Enterovirus infections cause pancreatitis and damage endocrine cells in the pancreatic islets. Epidemiological studies have shown an association between enterovirus infections and type 1 diabetes, and viral structures have been detected in the pancreas of diabetic patients. Our recent epidemiological studies have suggested that among all different enterovirus types, the group of coxsackie B viruses is linked to the initiation of beta-cell autoimmunity and development of type 1 diabetes. However, it is not known if this association is causal, and further studies are needed to address this important question. Current evidence suggest that enteroviruses can establish a slowly replicating persisting infection in the pancreas. In such case, the virus should be detectable by highly sensitive assays in the pancreas of diabetic and prediabetic patients. Our aim is to develop such assays, validate them in collaboration with other nPOD-V investigators and screen nPOD tissues for enteroviruses using the most optimal test panel.

Our primary aims include the development of different histological methods, as well as PCR-based techniques, for enterovirus detection in various samples. These techniques are utilized in detecting enteroviruses in various tissue samples – such as pancreas, duodenum and spleen – of T1D, pre-diabetic and non-diabetic donors, and further in comparing the prevalence of EV infections between different donor groups, as well as in different tissues. We are applying three main methods to accomplish our goals:

1. Immunohistochemistry (IHC) with a wide panel of both commercial and in-house antibodies suitable for FFPE and frozen samples.
2. Standardized in situ hybridization (ISH) assay suitable for FFPE and frozen samples. We are using novel probes for both general and serotype-specific detection of enteroviruses.
3. Highly sensitive RT-PCR method for the detection of viral RNA and for the sequencing of viral genome.

Our studies have shown that these markers of enterovirus infection are more prevalent in type 1 diabetic and pre-diabetic subjects than in non-diabetic controls, and that the presence of enterovirus in pancreas correlates with that in other tissues.