鸡白细胞介素-18对H9亚型禽流感灭活油乳苗的免疫增强作用

目的]探索鸡白细胞介素-18（IL-18）在H9禽流感（AI）灭活油乳苗免疫中的免疫佐剂作用.方法]从鸡脾淋巴细胞中克隆鸡IL-18基因,亚克隆到真核表达载体pcDNA3.1（＋）中,构建真核表达质粒pIL-18.将重组真核表达质粒pIL-18、H9亚型AI灭活油乳苗及其二者联合分别免疫14日龄SPF鸡,检测其细胞免疫和体液免疫水平,评价鸡IL-18在H9亚型禽流感灭活油乳苗中的免疫增强作用.结果]成功克隆了鸡IL-18全基因,大小为597 bp.质粒pIL-18和H9亚型AI灭活油乳苗联合免疫的SPF鸡所产生的HI抗体效价在接种第4周后明显高于H9亚型AI灭活油乳苗免疫组;其T淋巴细胞的增殖反应也强于H9亚型AI灭活油乳苗免疫组.结论]质粒pIL-18能提高H9亚型禽流感灭活油乳苗诱发的免疫应答,为研究防制禽流感的新型疫苗提供了新思路.

Immune Enhancement Effects of Chicken Interleukin-18 on Inactivated Oil Emulsion Vaccine of H9 Subtype Avian Influenza

Objective ] The research aimed to explore the immune adjuvant effect of interleukin - 18 （ IL-18 ） in the immunization of inactivated oil emulsion vaccine of H9 subtype avian influenza. Method] Chicken IL-18 gene was amplified from total RNA extracted from chicken spleen lymphocytes. PCR product was inserted into eukaryotic expression vector pcDNA3.1 （ ＋ ） to construct eukaryotic expression vector pIL-18. The recombinant eukaryotic expression vector pIL-18, inactivated oil emulsion vaccine of H9 subtype avian influenza and the mixture were used to im- munize 14 - day - old SPF chicken and detect its cellular immunity and humoral immunity levels. The immune enhancement effects of chicken on inactivated oil emulsion vaccine of H9 subtype avian influenza were evaluated. Result] Total IL-18 gene of chicken was successfully cloned, and its length was 597 bp. The titers of HI antibody produced in SPF chicken immunized with plasmid pIL-18 and inactivated oil emulsion vaccine of H9 subtype avian influenza in the four weeks after inoculation were obviously higher than that in inactivated oil emulsion vaccine of H9 subtype a- vian influenza. Its multiplication response of T lymphocyte was stronger than that in inactivated oil emulsion vaccine of H9 subtype avian influenza group. Conclusion] Plasmid pIL-18 could enhance the immune response induced by inactivated oil emulsion vaccine of H9 subtype avian influ- enza, which provided a new thought for studying and developing new vaccines of avian influenza.