Abstract

Background: Islet cells from pig could be used as an alternative to the current treatment of diabetic patients. However, xenotransplantation from pig to humans may be associated with the risk of transmission of porcine endogenous retroviruses (PERVs) that are present in the genome of all pigs and infect human cells in vitro. Although transplantation of pig islet cells for treatment of diabetes may be not accompanied by immunosuppression that may facilitate virus survival, since islets will be used encapsulated, it is nevertheless of importance to study whether islet cells release PERVs able to infect human cells during co-incubation.
Material/Methods: Isolated islets from German landrace pigs were incubated with highly susceptible human 293 cells for one week. In order to prevent microchimerism  293 cells were made neomycin-resistant (293[sup]neo+[/sup]), that allows the elimination of pig cells by a selection medium. The infection of 293[sup]neo+ [/sup]target cells was analysed by PCR using PERV-specific primers up to five weeks after co-cultivation. In addition, expression of viral mRNA in pig islet cells was studied by RT-PCR analysis, the expression of viral protein by FACS analysis.
Results: Despite the presence of numerous PERV proviruses in the genome of all pigs, no expression of PERV was observed in German landrace pig islet cells, neither as mRNA, nor as protein, nor as viral particles.
Conclusions: Islet cells from German landrace pigs do not express PERVs and may therefore be used for breeding genetically modified pigs suitable for xenotransplantation and treatment of diabetes.

Keywords: Xenotransplantation, Diabetes , Porcine Endogenous Retroviruses (PERV), islet cells