新型猫源干扰素FeIFN-ω与干扰素FeIFN-α的表达及抗病毒活性比较

Comparison of Antiviral Activitt Between FeIFN-ω and FeIFN-α

ω型干扰素(IFN-ω)与α型干扰素(IFN-α)同属于Ⅰ型干扰素,都具有抗病毒,抗增殖和免疫调节的功能,但它们之间的活性却存在较大差异。通过PCR扩增猫ω型干扰素基因(FeIFN-ω),根据GenBank公布的猫α型干扰素基因序列,合成猫α型干扰素基因(FeIFN-α)。分别构建原核表达载体pET-His/FeIFN-α和pET-His/FeIFN-ω,转化大肠杆菌Rosetta(DE3)进行表达。表达产物经Ni-NTA亲和层析纯化,复性后蛋白用细胞病变抑制法进行抗病毒活性测定。结果显示,重组猫ω型干扰素(FeIFN-ω)抗病毒活性明显高于重组猫α型干扰素(FeIFN-α),尤其对H9N2亚型禽流感病毒(AIV),FeIFN-ω的活性是FeIFN-α的160倍,对犬瘟热病毒(CDV),FeIFN-ω的活性是FeIFN-α的4倍,而日本同类产品Intercat对CDV和AIV均未表现活性。以上研究为以ω型干扰素为基础的抗病毒药物应用奠定了重要的理论基础。

Both IFN-ω and IFN-α belong to type I interferon and have antiviral, antiproliferative, immunomodulatory activities, but their bioactivities are usually different. FelFN-ω gene was amplified by PCR. FelFN-α gene was synthesized based on the published sequences of GenBank. 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 purified by affinity chromatography with immobilized nickel chelating NTA （Ni-NTA） and their antiviral activity was estimated according to the ability of IFNs to inhibit the cytopathic effects （CPE） of virus on cells. Results showed that the antiviral activities against various viruses of FeIFN-to were higher than those of FeIFN-α. Against H9N2 subtype avian influenza virus （AIV） and canine distemper virus （CDV）, the antiviral activities of FeIFN-ω were 160 folds and 4 folds higher than those of FeIFN-α.