中国农业科学 ›› 2010, Vol. 43 ›› Issue (3): 594-604 .doi: 10.3864/j.issn.0578-1752.2010.03.021

• 兽医 • 上一篇    下一篇

鸡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,谢彩华,吴志明,张志凌,刘光辉,刘梅芬

  

  1. (河南省动物疫病预防控制中心)
  • 收稿日期:2009-07-01 修回日期:2009-09-19 出版日期:2010-02-10 发布日期:2010-02-10
  • 通讯作者: 吴志明

Study on the Expression and Bioactivity of Chicken Interferon α /Chicken Interleukin-2 Fusion Protein in vivo and in vitro

YAN Ruo-qian, XIE Cai-hua, WU Zhi-ming, ZHANG Zhi-ling, LIU Guang-hui, LIU Mei-fen
  

  1. (河南省动物疫病预防控制中心)
  • Received:2009-07-01 Revised:2009-09-19 Online:2010-02-10 Published:2010-02-10
  • Contact: WU Zhi-ming

摘要:

【目的】研究高效广谱鸡基因工程重组复合抗病毒制剂以对鸡的病毒性疾病进行防治。【方法】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将鸡α干扰素(chicken interferon alpha,ChIFN-α)与鸡白细胞介素2(chicken interleukin-2,ChIL-2)基因构建成ChIFN-α-linker- ChIL-2嵌合基因并克隆入pGEM-T Easy载体,将嵌合基因亚克隆入pQE-30表达载体中进行原核表达。通过尿素变性、低浓度蛋白复性液复性、PBS溶液透析等步骤对表达的重组融合蛋白(rChIFN-α-linker-ChIL-2)进行纯化。采用细胞病变抑制法检测rChIFN-α-linker-ChIL-2蛋白在细胞上抑制水泡性口炎病毒(VSV)和传染性法氏囊病毒(IBDV)增殖活性。采用ChIL-2 ELISA试验方法检测rChIFN-α-linker-ChIL-2蛋白与抗ChIL-2单抗发生特异性免疫反应的活性。分别测定rChIFN-α-linker-ChIL-2蛋白在SPF鸡胚上对新城疫病毒(NDV)和禽流感H9N2亚型病毒(AIV H9N2)的抑制活性以测定其在鸡胚内抗病毒活性。分别测定rChIFN-α-linker-ChIL-2蛋白在鸡体内对NDV活疫苗和灭活疫苗的免疫增强作用以测定其在鸡体内的活性。【结果】成功构建并克隆了ChIFN-α-linker-ChIL-2嵌合基因。嵌合基因在大肠杆菌中表达的rChIFN-α-linker-ChIL-2蛋白分子量大小约35.9 kD,蛋白经纯化后纯度在96%以上。rChIFN-α-linker-ChIL-2蛋白在CEF细胞上具有明显抗病毒活性,其抗VSV和IBDV活性明显高于单一rChIFN-α的抗病毒活性;rChIFN-α-linker-ChIL-2蛋白可以和抗ChIL-2单抗发生特异性免疫反应。IFN-α活性单位为200 IU的rChIFN-α-linker-ChIL-2蛋白在SPF鸡胚内可明显降低NDV和AIV H9N2所引起的鸡胚死亡和胚体出血,并能显著延长鸡胚存活时间,但过高剂量的rChIFN-α-linker-ChIL-2蛋白抑制鸡胚死亡和出血能力有所下降。合适剂量的rChIFN-α-linker-ChIL-2蛋白在鸡体内具有显著的抗病毒活性和免疫增强活性。【结论】rChIFN-α-linker-ChIL-2蛋白在鸡体内外均具有ChIFN-α和ChIL-2蛋白的双重生物学活性,这为进一步研究以rChIFN-α-linker-ChIL-2蛋白为主要成分的基因工程抗病毒制剂在鸡体内抗病毒活性研究奠定了基础。

