表达猪圆环病毒2型Cap蛋白的重组猪瘟兔化弱毒疫苗株的构建与鉴定

Generation and characterization of recombinant classical swine fever virus C-strain expressing the cap protein of porcine circovirus type 2

摘要:

猪瘟 (CSF) 是由猪瘟病毒 (CSFV) 引起的一种毁灭性传染病，给养猪业造成重大经济损失。猪瘟兔化弱毒疫苗 (C株) 是一株非常安全、有效的优秀弱毒疫苗，其对各年龄和品种的猪都没有副作用，同时对不同基因亚型的CSFV均能提供有效的免疫保护。然而，在现地，CSFV和猪圆环病毒2型 (PCV2) 混合感染的现象时常发生，严重影响了对这两种疾病的有效防控。本研究首次构建了表达PCV2 Cap蛋白的重组C株，并评价了其在体内外的特性。结果表明，该重组病毒能够稳定表达Cap蛋白并与C株具有相似的生长动力学特性；此外，该重组病毒在家兔体内具有与C株相似的生物学特性，在免疫家兔后10 d，抗CSFV E2抗体全部转阳，然而抗Cap抗体未能转阳。本研究为进一步优化表达PCV2 Cap蛋白的重组C株奠定基础。

Abstract:

Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a devastating viral disease in swine, leading to significant economic losses to the pig husbandry. C-strainis one of the best modified live vaccines against CSF. The vaccine is highly safe and efficacious and can provide rapid and complete protection against essentially all genotypes of CSFV. Co-infections of pigs with CSFV and porcine circovirus type 2 (PCV2) occur frequently in the field, making it difficult to control the associated diseases. Here, a recombinant C-strain rHCLV-Cap expressing the Cap protein of PCV2 was constructed and evaluated in vitro and in vivo. The recombinant had comparable phenotypes to C-strain in rabbits. At ten days post-immunization, anti-E2, but not anti-Cap, antibodies were detected in the rabbits inoculated with the recombinant virus. Our study warrants further work to construct C-strain-based bivalent vaccines.