鸡IL-6真核表达载体的构建及其对新城疫LaSota疫苗的免疫增强作用研究

Construction of Eukaryotic Expression Plasmids Encoding Chicken Interleukin-6 and Study on Its Immunoenhancement on Newcastle Disease LaSota Vaccine

利用RT-PCR方法从ConA诱导的鸡脾淋巴细胞RNA中扩增出IL-6基因,与pCI-neo连接构建真核表达质粒pCI-IL-6,并研究pCI-IL-6在CEF细胞中的表达及其对新城疫LaSota疫苗的免疫增强作用。研究发现,pCI-IL-6在CEF细胞中得到表达,pCI-IL-6和LaSota疫苗联合免疫组HI抗体、CD4+、CD8+和CD3+T淋巴细胞百分含量从免疫后第14天起均高于LaSota疫苗单独免疫组。其中,HI抗体效价在第14、21和35天时差异显著(P<0.05),在第28天时差异极显著(P<0.01);CD4+、CD8+和CD3+T淋巴细胞百分含量在第14天后表现为差异显著(P<0.05)或极显著(P<0.01)。在免疫后第35天进行攻毒,pCI-IL-6和LaSota疫苗联合免疫组的保护率为89.5%,而LaSota疫苗单独免疫组的保护率为76.5%。结果表明,pCI-IL-6真核表达质粒在鸡体内成功表达,并能明显提高新城疫LaSota疫苗的免疫效果,具有免疫增强作用。

The chicken interleukin-6 （IL-6） was amplified from RNA of ConA-activated chicken splenic lymphocyte by RT-PCR, the gene was inserted into pCI-neo vector, and the recombinant plasmid pCI-IL-6 was acquired. The expression of pCI-IL-6 in CEF and its immunoenhancement effects on Newcastle disease LaSota vaccine were studied. The results showed that pCI-IL-6 can be expressed in CEF, the HI antibodies and percentage of CD4^＋ ,CD8^＋ and CD3^＋T lymphocyte of co-immunization group of pCI-IL-6 and LaSota vaccine were higher than those of LaSota vaccine group at 14 days post immunization, the difference of HI antibodies was significant （P〈 0.05）at 14,21 and 35 days post immunization and very significant （P〈0. 01）at 28 days post immunization respectively. The difference of percentage of CD4^＋, CD8^＋ and CD3^＋ T lymphocyte was significant （P〈0.05）or very significant （P〈0.01）at 14 days post immunization. Challenge test at 35 days post immunization showed that the protection ratio of co-immunization group of pCI-IL-6 and LaSota was 89.5%, while those of LaSota vaccine group was 76.5%. The results showed that chicken IL-6 was expressed in vivo and can improve the immunization level of NDV LaSota vaccine obviously, showing immunoenhancement effect. This paper provided data for the further research and utilization of chicken IL-6.