【摘要】 【目的】旨在研究鸡痘病毒ORF73和ORF214编码蛋白是否具有IL-18结合蛋白的功能,以及ORF73或ORF214基因缺失后对重组病毒诱导免疫应答的影响。【方法】以缺失ORF73或ORF214基因并表达H5亚型AIVHA基因的重组鸡痘病毒(rFPVLP-△73LRH5A、rFPVLP-△214LRH5A)作为研究对象,以未缺失ORF73或ORF214基因而表达H5亚型AIVHA基因的重组鸡痘病毒(rFPVLP-12LSH5A)作为对照,检测重组病毒体外诱导SPF鸡脾细胞和外周血淋巴细胞产生IFN情况,同时检测重组病毒免疫SPF鸡后诱导的体液免疫、CD4+/CD8+比值、外周血淋巴细胞的增殖能力和H5亚型AIV强毒攻击后的免疫保护效力。【结果】rFPVLP-△73LRH5A和rFPVLP-△214LRH5A体外诱导脾细胞产生的IFN量显著高于rFPVLP-12LSH5A,而免疫10d后的CD4+/CD8+比值显著低于rFPVLP-12LSH5A;3种重组鸡痘病毒诱导外周血淋巴细胞增殖的能力没有明显差异;3种重组病毒在SPF鸡均产生针对H5亚型AIV的HI抗体,免疫14d后rFPVLP-△214LRH5A组诱生的HI抗体水平显著低于rFPVLP-12LSH5A组的抗体,但3组在免疫21d后HPAIV的致死性攻击时,均100%被保护。【结论】鸡痘病毒ORF73和ORF214编码蛋白具有IL-18结合蛋白抑制IFN产生的功能,虽然缺失株和亲本株重组鸡痘病毒在细胞和体液免疫应答存在一定差异,但在SPF鸡均能诱导产生良好的免疫保护。更多还原

【Abstract】 Objective To determine if the fowlpox virus(FPV) ORF73 or ORF214 gene encoding protein has the function of IL-18 binding protein,and to assess the role that ORF73 or ORF214 gene in regulating the immune response.Methods We constructed recombinant fowlpox virus(rFPV ) vector-based rFPVLP-△73LRH5A or rFPVLP-△214LRH5A,expressing avian influenza haemagglutinin gene(H5A) with ORF73 or ORF214 gene deletion, respectively.The parental recombinant virus expressing avian influenza haemagglutinin(rFPVLP-12LSH5A) was used as the control virus.The production of interferon(IFN) in vitro by splenocytes and peripheral blood mononuclear leukocytes(PBML) of SPF chickens stimulated with rFPVs was detected.The immune efficacy,antibody responses,ratio of CD4 + / CD8 + T lymphocyte and multiplication capacity of PBML induced by the rFPVs vector-based rFPVLP-△73LRH5A, rFPVLP-△214LRH5A and rFPVLP-12LSH5A vaccine were evaluated in SPF chickens.Results The level of IFN production from splenocytes stimulated with rFPVLP-△73LRH5A and rFPVLP-△214LRH5A was significantly higher than that with rFPVLP-12LSH5A in vitro,whereas the ratio of CD4 + /CD8 + T lymphocyte in rFPVLP-△73LRH5A and rFPVLP-△214LRH5A groups was significantly lower than that in rFPVLP-12LSH5A groups after 10 days post immunization(dpi).These rFPVs stimulated the proliferation of PBML without significant difference.All chickens immunized with rFPVLP-△73LRH5A,rFPVLP-△214LRH5A or rFPVLP-12LSH5A produced HI antibodies against H5 AIV HA antigen, and rFPVLP-△214LRH5A induced significantly lower HI titer than rFPVLP-12LSH5A after 14 dpi.All immunized chickens were fully protected against lethal challenge of H5N1 AIV.Conclusion ORF73 and ORF214 encoding proteins blocked induction of IFN,suggesting that they are provided with IL-18BP functionality.Despite of decreasing humoral response and cell-mediated immune response,rFPVwith deleted FPV73 or FPV214 gene could induce the effective efficacy in SPF chickens.更多还原