Selective permeabilization of the host cell membrane of Plasmodium falciparum-infected red blood cells with streptolysin O and equinatoxin II
Selective permeabilization of the host cell membrane of Plasmodium falciparum-infected red blood cells with streptolysin O and equinatoxin II
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DOI：
10.1042/bj20061725
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发表时间：
2007-04-01
影响因子：
4.1
通讯作者：
Tilley, Leann
中科院分区：
文献类型：
--
作者：
Jackson, Katherine E.;Spielmann, Tobias;Tilley, Leann
恶性疟原虫在其人类宿主的成熟RBC（红细胞）中在PV（寄生虫空泡）中发育，PV将宿主细胞质与寄生虫表面分离。成孔毒素SLO（链球菌溶血素O）与含胆固醇的膜结合，可用于选择性透化宿主细胞膜，同时保持PV膜完整。我们发现，在感染和未感染的红细胞的混合物中，SLO优先裂解未感染的红细胞，而不是感染的红细胞，大概是因为限制膜的胆固醇含量的差异。这提供了产生活的环状阶段感染的RBC的纯制剂的方法。作为替代透化剂，我们对EqtII（马毒素II）进行了表征，这是一种真核成孔毒素，优先结合含鞘磷脂的膜。EqtII以相似的效率裂解感染和未感染RBC的界膜，但不破坏PV膜。它产生高达100 nm的孔，允许抗体进入免疫荧光和免疫金标记。本研究为分析这种重要的人类病原体提供了新的工具，并突出了疟原虫感染和未感染红细胞之间的差异。
Plasmodium falciparum develops within the mature RBCs (red blood cells) of its human host in a PV (parasitophorous vacuole) that separates the host cell cytoplasm from the parasite surface. The pore-forming toxin, SLO (streptolysin O), binds to cholesterol-containing membranes and can be used to selectively permeabilize the host cell membrane while leaving the PV membrane intact. We found that in mixtures of infected and uninfected RBCs, SLO preferentially lyses uninfected RBCs rather than infected RBCs, presumably because of differences in cholesterol content of the limiting membrane. This provides a means of generating pure preparations of viable ring stage infected RBCs. As an alternative permeabilizing agent we have characterized EqtII (equinatoxin II), a eukaryotic pore-forming toxin that binds preferentially to sphingomyelin-containing membranes. EqtII lyses the limiting membrane of infected and uninfected RBCs with similar efficiency but does not disrupt the PV membrane. It generates pores of up to 100 nm, which allow entry of antibodies for immunofluorescence and immunogold labelling. The present study provides novel tools for the analysis of this important human pathogen and highlights differences between Plasmodium-infected and uninfected RBCs.