高致病性猪繁殖与呼吸综合征弱毒疫苗病毒的开放阅读框1a在仔猪中和抗体诱导及体外病毒中和中起关键作用。

ORF1a of highly pathogenic PRRS attenuated vaccine virus plays a key role in neutralizing antibody induction in piglets and virus neutralization in vitro.

作者信息

Leng Chaoliang, Zhang Wuchao, Zhang Hongliang, Kan Yunchao, Yao Lunguang, Zhai Hongyue, Li Mingliang, Li Zhen, Liu Chunxiao, An Tongqing, Peng Jinmei, Wang Qian, Leng Yumin, Cai Xuehui, Tian Zhijun, Tong Guangzhi

机构信息

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427, Maduan Street, Nangang District, Harbin, 150001, China.

Henan Key Laboratory of Insect Biology in Funiu Mountain, Henan Provincial Engineering Laboratory of Insects Bio-reactor, China-UK-NYNU-RRes Joint Laboratory of Insect Biology, Nanyang Normal University, Nanyang, 473061, China.

出版信息

Virol J. 2017 Aug 22;14(1):159. doi: 10.1186/s12985-017-0825-2.

BACKGROUND

Currently, porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important viral pathogens in swine in most countries, especially China. Two PRRSV attenuated live vaccine strains (HuN4-F112 and CH-1R) are currently widely used in China. Our previous study showed that HuN4-F112, but not CH-1R, induced high anti-nucleocapsid (N) antibody and neutralizing antibody (NA) titers. Additionally, sera from HuN4-F112 inoculated pigs induced low cross neutralization of CH-1R.

METHODS

In the present study, 6 chimeric viruses through exchanging 5' untranslated region (UTR) + open reading frame (ORF)1a, ORF1b, and ORF2-7 + 3'UTR between HuN4-F112 and CH-1R were constructed and rescued based on the infectious clones of rHuN4-F112 and rCH-1R. The characteristics of these viruses were investigated in vitro and vivo.

RESULTS

All the three fragments, 5'UTR + ORF1a, ORF1b, and ORF2-7 + 3'UTR, could affect the replication efficiencies of rHuN4-F112 and rCH-1R in vitro. Additionally, both 5'UTR + ORF1a and ORF2-7 + 3'UTR affected the anti-N antibody and NA responses targeting rHuN4-F112 and rCH-1R in piglets.

CONCLUSIONS

The 5'UTR + ORF1a region of HuN4-F112 played a key role in inducing NAs in piglets. Furthermore, we confirmed for the first time that ORF1a contains a neutralization region. This study provides important information that can be used for further study of the generation of anti-PRRSV NAs.

背景

目前，猪繁殖与呼吸综合征病毒（PRRSV）是大多数国家（尤其是中国）养猪业中经济影响最为重大的病毒病原体之一。两种PRRSV减毒活疫苗株（HuN4 - F112和CH - 1R）目前在中国广泛使用。我们之前的研究表明，HuN4 - F112能诱导产生高抗核衣壳（N）抗体和中和抗体（NA）滴度，而CH - 1R则不能。此外，接种HuN4 - F112的猪血清对CH - 1R诱导的交叉中和作用较低。

方法

在本研究中，基于rHuN4 - F112和rCH - 1R的感染性克隆，通过交换HuN4 - F112和CH - 1R之间的5'非翻译区（UTR）+开放阅读框（ORF）1a、ORF1b以及ORF2 - 7 + 3'UTR，构建并拯救了6种嵌合病毒。对这些病毒的特性进行了体外和体内研究。

结果

所有三个片段，即5'UTR + ORF1a、ORF1b以及ORF2 - 7 + 3'UTR，均可在体外影响rHuN4 - F112和rCH - 1R的复制效率。此外，5'UTR + ORF1a和ORF2 - 7 + 3'UTR均影响仔猪针对rHuN4 - F112和rCH - 1R的抗N抗体和NA反应。