Chen Ron A-J, Jacobs Nathalie, Smith Geoffrey L
Department of Virology, Faculty of Medicine, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.
J Gen Virol. 2006 Jun;87(Pt 6):1451-1458. doi: 10.1099/vir.0.81736-0.
A characterization of the B14R gene from Vaccinia virus (VACV) strain Western Reserve (WR) is presented. Computational analyses of the B14R gene indicated high conservation in orthopoxviruses but no orthologues outside the Poxviridae. To characterize the B14 protein, the B14R gene was expressed in Escherichia coli and recombinant protein was purified and used to generate a rabbit polyclonal antiserum. This antiserum recognized a 15 kDa cytoplasmic protein in mammalian cells that were transfected with the B14R gene or infected with VACV WR, but not from cells infected with a VACV mutant (vdeltaB14) from which the B14R gene was deleted. Compared to wild-type and revertant virus controls, vdeltaB14 had normal growth kinetics in cell culture. The virulence of vdeltaB14 was assessed in two in vivo models. Mice infected intranasally with vdeltaB14 had similar weight loss compared to the controls, but in C57BL/6 mice infected intradermally vdeltaB14 induced a smaller lesion size compared with controls. Moreover, intradermal infection with vdeltaB14 caused an increased infiltration of cells into the infected lesion despite the smaller lesion size. Therefore, B14 is an intracellular protein that is non-essential for virus replication in cell culture but contributes to virus virulence in vivo and affects the host response to infection.
本文介绍了来自痘苗病毒（VACV）西储株（WR）的B14R基因的特征。对B14R基因的计算分析表明，其在正痘病毒中高度保守，但在痘病毒科以外没有直系同源物。为了表征B14蛋白，B14R基因在大肠杆菌中表达，重组蛋白被纯化并用于制备兔多克隆抗血清。该抗血清在转染了B14R基因或感染了VACV WR的哺乳动物细胞中识别出一种15 kDa的细胞质蛋白，但在感染了缺失B14R基因的VACV突变体（vdeltaB14）的细胞中未识别到。与野生型和回复病毒对照相比，vdeltaB14在细胞培养中具有正常的生长动力学。在两种体内模型中评估了vdeltaB14的毒力。经鼻感染vdeltaB14的小鼠与对照相比体重减轻相似，但在皮内感染的C57BL/6小鼠中，vdeltaB14诱导的病变大小比对照小。此外，尽管病变较小，但皮内感染vdeltaB14导致细胞向感染病变的浸润增加。因此，B14是一种细胞内蛋白，对细胞培养中的病毒复制不是必需的，但在体内有助于病毒毒力并影响宿主对感染的反应。
