Zendia GmbH, Rummler 5, 48324, Sendenhorst, Germany.
Parasitology, Centre for Infectious Diseases, Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
Parasitol Res. 2020 Dec;119(12):4297-4302. doi: 10.1007/s00436-020-06932-9. Epub 2020 Oct 22.
Malaria is caused by unicellular parasites of the genus Plasmodium, which reside in erythrocytes during the clinically relevant stage of infection. To separate parasite from host cell material, haemolytic agents such as saponin are widely used. Previous electron microscopy studies on saponin-treated parasites reported both, parasites enclosed by the erythrocyte membrane and liberated from the host cell. These ambiguous reports prompted us to investigate haemolysis by live-cell time-lapse microscopy. Using either saponin or streptolysin O to lyse Plasmodium falciparum-infected erythrocytes, we found that ring-stage parasites efficiently exit the erythrocyte upon haemolysis. For late-stage parasites, we found that only approximately half were freed, supporting the previous electron microscopy studies. Immunofluorescence imaging indicated that freed parasites were surrounded by the parasitophorous vacuolar membrane. These results may be of interest for future work using haemolytic agents to enrich for parasite material.
疟疾是由疟原虫属的单细胞寄生虫引起的，在感染的临床相关阶段存在于红细胞中。为了将寄生虫与宿主细胞物质分离，广泛使用溶血剂，如皂素。以前关于用皂素处理的寄生虫的电子显微镜研究报告了两种情况，一种是被红细胞膜包裹的寄生虫，另一种是从宿主细胞中释放出来的寄生虫。这些模棱两可的报告促使我们用活细胞延时显微镜研究溶血作用。我们使用皂素或链霉溶素 O 来裂解感染疟原虫的红细胞，发现裂殖体期寄生虫在溶血时能有效地从红细胞中逸出。对于晚期寄生虫，我们发现只有大约一半被释放出来，这支持了以前的电子显微镜研究。免疫荧光成像表明，释放的寄生虫被滋养液泡膜包围。这些结果可能对未来使用溶血剂富集寄生虫物质的工作有兴趣。
