Comparison On The Bioactivities Of FeIFN-ω And FeIFN-α

IFN-ωand IFN-αboth belong to typeâ… interferon which have antiviral, antiproliferative,immunomodulatory activities.The bio-activity of IFNs are limited by their species-specific,however,some reports indicated that the IFN-ωderived from human also has the same effects on other species,even could be higher effective than IFN-αon aspect of antiviral activity.1.The FeIFN-ωgene from a Burmese cat infected with feline infectious peritonitis virus(FIPV),FeIFN-αgene was cloned based on the Recombinent plasmid Pet-28a/FeIFNα.Then the two types of feline interferon genes were subcloned into the pET-His vector,and expressed in Escherichia coli Rosetta(DE3).Recombinant interferons were induced by IPTG and inclusion body was purified by affinity chromatography with immobilized nickel chelating NTA(Ni-NTA).In this study,we successfully construct the higher expression systems of FeIFN-ωand FeIFN-αin Escherichia coli Rosetta and seeked a effective method to purify the inclusion body. The purity of INFs reached to 95%.2.The comparison of the antiviral activity of two interferon:FeIFN-ω,FeIFN-αfocus on two aspects based on the control of Intercat(?).First,we compared antiviral activity of three subtypes of interferons against different viruses.Second,we compared the antiviral activity of them on different animal cells against VSV.The antiviral activity was assayed by the ability of FeIFNs to inhibit the cytopathic effects (CPE) of vesicular stomatitis virus.When the CPE reached 75～100%in viral control, the cells were strained with crystal violet absorbance was measured at 570 nm on a Sunrise microtiter plate reader.Through the research of bio-activity of FeIFNs,the results showed that:the antiviral activities against four viruses of FeIFN-ωwere higher than those of FeIFN-α.Against H₉N₂ subtype avian influenza virus(AIV) and canine distemper virus(CDV),the antiviral activities of FeIFN-ωwere 160 folds and 4 folds higher than those of FeIFN-α,and the Japanese product Intercat(?) showed no antiviral activity.The antiviral activities against VSV on five different mammal cells of FeIFN-ωwere higher than those of FeIFN-α.On VERO and MDBK cells,the antiviral activities of FeIFN-ωwere15 folds and 30 folds higher than those of FeIFN-α,on HeLa and PK-15,the antiviral activities of FelFN-ωwere100 folds higher than those of FelFN-α,and the Japanese product Intercat(?) showed no antiviral activity on these cells except CRFK cell.Meanwhile.All these results can provide strong support to antiviral therapy in clinic and new drug development of pets.