Morphology and kinetics of the three distinct phases of red blood cell invasion by Plasmodium falciparum merozoites
Morphology and kinetics of the three distinct phases of red blood cell invasion by Plasmodium falciparum merozoites
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DOI：
10.1016/j.ijpara.2008.09.007
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发表时间：
2009-01-01
影响因子：
4
通讯作者：
Crabb, Brendan S.
中科院分区：
文献类型：
--
作者：
Gilson, Paul R.;Crabb, Brendan S.
红血球的入侵是所有引起疟疾的疟原虫生命周期中的一个重要事件：然而，我们对这一过程的了解存在重大差距。在这里，我们使用视频显微镜来解决红细胞入侵动力学在人类疟疾寄生虫恶性疟原虫。在体外条件下，分裂子通常在从宿主红细胞释放后1分钟内识别新的靶红细胞。寄生虫随后进入，并在初次接触后平均27.6秒完成。这一时期可分为两个不同的阶段。第一个阶段类似于2005年的“侵袭前”阶段，通常包括明显的红细胞变形和恢复过程。第二个阶段是典型的“入侵”阶段，分殖子内化于红细胞内，类似于17s时期。入侵后，第三个“棘细胞增多”阶段开始，每次成功入侵后约36秒，感染的红细胞出现明显的脱水型形态。在这一阶段，刺胞效应在接下来的23.4秒内达到顶峰，之后感染的红细胞在5-11分钟内恢复。到那时，分裂殖子已经呈变形虫状，显然是游离在细胞质中。将我们的数据与早期对远亲灵长类寄生虫诺氏疟原虫的研究进行比较，发现了显著的相似性，这表明整个疟原虫属的入侵动力学是保守的。该研究为入侵相关的生理和分子事件提供了一个形态学和动力学框架。(C) 2008澳大利亚寄生虫学学会Elsevier Ltd.出版。版权所有。
The invasion of red blood cells (RBCs) is an essential event in the life cycle of all malaria-causing Plasmodium parasites: however, there are major gaps in our knowledge of this process. Here, we use video microscopy to address the kinetics of RBC invasion in the human malaria parasite Plasmodium falciparum. Under in vitro conditions merozoites generally recognise new target RBCs within 1 min of their release from their host RBC. Parasite entry ensues and is complete on average 27.6 s after primary contact. This period can be divided into two distinct phases. The first is an similar to 11 s 'pre-invasion' phase that involves art often dramatic RBC deformation and recovery process. The second is the classical 'invasion' phase where the merozoite becomes internalised within the RBC in a similar to 17 s period. After invasion, a third 'echinocytosis' phase commences when about 36 s after every successful invasion a dramatic dehydration-type morphology was adopted by the infected RBC. During this phase, the echinocytotic effect reached a peak over the next 23.4 s, after which the infected RBC recovered over a 5-11 min period. By then the merozoite had assumed an amoeboid-like state and was apparently free in the cytoplasm. A comparison of our data with that of an earlier study of the distantly related primate parasite Plasmodium knowlesi indicated remarkable similarities, suggesting that the kinetics of invasion are conserved across the Plasmodium genus. This study provides a morphological and kinetic framework onto which the invasion-associated physiological and molecular events can be overlaid. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.