An Aerolysin-like Pore-Forming Protein Complex Targets Viral Envelope to Inactivate Herpes Simplex Virus Type 1
An Aerolysin-like Pore-Forming Protein Complex Targets Viral Envelope to Inactivate Herpes Simplex Virus Type 1
复制标题
一种类似气溶素的成孔蛋白复合物靶向病毒包膜以灭活 1 型单纯疱疹病毒
DOI：
10.4049/jimmunol.2001056
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发表时间：
2021-08-01
影响因子：
4.4
通讯作者：
Zhang, Yun
中科院分区：
文献类型：
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作者：
Liu, Long;Deng, Cheng-Jie;Zhang, Yun
由于大多数动物病毒是有包膜的，这些病毒通过与细胞膜融合进入细胞质启动其入侵。然而，宿主细胞抵抗这些病毒进入细胞质的策略还不完全清楚。成孔毒素气溶素样蛋白（ALP）存在于整个动物王国，但其功能大多是未知的。本文报道了大铃蟾（Bombina maxima）βγ-晶状体蛋白融合的气溶素样蛋白和三叶因子复合物（βγ-CAT）通过干扰囊膜病毒侵入细胞质，直接阻断囊膜病毒的侵入。βγ-CAT靶向HSV 1型（HSV-1）包膜上的酸性鞘糖脂，以诱导孔形成，如蛋白质寡聚体形成以及钾和钙离子流出所示。同时，βγ-CAT在脂质体上形成直径约10 nm的环状寡聚体，并诱导脂质体释放染料，模拟病毒包膜。出乎意料的是，透射电子显微镜分析显示，βγ-CAT处理的HSV-1在视觉上与媒介物处理的HSV-1一样完整，表明βγ-CAT不裂解病毒包膜。而βγ-CAT处理的HSV-1进入HeLa细胞的胞质则完全受阻。在体内，局部应用βγ-CAT减弱了小鼠中HSV-1角膜感染。这些结果表明，βγ-CAT具有对抗包膜病毒侵袭的能力，其抗病毒作用方式具有一定的特异性。我们的研究结果也将在很大程度上有助于说明动物ALP的假定抗病毒活性。关键点βγ-CAT在HSV-1包膜上形成小孔，抑制病毒进入细胞质。βγ-CAT靶向HSV-1包膜上的酸性鞘糖脂以防止其侵入。
Because most of animal viruses are enveloped, cytoplasmic entry of these viruses via fusion with cellular membrane initiates their invasion. However, the strategies in which host cells counteract cytoplasmic entry of such viruses are incompletely understood. Pore-forming toxin aerolysin-like proteins (ALPs) exist throughout the animal kingdom, but their functions are mostly unknown. In this study, we report that βγ-crystallin fused aerolysin-like protein and trefoil factor complex (βγ-CAT), an ALP and trefoil factor complex from the frog Bombina maxima, directly blocks enveloped virus invasion by interfering with cytoplasmic entry. βγ-CAT targeted acidic glycosphingolipids on the HSV type 1 (HSV-1) envelope to induce pore formation, as indicated by the oligomer formation of protein and potassium and calcium ion efflux. Meanwhile, βγ-CAT formed ring-like oligomers of ∼10 nm in diameter on the liposomes and induced dye release from liposomes that mimic viral envelope. Unexpectedly, transmission electron microscopy analysis showed that the βγ-CAT–treated HSV-1 was visibly as intact as the vehicle-treated HSV-1, indicating that βγ-CAT did not lyse the viral envelope. However, the cytoplasmic entry of the βγ-CAT–treated HSV-1 into HeLa cells was totally hindered. In vivo, topical application of βγ-CAT attenuated the HSV-1 corneal infection in mice. Collectively, these results uncovered that βγ-CAT possesses the capacity to counteract enveloped virus invasion with its featured antiviral-acting manner. Our findings will also largely help to illustrate the putative antiviral activity of animal ALPs. Visual Abstract Key Points βγ-CAT forms pores on the HSV-1 envelope to inhibit viral cytoplasmic entry. βγ-CAT targets acidic glycosphingolipids on the HSV-1 envelope to prevent its invasion.