【摘要】 利用表达鸡γ干扰素的重组鸡痘病毒(rFPV-IFN-γ)与表达H5亚型禽流感病毒血凝素基因的重组鸡痘病毒(rFPV-HA)或灭活疫苗联合应用,接种SPF鸡、无母源抗体商品鸡和含有母源抗体商品鸡,研究鸡γ干扰素的免疫增强作用。结果发现,rFPV-IFN-γ和rFPV-HA联合应用诱导的HI抗体应答水平同rFPV-HA单独免疫相近;rFPV-IFN-γ和灭活疫苗联合应用后HI抗体应答水平略低于灭活疫苗单独免疫组。攻毒后,对于SPF鸡和无母源抗体商品鸡,rFPV-IFN-γ与rFPV-HA或灭活疫苗联合免疫诱导的保护率同相应疫苗单独免疫相当,均为95%~100%;对含有母源抗体的商品鸡,106PFU的rFPV-HA与105PFU 的rFPV-IFN-γ联合免疫组保护率(33.5%)高于rFPV-HA单独免疫组(11.4%~16.8%),而其它剂量组合的rFPV-HA与rFPV-IFN-γ联合应用不能提高免疫保护效力;rFPV-IFN-γ与灭活疫苗联合免疫含母源抗体商品鸡诱导的保护率同灭活疫苗单独免疫组相近。结果表明,rFPV-IFN-γ不能促进疫苗诱导的HI抗体应答;适当剂量组合的rFPV-HA与rFPV-IFN-γ联合免疫含有母源抗体的商品鸡,可提高免疫保护效力,发挥免疫增强作用。更多还原

【Abstract】 Vaccination trials using H5 avian influenza vaccines were carried out in SPF chickens and commercial chickens with and without maternal antibodies (Ab+ chickens and Ab- chickens, respectively) to evaluate the potential use of chicken type II interferon expressed by recombinant fowlpox virus (rFPV-IFN-γ ) as an immunopotentiator. Groups of chickens were immunized with recombinant fowlpox virus expressing haemagglutinin of H5 avian influenza virus (rFPV-HA), inactivated vaccine and vaccines plus rFPV-IFN-γ at different dosage preparations respectively. Chickens vaccinated with rFPV-HA plus rFPV-IFN-γ or rFPV-HA produced the same low level of HI antibodies. Inactivated vaccine plus rFPV-IFN-γ induced a little lower HI antibody comparing with inactivated vaccine. The rFPV-HA or inactivated vaccine plus rFPV-IFN-γ induced 95%~100% protection against challenge in SPF chickens and Ab- chickens and protective efficacies were equal to those induced by vaccines alone. The group of Ab+ chickens immunized with 106PFU rFPV-HA plus 105 PFU rFPV-IFN-γ showed more protection (33.5%) comparing with those (11.4%~16.8%) in groups immunized with rFPV-HA or rFPV-HA plus rFPV-IFN-γ at other dosage preparations. These results showed that rFPV-IFN-γ can not promote HI antibody response induced by H5 avian influenza vaccines in chickens. And the rFPV-IFN-γ enhances the protection of rFPV-HA in Ab+ chickens rather than SPF chickens and Ab- chickens when the rFPV-HA and rFPV-IFN-γ are used at appropriate combination of dosage.更多还原