The present invention provides methods and compositions related to the generation of host cells permissive for virus growth, particularly Porcine Reproductive and Respiratory Syndrome (PRRS) virus.本發明提供關於產生可允許病毒生長(尤其是豬生殖和呼吸症候群(PRRS)病毒生長)之宿主細胞的的方法和組成物。