This study presents nanoparticle-based vaccine development for Hepatitis E virus (HEV). Gold nanoparticles (GNP) of average size 12 nm were synthesized by citrate reduction method followed by functionalization with cysteamine hydrochloride for nano-conjugation. Immune response of nano-conjugates of GNP with 26 kDa protein (368-606 amino acids) and 54 kDa protein (112-606 amino acids) were evaluated. In vitro release kinetics of GNP-conjugated 54 kDa (GNP54) and 26 kDa (GNP26) proteins showed slower rate of release of 54 kDa protein as compared to 26 kDa protein. Humoral immune response of mice immunized intramuscularly with GNP54, GNP26 and GNP alone, exhibited HEV-specific IgG titer of 7.9 ± 2.9, 5.686 ± 4.098 and 0.698 ± 0.089, respectively, after 14 days of booster immunization. In addition to this, HEV-specific cell-mediated immune response was demonstrated by splenocyte proliferation assay. Analysis of results using one-way ANOVA, showed statistically significant (p value < 0.05) increase in splenocyte proliferation for GNP54- and GNP26-immunized mice in comparison to GNP alone immunized mice. Stimulation index of HEV ORF2 proteins in GNP54/GNP26-immunized mice were comparable to Concanavalin A-treated positive control. These results indicate GNP-based vaccine as a promising candidate for efficiently mediating both humoral and cell-mediated immune response against HEV.

这项研究提出了基于纳米粒子的戊型肝炎病毒（HEV）疫苗开发。通过柠檬酸盐还原法合成平均粒径为12 nm的金纳米颗粒（GNP），然后用半胱胺盐酸盐将其官能化以进行纳米缀合。评价了GNP纳米缀合物与26 kDa蛋白（368-606个氨基酸）和54 kDa蛋白（112-606个氨基酸）的免疫应答。与26 kDa蛋白相比，结合GNP的54 kDa（GNP54）和26 kDa（GNP26）蛋白的体外释放动力学显示54 kDa蛋白的释放速率较慢。加强免疫14天后，单独用GNP54，GNP26和GNP进行肌肉内免疫的小鼠的体液免疫反应分别显示出HEV特异性IgG效价为7.9±2.9、5.686±4.098和0.698±0.089。除此之外，HEV特异性细胞介导的免疫反应通过脾细胞增殖试验证明。使用单向方差分析进行的结果分析显示具有统计学意义（与仅用GNP免疫的小鼠相比，用GNP54和GNP26免疫的小鼠脾细胞增殖增加（p值<0.05）。在GNP54 / GNP26免疫的小鼠中，HEV ORF2蛋白的刺激指数与伴刀豆球蛋白A治疗的阳性对照相当。这些结果表明，基于GNP的疫苗是有效介导针对HEV的体液免疫和细胞介导的免疫应答的有前途的候选药物。