The role of Plasmodium berghei ookinete proteins in binding to basal lamina components and transformation into oocysts
The role of Plasmodium berghei ookinete proteins in binding to basal lamina components and transformation into oocysts
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DOI：
10.1016/s0020-7519(01)00298-3
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发表时间：
2002-01-01
影响因子：
4
通讯作者：
Hurd, H
中科院分区：
文献类型：
--
作者：
Arrighi, RBG;Hurd, H
动合子是疟原虫的一种能动形式，从蚊子的中肠腔行进，侵入上皮细胞并定居在基膜下。围绕动合子运动的停止及其转化为卵囊的事件知之甚少，但基板和寄生虫表面的组件之间的相互作用已被牵连。在这里，我们报告说，基底层成分和动合子蛋白之间发生的相互作用，这些相互作用抑制运动，并可能参与转化为卵囊。伯氏疟原虫动合子与纤连蛋白包被的微量滴定板威尔斯孔结合较弱，与层粘连蛋白和胶原IV包被的威尔斯孔结合更强。胶原蛋白和层粘连蛋白的1：1混合物显著增强结合。结合随孵育时间增加至10 h，不同组分随时间显示出不同的结合特征。两个寄生虫分子被证明是作为配体的基膜组件。Western印迹表明，表面分子Pbs 21强烈结合层粘连蛋白，但不结合胶原IV，而215 kDa的分子（可能PbCTRP）结合层粘连蛋白和胶原IV。此外，如果将寄生虫与抗Pbs 21单克隆抗体13.1预孵育，则发生高达90%的动合子与胶原IV/层粘连蛋白组合的结合抑制。在用层粘连蛋白或层粘连蛋白/胶原蛋白IV组合包被的威尔斯孔中发生了一些动合子向卵囊的转化，但单独的胶原蛋白IV不触发转化。未包被的威尔斯孔中未发生结合或转化。我们的数据支持的建议，动合子蛋白Pbs 21和215 kDa的蛋白质可能有多种作用，包括与中肠基底层成分，导致绑定，抑制运动和触发转换的相互作用。(C)2001年澳大利亚寄生虫学会。由爱思唯尔科技有限公司出版。保留所有权利。
The ookinete is a motile form of the malaria parasite that travels from the midgut lumen of the mosquito, invades the epithelial cells and settles beneath the basal lamina. The events surrounding cessation of ookinete motility and its transformation into an oocyst are poorly understood, but interaction between components of the basal lamina and the parasite surface has been implicated. Here we report that interactions occur between basal lamina constituents and ookinete proteins and that these interactions inhibit motility and are likely to be involved in transformation to an oocyst. Plasmodium berghei ookinetes bound weakly to microtitre plate wells coated with fibronectin and much more strongly to wells coated with laminin and collagen IV. A 1:1 mixture of collagen and laminin significantly enhanced binding. Binding increased with time of incubation up to 10 h and different components showed different binding profiles with time. Two parasite molecules were shown to act as ligands for basal lamina components. Western blots demonstrated that the surface molecule Pbs21 bound strongly to laminin but not to collagen IV whereas a 215 kDa molecule (possibly PbCTRP) bound to both laminin and collagen IV. Furthermore up to 90% inhibition of binding of ookinetes to collagen IV/laminin combination occurred if parasites were pre-incubated with anti-Pbs21 monoclonal antibody 13.1. Some transformation of ookinetes to oocysts occurred in wells coated with laminin or laminin/ collagen IV combinations but collagen IV alone did not trigger transformation. No binding or transformation occurred in uncoated wells. Our data support the suggestion that ookinete proteins Pbs21 and a 215 kDa protein may have multiple roles including interactions with midgut basal lamina components that cause binding, inhibit motility and trigger transformation. (C) 2001 Australian Society for Parasitology. Published by Elsevier Science Ltd. All rights reserved.