马传染性贫血病毒弱毒疫苗gp90多样性及其对病毒体外增殖的影响

gp90 genetic diversity of EIAV attenuated vaccine and its impact on EIAV's proliferation in vitro

为研究马传染性贫血病毒(EIAV)弱毒疫苗gp90基因多样性的生物学意义,本研究对EIAV驴胎皮肤细胞弱毒疫苗(EIAVFDDV13)gp90基因进行测序,在随机获得的15个克隆中,不同克隆推导的氨基酸平均差异率为2.7%(0~5.8%),其中克隆F13-15与感染性克隆pLGFD3-8的gp90之间的差异率均为4.8%。以pLGFD3-8为骨架,通过对gp90基因的替换方法构建了感染性克隆pLGFD13-15。将pLGFD13-15转染驴胎皮肤细胞后,拯救出一株衍生病毒vpLGFD13-15。比较vpLGFD13-15和vpLGFD3-8在驴胎皮肤细胞和马单核细胞来源的巨噬细胞中的复制特性显示,vpLGFD13-15在感染驴胎皮肤细胞后4 d^6 d内,上清液中的病毒含量明显高于vpLGFD3-8。但vpLGFD13-15在巨噬细胞中的复制较vpLGFD3-8明显延迟。结果表明,EIAV疫苗株中不同gp90基因的病毒克隆在体外复制特性存在差异。该研究结果为进一步分析EIAV弱毒疫苗基因多样性的生物学意义,特别是对其诱导免疫保护作用的研究奠定了基础。

To explore the biological significance in gp90 genetic diversity of equine infectious anemia virus （EIAV） attenuated vaccine, we analyzed the molecular characteristics of gp90 genes of EIAV attenuate dvaccine （EIAVFDDV13）, and the analysis results showed that the mean of the amino acid’s difference of the randomly selected 15 clones was 2.7% （0-5.8%） and in which the difference between F13-15 clones and the reference strains （pLGFD3-8） was 4.8%. Next we constructed pLGFD13-15 clone by using the way of genetic replacement on the basis of pLGFD3-8. After three blind passage, vpLGFD13-15, a derived virus, was rescued form fetal skin cells transfected by pLGFD13-15. Then we found there was a significant difference of replicate dynamics between vpLGFD13-15 and vpLGFD3-8 when compared their replicate characters in donkey fetal skin cells and monocyte-derived macrophages. Compared to vpLGFD3-8, the replication capacity of vpLGFD13-15 in FDD cells was significantly improved, which was indicated by higher tropism and virulence. In contrast, the vpLGFD13-15 replication was much slower than vpLGFD3-8 in equine MDM. Overall, these results showed that the genetic diversity of EIAV vaccine strain’s gp90 genes may have certain biological significance, The results of further analysis of EIAV attenuated vaccine biological significance of genetic diversity, particularly their role in inducing protective immunity research provided the foundation.