细菌细胞致死性膨胀毒素和严重急性呼吸综合征冠状病毒2(SARS-CoV-2)病毒利用依赖于细胞动蛋白(突触动蛋白-2)的途径进入细胞。
Cellugyrin (synaptogyrin-2) dependent pathways are used by bacterial cytolethal distending toxin and SARS-CoV-2 virus to gain cell entry.
作者信息
Boesze-Battaglia Kathleen, Cohen Gary H, Bates Paul F, Walker Lisa M, Zekavat Ali, Shenker Bruce J
机构信息
Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States.
Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
出版信息
Front Cell Infect Microbiol. 2024 Apr 18;14:1334224. doi: 10.3389/fcimb.2024.1334224. eCollection 2024.
cytolethal distending toxin (Cdt) is capable of intoxicating lymphocytes macrophages, mast cells and epithelial cells. Following Cdt binding to cholesterol, in the region of membrane lipid rafts, the CdtB and CdtC subunits are internalized and traffic to intracellular compartments. These events are dependent upon, cellugyrin, a critical component of synaptic like microvesicles (SLMV). Target cells, such as Jurkat cells, rendered unable to express cellugyrin are resistant to Cdt-induced toxicity. Similar to Cdt, SARS-CoV-2 entry into host cells is initiated by binding to cell surface receptors, ACE-2, also associated with cholesterol-rich lipid rafts; this association leads to fusion and/or endocytosis of viral and host cell membranes and intracellular trafficking. The similarity in internalization pathways for both Cdt and SARS-CoV-2 led us to consider the possibility that cellugyrin was a critical component in both processes. Cellugyrin deficient Calu-3 cells (Calu-3) were prepared using Lentiviral particles containing shRNA; these cells were resistant to infection by VSV/SARS-CoV-2-spike pseudotype virus and partially resistant to VSV/VSV-G pseudotype virus. Synthetic peptides representing various regions of the cellugyrin protein were prepared and assessed for their ability to bind to Cdt subunits using surface plasmon resonance. Cdt was capable of binding to a region designated the middle outer loop (MOL) which corresponds to a region extending into the cytoplasmic surface of the SLMV. SARS-CoV-2 spike proteins were assessed for their ability to bind to cellugyrin peptides; SARS-CoV-2 full length spike protein preferentially binds to a region within the SLMV lumen, designated intraluminal loop 1A. SARS-CoV-2-spike protein domain S1, which contains the receptor binding domains, binds to cellugyrin N-terminus which extends out from the cytoplasmic surface of SLMV. Binding specificity was further analyzed using cellugyrin scrambled peptide mutants. We propose that SLMV represent a component of a common pathway that facilitates pathogen and/or pathogen-derived toxins to gain host cell entry.
细胞致死性膨胀毒素(Cdt)能够使淋巴细胞、巨噬细胞、肥大细胞和上皮细胞中毒。Cdt与膜脂筏区域的胆固醇结合后,CdtB和CdtC亚基被内化并运输到细胞内区室。这些事件依赖于细胞动蛋白,它是突触样微囊泡(SLMV)的关键成分。诸如Jurkat细胞等无法表达细胞动蛋白的靶细胞对Cdt诱导的毒性具有抗性。与Cdt类似,严重急性呼吸综合征冠状病毒2(SARS-CoV-2)进入宿主细胞也是通过与细胞表面受体血管紧张素转换酶2(ACE-2)结合开始的,ACE-2也与富含胆固醇的脂筏相关;这种结合导致病毒和宿主细胞膜的融合和/或内吞作用以及细胞内运输。Cdt和SARS-CoV-2内化途径的相似性使我们考虑细胞动蛋白在这两个过程中都是关键成分的可能性。使用含有短发夹RNA的慢病毒颗粒制备了细胞动蛋白缺陷的Calu-3细胞(Calu-3);这些细胞对水疱性口炎病毒/ SARS-CoV-2刺突假型病毒感染具有抗性,对水疱性口炎病毒/水疱性口炎病毒糖蛋白(VSV-G)假型病毒具有部分抗性。制备了代表细胞动蛋白蛋白各个区域的合成肽,并使用表面等离子体共振评估它们与Cdt亚基结合的能力。Cdt能够与一个称为中间外环(MOL)的区域结合,该区域对应于延伸到SLMV细胞质表面的区域。评估了SARS-CoV-2刺突蛋白与细胞动蛋白肽结合的能力;SARS-CoV-2全长刺突蛋白优先与SLMV腔内的一个区域结合,该区域称为腔内环1A。包含受体结合域的SARS-CoV-2刺突蛋白结构域S1与从SLMV细胞质表面伸出的细胞动蛋白N末端结合。使用细胞动蛋白乱序肽突变体进一步分析了结合特异性。我们提出,SLMV代表了一条共同途径的一个组成部分,该途径促进病原体和/或病原体衍生毒素进入宿主细胞。