| 1. |
- Dunne, Jessica L., et al.
(författare)
-
Rationale for enteroviral vaccination and antiviral therapies in human type 1 diabetes
- 2019
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 62:5, s. 744-753
-
Tidskriftsartikel (refereegranskat)abstract
- In type 1 diabetes, pancreatic beta cells are destroyed by chronic autoimmune responses. The disease develops in genetically susceptible individuals, but a role for environmental factors has been postulated. Viral infections have long been considered as candidates for environmental triggers but, given the lack of evidence for an acute, widespread, cytopathic effect in the pancreas in type 1 diabetes or for a closely related temporal association of diabetes onset with such infections, a role for viruses in type 1 diabetes remains unproven. Moreover, viruses have rarely been isolated from the pancreas of individuals with type 1 diabetes, mainly (but not solely) due to the inaccessibility of the organ. Here, we review past and recent literature to evaluate the proposals that chronic, recurrent and, possibly, persistent enteroviral infections occur in pancreatic beta cells in type 1 diabetes. We also explore whether these infections may be sustained by different virus strains over time and whether multiple viral hits can occur during the natural history of type 1 diabetes. We emphasise that only a minority of beta cells appear to be infected at any given time and that enteroviruses may become replication defective, which could explain why they have been isolated from the pancreas only rarely. We argue that enteroviral infection of beta cells largely depends on the host innate and adaptive immune responses, including innate responses mounted by beta cells. Thus, we propose that viruses could play a role in type 1 diabetes on multiple levels, including in the triggering and chronic stimulation of autoimmunity and in the generation of inflammation and the promotion of beta cell dysfunction and stress, each of which might then contribute to autoimmunity, as part of a vicious circle. We conclude that studies into the effects of vaccinations and/or antiviral drugs (some of which are currently on-going) is the only means by which the role of viruses in type 1 diabetes can be finally proven or disproven.
|
|
| 2. |
- Krogvold, Lars, et al.
(författare)
-
Detection of a low-grade enteroviral infection in the islets of Langerhans of living patients newly diagnosed with type 1 diabetes
- 2015
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 64:5, s. 1682-1687
-
Tidskriftsartikel (refereegranskat)abstract
- The Diabetes Virus Detection study (DiViD) is the first to examine fresh pancreatic tissue at the diagnosis of type 1 diabetes for the presence of viruses. Minimal pancreatic tail resection was performed 3-9 weeks after onset of type 1 diabetes in 6 adult patients (age 24-35 years). The presence of enteroviral capsid protein 1 (VP1) and the expression of class I HLA were investigated by immunohistochemistry. Enterovirus RNA was analyzed from isolated pancreatic islets and from fresh frozen whole pancreatic tissue using PCR and sequencing. Non-diabetic organ donors served as controls. VP1 was detected in the islets of all type 1 diabetes patients (2 of 9 controls). Hyperexpression of class I HLA molecules was found in the islets of all patients (1 of 9 controls). Enterovirus specific RNA sequences were detected in 4 of 6 cases (0 of 6 controls). The results were confirmed in different laboratories. Only 1.7 % of the islets contained VP1 positive cells and the amount of enterovirus RNA was low. The results provides evidence for the presence of enterovirus in pancreatic islets of type 1 diabetic patients, being consistent with the possibility that a low grade enteroviral infection in the pancreatic islets contribute to disease progression in humans.
|
|
| 3. |
- Krogvold, Lars, et al.
(författare)
-
Insulitis and characterisation of infiltrating T cells in surgical pancreatic tail resections from patients at onset of type 1 diabetes
- 2016
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 59:3, s. 492-501
-
Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesisIt is thought that T cells play a major role in the immune-mediated destruction of beta cells in type 1 diabetes, causing inflammation of the islets of Langerhans (insulitis). The significance of insulitis at the onset of type 1 diabetes is debated, and the role of the T cells poorly understood.MethodsIn the Diabetes Virus Detection (DiViD) study, pancreatic tissue from six living patients with recent-onset type 1 diabetes was collected. The insulitis was characterised quantitatively by counting CD3+ T cells, and qualitatively by transcriptome analysis targeting 84 T and B lymphocyte genes of laser-captured microdissected islets. The findings were compared with gene expression in T cells collected from kidney biopsies from allografts with ongoing cellular rejection. Cytokine and chemokine release from isolated islets was characterised and compared with that from islets from non-diabetic organ donors.ResultsAll six patients fulfilled the criteria for insulitis (5–58% of the insulin-containing islets in the six patients had ≥ 15 T cells/islet). Of all the islets, 36% contained insulin, with several resembling completely normal islets. The majority (61–83%) of T cells were found as peri-insulitis rather than within the islet parenchyma. The expression pattern of T cell genes was found to be markedly different in islets compared with the rejected kidneys. The islet-infiltrating T cells showed only background levels of cytokine/chemokine release in vitro.Conclusions/interpretationInsulitis and a significant reserve reservoir for insulin production were present in all six cases of recent-onset type 1 diabetes. Furthermore, the expression patterns and levels of cytokines argue for a different role of the T cells in type 1 diabetes when compared with allograft rejection.
|
|
| 4. |
- Kuric, Enida, et al.
