PK-15 Cells Transfected with Porcine CD163 by PiggyBac Transposon System Are Susceptible to Porcine Reproductive and Respiratory Syndrome Virus

The PiggyBac (PB) transposon system is a non-viral DNA-transfer system in which a transposase directs integration of a PB transposon into a TTAA site in the genome. Transgenic expression of porcine CD163 is necessary and sufficient to confer non-permissive cells susceptible to infection with porcine reproductive and respiratory syndrome virus (PRRSV). Such permissive cells can be used as a tool for PRRSV cellular receptor and other studies. One of the problems in studying PRRSV is the lack of porcine cell lines. In this study, efficient transfection and expression of porcine CD163 in PK-15 cells by PB transposition was demonstrated. The stable PK-15CD163 cell line was used in PRRSV infection assays. The data indicated that the average PB transgene copy number per genome was approximately 10. In line with previous literature the integration of PB into the genome had a bias toward the TTAA chromosomal site. The PK-15CD163 cell line was susceptible to infection by different PRRSV strains and the virus grew to similar titers compared to the Marc-145 cell line. This simplification of PK-15CD163 cell line production will provide a valuable tool to facilitate PRRSV cellular receptor studies and to accelerate existing vectors for PK-15 cell-based gene transfer and expression.