疟原虫受精前后抗原Pbg37和PSOP26复合疫苗传播阻断潜能及其效应机制的研究

Malaria is one of the infectious diseases that seriously threatens human health. Transmission blocking vaccine (TBV), which targets the proteins expressed in mosquitoes, is a new strategy to control and eliminate malaria. Due to the complex life cycle of malaria, the combination vaccine which composed of multi-epitope is the key point in malaria vaccine research. However, the development of TBV has been hampered by multiple obstacles, there is no effective combination transmission blocking vaccine. Here, we screened Pbg37 and PSOP26 which specific expressed on parasite sexual stage-the gametocyte and ookinete membrane. It has proved that Pbg37 and PSOP26 seriously influenced the development of sexual stage of plasmodium by gene function analysis, suggesting that both have the potential to be TBV candidates. Based on the above, we will combine two genes to prepare a Plasmodium berghei combination vaccine about gametocyte and ookinete (Pb Com-GO). Fusion proteins were expressed by different protein expression systems. Polyclonal antibodies were obtained with different adjuvants to detect the level of immune response and subcellular localization. The TB potential of combined vaccine was assessed using an in vitro ookinete formation assay and direct mosquito feeding assay. The mechanism of transmission blocking effect was clarified by transmission electron microscopy and protein spectrum analysis. This study is intended to provide theoretical basis for the development of highly effective combination transmission blocking vaccine.

疟疾是严重威胁人类健康的感染性寄生虫病。传播阻断疫苗（TBV）针对疟原虫有性阶段发育发挥作用，是加速疟疾控制和消除的根本策略。鉴于疟原虫复杂的生活史，研制多抗原复合疫苗是当今疟疾疫苗的发展趋势。但迄今为止TBV的研发受到多重阻碍，尚无有效的传播阻断复合疫苗。我们在前期研究中筛选了两个基因Pbg37和PSOP26，分别特异性表达于疟原虫有性发育的两个关键阶段-配子体和动合子表面。基因功能分析发现Pbg37和PSOP26显著阻止疟原虫有性阶段的发育，提示其具有成为新型TBV候选抗原的潜能。在此基础之上，我们将构建上述基因的双靶位复合疫苗Pb Com-GO，通过不同蛋白表达系统表达融合蛋白；辅以不同免疫佐剂制备多克隆抗体，检测免疫应答水平及亚细胞定位；通过体内外传播阻断实验评估其传播阻断活性；进一步通过透射电镜和蛋白质组学阐明其传播阻断效应机制。旨在为高效传播阻断复合疫苗的研发提供新的理论依据。

疟疾是严重威胁人类健康的感染性寄生虫病。传播阻断疫苗（TBV）针对疟原虫有性阶段发育发挥作用，是加速疟疾控制和消除的根本策略。鉴于疟原虫复杂的生活史，研制多抗原复合疫苗是当今疟疾疫苗的发展趋势。但迄今为止TBV的研发受到多重阻碍，尚无有效的传播阻断复合疫苗。我们在前期研究中筛选了两个基因Pbg37和PSOP26，PSOP25分别特异性表达于疟原虫有性发育的两个关键阶段-配子体和动合子表面。基因功能分析发现Pbg37和PSOP26, PSOP25显著阻止疟原虫有性阶段的发育，提示其具有成为新型TBV候选抗原的潜能。在此基础之上，我们将构建上述基因的双靶位复合疫苗Pb Com-GO, Pb Com-OO，通过原核蛋白表达系统表达融合蛋白；免疫小鼠后，利用抗血清检测亚细胞定位；通过体内外传播阻断实验评估其传播阻断活性。选择PSOP25重组蛋白辅以不同免疫佐剂制备多克隆抗体，检测T, B细胞免疫应答水平，及旨在为高效传播阻断复合疫苗的研发提供新的理论依据。