畜牧兽医学报 ›› 2009, Vol. 40 ›› Issue (2): 248-255.doi:

• 基础兽医 • 上一篇    下一篇

猪α干扰素/白细胞介素2基因的融合表达及活性研究

闫若潜,吴志明*,张志凌,盛敏,刘光辉,赵明军   

  1. 河南省动物疫病预防控制中心,郑州 450008
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2009-02-24 发布日期:2009-02-24
  • 通讯作者: 吴志明

Study on the Expression and Bioactivity of Porcine Interferon Alpha/Porcine Interleukin-2 Fusion Protein

YAN Ruo-qian,WU Zhi-ming*,ZHANG Zhi-ling,SHENG Min,
LIU Guang-hui,ZHAO Ming-jun
  

  1. Henan Centre for Animal Disease Control and Prevention,Zhengzhou 450008, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2009-02-24 Published:2009-02-24

摘要: 为了研究高效广谱的猪基因工程抗病毒制剂,作者采用重叠延伸PCR(Splicing by overlap extension-PCR,SOE-PCR)方法通过一基因柔性接头(linker)(G4S)3将猪α干扰素(Porcine interferon alpha, PoIFN-α)与猪白细胞介素2(Porcine interleukin-2, PoIL-2)成熟肽基因连接,构建成PoIFN-α-linker-PoIL-2嵌合基因,并克隆入pGEM-T Easy载体,将PoIFN-α-linker-PoIL-2嵌合基因亚克隆入pQE-30表达载体进行原核表达。通过尿素变性、复性液复性、PBS溶液透析等步骤对表达的重组融合蛋白(rPoIFN-α-linker-PoIL-2)进行纯化。采用细胞病变抑制法检测rPoIFN-α-linker-PoIL-2蛋白中的PoIFN-α在不同细胞系上对不同病毒增殖活性的抑制作用;分别采用MTT法和PoIL-2 ELISA试验方法检测rPoIFN-α-linker-PoIL-2蛋白中PoIL-2的生物学活性。结果表明成功构建并克隆PoIFN-α-linker-PoIL-2嵌合基因。嵌合基因在大肠杆菌中得到高效表达,表达的rPoIFN-α-linker-PoIL-2蛋白相对分子质量约36.7 ku,蛋白经纯化后纯度在96%以上。rPoIFN-α-linker-PoIL-2蛋白在细胞上具有与单一rPoIFN-α蛋白相近的抑制病毒增殖活性,其中在PK-15细胞上抗VSV的活性单位为1.891×104 IU·mL-1,在Marc-145细胞上抑制高致病性PRRSV增殖的活性单位为905 U·mL-1;rPoIFN-α-linker-PoIL-2蛋白具有与单一rPoIL-2蛋白对照相近的生物学活性,可明显促进CTLL-2细胞的增殖,并可与抗PoIL-2单抗发生特异性免疫反应。这表明rPoIFN-α-linker-PoIL-2蛋白具有rPoIFN-α和rPoIL-2蛋白双重的生物学活性,为基因工程抗病毒制剂的开发以及高致病性猪繁殖与呼吸综合征等病毒性疾病的预防和治疗等研究奠定了基础。

Abstract: To exploit the high efficient porcine gene engineering antiviral agent to prevent and control the porcine viral disease, the recombination chimeric gene of PoIFN-α-linker-PoIL-2 was constructed by linking porcine interferon alpha (PoIFN-α) mature peptide gene and porcine interleukin-2 (PoIL-2) mature peptide gene via a 15-amino acid glycine-rich linker [linker,(G4S)3] by SOEPCR (splicing by overlap extension-PCR) method. Then the recombinant gene was cloned into pGEM-T Easy vector and subsequently sub-cloned into prokaryotic expression vector pQE30. The recombinant PoIFN-α-linker-PoIL-2 (rPoIFN-α-linker-PoIL-2) protein was expressed in E.coli JM109 and purified under the process of denaturing by 8 mol·L-1 urea, refolding by a self-innovative renaturation buffer and dialyzing by PBS buffer etc. The antiviral bioactivity of rPoIFN-α-linker-PoIL-2 protein was tested by inhibiting the 50 percent appearance of cytopathic effect (CPE) of vesicular stomatitis virus (VSV) on porcine kidney 15 (PK15) cell lines and highpathogenic porcine reproductive and respiratory syndrome virus (PRRSV) on Marc-145 cell lines. The PoIL-2 bioactivities of rPoIFN-α-linker-PoIL-2 protein were estimated by the methods of IL-2 MTT assay and porcine IL-2 ELISA assay for detection PoIL-2 protein,respectively. The results showed that the correct PoIFN-α/PoIL-2 fusion protein had been obtained. The antiviral activity of rPoIFN-α-linker-PoIL-2 protein to inhibit the reproduce of VSV on PK15 cell line was 1.891×104 IU·mL-1, and the lowest effective dose of rPoIFN-α-linker-PoIL-2 protein to inhibit the proliferation of high-pathogenic PRRSV on marc-145 cells was 905 U·mL-1, which were similar to the antiviral activity of recombinant PoIFN-α protein (rPoIFN-α) control. The rPoIFN-α-linker-PoIL-2 protein displayed the ability to stimulate the proliferation of IL-2-dependent CTLL-2 cells and the specific immune response for monoclonal antibody (MAb) of PoIL-2 by ELISA assay respectively,which were similar to the bioactivity of recombinant PoIL-2 protein (rPoIL-2) control. Our study indicated that the rPoIFN-α-linker-PoIL-2 protein had the duplex bioactivity of PoIFN-α protein and PoIL-2 protein on cells,which laid a foundation for further wide using the rPoIFN-α-linker-PoIL-2 protein as the main ingredient of porcine gene engineering antiviral agent to prevent and control the high-pathogenic porcine reproductive and respiratory syndrome and other porcine viral diseases.