3D human-based microvessel bed for the study of Plasmodium falciparum interacting with vessel wall

 描述(由申请人提供)：恶性疟原虫感染红细胞的细胞黏附是一种主要的毒力决定因素，使寄生虫能够通过结合血管内皮细胞衬里从血液循环中隔离出来，并避免依赖脾的杀伤机制。虽然感染的红细胞会在各种微血管床上隔离，但脑型疟疾是一种威胁生命的疾病并发症，与脑微血管中的大量隔离有关。脑型疟疾伴随着感染的红细胞隔离部位的内皮激活、血脑屏障破坏和纤维蛋白血栓。虽然在了解受感染红细胞的结合特性方面已经取得了进展，但关于脑型疟疾发病机制的关键问题仍然没有得到回答。恶性疟原虫红细胞膜蛋白1(PfEMP1)家族是恶性疟原虫红细胞膜蛋白1(PfEMP1)家族的成员。我们最近发现，严重疟疾与PfEMP1变异体的一个独特子集有关，该变异体与内皮蛋白C受体结合，内皮蛋白C受体是血液凝固和内皮激活的重要调节因子。我们的初步发现表明，寄生虫可能损害EPCR功能，并导致脑型疟疾并发症。然而，研究人类脑型疟疾的疾病机制的一个重要障碍是无法接触到大脑。该项目将利用微血管工程技术在人类脑型疟疾研究中的新进展。通过建立人脑微血管模型，我们将：1.利用体外三维人体微血管系统表征恶性疟原虫感染的红细胞黏附于人脑内皮细胞和其他微血管床的分子机制。2.确定血管壁屏障和血栓形成特性的后续变化。3.确定与内皮功能障碍或保护相关的感染红细胞-内皮细胞激活所涉及的宿主信号通路。该项目的成功将揭示与脑型疟疾相关的致病机制，并可能指导潜在的治疗开发。

 DESCRIPTION (provided by applicant): Cytoadhesion of Plasmodium falciparum infected erythrocytes is a major virulence determinant that enables parasites to sequester from blood circulation by binding to the endothelial lining of blood vessels and avoid spleen-dependent killing mechanisms. Whereas infected erythrocytes sequester in a variety of microvascular beds, cerebral malaria is a life-threatening disease complication that is associated with massive sequestration in brain microvessels. Cerebral malaria is accompanied by endothelial activation, blood-brain barrier disruption and fibrin thrombi at sites of infected erythrocyte sequestration. While progress has been made in understanding the binding properties of infected erythrocytes, critical questions remain unanswered about the mechanisms of cerebral malaria pathogenesis. Binding of P. falciparum- infected erythrocytes is mediated by the large and diverse P. falciparum erythrocyte membrane protein 1 (PfEMP1) family. We recently showed that severe malaria is associated with a distinct subset of PfEMP1 variants that binds to endothelial protein C receptor, an important regulator of blood clotting and endothelial activation. Our preliminary findings suggest that parasites may impair EPCR function and lead to cerebral malaria complications. However, a significant barrier to investigating disease mechanisms in human cerebral malaria is the inaccessibility of the brain. This project will exploit new advances in microvascular engineering technology in the study of human cerebral malaria. By building a human brain microvascular model, we will: 1. Characterize the molecular mechanisms by which P. falciparum-infected erythrocytes adhere to human brain endothelial cells and other microvascular beds using in vitro 3D human microvascular systems. 2. Determine the consequent changes on the barrier and thrombogenic properties of the vessel wall. 3. Determine host signaling pathways engaged by the infected erythrocyte-endothelial activation that are associated with endothelial dysfunction or protection. The success of the project will shed light on the pathogenic mechanisms associated with cerebral malaria and may guide potential therapeutic development.