热灭活WSSV诱导的中国明对虾(Fenneropenaeus chinensis)在不同温度下的免疫致敏反应

Immune Priming Response Induced by Heat-Inactivated WSSV on Fenneropenaeus chinensis at Different Temperature

中文关键词: 免疫致敏  热灭活  存活率  绝对荧光定量  白斑综合征病毒

英文关键词: Immune priming  Heat-inactivated  Survival rate  Absolute quantitation  WSSV

中文摘要:

      本研究拟探究经热灭活的白斑综合征病毒(White spot syndrome virus, WSSV)能否诱导中国明对虾(Fenneropenaeus chinensis)产生免疫致敏反应。将具有典型白斑综合征症状的对虾肌肉剁碎后经60℃灭活1 h，采用单尾定量口饲的方法，连续6 d投喂不同水温条件(15℃、23℃、28℃、32℃)下的实验组对虾(E15℃、E23℃、E28℃、E32℃)；同时设置常温(23℃)条件下阳性对照组C23℃(投喂未经灭活的WSSV毒饵)、对照组CF23℃(只投喂商业配合饲料)。在实验第13天对存活个体进行第二次人工WSSV感染，结果显示，WSSV经60℃处理1 h可彻底失活，表现为连续投喂6 d至第二次人工感染期间无对虾死亡，而阳性对照组C23℃死亡率为100%。截止实验第19天，E15℃、E23℃、E28℃、E32℃各组存活率分别为80.41%、33.29%、8.47%、16.43%，CF23℃组的存活率为8.89%，E15℃组与其他各实验组差异极显著(P<0.01)，E23℃与CF23℃、E28℃、E32℃组差异显著(P<0.05)，E28℃和E32℃组差异不显著(P>0.05)；对各组实验材料进行WSSV绝对荧光定量检测，结果显示，经热灭活WSSV诱导的中国明对虾二次感染WSSV后，28℃环境下病毒增殖速度最快，高温(32℃)和低温(15℃)都会不同程度抑制WSSV的增殖速度。实验表明，热灭活WSSV可以诱导中国明对虾产生免疫致敏反应，对受WSSV感染的中国明对虾具有一定的保护作用；温度与WSSV的增殖速度密切相关。

英文摘要:

      This study was designed to explore whether the heat-inactivated WSSV could induce immune priming response on Fenneropenaeus chinensis. During the initial 6 days, four experiment groups (E15℃, E23℃, E28℃, and E32℃) were fed with typical symptoms of WSSV prawn muscle, which was dealt with at 60℃ for 1 h using the equivalent and quantitative test method. At the same time, we set a positive control group C23℃ (fed with the unheat-inactivated WSSV muscle) and a control group CF23℃ (fed with commercial compound feed only). At the 13th day of the experiment, all shrimps were infected with WSSV again. The result showed that 60℃ could decrease the activity of WSSV absolutely, there were no dead shrimp in the initial 12 d, but the mortality of positive control group C23℃ was 100%. The survival rates of different experiment (E15℃, E23℃, E28℃, and E32℃) and control groups were 80.41%, 33.29%, 8.47% , 16.43% and 8.89%, respectively, after 19 days. The survival rate of E15℃ showed highly significant difference from other experiments (P<0.01). In addition, there was a significant difference between E23℃ experiment group and other experiment groups (P<0.05). Nevertheless, there was no significant difference between E28℃ and E32℃ groups (P>0.05). Compared to the results of absolute quantitation, it was found that the multiplication rate of WSSV was the highest under 28℃, high (32℃) and low (15℃) temperature would inhibit the multiplication of WSSV in the shrimps which accepted the subsequent rechallenge of WSSV after the heat-inactivated WSSV induced. Experimental results showed that heat-inactivated WSSV could induce immune priming response and provide some protection to the infected shrimp by WSSV. The multiplication rate of WSSV is closely related to temperature.