关键词: face=Verdana>鸡α干扰素, 鸡白细胞介素2, 嵌合基因, 融合表达, 活性

Abstract: 【Objective】 The aim of this study was to explore a high efficient chicken gene engineering antiviral agent to prevent and control the chicken viral disease. 【Method】 The recombinant chimeric gene of ChIFN-α-linker-ChIL-2 constructed by chicken interferon α ( ChIFN-α) gene linked chicken interleukin-2 (ChIL-2) gene via a glycine-rich linker by SOE-PCR (splicing by overlap extension-PCR) method was cloned into pGEM-T Easy vector and subsequently sub-cloned into prokaryotic expression vector pQE30. The recombinant ChIFN-α-linker-ChIL-2 (rChIFN-α-linker-ChIL-2) protein was expressed in E.coli JM109 and purified with the innovated recombinant fusion protein purification method and denatured by 8 M urea, refolded by a self-innovative renaturation buffer and dialyzed by PBS buffer, etc. The antiviral bioactivities of rChIFN-α-linker-ChIL-2 protein were tested by inhibiting the 50 percent appearance of cytopathic effect (CPE) of vesicular stomatitis virus (VSV) and infectious bursal disease virus (IBDV) on chicken embryo fibroblast (CEF) cell lines. The ChIL-2 bioactivities of rChIFN-α-linker-ChIL-2 protein were estimated by the method of chicken IL-2 ELISA assay for detection of the specific immunoactivity of ChIL-2 protein. The antivirus bioactivity of rChIFN-α-linker-ChIL-2 protein was evaluated by inhibiting the reproduction of NDV and AIV (H9N2) in chicken embryos, respectively. The bioactivity of rChIFN-α-linker-ChIL-2 protein in chicken was estimated by detecting the NDV hemagglutination inhibition (HI) antibody titer induced by NDV oil-adjuvant inactivated vaccine and attenuated live vaccine, respectively. 【Result】 The chimeric gene of ChIFN-α-linker-ChIL-2 was successfully constructed and cloned into pGEM-T Easy vector, respectively. The rChIFN-α-linker-ChIL-2 protein was abundantly fusion expressed in E.coli and successfully purified with a molecular mass of about 35.9 kD and purity more than 96% on SDS-PAGE, which indicated that the correct rChIFN-α-linker-ChIL-2 fusion protein had been obtained. The antiviral activity units of rChIFN-α-linker-ChIL-2 protein inhibiting the reproduction of VSV and IBDV on CEF cell line were 1.14×108IU?mg-1 and 1.59×106 IU?mg-1 ,respectively, which were much higher than that of the recombinant ChIFN-α protein (rChIFN-α) of control (4.09×106 IU?mg-1, 2.78×105 IU?mg-1). The rChIFN-α-linker-ChIL-2 protein showed the ability of the specific immune response to monoclonal antibody (MAb) of ChIL-2 by ELISA assay, which was similar to the bioactivity of recombinant ChIL-2 protein (rChIL-2) of control. The rChIFN-α-linker-ChIL-2 protein with 200 international unit of IFN-α could obviously decrease the death rate and haemorrhage degree as well as prolong the living time of chicken embryos inoculated by NDV and AIV H9N2, whereas the excessive dose of rChIFN-α-linker-ChIL-2 protein displayed the lower ability of decreasing the death rate and haemorrhage degree of chicken embryos. The rChIFN-α-linker-ChIL-2 protein with appropriate dose exhibited the prominent abilities of antivirus and immunopotentiation in chicken.【Conclusion】 The results of study indicated that the rChIFN-α-linker-ChIL-2 protein had the duplex bioactivity of ChIFN-α protein and ChIL-2 protein on cells, in chicken embryos and chicken, thus laid a foundation for further widely use of rChIFN-α-linker-ChIL-2 protein acting as a main ingredient of chicken gene engineering antiviral agent to prevent and control the chicken viral diseases.

Key words: chicken interferon alpha, chicken interleukin-2, chimeric gene, fusion expressed, bioactivity