Coxsackie-adenovirus receptor expression is enhanced in pancreas from patients with type 1 diabetes.

OBJECTIVES: One of the theories connecting enterovirus (EV) infection of human islets with type 1 diabetes (T1D) is the development of a fertile field in the islets. This implies induction of appropriate proteins for the viral replication such as the coxsackie-adenovirus receptor (CAR). The aim of this study was to investigate to what extent CAR is expressed in human islets of Langerhans, and what conditions that would change the expression. DESIGN: Immunohistochemistry for CAR was performed on paraffin-embedded pancreatic tissue from patients with T1D (n=9 recent onset T1D, n=4 long-standing T1D), islet autoantibody-positive individuals (n=14) and non-diabetic controls (n=24) individuals. The expression of CAR was also examined by reverse transcription PCR on microdissected islets (n=5), exocrine tissue (n=5) and on explanted islets infected with EV or exposed to chemokines produced by EV-infected islet cells. RESULTS: An increased frequency of patients with T1D and autoantibody-positive individuals expressed CAR in the pancreas (p<0.039). CAR staining was detected more frequently in pancreatic islets from patients with T1D and autoantibody-positive subjects (15/27) compared with (6/24) non-diabetic controls (p<0.033). Also in explanted islets cultured in UV-treated culture medium from coxsackievirus B (CBV)-1-infected islets, the expression of the CAR gene was increased compared with controls. Laser microdissection of pancreatic tissue revealed that CAR expression was 10-fold higher in endocrine compared with exocrine cells of the pancreas. CAR was also expressed in explanted islets and the expression level decreased with time in culture. CBV-1 infection of explanted islets clearly decreased the expression of CAR (p<0.05). In contrast, infection with echovirus 6 did not affect the expression of CAR. CONCLUSIONS: CAR is expressed in pancreatic islets of patients with T1D and the expression level of CAR is increased in explanted islets exposed to proinflammatory cytokines/chemokines produced by infected islets. T1D is associated with increased levels of certain chemokines/cytokines in the islets and this might be the mechanism behind the increased expression of CAR in TID islets.

Enterovirus infection of human islets of Langerhans affects ß-cell function resulting in disintegrated islets, decreased glucose stimulated insulin secretion and loss of Golgi structure.

AIMS/HYPOTHESIS: In type 1 diabetes (T1D), most insulin-producing ß cells are destroyed, but the trigger is unknown. One of the possible triggers is a virus infection and the aim of this study was to test if enterovirus infection affects glucose stimulated insulin secretion and the effect of virus replication on cellular macromolecules and organelles involved in insulin secretion. METHODS: Isolated human islets were infected with different strains of coxsackievirus B (CVB) virus and the glucose-stimulated insulin release (GSIS) was measured in a dynamic perifusion system. Classical morphological electron microscopy, large-scale electron microscopy, so-called nanotomy, and immunohistochemistry were used to study to what extent virus-infected ß cells contained insulin, and real-time PCR was used to analyze virus induced changes of islet specific genes. RESULTS: In islets infected with CVB, GSIS was reduced in correlation with the degree of virus-induced islet disintegration. The expression of the gene encoding insulin was decreased in infected islets, whereas the expression of glucagon was not affected. Also, in islets that were somewhat disintegrated, there were uninfected ß cells. Ultrastructural analysis revealed that virus particles and virus replication complexes were only present in ß cells. There was a significant number of insulin granules remaining in the virus-infected ß cells, despite decreased expression of insulin mRNA. In addition, no typical Golgi apparatus was detected in these cells. Exposure of islets to synthetic dsRNA potentiated glucose-stimulated insulin secretion. CONCLUSIONS/INTERPRETATION: Glucose-stimulated insulin secretion; organelles involved in insulin secretion and gene expression were all affected by CVB replication in ß cells.

Simultaneous liver-pancreas transplantation for cystic fibrosis-related liver disease: a multicenter experience.

BACKGROUND: Diabetes is associated with increased morbidity and mortality in patients with cystic fibrosis (CF). While liver transplantation is well established for CF-related liver disease (CFLD), the role of simultaneous liver-pancreas transplantation is less understood. METHODS: We polled 81 pediatric transplantation centers to identify and characterize subjects who had undergone simultaneous liver-pancreas transplantation and obtain opinions about this procedure in CFLD. RESULTS: Fifty (61.7%) polled transplant centers responded and 94% reported that they would consider simultaneous liver-pancreas transplantation for CFLD and diabetes. A total of 8 patients with simultaneous liver-pancreas transplantation were identified with median follow up of 38 months. All patients had pre-existing diabetes. Exocrine and endocrine pancreatic function was initially restored in all patients with later functional loss in one patient. Body mass index Z-score increased between one year pre-transplantation and one year post-transplantation (P=0.029). CONCLUSIONS: Patients with CFLD undergoing initial assessment for liver transplantation may benefit from consideration of simultaneous liver-pancreas transplantation.

Tropism Analysis of Two Coxsackie B5 Strains Reveals Virus Growth in Human Primary Pancreatic Islets but not in Exocrine Cell Clusters In Vitro.

Human Enteroviruses (HEVs) have been implicated in human pancreatic diseases such as pancreatitis and type 1 diabetes (T1D). Human studies are sparse or inconclusive and our aim was to investigate the tropism of two strains of Coxsackie B virus 5 (CBV-5) in vitro to primary human pancreatic cells. Virus replication was measured with TCID50 titrations of aliquots of the culture medium at different time points post inoculation. The presence of virus particles or virus proteins within the pancreatic cells was studied with immunohistochemistry (IHC) and electron microscopy (EM). None of the strains replicated in the human exocrine cell clusters, in contrast, both strains replicated in the endocrine islets of Langerhans. Virus particles were found exclusively in the endocrine cells, often in close association with insulin granules. In conclusion, CBV-5 can replicate in human endocrine cells but not in human exocrine cells, thus they might not be the cause of pancreatitis in humans. The association of virus with insulin granules might reflect the use of these as replication scaffolds.