Characteristics Of Swine Interferon ω And δ Gene Families And Their Application Against PRRS

Interferon-ωis a member of the type I interferon family. In this work,8 functional porcine interferon-ωgenes and 4 pseudogenes present on porcine chromosome 1 were identified in the porcine genome database by BLAST scanning. Their genetic and genomic characteristics were investigated using bioinformatics tools. Then the PoIFN-ωfunctional subtype genes were isolated and expressed in BHK-21 cells. The PoIFN-co subtypes possessed about104 to 105 units of antiviral activity per milliliter. PoIFN-ω7 had the highest antiviral activity, about 20 times that of PoIFN-ω4, which had the lowest antiviral activity. Differential expression of the subtypes was detected in PK15 cells and porcine peripheral blood mononuclear cells (PBMCs) in response to pseudorabies virus (PRV) and poly(I).poly(C). Expression of PoIFN-ω2/-ω6 was up-regulated to the greatest extent by virus infection. IFN-δwas first discovered in porcine genome. In this research, we analyzed 11 IFN-δgenes and 7 pseudogenes from the porcine genome database, and further studied their genome loci, sequence and evolutionary properties. Based on the bioinformatical results, we chose three of them, expressed and functionally studied. The anti-PRV study showed that, all IFN-δsubtypes have the antiviral ability, which is considered the basic property of type I interferons. But the subtypes differed greatly in the actibity. Further experiments were performed in detection of the every step in their function performance. We find that, although differ in subtypes, all IFN-δs can bind to the type I interferon receptors IFNARs, and activated STAT, thus activated the ISGs (interferon stimulatory genes) for antiviral via JAK/STAT signaling pathway. Therefore, they can modulate the host immune system in inducing other cytokines. Porcine reproductive and respiratory syndrome virus (PRRSV) is a major concern within the pig industry as safe and effective vaccines have yet to be developed and implemented. In this study, we detected PoIFN-δ8 for anti-PRRSV analysis both as a direct viral-inhibitor or as vaccine adjuvant. PoIFN-δ8 effectively protected pigs from PRRSV infection, both as a direct viral inhibitor and as an adjuvant of a PRRSV killed virus (KV) vaccine. PoIFN-δ8 induced both cellular and humoral immunity, promoted viral clearance, protected pigs from PRRSV-induced pathology, and increased pig survival rate following viral-challenge. Here, we demonstrate for the first time the antiviral and vaccine adjuvant potential of PoIFN-δagainst PRRSV infection in vivo. Our investigation identifies a promlsing target for mammalian antiviral studies, which will help in the development of new strategies for battling with serious porcine diseases. Most of our knowledge of helical cytokine-like molecules in invertebrates relies on functional assays and similarities at the physicochemical level. It is hard to predict helical cytokines in invertebrate based on sequences from mammals and vertebrates, because of their long evolutionary divergence. In this paper, we collected twelve kinds of fish cytokines and constructed their respective consensus sequences using Hidden Markov Models; then, the conserved domains region of each consensus sequence were further extracted by the SMART tool, and used as the query sequence for PSI-BLAST analysis in Drosophila melanogaster. After two filtering processes based on the properties of helical cytokines, we obtained one protein named CG14629, which shares 25% identities/46% positives to fish M17 cytokine in the half length of the N-terminal. Considering the homology between M17 and LIF/CNTF (leukemia inhibitory factor/ciliary neurotrophic factor), and the close relation between Dome, the putative cytokine receptor in Drosophila cells, and LIFR/CNTFR, the results suggest that CG14629 is a good candidate for the helical cytokine ortholog in Drosophila melanogaster.