疟疾传播阻断疫苗Pys25重组蛋白免疫活性的实验研究

为探讨约氏疟原虫传播阻断疫苗Pys25重组蛋白的免疫效果及其效应,我们以酵母菌表达的Pys25重组蛋白皮下免疫DBA/2小鼠,采用ELISA检测免疫后不同时间小鼠血清中的特异性抗体水平,并通过IFA观察免疫血清对有性阶段虫体发育的阻断效应。初次免疫后2周,小鼠血清中特异性IgG抗体水平开始升高,并于加强免疫后2周达到峰值;感染血液与免疫血清共同培养后,配子体向合子和动合子的发育明显受阻,并且其传播阻断效应与免疫血清呈剂量依赖性。实验表明,酵母菌表达的Pys25重组蛋白具有良好的免疫原性,其免疫血清可显著抑制有性阶段原虫的进一步发育。

THE IMMUNOCOMPETENCE OF RECOMBINANT PYS25 AS A CANDIDATE FOR A MALARIA TRANSMISSION-BLOCKING VACCINE

To evaluate the immunocompetence of recombinant Pys25 as a candidate malaria transmission-blocking vaccine,the Pys25 was expressed in Saccharomyces cerevisiae as a secreted recombinant protein.The antibody titer and transmission-blocking effect of antisera from DBA/2 mice vaccinated with the recombinant Pys25 were measured by ELISA or IFA,respectively.Antibody titer started rising two weeks after the first immunization and reached peak value two weeks after booster immunization.The antisera could markedly inhibit the development of Plasmodium yoelii gametocytes into zygotes and ookinetes when sexual-stage parasites were cultured with the antisera in vitro,and it was also found the inhibitory effect of antisera on development of malaria parasites showed a dose dependence relationship.The results indicate that recombinant Pys25,expressed in S.cerevisiae,possesses a pretty immunogenicity expected,and antisera against the immunogen can remarkably inhibit the further development of sexual-stage parasites.