Porcine endogenous retroviruses (PERVs) and xenotransplantation: Safety evaluation, diagnostics and inhibition by siRNA

• Applicant: Professor Dr. Ralf R. Tönjes
• Subject Area: Cardiac and Vascular Surgery
• Term: from 2004 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5470814

Methods to analyse expression and genomic distribution of proviral PERV as well as of viral proteins and released particles will be developed and used for screening during breeding of pigs that are safe for xenotransplantation (XTx) in terms of retroviral infections. Firstly, the distribution and expression of functional proviruses and genetic recombinations between different endogenous retroviruses in the course of infections of human cells will be investigated based on genomes of genetically modified animals. The presence of these proviruses in porcine genomes is not fixed and is polymorphic in subspecies and individuals. Thus, animals harbouring higher or smaller numbers of PERV exist. Existing as well as newly developed pig strains will be screened for the genomic distribution of polytropic and ecotropic classes PERV-A, -B and -C or recombinants thereof. In addition, the types of PERV long terminal repeats demonstrating different levels of promoter activities will be evaluated. Secondly, the expression and the release of virus particles in cells, tissues and organs from transgenic animals will be studied using highly sensitive methods. This includes analyses of PERV mRNA by RT-PCR as well as protein expression. A special assay was developed to discriminate high and low producer pigs. These methods detect recombinant and/or complementary viruses or the expression of viral proteins which can not be detected by methods described under topic 1.

• DFG Programme: Research Units
• Subproject of: FOR 535: Xenotransplantation