(författare)
-
Demonstration of Tissue Resident Memory CD8 T Cells in Insulitic Lesions in Adult Patients with Recent-Onset Type 1 Diabetes
- 2017
-
Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 187:3, s. 581-588
-
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.
|
|
| 5. |
- Lundberg, Marcus, et al.
(författare)
-
Expression of Interferon-Stimulated Genes in Insulitic Pancreatic Islets of Patients Recently Diagnosed With Type 1 Diabetes
- 2016
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 65:10, s. 3104-3110
-
Tidskriftsartikel (refereegranskat)abstract
- A primary insult to the pancreatic islets of Langerhans, leading to the activation of innate immunity, has been suggested as an important step in the inflammatory process in type 1 diabetes (T1D). The aim of this study was to examine whether interferon (IFN)-stimulated genes (ISGs) are overexpressed in human T1D islets affected with insulitis. By using laser capture microdissection and a quantitative PCR array, 23 of 84 examined ISGs were found to be overexpressed by at least fivefold in insulitic islets from living patients with recent-onset T1D, participating in the Diabetes Virus Detection (DiViD) study, compared with islets from organ donors without diabetes. Most of the overexpressed ISGs, including GBP1, TLR3, OAS1, EIF2AK2, HLA-E, IFI6, and STAT1, showed higher expression in the islet core compared with the peri-islet area containing the surrounding immune cells. In contrast, the T-cell attractant chemokine CXCL10 showed an almost 10-fold higher expression in the peri-islet area than in the islet, possibly partly explaining the localization of T cells mainly to this region. In conclusion, insulitic islets from recent-onset T1D subjects show overexpression of ISGs, with an expression pattern similar to that seen in islets infected with virus or exposed to IFN-gamma/interleukin-1 beta or IFN-alpha.
|
|
| 6. |
- Vecchio, Federica, et al.
(författare)
-
Abnormal neutrophil signature in the blood and pancreas of presymptomatic and symptomatic type 1 diabetes
- 2018
-
Ingår i: JCI Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 3:18
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neutrophils and their inflammatory mediators are key pathogenic components in multiple autoimmune diseases, while their role in human type 1 diabetes (T1D), a disease that progresses sequentially through identifiable stages prior to the clinical onset, is not well understood. We previously reported that the number of circulating neutrophils is reduced in patients with T1D and in presymptomatic at-risk subjects. The aim of the present work was to identify possible changes in circulating and pancreas-residing neutrophils throughout the disease course to better elucidate neutrophil involvement in human T1D.METHODS: Data collected from 389 subjects at risk of developing T1D, and enrolled in 4 distinct studies performed by TrialNet, were analyzed with comprehensive statistical approaches to determine whether the number of circulating neutrophils correlates with pancreas function. To obtain a broad analysis of pancreas-infiltrating neutrophils throughout all disease stages, pancreas sections collected worldwide from 4 different cohorts (i.e., nPOD, DiViD, Siena, and Exeter) were analyzed by immunohistochemistry and immunofluorescence. Finally, circulating neutrophils were purified from unrelated nondiabetic subjects and donors at various T1D stages and their transcriptomic signature was determined by RNA sequencing.RESULTS: Here, we show that the decline in β cell function is greatest in individuals with the lowest peripheral neutrophil numbers. Neutrophils infiltrate the pancreas prior to the onset of symptoms and they continue to do so as the disease progresses. Of interest, a fraction of these pancreas-infiltrating neutrophils also extrudes neutrophil extracellular traps (NETs), suggesting a tissue-specific pathogenic role. Whole-transcriptome analysis of purified blood neutrophils revealed a unique molecular signature that is distinguished by an overabundance of IFN-associated genes; despite being healthy, said signature is already present in T1D-autoantibody-negative at-risk subjects.CONCLUSIONS: These results reveal an unexpected abnormality in neutrophil disposition both in the circulation and in the pancreas of presymptomatic and symptomatic T1D subjects, implying that targeting neutrophils might represent a previously unrecognized therapeutic modality.FUNDING: Juvenile Diabetes Research Foundation (JDRF), NIH, Diabetes UK.
|
|
| 7. |
|
|
