HYPOTHESIS: Enteroviruses, such as the Coxsackievirus B (CVB) infections, potentially initiate and accelerate pancreatic β-cell death leading to type 1 diabetes. We hypothesised that Enterovirus infection induces a specific gene expression pattern that results in β-cell death.
METHODS: To examine the susceptibility of Human islet-clusters (HICS) derived from pancreatic islets to infection with CV group B (CVB), purified cultured Human islet-clusters (HICS) were infected with CVB3 (Nancy), CVB4 (Clinical strain) and CVB5 (Faulkner) strains. The changes in the expression levels of Coxsackievirus-adenovirus receptor (CAR), Decay accelerating factor (DAF), insulin and Pdx-1 genes in the infected cells were analysed with TaqMan real-time PCR. Enterovirus specific capsid protein (VP1) was also measured in the infected cells. Infected and non-infected HICS were stained with virus specific capsid protein (VP1), CAR and DAF receptors, Pdx-1 and insulin gene specific antibodies.
RESULTS: CVB3, 4, and 5 infected and replicated in the HICS, which expressed the human CAR and DAF receptors, and remained intact with no apparent Cytopathic effect for up to 20 days post infection. Infected HICS did not show any changes in the expression levels of insulin and Pdx-1 genes at day 3 post infection.
CONCLUSION: Taken together, these results indicate that HICS are natural targets and reservoirs for persistent CVB infection. HICS are a useful cellular model for examining enterovirus infection of β-cells and may further our understanding the virus induced diabetes.