PDF(Pubmed)
Abstract：
Dengue virus is an enveloped virus with an icosahedral assembly of envelope proteins (E). The E proteins are arranged as a head-to-tail homodimer, and domain III (EDIII) is placed at the edge of the dimer, converging to a pentamer interface. For a structure-based approach, cholera toxin B (CTB) was harnessed as a structural scaffold for the five-fold symmetry of EDIII. Pivoted by an RNA-mediated chaperone for the protein folding and assembly, CTB-EDIII of dengue serotype 1 (DV1) was successfully produced as soluble pentamers in an E. coli host with a high yield of about 28 mg/L. Immunization of mice with CTB-DV1EDIII elicited increased levels of neutralizing antibodies against infectious viruses compared to the control group immunized with DV1EDIII without CTB fusion. IgG isotype switching into a balanced Th1/Th2 response was also observed, probably triggered by the intrinsic adjuvant activity of CTB. Confirming the immune-enhancing potential of CTB in stabilizing the pentamer assembly of EDIII, this study introduces a low-cost bacterial production platform designed to augment the soluble production of subunit vaccine candidates, particularly those targeting flaviviruses.
摘要：
登革热病毒是具有包膜蛋白(E)的二十面体组装的包膜病毒。E蛋白排列成头尾同源二聚体，并且结构域III（EDIII）位于二聚体的边缘，收敛到五聚体接口。对于基于结构的方法，霍乱毒素B（CTB）被用作EDIII五倍对称的结构支架。由RNA介导的分子伴侣进行蛋白质折叠和组装，登革热血清型1（DV1）的CTB-EDIII在大肠杆菌宿主中以可溶性五聚体的形式成功生产，产量约为28mg/L。与未经CTB融合的用DV1EDIII免疫的对照组相比,用CTB-DV1EDIII免疫小鼠引起针对感染性病毒的中和抗体水平升高。也观察到IgG同种型转换为平衡的Th1/Th2应答,可能是由CTB的内在佐剂活性引发的。证实了CTB在稳定EDIII五聚体组装中的免疫增强潜力，这项研究引入了一个低成本的细菌生产平台，旨在增加亚单位疫苗候选物的可溶性生产，特别是那些针对黄病毒的。
