感染性分子克隆衍生的马传染性贫血病毒的免疫学特性

将马传染性贫血病毒驴白细胞毒疫苗(DLA EIAV)、DLA EIAV感染性分子克隆衍生毒(vOK8226)以及强弱毒嵌合毒(vOKVltr)分别接种健康马,并于接种后第 220 d,用 EIAV强毒辽宁株(L EIAV)攻击,观察临床变化,并测定接种后各结构蛋白的抗体变化。结果发现,攻毒后,2匹非免疫对照马和克隆衍生毒接种组中的 1 匹马体温均出现典型的稽留热并死亡,死亡马呈现典型的马传染性贫血的病理组织学变化,其他免疫马未见任何临床变化;在攻毒后第 450 d剖杀所有存活马,也未见任何病理组织学变化。抗体检测结果表明,免疫接种后攻毒前各组 p11 和 p9 抗体均检测不到,嵌合毒接种组p15、p26和gp45抗体水平高于其他组。攻毒后非免疫对照马体内抗p9、p11、p15、p26和 gp45抗体均显著升高,并持续至死亡;嵌合病毒接种马体内各结构蛋白抗体水平与攻毒前没有显著变化,克隆衍生毒接种马体内各结构蛋白抗体水平比攻毒前有所升高。通过临床观察、病理组织学检测以及攻毒后各结构蛋白抗体记忆反应情况分析,置换了强毒 LTR 的DLA EIAV感染性分子克隆衍生毒(强弱毒嵌合病毒)免疫马能够抵抗马传染性贫血病毒强毒的攻击,获得完全保护,而DLA EIAV感染性分子克隆衍生毒免疫马未能完全抵抗强毒的攻击。

Immunological characteristics of equine infectious anemia virus derived from infectious molecular clone

Five healthy horses were inoculatedwith the equine infectious anemia virus donkey leucocyte attenuated vaccine(DLA-EIAV), the virus derived from infectious molecular clone of DLA-EIAV(vOK8226) and the chimeric virus based on vOK8226 with substitution of LTR from virulent EIAV(vOKVltr), respectively. On day 220 post-inoculation, the five inoculated horses and two control horses were challenged with the virulent EIAV, all the horses were subjected to clinical observation, tissue patho- logical determination, and antibody detection. The results showed that the two (control) horses and one horse inoculatedwith vOK8226 developed typical EIA clinical signs and died of high fever after being (challenged,) and typical pathological changes were observed in tissues of the dead (horses,) while the other horses remained clinically and histologically (normal.) The antibody detection indicated that serum (antibo-) dies to p11 and p9 of EIAV were not detectable after inoculation in all the five horses, and antibody levels to p15, p26 and gp45 in the horses inoculatedwith the chimeric virus were higher than that in other group. After challenge, antibody to all structural proteins increased rapidly and lasted until death in the two control horses; antibody level slightly increased in the horses inoculated with vOK8226, but no responses were found in the horses inoculated with vOKVltr after challenge. The chimeric virus vOKVltr could offer complete protection for horses against challenge by virulent EIAV, while vOK8226 could only provide partial protection.