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- Anagandula, Mahesh, 1982-, et al.
(författare)
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Enterovirus-induced changes in explanted human islet of Langerhans resemble findings in islets of fulminant and conventional type 1 diabetes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Hypothesis: Fulminant Type 1 diabetes is a unique subtype of T1D, mostly reported in the Japanese population, which is characterized by extensive beta cell death already at onset, often without any insulitis. Enterovirus (EV) infections are associated with the etiology of both fulminant and conventional T1D. However the causative mechanism is not known for any of these diseases. EVs capability to cause lytic vs non-lytic infection in explanted human islets may have implications on the pathogenesis of these two types of T1D.Aim: To study the effect of infection of explanted human pancreatic islets with lytic (CBV-1) and non-lytic (CBV-4) Coxsackie B virus strains on cytopathic effect/islet disintegration and to what extent genes involved in viral sensing, antiviral defense and encoding of islet auto-antigens are affected by the viral replication. Also, to compare these findings with the findings reported in fulminant and conventional T1D.Methods: Degree of cytopathic effect/islet disintegration was studied and viral replication was measured. Genes involved in viral sensing (NOD2, TLR7 and TLR4), antiviral pathways (OAS2, MX1, PKR, and IRF7), genes coding for known islet auto antigens (GAD65, ZNT8) and the islet hormones, insulin and glucagon, were studied. Mock-infected explanted islet served as controls.Results: All CBV strains replicated in the explanted islets but only the CBV-1 strains caused cytopathic effect/islet cell disintegration. Infection with all CBV strains resulted in the induction of genes encoding OAS2 and MX1. In contrast, mRNA expression levels of the gene encoding insulin was reduced. The gene encoding PKR was induced by one of the lytic strains (CBV-1-11) and also by the non-lytic CBV4 strain, while the mRNA expression levels of genes encoding glucagon, NOD2, TLR7, TLR4, MCL1, GAD65 and ZNT8 were not significantly affected.
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| 2. |
- Anagandula, Mahesh, et al.
(författare)
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Infection of Human Islets of Langerhans With Two Strains of Coxsackie B Virus Serotype 1 : Assessment of Virus Replication, Degree of Cell Death and Induction of Genes Involved in the Innate Immunity Pathway
- 2014
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 86:8, s. 1402-1411
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes mellitus is believed to be triggered, in part, by one or more environmental factors and human enteroviruses (HEVs) are among the candidates. Therefore, this study has examined whether two strains of HEV may differentially affect the induction of genes involved in pathways leading to the synthesis of islet hormones, chemokines and cytokines in isolated, highly purified, human islets. Isolated, purified human pancreatic islets were infected with strains of Coxsackievirus B1. Viral replication and the degree of CPE/islet dissociation were monitored. The expression of insulin, glucagon, CXCL10, TLR3, IF1H1, CCL5, OAS-1, IFN beta, and DDX58 was analyzed. Both strains replicated in islets but only one of strain caused rapid islet dissociation/CPE. Expression of the insulin gene was reduced during infection of islets with either viral strain but the gene encoding glucagon was unaffected. All genes analyzed which are involved in viral sensing and the development of innate immunity were induced by Coxsackie B viruses, with the notable exception of TLR3. There was no qualitative difference in the expression pattern between each strain but the magnitude of the response varied between donors. The lack of virus induced expression of TLR3, together with the differential regulation of IF1H1, OAS1 and IFN beta, (each of which has polymorphic variants influence the predisposition to type 1 diabetes), that might result in defective clearance of virus from islet cells. The reduced expression of the insulin gene and the unaffected expression of the gene encoding glucagon by Coxsackie B1 infection is consistent with the preferential beta-cell tropism of the virus.
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| 3. |
- Berg, Anna-Karin, et al.
