Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1
Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1
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DOI：
10.1128/mbio.00420-19
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发表时间：
2019-05-01
期刊：
影响因子：
6.4
通讯作者：
Smith, Joseph D.
中科院分区：
文献类型：
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作者：
Bernabeu, Maria;Gunnarsson, Celina;Smith, Joseph D.
脑型疟疾是一种严重的神经系统并发症，与恶性疟原虫感染的红细胞(IE)在脑微血管中的隔离有关，但具体的结合作用仍存在争议。在这里，我们建立了一个工程化的三维(3D)人脑内皮细胞微血管模型，并研究了在健康和疾病发生的大范围生理流速下恶性疟原虫的结合。3D微血管的血流灌注分析显示，寄生虫与肿瘤坏死因子α(TNF-α)激活的脑内皮细胞结合的表型异质性在以前是不为人知的。表达B组恶性疟原虫红细胞膜蛋白1(PfEMP1)的克隆性寄生虫与激活的3D微血管的结合增加，而表达DC8-PfEMP1的恶性疟原虫IE的结合减少。对内皮细胞活化的差异反应是通过内皮蛋白C受体(EPCR)和细胞间黏附分子1(ICAM-1)表面表达的变化来介导的。这些发现证明了寄生虫结合的异质性，并为寄生虫策略适应感染期间不断变化的微血管环境提供了证据。工程化的3D人脑微血管模型为寄生虫结合提供了新的机制见解，并为进一步研究疟疾的发病机制和寄生虫与血管的相互作用提供了机会。在这里，我们开发了一个工程化的3D人脑微血管模型，它模拟了小血管的血流速度和结构，以研究感染恶性疟原虫的人红细胞如何附着于脑内皮细胞。通过对具有不同粘附性的寄生虫株的研究，我们发现疟疾寄生虫的结合率是异质性的，并且强烈地受到血流的生理差异以及内皮细胞是否先前被肿瘤坏死因子-α激活的影响，肿瘤坏死因子-α是一种与疟疾疾病严重程度相关的促炎细胞因子。我们还展示了人EPCR和ICAM-1在寄生虫结合中的重要性。我们的模型为恶性疟原虫如何结合在脑微血管内提供了新的线索，并为未来研究人类大脑病原体招募到脑血管衬里提供了一种强有力的方法。
Cerebral malaria is a severe neurological complication associated with sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the brain microvasculature, but the specific binding interactions remain under debate. Here, we have generated an engineered three-dimensional (3D) human brain endothelial microvessel model and studied P. falciparum binding under the large range of physiological flow velocities that occur in both health and disease. Perfusion assays on 3D microvessels reveal previously unappreciated phenotypic heterogeneity in parasite binding to tumor necrosis factor alpha (TNF-alpha)-activated brain endothelial cells. While clonal parasite lines expressing a group B P. falciparum erythrocyte membrane protein 1 (PfEMP1) present an increase in binding to activated 3D microvessels, P. falciparum-IE expressing DC8-PfEMP1 present a decrease in binding. The differential response to endothelium activation is mediated by surface expression changes of endothelial protein C receptor (EPCR) and intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate heterogeneity in parasite binding and provide evidence for a parasite strategy to adapt to a changing microvascular environment during infection. The engineered 3D human brain microvessel model provides new mechanistic insight into parasite binding and opens opportunities for further studies on malaria pathogenesis and parasite-vessel interactions.IMPORTANCE Cerebral malaria research has been hindered by the inaccessibility of the brain. Here, we have developed an engineered 3D human brain microvessel model that mimics the blood flow rates and architecture of small blood vessels to study how P. falciparum-infected human erythrocytes attach to brain endothelial cells. By studying parasite lines with different adhesive properties, we show that the malaria parasite binding rate is heterogeneous and strongly influenced by physiological differences in flow and whether the endothelium has been previously activated by TNF-alpha, a proinflammatory cytokine that is linked to malaria disease severity. We also show the importance of human EPCR and ICAM-1 in parasite binding. Our model sheds new light on how P. falciparum binds within brain microvessels and provides a powerful method for future investigations of recruitment of human brain pathogens to the blood vessel lining of the brain.