College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China; Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, China.
Shanghai Veterinary Research Institute, CAAS, Shanghai, 200241, China.
Antiviral Res. 2020 Jan;173:104652. doi: 10.1016/j.antiviral.2019.104652. Epub 2019 Nov 18.
Both classical swine fever (CSF) and pseudorabies are highly contagious, economically significant diseases of swine in China. Although vaccination with the C-strain against classical swine fever virus (CSFV) is widely carried out and severe outbreaks of CSF seldom occur in China, CSF is sporadic in many pig herds and novel sub-subgenotypes of CSFV endlessly emerge. Thus, new measures are needed to eradicate CSFV from Chinese farms. The emergence of a pseudorabies virus (PRV) variant also posed a new challenge for the control of swine pseudorabies. Here, the recombinant PRV strain JS-2012-ΔgE/gI-E2 expressing E2 protein of CSFV was developed by inserting the E2 expression cassette into the intergenic region between the gG and gD genes of the gE/gI-deletion PRV variant strain JS-2012-ΔgE/gI. The recombinant virus was stable when passaged in vitro. A single vaccination of JS-2012-ΔgE/gI-E2 via intramuscular injection fully protected against lethal challenges of PRV and CSFV. Vaccination of piglets with the recombinant JS-2012-ΔgE/gI-E2 in the presence of high levels of maternally derived antibodies (Abs) to PRV can provide partial protection against lethal challenge of CSFV. Vaccination of the recombinant PRV JS-2012-ΔgE/gI-E2 strain did not induce the production of Abs to the gE protein of PRV or to the CSFV proteins other than E2. Thus, JS-2012-ΔgE/gI-E2 appears to be a promising recombinant marker vaccine candidate against PRV and CSFV for the control and eradication of the PRV variant and CSFV.
猪瘟（Classical swine fever，CSF）和伪狂犬病（Pseudorabies）都是中国猪群中具有高度传染性且经济意义重大的疾病。虽然中国广泛使用 C 株疫苗来预防猪瘟病毒（Classical swine fever virus，CSFV）感染，但 CSF 在中国很少出现严重疫情，但在许多猪场仍呈散发状态，CSFV 的新型亚亚群不断出现。因此，需要采取新措施从中国农场根除 CSFV。猪伪狂犬病病毒（Pseudorabies virus，PRV）变异株的出现也给猪伪狂犬病的控制带来了新挑战。本研究通过将 E2 表达盒插入 gE/gI 缺失的 PRV 变异株 JS-2012-ΔgE/gI 的 gG 和 gD 基因之间的基因间隔区，构建了表达 CSFV E2 蛋白的重组 PRV 株 JS-2012-ΔgE/gI-E2。该重组病毒在体外传代时稳定。肌肉注射接种重组病毒 JS-2012-ΔgE/gI-E2 可完全保护猪免受 PRV 和 CSFV 的致死性攻击。在 PRV 母源抗体（Abs）水平较高的情况下，仔猪接种重组 JS-2012-ΔgE/gI-E2 可部分保护其免受 CSFV 的致死性攻击。接种重组 PRV JS-2012-ΔgE/gI-E2 不会诱导针对 PRV 的 gE 蛋白或 CSFV 除 E2 以外的其他蛋白的 Abs 产生。因此，JS-2012-ΔgE/gI-E2 似乎是一种有前途的 PRV 和 CSFV 重组标记疫苗候选株，可用于控制和根除 PRV 变异株和 CSFV。
