疟原虫配子体蛋白Pys48核酸疫苗的构建与免疫活性观测

为探讨约氏疟原虫配子体蛋白Pys48核酸疫苗的免疫效果及其效应，以约氏疟原虫Pys48全基因序列克隆和真核表达载体pcDNA3．1为基础获得核酸重组质粒，肌肉注射免疫BALB／c小鼠，ELISA检测小鼠血清中特异性抗体水平，并通过IFA检测疫苗的免疫活性以及免疫血清对有性阶段虫体发育的阻断效应。测序结果和酶切鉴定均证实构建的质粒为Pys48全基因插入质粒。ELISA结果显示疫苗免疫小鼠血清特异性抗体滴度明显高于对照组；IFA结果显示免疫血清能够明显阻断配子体向合子与动合子的发育，并且其传播阻断效应与免疫血清呈剂量依赖性关系。实验表明，真核表达载体pcDNA3．1表达的Pys48核酸疫苗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 DNA Plasmid Pys48 as a Candidate for a Malaria Transmission Blocking Vaccine

To evaluate the immunocompetence of DNA plasmid Pys48 as a candidate of malaria transmission blocking vaccine, the entire coding sequence of Pys48 was amplified by PCR and sub-eloned into peDNA3.1 . The antibody titer and transmission blocking effect of immune sera from BALB/c mice vaccinated with the DNA plasmid Pys48 were measured by ELISA and IFA, respectively. Gene sequencing and restriction enzyme digestion confirmed the success Pys48 plasmid construction. ELISA showed that the specific antibody titer from vaccine immunized mouse sera was higher than that from control mouse. The antisera could markedly inhibit the development of Plasmodium yoelii from gametoeytes into zygotes and ookinetes when sexual stage parasites were cultured with the antisera in vitro, moreover this inhibitory effect was dose dependent fashion. The results indicate that DNA vaccine Pys48 expressed in pcDNA3.1, possesses a pretty immunogenicity, and antisera against the immunogen can remarkably inhibit the further development of sexual stage parasites.