Analysis of host invasion mechanisms of Plasmodium sporozoites focusing on rhoptry proteins.

为了阐明疟原虫孢子子侵入靶细胞的分子机制，我们试图鉴定孢子子中的虫体蛋白。通过对子孢子的基因表达、蛋白表达和定位分析，鉴定出8个新的子孢子形态分子。由于这些蛋白也在子孢子中表达，因此需要开发子孢子阶段特异性基因沉默系统来进行功能分析。为了达到这个目的，筛选合适的候选启动子进行交换。通过同源重组系统将原启动子与候选启动子交换，我们成功地获得了孢子子阶段特异性基因沉默转基因寄生虫。利用该系统，我们发现其中一种构象蛋白参与了孢子子的涎腺入侵。

To elucidate the molecular mechanisms of Plasmodium sporozoite invasion of the target cells, we attempted to identify rhoptry proteins in sporozoites. Gene expression, protein expression and localization analyses in sporozoites were performed, then 8 novel sporozoite rhoptry molecules were identified. Since these proteins are also expressed in merozoites, development of sporozoite stage-specific gene silencing system is required for functional analysis. To achieve this purpose, screening for suitable candidate promoters to swap was performed. By swapping the original promoter with the candidate promoter using homologous recombination system, we succeeded to generate sporozoite stage-specific gene silencing transgenic parasites. Using this system, it was indicated that one of the rhoptry proteins is involved in sporozoite salivary gland invasion.