Infected erythrocytes expressing DC13 PfEMP1 differ from recombinant proteins in EPCR-binding function.
Infected erythrocytes expressing DC13 PfEMP1 differ from recombinant proteins in EPCR-binding function.
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DOI：
10.1073/pnas.1712879115
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发表时间：
2018-01-30
影响因子：
11.1
通讯作者：
Rowe JA
中科院分区：
文献类型：
--
作者：
Azasi Y;Lindergard G;Ghumra A;Mu J;Miller LH;Rowe JA
恶性疟原虫感染的红细胞（IEs）在脑微血管中的隔离是脑型疟疾病理的基础。表达恶性疟原虫结构域盒（DC） 8和DC13型红细胞膜蛋白1的寄生虫与脑内皮细胞结合。最近的研究主要基于重组蛋白，已经确定内皮蛋白C受体（EPCR）是内皮细胞结合的关键受体。使用表达DC8和DC13的IEs，我们发现DC13 IEs与脑内皮细胞的结合不依赖于epcr，并且epcr结合的DC8 IEs与脑内皮细胞的细胞粘附被人血清阻断。这项研究强调了重组蛋白和天然蛋白在epcr结合特性上的差异，并表明脑型疟疾也需要其他受体进行隔离。最近的进展已经确定了脑型疟疾发病机制的新范式，其中内皮蛋白C受体（EPCR）是脑和其他重要器官中恶性疟原虫感染的红细胞（IEs）的主要宿主受体。结合EPCR的寄生虫粘附素是IE变异体表面抗原家族的成员，恶性疟原虫红细胞膜蛋白1 （PfEMP1）含有特异性粘附结构域，称为结构域盒（DC） 8和DC13。利用重组蛋白进行生物物理和晶体学研究，确定了PfEMP1与EPCR之间的结合相互作用位点。然而，关于IE表面天然PfEMP1与EPCR相互作用的研究很少。我们的目的是研究表达DC8和DC13 PfEMP1变体的IEs与EPCR的结合，这些变体的重组蛋白已用于关键的功能和结构研究。通过静态和流动黏附实验检测了IE与固定在塑料和人脑内皮细胞上的EPCR的结合。出乎意料的是，我们发现表达DC13 PfEMP1变体HB3var03或IT4var07的IEs在塑料上不与EPCR结合，并且这些变体与脑内皮细胞的结合不依赖于EPCR。表达DC8变体IT4var19的IEs确实与EPCR结合，但如果存在正常的人血清或血浆，这种相互作用被抑制，这提高了在生理条件下血浆成分可能阻止IE-EPCR相互作用的可能性。这些数据强调了PfEMP1重组蛋白与IEs之间epcr结合活性的差异，并表明迫切需要进一步研究以了解PfEMP1 - epcr相互作用的病理生理意义。
Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain microvasculature underlies the pathology of cerebral malaria. Parasites that express P. falciparum erythrocyte membrane protein 1 of domain cassette (DC) 8 and DC13 types bind to brain endothelial cells. Recent studies, largely based on recombinant proteins, have identified endothelial protein C receptor (EPCR) as the key receptor for endothelial cell binding. Using DC8- and DC13-expressing IEs, we show that binding of DC13 IEs to brain endothelial cells is not EPCR-dependent and that cytoadhesion of EPCR-binding DC8 IEs to brain endothelial cells is blocked by human serum. This study highlights differences between recombinant protein and native protein in EPCR-binding properties and suggests that other receptors are also required for sequestration in cerebral malaria. Recent advances have identified a new paradigm for cerebral malaria pathogenesis in which endothelial protein C receptor (EPCR) is a major host receptor for sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain and other vital organs. The parasite adhesins that bind EPCR are members of the IE variant surface antigen family Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) containing specific adhesion domains called domain cassette (DC) 8 and DC13. The binding interaction site between PfEMP1 and EPCR has been mapped by biophysical and crystallography studies using recombinant proteins. However, studies examining the interaction of native PfEMP1 on the IE surface with EPCR are few. We aimed to study binding to EPCR by IEs expressing DC8 and DC13 PfEMP1 variants whose recombinant proteins have been used in key prior functional and structural studies. IE binding to EPCR immobilized on plastic and on human brain endothelial cells was examined in static and flow adhesion assays. Unexpectedly, we found that IEs expressing the DC13 PfEMP1 variant HB3var03 or IT4var07 did not bind to EPCR on plastic and the binding of these variants to brain endothelial cells was not dependent on EPCR. IEs expressing the DC8 variant IT4var19 did bind to EPCR, but this interaction was inhibited if normal human serum or plasma was present, raising the possibility that IE–EPCR interaction may be prevented by plasma components under physiological conditions. These data highlight a discrepancy in EPCR-binding activity between PfEMP1 recombinant proteins and IEs, and indicate the critical need for further research to understand the pathophysiological significance of the PfEMP1–EPCR interaction.
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DOI：
10.1073/pnas.1120455109
发表时间：
2012-06-26
影响因子：
11.1
作者：
Lavstsen, Thomas;Turner, Louise;Theander, Thor G.
通讯作者：
Theander, Thor G.
影响因子：
56.9
作者：
Fried, M;Duffy, PE
通讯作者：
Duffy, PE
影响因子：
6.7
作者：
Magallón-Tejada A;Machevo S;Cisteró P;Lavstsen T;Aide P;Rubio M;Jiménez A;Turner L;Valmaseda A;Gupta H;De Las Salas B;Mandomando I;Wang CW;Petersen JE;Muñoz J;Gascón J;Macete E;Alonso PL;Chitnis CE;Bassat Q;Mayor A
通讯作者：
Mayor A
影响因子：
2.4
作者：
COOKE, BM;MORRISJONES, S;NASH, GB
通讯作者：
NASH, GB
影响因子：
11.1
作者：
Jespersen, Jakob S.;Wang, Christian W.;Laystsen, Thomas
通讯作者：
Laystsen, Thomas