
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| 6. |
- Seiron, Peter, et al.
(författare)
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Transcriptional analysis of islets of Langerhans from organ donors of different ages
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- Insulin secretion is impaired with increasing age. In this study, we aimed to determine whether aging induces specific transcriptional changes in human islets. Laser capture microdissection was used to extract pancreatic islet tissue from 37 deceased organ donors aged 1-81 years. The transcriptomes of the extracted islets were analysed using Ion AmpliSeq sequencing. 346 genes that co-vary significantly with age were found. There was an increased transcription of genes linked to senescence, and several aspects of the cell cycle machinery were downregulated with increasing age. We detected numerous genes not linked to aging in previous studies likely because earlier studies analysed islet cells isolated by enzymatic digestion which might affect the islet transcriptome. Among the novel genes demonstrated to correlate with age, we found an upregulation of SPP1 encoding osteopontin. In beta cells, osteopontin has been seen to be protective against both cytotoxicity and hyperglycaemia. In summary, we present a transcriptional profile of aging in human islets and identify genes that could affect disease course in diabetes.
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| 7. |
- Stenwall, Per-Anton, et al.
(författare)
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Improving the anti-inflammatory effect of serum eye drops using allogeneic serum permissive for regulatory T cell induction
- 2015
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Ingår i: Acta Ophthalmologica. - : Wiley. - 1755-375X .- 1755-3768. ; 93:7, s. 654-657
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Tidskriftsartikel (refereegranskat)abstract
- PurposeTo investigate the cytokine composition and anti-inflammatory effects of allogeneic serum preparations for improved use as serum eye drops. MethodsSerum of 15 healthy blood donors was extensively screened for cytokines, including IL-1, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p70, IL-13, IL-15, 1L-17A, E and F, IL-21, IL-22, IL-23, IL-27, IL-28A, IL-31, IL-33, granulocyte macrophage colony-stimulating factor (GM-CSF), chemokine ligand 20 (CCL20), tumour necrosis factor (TNF)- and TNF-, interferon (IFN)- and transforming growth factor (TGF)-. The levels of cytokines were assessed before and after heat-induced inactivation. Individual serum preparations were tested for their anti-inflammatory effect using an invitro test to differentiate effector T lymphocytes into anti-inflammatory regulatory T cells. ResultsThe anti-inflammatory cytokine TGF- was readily detected in the serum of all blood donors and was only modestly affected by heat-induced inactivation. Serum containing high amounts of TGF- was more effective at inducing anti-inflammatory regulatory T cells. The serum of one healthy blood donor displayed high levels of inflammatory cytokines. ConclusionWe propose that serum used as eye drops is screened for its cytokine content, making it possible to correlate the composition to the clinical outcome. Based on the findings in this study, tailored serum eye drops produced from allogeneic donors may provide increased anti-inflammatory effects. This may be superior to autologous serum eye drops, which in many cases are retrieved from patients with inflammatory diseases.
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