Plasmodial Proteins Expressed on The Surface of Infected Hepatocytes

为了提高孢子体体外感染的效率，我们建立了小规模原代肝细胞培养方法。将蚊子的腹腔、胸腔和唾液腺分开，每隔一天血餐后计数孢子虫感染数。血餐后12天腹腔孢子数最多。血餐后第18天胸腔和唾液腺孢子体数量最多。血餐后14 ~ 16天获得的孢子体对小鼠具有传染性。为了寻找获得大量孢子虫的较好实验条件，我们以DBA/1和c5缺失的DBA/2小鼠为实验宿主，研究补体对疟原虫对蚊虫感染性的影响。卵囊对以DBA/1为食的斯氏按蚊的感染性显著低于以DBA/2为食的斯氏按蚊。热灭活DBA/1血清注射到DBA/2小鼠体内，对卵囊的感染性没有降低作用。与对照组相比，DBA/2小鼠注射新鲜DBA/1血清可显著降低感染性。此外，用人C5恢复的雄性DBA/2小鼠血清明显降低了传染性。与传染性降低相反，受感染蚊子的数量并没有减少。综上所述，小鼠血清中补体的替代途径显著降低了约氏疟原虫对斯蒂芬氏单胞菌的感染性，但并未完全消除。传染性降低的主要原因是受精卵在蚊子中肠内无法转化为卵母细胞。DBA/2小鼠似乎是获得大量体外感染孢子子的合适小鼠品系。

We established the small scale method of primary hepatocyte culture, in order to increase the efficiency of in vitro infection of sporozoites. The abdominal cavity and thorax and salivary glands of the mosquitoes were separated each other, and then the infected numbers of sporozoites were counted every other day after blood meal. The number of sporozoites obtained from the abdominal cavity were maximal 12 days after blood meal. The number of sporozoites obtained from the thorax and salivary gland were maximal 18 days after blood meal. The sporozoites obtained 14 to 16 days after blood meal were infectious to mice. To look for the better experimental conditions for obtaining a lot of sporozoites, we used DBA/1 and C5-deficient DBA/2 mice for the experimental host to determine the effects of complement on the infectivity of malaria parasites to mosquitoes. The infectivity of oocysts to Anopheles stephensi fed on DBA/1 mice was significantly less than those fed on DBA/2 mice. Heat inactivated DBA/1 sera injected into DBA/2 mice did not reduce the infectivity of oocysts. By comparison to these controls, fresh DBA/1 sera injected into DBA/2 mice significantly reduced the infectivity. Moreover, male DBA/2 mouse sera restored with human C5 significantly reduced the infectivity. In contrast to the reduction of infectivity, the numbers of infected mosquitoes were not reduced. In conclusion, the alternative pathway of complement in the mouse serum significantly reduced, but did not eliminate, the infectivity of Plasmodium yoelii to A.stephensi. The reduction of the infectivity is mainly due to the inability of the zygote to transform into the ookinete in the mosquito midgut. And DBA/2 mouse seems to be a suitable mouse strain to obtain a lot of sporozoites for in vitro infection.