重症登革热患者血管通透性显著增加、血浆渗漏症状明显，是患者死亡的主要原因之一。但该现象至今机制不明，缺乏有效防治手段。课题组前期研究发现，登革病毒感染时，细胞可分泌IFN-λ，并通过其特异性受体IFNL1R上调细胞的内皮跨膜电阻值。这提示IFN-λ在登革感染时，有可能抵抗因血管通透性增加导致的血浆渗漏症状。为此本项目拟在原有工作基础上，深入了解登革病毒感染时，IFN-λ通过细胞旁途径改善内皮屏障的具体作用；分析IFN-λ对Rho家族成员活化的影响，观察细胞紧密连接组成蛋白ZO-1和claudin-5共区域化情况；明确IFN-ɑ/β、TNF-ɑ、IL-1β等促渗漏发生细胞因子与IFN-λ途径调控间的内在联系。通过上述研究，我们希望阐明IFN-λ作为保护性因素，增强登革病毒感染后血管内皮细胞屏障功能的具体机制。

Vascular permeability, with plasma leakge, is a leading cause of death in patietnts with severe dengue. The underlying mechnism contributing to Vascular permeability as well as plasma leakge is undefined,leaving a lack of adequate control measures against the disease.We found that the dengue virus-infected vascular endothelial cells released IFN-λ and were rendered capable of increasing ransepithelial electrical resistance (TEER) by binding of IFN-λ to IFNLR1, suggesting that IFN-λ could prevent plasma leakge by inhibiting Vascular permeability. In this project, on the basis of our initial findings, we will further investigate the exact role for IFN-λ—via paracellular pathway— in improving endothelial permeability; evaluate the effect of IFN-λ on cascade activation of members of the Rho family; observe colocalization of ZO-1/ claudin-5 (tight junction proteins); reveal cross-talk between the promoting-leakage cytokines (IFN-ɑ/β、TNF-ɑ、IL-1β) and the IFN-λ-driven cascade. Taken together, we expect to unravel the exact mechanism by which IFN-λ, as a pretective agent, could enhance endothelial barrier function by inhibiting cell permeability following dengue viurs infection.

在本研究中，我们对IFN-λ特异性受体IFNLR1在血管内皮细胞上存在可能，以及IFN-λ对血管内皮细胞潜在功能进行了探索。经研究发现，原代人脐静脉内皮细胞表达IFNLR1。IFN-λ可诱导细胞产生IL-8, 但对IL-12的产生没有影响。外源性IFN-λ作用于人原代脐静脉内皮细胞后可导致单层细胞TEER值增高，通透性降低。登革病毒感染人原代脐静脉内皮细胞时，经IFNLR1受体传递的信号参与了登革病毒感染时对通透性增加的负向调控作用。IFNLR1经单克隆抗体封闭后，C57BL/6小鼠被登革病毒感染组织渗漏情况显著增加。本项目的研究使我们认识到IFNLR1存在于血管内皮细胞上，IFN-λ经该受体对血管内皮细胞通透性进行调控，这丰富了我们对IFN-λ生物学功能的认知。