(författare)
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Antiviral Treatment of Coxsackie B Virus Infection in Human Pancreatic Islets
- 2007
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Ingår i: Antiviral Research. - : Elsevier BV. - 0166-3542 .- 1872-9096. ; 74:1, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Enterovirus infections of the pancreatic islets are believed to trigger or precipitate the near total destruction of β-cells that constitutes type 1 diabetes (T1D). This study investigated the ability of an anti-picornaviral compound, pleconaril, to block the replication of two β-cell tropic Coxsackie B4 virus (CBV-4) strains in isolated human islets. The two strains, VD2921 and V89 4557, with demonstrated abilities to cause non-lytic persistence or lytic infection, respectively, in islets, represented two different potential mechanisms behind virus-induced T1D. The virus replication in the islets was studied with and without addition of pleconaril. In addition, islet morphology was studied every day. To test the effects of pleconaril and/or DMSO on the β-cells’ insulin secretion, glucose perifusions were performed on treated and untreated islets. Virus titrations showed a clear reduction of the replication of both strains after pleconaril treatment. The VD2921 strain was inhibited to undetectable levels. The V89 4557 strain, however, showed an initial reduction of titers but virus titers then increased despite the addition of a second dose of pleconaril. This incomplete inhibition of viral replication suggested the existence of a resistant subtype within this strain. Pleconaril treatment reduced the β-cells’ insulin secretion in response to glucose stimulation in some experiments and induced slight morphological changes to the islets compared to untreated controls. In summary, pleconaril reduced the replication of the two β-cell tropic CBV-4 strains in human islets. However, genetic differences between these strains influenced the effectiveness of pleconaril treatment. This stresses the importance of using multiple viral strains in antiviral tests.
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| 7. |
- Berg, Anna-Karin, 1976-
(författare)
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Enterovirus Infections of β-Cells : A Mechanism of Induction of Type 1 Diabetes?
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The process of β-cell destruction that leads to type 1 diabetes (T1D) is incompletely understood and it is believed to be a result of both genetic and environmental factors. Enterovirus (EV) infections of the β-cells have been proposed to be involved, however, the effects of EV infections on human β-cells have been little investigated. This thesis summarises studies of three different Coxsackie B4 virus strains that have previously been shown to infect human islets. The effects of infections with these EV were studied in vitro in human islets and in a rat insulin-producing cell line. In addition, a pilot study was performed on isolated human islets to investigate the ability to treat such infections with an antiviral compound.It was found that one of the virus strains replicated in human β-cells without affecting their main function for at least seven days, which in vivo may increase a virus’s ability to persist in islets.Nitric oxide was induced by synthetic dsRNA, poly(IC), but not by viral dsRNA in rat insulinoma cells in the presence of IFN-γ, suggesting that this mediator is not induced by EV infection in β-cells and that poly(IC) does not mimic an EV infection in this respect.All three virus strains were able to induce production of the T-cell chemoattractant interferon-γ-inducible protein 10 (IP-10) during infection of human islets, suggesting that an EV infection of the islets might trigger insulitis in vivo.Antiviral treatment was feasible in human islets, but one strain was resistant to the antiviral compound used in this study.To conclude, a potential mechanism is suggested for the involvement of EV infections in T1D. If EV infections induce IP-10 production in human islet cells in vivo, they might recruit immune cells to the islets. Together with viral persistence and/or virus-induced β-cell damage, this might trigger further immune-mediated β-cell destruction in vivo.
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| 8. |
- Berg, Anna-Karin, et al.
