摘要
目的:利用针对不同病原的重组鸡痘病毒(rFPV)在鸡群进行间隔性的多次免疫时,后期免疫会受到前期免疫所诱生的载体特异性免疫反应的干扰,并导致其免疫效力下降。将这些rFPVs进行联合免疫或许是解决此问题的一种策略。为验证rFPVs联合免疫的可行性,研究中将三种针对不同病原的rFPVs以联合或单独的方式分别进行免疫,并对它们的免疫效力进行比较。方法:rFPV-12LSH9A、rFPV-12LSH5NA及rFPV-12LSHN为分别表达H9亚型禽流感病毒(AIV)HA基因、H5亚型AIV的HA和NA基因及新城疫病毒(NDV)HN基因的三种rFPVs。将这三种rFPVs分别在SPF鸡和带有针对H9、H5亚型AIV及NDV三种病原母源抗体的商品鸡上进行联合或单独免疫。结果:这三株rFPVs在SPF鸡上进行联合免疫时,所诱生的体液免疫应答受到了一定程度的抑制;个别成员株的排毒及死亡保护也受到了显著的干扰。结论:在进行rFPVs联合免疫时,有必要对各成员株rFPV的免疫效力进行比较分析,以确定其可行性。
Objective：When recombinant fowlpox viruses （rFPVs） against different pathogens are used in a flock consecutively, the subsequent rFPV vaccination usually can not confer good protection due to the pre-existing vector-specific immunity. Combination of different rFPVs may be a strategy to solve the problem. However, it is unclear whether the same levels of protection against each pathogen might be conferred by such combined rFPVs as those by individual rFPV alone, is unclear. The aim in this study is to evaluate the ability of the combined rFPVs vaccination to induce protection in chickens. Methods： Three rFPVs： rFPV-12LSH9A expressing HA gene of H9N2 avian influenza virus （AIV）, rFPV-12LSH5NA expressing HA and NA genes of H5N1 AIV and rFPV-12LSHN expressing HN gene of Newcastle disease virus （NDV） ,were constructed using FPV strain LP. SPF chickens and commercial chickens with maternal antibodies to H9,H5 subtypes AIV and NDV were injected with these rFPV vaccines, either alone or in combination. Twenty eight days after vaccination, the chickens in both pattern of vaccination were divided into three subgroups,which were challenged with homologous HgN2 AIV, highly pathogenic HSN1 AIV or velogenic NDV, respectively. Individual vaccination groups were also challenged with the corresponding vindent virus. Serum samples were collected at appropriate intervals after immunization. Five days after challenge, tracheal （ H9N2 AIV challenged groups） or cloacal （ H5N1 AIV and NDV challenged groups） swabs were collected for virus isolation. The birds were monitored for 14 days for mortality. Results： In SPF chickens, administration of rFPVs in combination induced significant antibody responses to H9,H5 subtype AIV and NDV,but the HI titers were lower than those of individually vaccinated chickens. No death or vires shedding were seen after respective challenge except for the groups challenged with NDV, in which combined rFPV vaccinated group showed significantly higher virus recovery rate than rFPV-12LSHN immunized group（ 12/16 vs 3/ 16）. In commercial chickens, no obvious increase in HI titers after inoculation was detected in all the rFPV vaccinated groups. Among the groups challenged with H5N1 AIV, the combined vaccination group experienced a higher mortality （6/25） than the rFPV-12LSH5NA group （4/ 25 ）, but the difference was not significant. The mortality in combined vaccination group （13/25） was significantly higher than that of the rFPV- 12LSHN group （5/25）, suggesting that the protective efficacy of rFPV-12LSHN was influenced by the other two rFPVs when used in combina-tion. No significant difference in the rate of virus recovery was observed between the combined group （17/25） and rFPV-12LSH9A group （13/ 25 ） after challenged with H9N2 AIV. Conclusion： The protective efficacies of some rFPVs, when inoculated in combination, might be influenced by other rFPVs, Therefore, it is wise to test each rFPV for efficacies in chickens vaccinated either with single FPV or with multiple rFPVs in combination, prior to determination to vaccinate several rFPVs in combination in the field.
出处
《中国免疫学杂志》
CAS
CSCD
北大核心
2008年第6期538-541,共4页
Chinese Journal of Immunology
基金
“十一五”国家863项目(2006AA10A205)
“十一五”国家支撑计划项目(2006BAD06A08,2006BAD06A16)
江苏省高新技术研究项目(BG2007336)资助
关键词
重组鸡痘病毒
联合免疫
H5亚型禽流感病毒
H9亚型禽流感病毒
新城疫病毒
Recombinant fowlpox virus
combined vaccination
H5 subtype avian influenza virns
H9 subtype avian influenza virus
Newcastle disease virus
