METHODS: Membrane proteins with increased gene expression levels from the gamete to oocyst stages in P. berghei were investigated utilizing PlasmoDB, the functional genomic database for Plasmodium spp. Based on this analysis, we selected the 184-kDa membrane protein, Pb184, for further study. The expression of Pb184 was further confirmed through immunofluorescence staining, following which we examined whether Pb184 is involved in fertilization using antibodies targeting the C-terminal region of Pb184 and biotin-labeled C-terminal region peptides of Pb184.
RESULTS: Pb184 is expressed on the surface of male and female gametes. The antibody inhibited zygote and ookinete formation in vitro. When mosquitoes were fed on parasite-infected blood containing the antibody, oocyst formation decreased on the second day after feeding. Synthesized biotin-labeled peptides matching the C-terminal region of Pb184 bound to the female gamete and the residual body of male gametes, and inhibited differentiation into ookinetes in the in vitro culture system.
CONCLUSIONS: These results may be useful for the further studying the fertilization mechanism of Plasmodium protozoa. There is also the potential for their application as future tools to prevent malaria transmission.
方法:利用PlasmoDB研究了伯氏疟原虫从配子到卵囊阶段基因表达水平增加的膜蛋白,疟原虫的功能基因组数据库。基于这一分析,我们选择了184kDa的膜蛋白,Pb184,供进一步研究。免疫荧光染色进一步证实了Pb184的表达,随后,我们使用靶向Pb184的C末端区域和生物素标记的Pb184的C末端区域肽的抗体检查Pb184是否参与受精。
结果:Pb184在雄性和雌性配子的表面上表达。该抗体在体外抑制合子和卵分裂体的形成。当蚊子以含有抗体的寄生虫感染血液为食时,饲喂后第二天卵囊形成减少。合成的生物素标记肽与Pb184的C末端区域相匹配,与雌配子和雄配子的残体结合,并在体外培养系统中抑制分化为卵细胞。
结论:这些结果可能有助于进一步研究疟原虫的受精机制。它们也有可能成为预防疟疾传播的未来工具。