Characterization of the porcine alpha interferon multigene family.

State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, 220 Handan Road, Shanghai 200433, PR China.
Gene (Impact Factor: 2.2). 12/2006; 382:28-38. DOI: 10.1016/j.gene.2006.06.013
Source: PubMed

ABSTRACT The availability of data on the pig genome sequence prompted us to characterize the porcine IFN-alpha (PoIFN-alpha) multigene family. Fourteen functional PoIFN-alpha genes and two PoIFN-alpha pseudogenes were detected in the porcine genome. Multiple sequence alignment revealed a C-terminal deletion of eight residues in six subtypes. A phylogenetic tree of the porcine IFN-alpha gene family defined the evolutionary relationship of the various subtypes. In addition, analysis of the evolutionary rate and the effect of positive selection suggested that the C-terminal deletion is a strategy for preservation in the genome. Eight PoIFN-alpha subtypes were isolated from the porcine liver genome and expressed in BHK-21 cells line. We detected the level of transcription by real-time quantitative RT-PCR analysis. The antiviral activities of the products were determined by WISH cells/Vesicular Stomatitis Virus (VSV) and PK 15 cells/Pseudorabies Virus (PRV) respectively. We found the antiviral activities of intact PoIFN-alpha genes are approximately 2-50 times higher than those of the subtypes with C-terminal deletions in WISH cells and 15-55 times higher in PK 15 cells. There was no obvious difference between the subtypes with and without C-terminal deletion on acid susceptibility.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Japanese encephalitis virus (JEV) causes serious zoonosis in South Asia, Southeast Asia and other areas. Pigs are an important reservoir for this virus in nature. The treatment of JEV infection in pigs is important for controlling the prevalence of JEV in humans and economic losses in pig farming. In this study, we selected a high activity porcine alpha-interferon to inhibit JEV replication in porcine kidney cell lines (PK-15). Alpha interferon exhibited high antiviral activity against JEV; the expression of three interferon-stimulated genes (ISGs), ISG15, Mx2 and OAS L, increased significantly after interferon treatment. Furthermore, we verified the anti-JEV effect of these ISGs by RNAi and overexpression. Mx2 and OAS L exhibited strong anti-JEV effects in PK-15 cells. Based on these novel results, alpha interferon (IFN-α) should be considered to be a potential drug against JEV in pigs.
    Research in Veterinary Science 08/2013; · 1.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we provide the first comprehensive annotation of the entire family of canine interferons (IFNs). Canine IFN-ɛ (IFNE), IFN-κ (IFNK), and IFN-λ (IFNL) were discovered for the first time. Ten functional and 2 truncated IFN-α (IFNA) pseudogenes were found in the genome, which also enriched the existing knowledge about canine IFNA. The canine type I IFN genes are clustered on chromosome 11, and their relative arrangements are illustrated. To further investigate the biological activity of canine IFNE, it was expressed and purified in Escherichia coli. Recombinant canine IFNE (rCaIFN-ɛ) displayed potent antiviral activity on both homologous and heterologous animal cells in vitro, indicating that rCaIFN-ɛ has more broad cross-species activity than recombinant canine IFNA (rCaIFN-α). The antiviral activities of rCaIFN-ɛ and rCaIFN-α7 against different viruses on MDCK cells were also evaluated. The antiviral activities of recombinant canine IFNK and IFNL were demonstrated using a VSV-MDCK virus-target cell system. rCaIFN-ɛ exhibited a significant anti-proliferative response against A72 canine tumor cells and MDCK canine epithelial cells in a dose-dependent manner. rCaIFN-α7 was approximately 16-fold more potent than rCaIFN-ɛ in promoting natural killer cell cytotoxicity activity. Further, rCaIFN-ɛ can activate the JAK-STAT signaling pathway.
    Journal of interferon & cytokine research: the official journal of the International Society for Interferon and Cytokine Research 08/2013; · 1.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Interferon-α (IFN-α) genes have been cloned from a variety of animals, but information regarding crane IFN-α has not been reported to date. In this study, we cloned a full-length Red-crowned Crane interferon-α (crIFN-α) gene sequence consisting of a 486 bp partial 5′ UTR, 741 bp complete ORF and 559 bp partial 3′ UTR. This gene encodes a protein of 246 amino acids and shares 60 to 80% identity with avian IFN-α and less than 45% identity with mammalian IFN-α. The expression of crIFN-α with an N-terminal His-tag was investigated in Escherichia coli, and the protein was purified on a nickel column. To obtain activated proteins, crIFN-α inclusion bodies were renatured by dialysis. In vitro cytopathic inhibition assays indicated that the recombinant crIFN-α could inhibit the replication of vesicular stomatitis virus in chicken fibroblasts. These antiviral activities were abrogated by rabbit anti-crIFN-α antibodies in vitro. In addition, an immunofluorescence assay indicated that crIFN-α could be expressed in chicken fibroblasts and was primarily located in the cytoplasm. Taken together, our results suggest that the crIFN-α gene may play an important role in inhibiting the replication of viruses.
    Gene 01/2014; 544(1):49–55. · 2.20 Impact Factor