性疟原虫DNA疫苗免疫效果的评估

以霍乱毒素Ｂ亚基（ＣＴＢ）为载体，由其基因构建了含有不同时期不同抗原表位的恶性疟原虫的融合基因ＣＴＢ～ＡＷＴＥ、ＣＴＢ～ＮＡＮＰ，前者除含有恶性疟原虫裂殖子表面主要抗原表位杂合多肽基因ＳＰｆ６６外，还含有很强的Ｔ辅助细胞表位ＣＳＴ３和Ｔｃ细胞表位，后者含有子孢子期的Ｂ、Ｔｈ细胞表位。将纯化的质粒免疫Ｂａｌｂ／ｃ纯系小鼠，３次免疫后诱导机体产生了体液免疫和细胞免疫，免疫的小鼠进行疟原虫子孢子攻击实验，保护率为６０％一８０％。将纯化的质粒混合后免疫恒河猴，３次免疫后诱导机体产生了体液免疫和细胞免疫，免疫的恒河猴进行食蟹疟原虫攻击实验，显示了一定的保护作用。

Assessment of Malaria DNA Vaccines in Mice and Monkeys

Cholera toxin B subunit is a good carrier protein and an effective adjuvant which can boost both cellular and humoral immunity. DNA fragments encoding B cell, Th cell and CTL epitopes of P. falciparum CS, MSA--l, MSA--2 and RESA antigens were cloned down--, stream of cholera toxin B subunit gene in the same reading frame. High bier of anti--malaria epitopes antibodies and strong cellular immunogenicity were elicited after Balb/c mice were immunized three times with 100ug recombinant plasmid DNA dissolved in 100ul PBS. A total of 120 vaccinees were challenged with mouse Plasmodium yoelli to investigate if cross protection existed. The protective efficacy was about 60%-- 80%. Four rhesus monkeys were challanged with 10~8 of P. cynomalgi, better results were obtained in the groups itnmunized with mixed plasmids including NANP, AWTE.