Journal of Integrative Agriculture

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小反刍兽疫病毒中国现地分离株山羊感染模型的建立及疫苗效力评估

  

  • 修回日期:2024-03-12

Establishment of goat infection model of the peste ruminants virus isolated in China for vaccine efficacy evaluation

Xue Wang1*, Hefeng Chen1*, Xianfeng Zhang1, Zhengshuang Wu1, Shuai Zhang1, Lei Shuai1, Lulu Wang1, Weijie Li1, Jinliang Wang1, Wenxing Liu1, Xijun Wang1, Zhiyuan Wen1, Jinying Ge1, Yuntao Guan1, Xijun He1#, Weiye Chen1#, Zhigao Bu1, 2#   

  1. 1State Key Laboratory for Animal Disease Control and Prevention, National High Containment Facilities for Animal Diseases Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China

    2Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China.

  • Revised:2024-03-12
  • About author:Xue Wang, E-mail: 18853857958@163.com; Hefeng Chen, E-mail: 1945989851@qq.com; #Correspondence Zhigao Bu, E-mail: buzhigao@caas.cn; Weiye Chen, E-mail: chenweiye@caas.cn; Xijun He, E-mail: hexijun@caas.cn * indicates the authors who contributed equally to this study.

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摘要： 2013年，中国再次爆发小反刍兽疫（peste des petits ruminants, PPR）疫情，并传播至全国大部分省份，导致巨大经济损失。虽然通过全国强制接种减毒活疫苗使得疫情得到了有效控制，但目前仍然有局部疫情发生，危害依然巨大。我国和FAO都制定了小反刍兽疫净化和根除计划，但目前仍然缺乏能够区分自然感染疫苗免疫的DIVA疫苗（differentiating infected from vaccinated animals），导致净化根除难度大、成本高，研制PPR DIVA疫苗势在必行。目前对中国现地小反刍兽疫病毒（peste des petits ruminants virus，PPRV）分离株的生物学特性研究非常有限，疫苗评价缺乏稳定可靠的动物模型，这是制约我国PPR疫苗研发和防控政策制定的关键瓶颈。本研究利用表达山羊信号淋巴细胞激活分子（signalling lymphocyte activation molecule，slam）的Vero易感细胞，从中国现地的临床样本中分离出了一株PPRV（HLJ/13）。对HLJ/13全基因组进行测序并进行遗传进化分析，结果表明其属于PPRV Ⅳ系。随后，在山羊上通过鼻腔和皮下联合途径感染了2×106 TCID50剂量的HLJ/13，所有羊均出现典型的PPR临床症状，包括发热、眼部和鼻腔分泌物、口腔炎和腹泻等，致死率为100%，成功建立PPRV山羊感染模型。为了进一步了解病毒在体内的复制情况，开展了病毒载量、病理学检查和免疫组织化学分析，结果表明HLJ/13的主要靶标为呼吸系统、消化道和淋巴等器官的上皮和免疫细胞。本文作者之前研发了可作为DIVA（differentiating infected from vaccinated animals）疫苗的PPR重组山羊痘病毒载体疫苗，但由于一直缺乏动物模型导致疫苗研发进度停滞。本研究利用上述建立的PPRV山羊感染模型系统评价了该疫苗对HLJ/13的攻毒保护效力，结果表明疫苗免疫能够提供针对HLJ/13充分的攻毒保护，保护率为100%。该研究为PPRV中国现地分离株的生物学特性、致病特性和动物感染模型的首次全面的报告，突破了我国小反刍兽疫防控的重要瓶颈，对于PPR相关的应用和基础研究均具有重要意义。

Abstract: In 2013, peste des petits ruminants (PPR) re-emerged in China and spread to the majority of provinces across the country. The disease was effectively controlled through a vaccination campaign employing live attenuated vaccines, although sporadic cases still occurred. However, limited information is currently available regarding the peste des petits ruminants virus (PPRV) endemic in China. Here, a PPRV strain (HLJ/13) was isolated from a field sample in China by using Vero cells expressing goat signalling lymphocyte activation molecule. Phylogenetic analysis indicated that HLJ/13 belonged to lineage Ⅳ. Subsequent intranasal and subcutaneous inoculation of goats with a dose of 2×106 TCID50 of HLJ/13 resulted in the development of typical clinical symptoms of PPR, including pyrexia, ocular and nasal discharges, stomatitis, and diarrhea. All infected goats succumbed to the disease by day 8. To gain further insight, viral loading, pathological examination and immunohistochemical analyses were conducted, elucidating the main targets of HLJ/13 as the respiratory system, digestive tract and lymphoid organs. Employing the goat infection model established above, the goat poxvirus-vectored PPR vaccine, which was previously developed and could be used as DIVA (differentiating infected from vaccinated animals) vaccine, provided complete protection against the challenge of HLJ/13. It is important to note that this study represents the first comprehensive report delineating the biology and pathogenicity characterization, and infection model of PPRV isolated in China.

Key words: Peste des petits ruminants virus , Chinese , isolate ,  , goat infection model ,  , vaccine efficacy evaluation