表达MDVgB和/或鸡γ干扰素基因的重组鸡痘病毒免疫效力试验

Protection Efficacy of Recombinant Fowlpox Virus Expressing Marek's Disease Virus Glycoprotein B and /or Chicken Type two Interferon Genes

将表达鸡 干扰素基因、表达MDVgB基因、共表达MDVgB和鸡 干扰素基因的重组鸡痘病毒进行组合免疫 ,观察在SPF鸡、狼山鸡中的免疫保护作用。在狼山鸡中随rFPV gB剂量的减少 ,保护效力逐渐下降 ,而在SPF鸡中 10 4 与 10 6PFU的rFPV gB提供相同的保护效力 ,但存在减缓增重的副反应 ;在所有的疫苗组合中 ,由10 6PFU的rFPV gB、10 5PFU的rFPV IFN Ⅱ和 40 0 0PFUHVT组成三价疫苗的保护效力最高且不影响增重 ,表明鸡 干扰素既可降低重组鸡痘病毒的减缓增重的副反应 ,又具有免疫佐剂作用 ,与重组鸡痘病毒及HVT配合成疫苗是预防MD有效的冻干制剂。

Vaccines included recombinant fowlpox virus expressing chicken type two interferon gene,Marek's disease virus glycoprotein B gene or both two genes.Vaccination trials for evaluating protective efficacy of rFPVs against very virulent MDV challenge were carried out in SPF and wolfhill commercial production chicken.For Ab+ wolfhill chickens,the PI was lower with lower dosage of rFPV,however for Ab- SPF chickens,the PI induced by rFPV-gB at dose range from 104 to 106 PFU were at the same level,whereas the body weight gain of chickens inoculated by rFPV-gB was significantly lower than that of control group .Among all the vaccine combinations,106 PFU rFPV-gB plus 105 PFU rFPV-IFN-Ⅱ and 4 000 PFU HVT provided the best protective efficacy,and body weight gain of this group was same as that of control group.Results showed that type Ⅱ interferon could significantly diminish the side-effect of FPV inoculation and enhance the immune protection efficacy. Protective synergism was also observed among rFPV-INF-Ⅱ,rFPV-gB and HVT.