恶性疟原虫保护性抗原复合基因痘苗病毒重组活疫苗株在换人血猕猴模的抗攻击试验

Evaluation of protective immunity of a vaccinia virus vectored multi-epitope live vaccine candidate for plasmodium falciparum using multiple partialy replacement transfused human blood macaca monkey models

探讨恶性疟原虫保护性抗原复合基因 痘苗病毒重组活疫苗候选株在实验动物的抗疟原虫攻击能力 ,为下一步进入夜猴及人体试验奠定基础。方法 :利用多次部分换人血猕猴模经静脉输血法进行了抗疟原虫红内期虫体的攻击试验。结果 :在免疫后 1个月攻虫 ,重组痘苗病毒免疫猴从第 3天一直到第 12d的采血检查中均未发现疟原虫 ;非重组痘苗病毒(对照病毒 )免疫猴第 3天后原虫感染率上升 ,第 6天原虫感染率最高达到 6 .0 % ,而后原虫感染率逐渐下降 ,原虫持续时间为13天 ;空白对照猴第 3天后原虫感染率也上升 ,第 8天原虫感染率最高达到 2 .5 % ,而后原虫感染率逐渐下降 ,原虫持续出现时间为 12d。结论 :初步说明该候选疫苗株具有一定的抗恶性疟原虫红内期虫体攻击的能力。

Objective:To evaluate the protective ability of vaccinia virus vectored multi-epitope live vaccine candidate for plasmodium falciparum(P.f)in experimental animals, and to lay foundation for next testing on Aotus sp. monkey or human volunteers. Methods:The multiple partialy replacement transfused human blood macaca monkey models were used. Challenge was made after one month of immunization by vein. Results:The parasitemia of recombinant virus immunized monkey was 0.01%in first two days of post-challenge. No parasites were determined from third to 12th day. Whereas the parasitemia of control virus immunized-monkey and blank control monkey rose progressively,went to 2.5%～6.0% at 6th～8th days of post-challenge, and the time of parasitemia was 12～13 days. Conclusion:These results preliminary indicated that the monkey model immunized with recombinant vaccinia virus could resist the challenge of blood stage P.f.