Examining the potential for porcine-derived islet cells to harbour viral pathogens

With an onus on safety in the potential use of porcine islet cells as a treatment for diabetes, the use of animals lacking exogenous pathogens is clearly important and multilevel screening strategies have been presented on testing animals and the product. In this study, we wished to investigate whether islet cells indeed harboured the same viral pathogens of concern in the source animal. PMBC and islet cells from both adult and neonatal source animals were directly compared and tested for PCMV, PLHV, PCV2, PPV and HEV using both molecular and serological assays. Adult PBMC were found positive for all viruses with the exception of PCV2 and HEV. Neonatal PBMC were only found positive for PCMV and HEV. All animals were found negative for HEV antibodies. Interestingly, islet cells were negative for all viruses tested regardless of status in the animal-derived PBMC. Given that other laboratories have demonstrated the lack of virus detection during the culture of islets, this study also demonstrates that the hygiene status of the herd may not reflect the status of the product. This is important for establishing guidelines for any risk evaluation and mitigation process utilised during product manufacture.