摘要
将共表达鸡传染性支气管炎病毒(IBV)S1基因和鸡干扰素-γ基因的重组鸡痘病毒(rFPV-IFNγS1)接种4周龄SPF鸡,免疫3周后用同源(LX4株)及异源强毒株(LTJ95I)攻毒,评价重组疫苗对异源病毒的保护作用。结果显示,重组疫苗接种1周后,免疫鸡产生抗IBV的抗体;而且外周血中CD4+和CD8+T淋巴细胞的含量略高于非免疫对照组;攻毒后,异源强毒株攻毒的免疫组CD4+T淋巴细胞呈下降趋势,并且该组低水平CD4+的状态一直持续到试验结束,而其他组CD4+T淋巴细胞均迅速上升,峰值达到14.5%;同源强毒株攻毒的免疫组CD8+T淋巴细胞呈高水平的表达,而其他组攻毒后均无明显变化;保护率结果显示,同源强毒株攻毒免疫组的发病率和死亡率为21.43%和0%,与其他各组相比均有显著差异;另外同源强毒株攻毒的免疫组病理损伤与异源强毒株攻毒的试验组相比明显减轻,其排毒时间和排毒量也均有所减少;强毒攻毒后所有试验组体重无显著差异。以上结果可以说明,重组疫苗能对同源强毒株产生较好的免疫保护,但不能对遗传关系较远的强毒株产生有效的免疫应答。
4-week-old SPF chickens were inoculated with the recombinant fowlpox virus （rFPV-IFN-γ S1） co-expressing the infectious bronchitis virus （IBV） S1 gene and the chicken interferon-γ gene. To evaluate the efficacy of the recombinant fowlpox virus vaccine against the heterotype IBV, the chickens were challenged with the homotype IBV LX4 strain and the heterotype IBV LTJ951 strain after three weeks post vaccination. Antibodies against IBV were detected in vaccinated chickens one week post inoculation. The CD4＋ T-lymphocytes in the peripheral blood increased rapidly in all groups challenged with IBV, except for the vaccinated group challenged by heterotype strain and the low level of CD4＋ T-lymphocytes remained until end of the experiment. In all the groups, a high level of CD8＋ T-lymphocytes only was observed in the vaccinated group after challenging with IBV homotype strain. The morbidity and the mortality of this group were 21.43 % and 0 %, respectively, which showed significant difference with other groups. In addition, the lesions of chickens and virus shedding were less in the vaccinated group challenged by IBV homotype strain comparing with other groups, but there was no difference for the average body weight of chickens in all groups. These results indicated that the rFPV-IFN γ, S1 could protect chickens against the challenge of the homotype strain but not against the challenge of the heterotype strain.
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2009年第3期226-230,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
国家"863"计划资助项目(2003AA213020)
