猪繁殖与呼吸综合征病毒传代与免疫原性变化的关联研究  

Study on the Correlation Between in vitro Passage and Antigenic Variations of Porcine Reproductive and Respiratory Syndrome Virus

作　　者：刘萍[1,2] 柏亚军 蒋晓虹 夏水利 马俊 孙志 袁世山 姚火春 LIU Ping;BAI Yajun;JIANG Xiaohong;XIA Shuili;MA Jun;SUN Zhi;YUAN Shishan;YAO Huochun(College of Veterinary Medicine,Nanjing Agriculture University,Nanjing 210095,China;Boehringer-Ingelheim Vetmedica(China)Co.,Ltd.,Shanghai Branch,Shanghai 201203,China)

机构地区：[1]南京农业大学动物医学院,南京210095 [2]勃林格殷格翰动物保健(中国)有限公司上海分公司,上海201203

出　　处：《中国动物传染病学报》2022年第4期1-12,共12页Chinese Journal of Animal Infectious Diseases

摘　　要：本研究以高致病性猪繁殖与呼吸综合征疫苗候选株JXM105以及其传代毒株JXM125和JXM135为研究对象,通过3株传代毒株对其母源强毒株JX143攻毒免疫保护效力评价和全基因序列分析,解析病毒体外传代与毒株免疫原性间的关联。结果显示:JXM105、JXM125和JXM135免疫后的仔猪在21 d观察期内未出现异常临床表现,剖检猪无显著肺脏损伤。攻毒JX143后,免疫JXM105的动物组无发病和死亡,免疫JXM125或JXM135的动物组虽无死亡,但分别有20%的发病率。全基因组测序结果显示,与亲本病毒JX143相比,JXM105含有47处突变,包括23处氨基酸突变、位于nsp2的88个连续氨基酸缺失和GP2碳端的11个氨基酸截短。与JXM105相比,JXM125和JXM135仅增加了8处核苷酸突变,其中2处导致氨基酸突变。研究表明:3株传代毒株对仔猪均无致病力;JXM105对4周龄仔猪的保护率可以达到100%,JXM125和JXM135不能提供完全保护、已出现过度弱化的现象。23处分散在不同区域的氨基酸突变可能与JX143致弱相关。In this study,the immunogenicity of 3 vaccine candidate strains(JXM105,JXM125 and JXM135)derived from the parental strain JX143 of Porcine reproductive and respiratory syndrome virus(PRRSV)were investigated to address the correlation between in vitro passage and antigenic variations.In the animal immunization study,piglets were vaccinated with each of these 3 candidate strains.No abnormal clinical signs were observed in all vaccinated piglets for 21 days post vaccination(dpv),indicating their safety.Subsequently,10 piglets per immunization group were challenged with HP-PRRSV strain JX143 at 28 dpv to evaluate the immunogenicity of these vaccine candidates.After challenge,the piglets immunized with JXM105 had no morbidity while the piglets immunized with JXM125 or JXM135 showed 20%morbidity,respectively.To further investigate the role of viral genes in PRRSV attenuation,the full-length genomic sequence analysis of these candidate strains was performed to identify the occurrence of antigenic variations.In comparison with that of the parental virus JX143,the genome of JXM105 contained 47 mutations,including 23 nonsynonymous mutations,a deletion of consecutive 88 aa in nsp2 and 11 aa truncation at the C terminus of GP2. In comparison with JXM105, JXM125 and JXM135 contained 8 more nucleotide mutations, among which only two led to amino acid changes. Taken together, these results suggested that these 3 vaccine candidates had no pathogenicity to piglets and JXM105 provided full protection against HP-PRRSV strain JX143 challenge. JXM125 and JXM135 provided partial protection, suggesting that 125 in vitro passages might have represented over-attenuation. Genomic sequence analysis indicated that 23 nonsynonymous mutations across PRRSV genome of JXM105 likely correlated with the attenuation of the parent JXM virus.

关 键 词：猪繁殖与呼吸综合征病毒 安全性 免疫效力 致弱 

分 类 号：S852.651[农业科学—基础兽医学]