(författare)
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Enterovirus Markers and Serum CXCL10 in Children With Type 1 Diabetes
- 2010
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 82:9, s. 1594-1599
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Tidskriftsartikel (refereegranskat)abstract
- Most patients with type 1 diabetes are considered to have a T-cell mediated autoimmune disease. The chemokine CXCL10 promotes the migration of activated T-cells. Virus infections might contribute to the pathogenesis of type 1 diabetes and enterovirus protein and/or genome have been detected in beta-cells from a majority of tested newly diagnosed children with type 1 diabetes. The chemokine CXCL10 is induced in human islet cells by enterovirus infections in vivo and in vitro, but is not expressed in islets from normal organ donors. Since CXCL10 is a chemokine known to be induced by virus infections and/or cellular damage, our aim was to study if levels of CXCL10 are elevated in serum from children with type 1 diabetes and whether it correlates to the presence of enterovirus markers. CXCL10, neutralizing antibody titer rises against certain enterovirus, and antibodies against GAD65 were measured in serum, and enterovirus PCR was performed on whole blood from 83 type 1 diabetes patients at onset, 48 siblings and 69 controls. CXCL10 was also measured in serum from 46 patients with proven enterovirus infection and in serum from 46 patients with other proven virus infections. The CXCL10 serum levels were not elevated in children at onset of type 1 diabetes and there was a considerable overlap between the groups with 99(8-498) pg/ml in serum from children with type 1 diabetes, 120 (17-538) pg/ml in serum from controls, and 117 (7-448) pg/ml in siblings of the children with type 1 diabetes. The CXCL10 serum levels in patients with proven enterovirus infection were slightly increased compared to the levels in the other groups, 172 (0-585) pg/ml but there was no statistically significant difference. In contrast, CXCL10 serum levels in patients with other proven virus infections were clearly elevated 418 (34-611) pg/ml. Despite that elevated CXCL10 levels have been demonstrated in some groups of patients with type 1 diabetes, in this study the mean CXCL10 serum levels were not elevated in patients with type 1 diabetes neither in patients with proven enterovirus infection. In contrast, in patients with other virus infections the CXCL10 levels were elevated, presumably reflecting the severity or the site of infection. This suggests that local production of CXCL10 in the affected organ cannot be measured reproducible in serum and that its potential use in clinical practice is limited.
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| 9. |
- Berg, Anna-Karin, et al.
(författare)
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Induction of the chemokine interferon-gamma-inducible protein-10 in human pancreatic islets during enterovirus infection
- 2006
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 49:11, s. 2697-2703
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: Enterovirus infections have long been suspected to be environmental factors that may cause type 1 diabetes, but the pathways leading from infection to beta cell destruction are still unknown. We therefore examined whether enterovirus infection of human islets leads to upregulation of interferon-gamma-inducible protein (IP-10, now known as chemokine [C-X-C motif] ligand 10 [CXCL10]), a chemokine important for the induction of insulitis. Methods: Isolated human islets were infected with three different strains of Coxsackie B4 virus. IP-10 expression and secretion from the infected human islets were then measured using RT-PCR and ELISA at several time points. Results: IP-10 was clearly upregulated in and secreted from human islets during enterovirus infection. This was demonstrated with three different strains of Coxsackie B4 virus, two of which are lytic to islets and one which is non-lytic and can establish a persistent infection in human islets. Conclusions/interpretation: We propose that enterovirus-induced upregulation of IP-10 during infection of the islets in vivo is the first step towards destructive insulitis. Our findings support the idea that enterovirus infection triggers immune-mediated beta cell destruction, and for the first time suggest a possible mechanism behind enterovirus-induced diabetes.
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| 10. |
- Busse, Niels, et al.
(författare)
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Detection and localization of viral infection in the pancreas of patients with type 1 diabetes using short fluorescently-labelled oligonucleotide probes
- 2017
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Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:8, s. 12620-12636
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Tidskriftsartikel (refereegranskat)abstract
- Enteroviruses, specifically of the Coxsackie B virus family, have been implicated in triggering islet autoimmunity and type 1 diabetes, but their presence in pancreata of patients with diabetes has not been fully confirmed. To detect the presence of very low copies of the virus genome in tissue samples from T1D patients, we designed a panel of fluorescently labeled oligonucleotide probes, each of 17-22 nucleotides in length with a unique sequence to specifically bind to the enteroviral genome of the picornaviridae family. With these probes enteroviral RNA was detected with high sensitivity and specificity in infected cells and tissues, including in FFPE pancreas sections from patients with T1D. Detection was not impeded by variations in sample processing and storage thereby overcoming the potential limitations of fragmented RNA. Co-staining of small RNA probes in parallel with classical immunstaining enabled virus detection in a cell-specific manner and more sensitively than by viral protein.
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