Porcine reproductive and respiratory syndrome virus counteracts the porcine intrinsic virus restriction factors-IFITM1 and Tetherin in MARC-145 cells.

•The PRRSV Nsp3 or E protein was demonstrated to interact with IFITM1 or Tetherin.•The Nsp3 was shown to induce the proteasome-dependent degradation of IFITM1.•The E protein was proposed to partially remove Tetherin away from cell surface.•PRRSV might counteract cellular IFITM1 and Tetherin by its Nsp3 and E protein.