Data Sheet 2_Distinct ZIKV strain signatures and type I IFN modulation reveal a protective role of brain endothelial interferon signaling in vitro and in vivo.pdf

IntroductionZika virus (ZIKV) infection has been associated with neurological syndromes, particularly during outbreaks caused by Asian lineage strains. However, experimental models suggest that African strains may exhibit an equal or more virulent profile. Neuroinvasion by systemic viruses often requires crossing the blood–brain barrier (BBB), which disruption amplifies viral dissemination and neuropathology. Type I interferons (IFNs) are key to restricting ZIKV replication, but their specific role in preserving BBB integrity remains poorly defined.
MethodsHere, we used human brain microvascular endothelial cells (HBMECs) as a simplified BBB model to compare transcriptional responses and IFN modulation following infection with either the African prototype strain ZIKVMR766 or the Asian epidemic strain ZIKVPE243. The role of endothelial cell–mediated IFN responses was further assessed in vivo by intravascular inoculation of mice with endothelial-specific IFNAR depletion using ZIKVMR766.
Results and discussionInfection of HBMEC with ZIKVMR766 triggered a greater number and broader range of differentially expressed genes, especially ones associated with interferon signaling and translational pathways, whereas ZIKVPE243-infected samples clustered closer to non-infected ones. ZIKVMR766 infection also resulted in higher viral titers and faster dissemination across endothelial monolayers. Both strains induced IFN-β expression but suppressed downstream IFN signaling by reducing STAT1 phosphorylation and promoting STAT2 degradation, with these effects being more pronounced for ZIKVMR766. Despite these evasion mechanisms, neutralization assays revealed that endothelial cells-derived IFNs production and response partially restricted viral replication, preserved HBMEC viability, and protected against barrier disruption, with ZIKVPE243 showing greater sensitivity to IFN-β. Importantly, in vivo infection of mice lacking endothelial IFNAR signaling resulted in elevated CNS viral load and increased lethality following ZIKVMR766 infection, underscoring the pivotal role of endothelial IFN responses in viral control, maintenance of BBB integrity, and protection against neuroinvasion.

引言
寨卡病毒（Zika virus, ZIKV）感染与神经系统综合征密切相关，这一关联在亚洲谱系毒株引发的暴发疫情中尤为显著。然而，实验模型研究表明，非洲谱系毒株的毒力特征可能与之相当甚至更强。全身性病毒的神经侵袭通常需要跨越血脑屏障（blood–brain barrier, BBB），血脑屏障的破坏会加剧病毒播散与神经病理损伤。I型干扰素（Type I interferons, IFNs）是限制寨卡病毒复制的关键因子，但其在维持血脑屏障完整性中的具体作用仍未明确。
方法
本研究以人脑微血管内皮细胞（human brain microvascular endothelial cells, HBMECs）作为简化的血脑屏障模型，对比非洲原型毒株ZIKVMR766与亚洲流行毒株ZIKVPE243感染后，细胞的转录组应答与干扰素调控模式。此外，本研究通过血管内接种ZIKVMR766，并对小鼠实施内皮特异性干扰素α/β受体（IFNAR）敲除，在体内进一步评估内皮细胞介导的干扰素应答的作用。
结果与讨论
ZIKVMR766感染人脑微血管内皮细胞后，触发的差异表达基因数量更多、涉及通路范围更广，尤其是与干扰素信号通路及翻译通路相关的基因；而ZIKVPE243感染的样本转录组聚类结果与未感染样本更为接近。ZIKVMR766感染还可导致更高的病毒滴度，并更快地穿过内皮单层细胞。两种毒株均可诱导β干扰素（IFN-β）的表达，但同时通过降低STAT1磷酸化水平、促进STAT2降解来抑制下游干扰素信号通路，且ZIKVMR766的此类抑制效应更为显著。尽管存在上述免疫逃逸机制，中和试验结果显示，内皮细胞来源的干扰素产生与应答可部分限制病毒复制、维持人脑微血管内皮细胞活力，并抵御血脑屏障破坏；其中ZIKVPE243对β干扰素的敏感性更高。值得注意的是，体内实验中，内皮IFNAR信号缺失的小鼠在感染ZIKVMR766后，中枢神经系统病毒载量升高且致死率增加，这进一步证实了内皮细胞干扰素应答在病毒控制、维持血脑屏障完整性以及抵御神经侵袭中的关键作用。