Distribution of ifitm3 in yellow-feathered broilers and inhibition of avian reovirus multiplication by IFITM3

Abstract

This study was carried to express the interferon-induced transmembrane protein 3 (IFITM3) in vitro and examine its function in inhibition of avian reovirus (ARV) replication. The recombinant prokaryotic vector expressing yellow-feathered broiler IFITM3 was successfully constructed, and the recombinant protein was expressed in competent Escherichia coli BL21 cells. New Zealand white rabbits were immunized with the purified recombinant protein to prepare a polyclonal antibody, with a titer of 1:128,000. Immunohistochemistry, reverse transcription–PCR, and real-time fluorescence quantitative PCR showed that IFITM3 was distributed in the yellow-feathered broiler immune organs, and the expression of IFITM3 in bursa of Fabricius was more than in spleen and thymus. It was found that in the thymus, spleen and bursa of Fabricius the mRNA expression levels of IFNα and IFITM3 were significantly induced after ARV infection. And it was also certified in the chicken embryo fibroblasts (CEFs) which infected with ARV. Then the IFNα was added into the cell culture medium before CEFs were infected with ARV. The results indicated that the mRNA of IFITM3 expression was significantly increased and ARV multiplication was significantly inhibited. And when the expression of IFITM3 was knocked down by siRNA-IFITM3, the expression of IFITM3 was significantly reduced, but the ARV multiplication was significantly increased, which indicated that IFITM3 protein could inhibit the ARV replication.