克氏原螯虾口服疫苗免疫对白斑综合征病毒人工感染的保护作用

Oral Vaccination Trail with Cambarus proclarkii to Induce Protection Against White Spot Syndrome Virus

利用家蚕-杆状病毒表达系统在蚕蛹体内表达的重组病毒囊膜蛋白rV p28制成的疫苗,口服免疫克氏原螯虾,观察了其对白斑综合征病毒人工感染的保护作用。对试验虾分别进行了2%rV p28、2%普通蚕蛹液(阳性对照)和普通饲料(阴性对照)等3个处理,持续口服免疫75 d。免疫35 d后口服攻毒,20 d内rV p28组的累积死亡率为36.67%,与阴性对照相比差异显著(P<0.05),免疫保护率(PRP)达59.26%;注射攻毒后20 d内,rV p28组的PRP为49.99%。免疫后55 d对存活虾再口服攻毒,20 d内rV p28组的累积死亡率为36.84%,与阴性对照相比差异显著(P<0.05),PRP为63.16%;2次注射攻毒后,rV p28组的PRP为31.25%。结果表明,重组囊膜蛋白rV p28免疫后,对口服感染具有显著的保护作用,对注射感染有一定的保护作用。

White ＇spot syndrome virus causes high mortality and considerable economic damage to the shrimp farming industry all around the world. Now no adequate treatments against this virus are available. We investigated the potential of oral vaccination of Cambarus proclarkii with vaccines consisting of WSSV virion envelope protein. Cambarus proclarkii were fed food pellets mixed with silkworm pupa overexpressing WSSV envelope protein rVp28 during 75 days. Vaccination 2% rVp28 showed a significantly lower cumulative mortality compared to negative control （P〈0.05） via oral challenge（PRP value 59. 26%）. rVp28 induced some resistance after intramuscular injection challenge with WSSV,with PRP value of 49. 99%. The survival shrimps were rechallenged on the 55th day post vaccination, rVp28 induced a significantly higher resistance via oral rechallenge （P〈0. 05） ,with PRP value of 63.16%. rVp28 induced some resistance by intramuscular injection re-challenge,with PRP value of 31.25%. These results indicate that the vaccination of shrimp with recombinant protein has significant effect on oral infection,and has some resistance against intramuscular injection challenge. This suggested a specific immune response and protection can be induced in shrimp by recombinant protein rVp28.