Chang Chia-Jung, Sun Baojian, Robertsen Børre
Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway.
Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway.
Vaccine. 2015 May 15;33(21):2442-8. doi: 10.1016/j.vaccine.2015.03.093. Epub 2015 Apr 9.
There is a need for more efficient vaccines to combat viral diseases of Atlantic salmon and other farmed fish. DNA vaccines are highly effective against salmonid rhabdoviruses, but have shown less effect against other viruses. In the present work we have studied if type I IFNs might be used as adjuvants in fish DNA vaccines. For this purpose we chose a DNA vaccine model based on the hemagglutinin-esterase (HE) gene of infectious salmon anemia virus (ISAV) as antigen. Salmon presmolts were injected with a plasmid encoding HE alone or together with a plasmid encoding Atlantic salmon type I IFN (IFNa1, IFNb or IFNc). Sera were harvested after 7-10 weeks for measurements of antibody against ISAV and the fish were challenged with ISAV to measure protective effects of the vaccines. The results showed that all three IFN plasmids delivered together with HE plasmid potently enhanced protection of salmon against ISAV mediated mortality and stimulated an increase in IgM antibodies against the virus. In contrast, HE plasmid alone gave low antibody titers and a minor protection against ISAV. This demonstrates that type I IFNs stimulate adaptive immune responses in fish, which may be a benefit also in other fish DNA vaccines. Quantitative RT-PCR studies showed that the salmon IFNs caused an increased influx of B-cells and cytotoxic T-cells at the muscle injection site, which may in part explain the adjuvant effect of the IFNs.
需要更有效的疫苗来对抗大西洋鲑鱼和其他养殖鱼类的病毒性疾病。DNA疫苗对鲑鱼弹状病毒高度有效，但对其他病毒的效果较差。在本研究中，我们研究了I型干扰素是否可用作鱼类DNA疫苗的佐剂。为此，我们选择了一种基于传染性鲑鱼贫血病毒（ISAV）血凝素酯酶（HE）基因作为抗原的DNA疫苗模型。将鲑鱼幼鱼注射单独编码HE的质粒或与编码大西洋鲑鱼I型干扰素（IFNa1、IFNb或IFNc）的质粒一起注射。7-10周后采集血清，测量抗ISAV抗体，并用ISAV攻击鱼以测量疫苗的保护效果。结果表明，与HE质粒一起递送的所有三种干扰素质粒均能有效增强鲑鱼对ISAV介导的死亡率的保护作用，并刺激针对该病毒的IgM抗体增加。相比之下，单独的HE质粒产生的抗体滴度较低，对ISAV的保护作用较小。这表明I型干扰素可刺激鱼类的适应性免疫反应，这在其他鱼类DNA疫苗中可能也有益处。定量RT-PCR研究表明，鲑鱼干扰素导致肌肉注射部位B细胞和细胞毒性T细胞的流入增加，这可能部分解释了干扰素的佐剂作用。
