College of Veterinary Medicine, Jilin University, Changchun, 130033, Jilin, China; Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China.
Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China.
Int J Biol Macromol. 2020 Jul 15;155:1532-1540. doi: 10.1016/j.ijbiomac.2019.11.130. Epub 2019 Nov 15.
Foot and mouth disease virus (FMDV) is a highly contagious pathogen propagating among cloven-hoofed animals. As a major immunogenic protein, VP1 plays a pivotal role in the induction of neutralizing antibodies, which therefore is an ideal target for developing subunit vaccines. In current study, four prokaryotic expression clones (rV4C, rC4V, rV5F and rF5V) were constructed by fusing truncated calreticulin (CRT) (120-250 aa or 120-308 aa) at the N/C terminal of vp1 gene, and co-expressed with chaperone trigger factor 16 (Tf16) in E.coli, respectively. The soluble recombinant CRT-fused VP1 proteins could form into homogeneous reactive polymers with average hydrodynamic diameters around 100 nm according to the dynamic light scattering (DLS) data. Immunization of guinea pigs with 10 μg purified CRT-fused VP1 proteins induced high levels of antibodies against naked-VP1 through indirect ELISA. Sandwich ELISA showed that only rC4V could elicit the same level of antibody against FMD virus as commercial inactivated vaccine after booster. The lymphocyte cytokines secretion of immunized rC4V was higher than the other CRT-fused VP1 proteins in guinea pigs. These results showed that the soluble CRT-fused VP1 proteins, especially rC4V, expressed with Tf16 in E. coli might have potential to be used as subunit vaccine candidate against FMDV.
口蹄疫病毒(FMDV)是一种在偶蹄类动物中传播的高度传染性病原体。作为主要的免疫原性蛋白,VP1 在诱导中和抗体中起着关键作用,因此是开发亚单位疫苗的理想目标。在本研究中,通过将截短的钙网蛋白(CRT)(120-250 aa 或 120-308 aa)融合到 vp1 基因的 N/C 端,构建了四个原核表达克隆(rV4C、rC4V、rV5F 和 rF5V),并在大肠杆菌中与伴侣蛋白触发因子 16(Tf16)共同表达。根据动态光散射(DLS)数据,可溶性重组 CRT 融合 VP1 蛋白可以形成均相反应性聚合物,平均水动力直径约为 100nm。用 10μg 纯化的 CRT 融合 VP1 蛋白免疫豚鼠,通过间接 ELISA 诱导针对裸 VP1 的高水平抗体。夹心 ELISA 表明,rC4V 增强后可诱导与商品化灭活疫苗相同水平的抗 FMD 病毒抗体。免疫 rC4V 的淋巴细胞细胞因子分泌高于豚鼠中其他 CRT 融合 VP1 蛋白。这些结果表明,用 Tf16 在大肠杆菌中表达的可溶性 CRT 融合 VP1 蛋白,特别是 rC4V,可能有潜力作为 FMDV 的亚单位疫苗候选物。