A simple and efficient method for the generation of a porcine alveolar macrophage cell line for high-efficiency Porcine reproductive and respiratory syndrome virus 2 infection

Abstract

CD163 is a cellular receptor for Porcine reproductive and respiratory syndrome virus (PRRSV). Transgenic expression of CD163 can predispose a variety of PRRSV non-permissive cells to PRRSV infection. These resulting cells can then be used for PRRSV production and the study of PRRSV biology. The PiggyBac (PB) transposon is a non-viral, plasmid-based mobile genetic element that can be used for gene delivery into mammalian cells. In this study, a simple and efficient method for the transfection of the porcine CD163 transgene into an immortalized porcine alveolar macrophage cell line (3D4/21), a non-permissive cell line to PRRSV infection, by PB transposition was demonstrated. The resultant stably transformed 3D4/21/CD163 cells expressed CD163 constitutively and were shown to be fully permissive for PRRSV-2 strains and yielded an excess of 106 TCID50/mL of progeny virus. The PRRSV replicated more efficiently in the 3D4/21/CD163 cells than in Marc-145 cells, and the titers of the progeny PRRSV produced in the 3D4/21/CD163 cells were higher than those produced in Marc-145 cells. This simplified PB transposon-generated PRRSV-2 permissive 3D4/21/CD163 cell line could facilitate PRRSV production and accelerate the study of virus-host interactions in vitro.