IFN-α对山羊副流感病毒3型的抗病毒活性

旨在探讨原核表达纯化的山羊α干扰素(IFN-α)对山羊副流感病毒3型(CPIV3)的抗病毒活性。通过分析山羊IFN-α的序列特点，比对不同种属IFN-α的同源性，进而构建山羊IFN-α成熟蛋白编码基因(去除信号肽基因序列)的原核表达载体pET-30a-gIFN-α,将其转化至感受态细胞Rosetta (DE3),IPTG诱导后镍柱及亲和纯化获得山羊IFN-α。利用RT-qPCR测定山羊IFN-α作用于牛肾细胞(Madin-Darby bovine kidney cell, MDBK cell)后6种干扰素刺激基因(interferon-stimulated genes, ISGs)的相对表达水平；同时，利用TCID₅₀及Western blot测定其对CPIV3的抗病毒活性。结果表明，原核表达的山羊IFN-α蛋白含量为0.20 mg·mL^-1,Western blot结果表明表达产物相对分子质量约为20 ku,与预期结果相符。RT-qPCR结果显示，山羊IFN-α孵育MDBK细胞后，可显著刺激RSAD2、STAT1及ISG15等6种ISGs基...

The Antiviral Activity of Goat Interferon Alpha to Caprine Parainfluenza Virus 3

The aim of this study was to investigate the antiviral activity of goat interferon α (IFN-α) to caprine parainfluenza virus 3 (CPIV3). The sequence characteristics of goat IFN-α was analyzed, and the homology of IFN-α from different species was compared. Then the recombinant expression plasmid pET-30a-gIFN-α by inserting goat IFN-α gene (removing the signal peptide gene sequence) into vector pET-30a was constructed and transformed into Rosetta (DE3), after induced by IPTG, the goat IFN-α was expressed and purified. Then the relative expression level of interferon-stimulated genes (ISGs) was measured, and the anti-CPIV3 activity was measured after exogenous goat IFN-α treatment on Madin-Darby bovine kidney cell(MDBK cell) by TCID₅₀ and Western blot. The results showed that, the protein concentration of goat IFN-α was 0.20 mg·mL^-1, and Western blot analysis showed that the relative molecular weight was about 20 ku, which was consistent with expectations. The RT-qPCR result showed that the incubation of goat IFN-α on MDBK cells induced the up-regulation of the six ISGs including RSAD2, STAT1 and ISG15. Meanwhile, the goat IFN-α inhibited the CPIV3 replication, and down-regulated the expression level of the viral nonstructural protein C. All above results indicated that goat IFN-α could significantly inhibit the proliferation of CPIV3 on MDBK cells. This study extended the research type I interferon, and promoted the prevention and control of ruminant diseases.