Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore.
Virol J. 2010 Feb 1;7:24. doi: 10.1186/1743-422X-7-24.
Dengue virus (DENV) is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined.
In this study, we have used a targeted small interfering RNA (siRNA) library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study.
Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti-viral strategies and treatment of DENV infection.
登革热病毒（DENV）是登革热和危及生命的登革出血热或登革休克综合征的病原体。在没有抗病毒药物或疫苗的情况下，迫切需要针对这种具有医学重要性的病毒病原体开发有效的抗病毒策略。DENV 与宿主细胞的初始相互作用可能代表潜在的抗病毒靶向部位之一。目前，介导登革热病毒感染的人类膜转运宿主基因或因子的参与尚不清楚。
在这项研究中，我们使用了靶向性小干扰 RNA（siRNA）文库来鉴定和分析参与内吞作用、细胞骨架动力学和内体运输过程的关键细胞基因，这些过程对于 DENV 感染很重要且必不可少。DENV 进入 Huh7 细胞的感染被证明被针对与网格蛋白介导的内吞作用相关的基因的 siRNA 强烈抑制。网格蛋白介导的内吞作用的重要作用通过该途径中基因的特征明确的显性负突变体的表达和使用网格蛋白内吞抑制剂氯丙嗪得到证实。此外，DENV 感染对调节早期到晚期内体运输以及内体酸性 pH 的人类基因的破坏敏感。在这项研究中，还揭示了肌动蛋白和微管动力学在介导 DENV 感染性进入中的重要性和参与。
总之，这项研究的结果提供了对人类膜转运细胞基因的详细分析，并深入了解这些宿主基因与 DENV 相互作用以启动感染的机制，从而拓宽了我们对这种具有医学重要性的病毒病原体进入途径的理解。这些数据也可能为开发抗病毒策略和治疗 DENV 感染提供新的潜在途径。
