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- Mercalli, A., et al.
(författare)
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No evidence of enteroviruses in the intestine of patients with type 1 diabetes
- 2012
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 55:9, s. 2479-2488
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate whether the gut mucosa is a reservoir for enterovirus persistence in patients with type 1 diabetes. Small intestine biopsy samples from 25 individuals at different stages of type 1 diabetes, 21 control individuals and 27 individuals with coeliac disease were analysed for the presence of enterovirus RNA by using both radioactive in-situ hybridisation and real-time RT-PCR and for the presence of enterovirus proteins by immunostaining with antibodies against VP1 and VP4-2-3 capsid proteins and virus polymerase. Lymphocytic enteropathy and serum anti-VP1 antibodies were also evaluated at the time of biopsy. Moreover, high-throughput sequencing was performed to identify viral transcripts or genomes. Enterovirus was not detected by in-situ hybridisation or RT-PCR in any of the individuals tested. Immunohistology revealed a few stained cells in the intestinal epithelium in a low number of individuals, with no difference between diabetic and non-diabetic individuals. Levels of serum IgG against VP1 did not differ between control individuals and those with diabetes or coeliac disease and no evidence of diabetes-related lymphocytic enteropathy was detected. High-throughput sequencing did not reveal specific enterovirus sequences in the gut mucosa of individuals with type 1 diabetes. Prolonged/persistent enterovirus infections in gut mucosa are not common in patients with type 1 diabetes.
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| 2. |
- Ylipaasto, P., et al.
(författare)
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Enterovirus-induced gene expression profile is critical for human pancreatic islet destruction
- 2012
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 55:12, s. 3273-3283
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis Virally induced inflammatory responses, beta cell destruction and release of beta cell autoantigens may lead to autoimmune reactions culminating in type 1 diabetes. Therefore, viral capability to induce beta cell death and the nature of virus-induced immune responses are among key determinants of diabetogenic viruses. We hypothesised that enterovirus infection induces a specific gene expression pattern that results in islet destruction and that such a host response pattern is not shared among all enterovirus infections but varies between virus strains. Methods The changes in global gene expression and secreted cytokine profiles induced by lytic or benign enterovirus infections were studied in primary human pancreatic islet using DNA microarrays and viral strains either isolated at the clinical onset of type 1 diabetes or capable of causing a diabetes-like condition in mice. Results The expression of pro-inflammatory cytokine genes (IL-1-a, IL-1-β and TNF-a) that also mediate cytokineinduced beta cell dysfunction correlated with the lytic potential of a virus. Temporally increasing gene expression levels of double-stranded RNArecognition receptors, antiviral molecules, cytokines and chemokines were detected for all studied virus strains. Lytic coxsackievirus B5 (CBV-5)-DS infection also downregulated genes involved in glycolysis and insulin secretion. Conclusions/interpretation The results suggest a distinct, virusstrain- specific, gene expression pattern leading to pancreatic islet destruction and pro-inflammatory effects after enterovirus infection. However, neither viral replication nor cytotoxic cytokine production alone are sufficient to induce necrotic cell death. More likely the combined effect of these and possibly cellular energy depletion lie behind the enterovirus-induced necrosis of islets.
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