Sadlova Jovana, Myskova Jitka, Lestinova Tereza, Votypka Jan, Yeo Matthew, Volf Petr
Department of Parasitology,Faculty of Science,Charles University,Vinicna 7, 128 44 Prague 2,Czech Republic.
Department of Pathogen Molecular Biology,Faculty of Infectious and Tropical Diseases,London School of Hygiene and Tropical Medicine,Keppel Street, WC1E 7HTLondon,UK.
Parasitology. 2017 Apr;144(4):403-410. doi: 10.1017/S0031182016002067. Epub 2016 Nov 23.
Leishmania parasites alternate in their life cycle between promastigote stages that develop in the gut of phlebotomine sand flies and amastigotes residing inside phagocytic cells of vertebrate hosts. For experimental infections of sand flies, promastigotes are frequently used as this way of infection is technically easier although ingestion of promastigotes by sand flies is unnatural. Here we aimed to answer a critical question, to what extent do promastigote-initiated experimental infections differ from those initiated with intracellular amastigotes. We performed side-by-side comparison of Leishmania development in Phlebotomus argentipes females infected alternatively with promastigotes from log-phase cultures or amastigotes grown ex vivo in macrophages. Early stage infections showed substantial differences in parasite load and representation of morphological forms. The differences disappeared along the maturation of infections; both groups developed heavy late-stage infections with colonization of the stomodeal valve, uniform representation of infective metacyclics and equal efficiency of transmission. The results showed that studies focusing on early phase of Leishmania development in sand flies should be initiated with intracellular amastigotes. However, the use of promastigote stages for sand fly infections does not alter significantly the final outcome of Leishmania donovani development in P. argentipes and their transmissibility to the vertebrate host.
利什曼原虫寄生虫在其生命周期中在白蛉肠道中发育的前鞭毛体阶段和脊椎动物宿主吞噬细胞内的无鞭毛体之间交替。对于白蛉的实验性感染，前鞭毛体经常被使用，因为这种感染方式在技术上更容易，尽管白蛉摄取前鞭毛体是不自然的。在这里，我们旨在回答一个关键问题，即前鞭毛体引发的实验性感染与细胞内无鞭毛体引发的感染在多大程度上不同。我们对感染了对数期培养物中的前鞭毛体或在巨噬细胞中体外培养的无鞭毛体的银足白蛉雌性体内利什曼原虫的发育进行了并行比较。早期感染在寄生虫负荷和形态形式表现上存在显著差异。随着感染的成熟，这些差异消失了；两组都发展为严重的晚期感染，口道瓣膜定植，感染性后循环体表现一致，传播效率相同。结果表明，关于利什曼原虫在白蛉中发育早期阶段的研究应以细胞内无鞭毛体开始。然而，使用前鞭毛体阶段感染白蛉并不会显著改变杜氏利什曼原虫在银足白蛉中的最终发育结果及其向脊椎动物宿主的传播能力。
