DataSheet_1_Exposure to Dengue Envelope Protein Domain III Induces Nlrp3 Inflammasome-Dependent Endothelial Dysfunction and Hemorrhage in Mice.docx

Typically occurring during secondary dengue virus (DENV) infections, dengue hemorrhagic fever (DHF) causes abnormal immune responses, as well as endothelial vascular dysfunction, for which the responsible viral factor remains unclear. During peak viremia, the plasma levels of virion-associated envelope protein domain III (EIII) increases to a point at which cell death is sufficiently induced in megakaryocytes in vitro. Thus, EIII may constitute a virulence factor for endothelial damage. In this study, we examined endothelial cell death induced by treatment with DENV and EIII in vitro. Notably, pyroptosis, the major type of endothelial cell death observed, was attenuated through treatment with Nlrp3 inflammasome inhibitors. EIII injection effectively induced endothelial abnormalities, and sequential injection of EIII and DENV-NS1 autoantibodies induced further vascular damage, liver dysfunction, thrombocytopenia, and hemorrhage, which are typical manifestations in DHF. Under the same treatments, pathophysiological changes in the Nlrp3 inflammasome–deficient mice were notably reduced compared with those in the wild-type mice. These results suggest that the Nlrp3 inflammasome constitutes a potential therapeutic target for treating DENV-induced hemorrhage in DHF.

登革出血热（dengue hemorrhagic fever, DHF）通常继发于登革病毒（dengue virus, DENV）感染，会引发异常免疫应答与内皮血管功能障碍，但其致病的病毒相关因子至今尚不明确。在病毒血症峰值阶段，病毒粒子结合的包膜蛋白结构域III（envelope protein domain III, EIII）的血浆水平会升高至可在体外有效诱导巨核细胞死亡的程度。因此，EIII或可作为引发内皮损伤的毒力因子。本研究中，我们体外检测了登革病毒与EIII处理所诱导的内皮细胞死亡。值得注意的是，所观测到的主要内皮细胞死亡类型——焦亡（pyroptosis），经NLRP3炎性小体（Nlrp3 inflammasome）抑制剂处理后可被显著减弱。EIII注射可有效诱导内皮异常，而依次注射EIII与登革病毒NS1自身抗体则会进一步引发血管损伤、肝功能障碍、血小板减少症与出血，这些均为登革出血热的典型临床表现。在相同处理条件下，与野生型小鼠相比，NLRP3炎性小体缺陷型小鼠的病理生理变化显著减轻。上述结果表明，NLRP3炎性小体可作为治疗登革出血热中登革病毒诱导性出血的潜在治疗靶点。