森林脑炎病毒分子生物学研究进展

The molecular biology of tick-borne encephalitis virus

森林脑炎(TBE)病毒属黄病毒科,基因姐RNA含有单个开放阅读框架,5′端编码病毒的结构蛋白,3′端编码非结构蛋白。翻译成聚蛋白后,通过细胞和病毒编码的蛋白酶裂解产生单个的病毒蛋白。成熟的病毒是由两个相关的E和M膜蛋白脂质包膜所包围的立体对称的核衣壳组成。包膜E蛋白在病毒的感染周期中对细胞的识别和穿入细胞具有极其重要的功能,同时E蛋白诱导保护性的免疫反应,E蛋白内某一位点单个氨基酸的改变可引起病毒毒力的改变。因此,对TBE病毒分子生物学的研究有助于了解病毒与宿主细胞相互作用的机理,为病毒感染的特异性诊断、疫苗的研制和抗病毒药物的设计提供理论依据。

Tick-borne encephalitis (TBE) virus is a member of the flavivirus genus and the family Flaviviridae. Like other flaviviruses, the virion RNA contains a single long open reading frame that codes for the structural proteins at the 5' end and the nonstructural proteins at the 3' end. Co- and posttranslational cleavages by a viral and cellular proteases lead to the formation of individual virul proteins. The mature virion is composed of an isometric capsid surrounded by a lipid envelope with two membrane-associated proteins. One of these, protein E, is of paramount importance for several important viral functions. Especially during the entry phase of the viral life cycle. Protein E is also responsible for the induction of a protective immune response. A detailed map of antigenic sites has been extablished and the structure of an anchor-free form of E is currently being investigated by X-ray diffraction analysis. Understanding the molecular basis of the function of this proteins together with the knowledge of its three-dimensional structure may provide clues for developing specific antiviral agents. Protein E has also been shown to be an important determinant of virulence, with single ammo acid substitution at selected sitea leading to attenuation.