ABSTRACT
@#Objective To analyze the topology of IFN-induced transmembrane(IFITM) protein in porcine peripheral blood lymphocytes(PBMCs) and detect the change of IFITM mRNA transcription in PBMCs after porcine reproductive and respiratory syndrome virus(PRRSV) infection in vitro.Methods PRRSV,porcine circovirus 2(PCV2) and Japanese encephalitis virus(JEV) negative anticoagulant blood of piglets were collected aseptically and isolated for PBMCs.Porcine IFITM CDS sequence was amplified by PCR,sequenced and analyzed for topology.PBMCs were infected with PRRSV in vitro.Cell samples were collected at 12,24,36 and 48 h after infection,detected for PRRSV infection by RT-PCR,and detected for mRNA transcription level changes of IFITM1,IFITM2 and IFITM3 by RT-PCR.Results The porcine PBMCs were successfully isolated and the full-length sequence of IFITM CDS derived from PBMCs was cloned.The porcine IFITM protein might have two topological structures.PBMCs inoculated with PRRSV for 24 h produced obvious cytopathic effect.PRRSV was replicated in PBMCs.The transcription levels of IFITM1,IFITM2 and IFITM3 mRNA in PBMCs were significantly up-regulated at the early stage of PRRSV infection,and reached the peak at 12h after infection,and then gradually decreased;The transcription level of IFITM1 mRNA increased at 36 h after virus infection and then declined rapidly.Conclusion PRRSV infection in vitro significantly up-regulated the transcription level of IFITM mRNA in PBMCs,indicating that IFITM was involved in the antiviral immune response of PBMCs.This study provided a reference for revealing the natural immune response against PRRSV in vivo.