Lee Su-Hwa, Chu Ki-Back, Kim Min-Ju, Quan Fu-Shi
Department of Medical Zoology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
Infect Drug Resist. 2023 Sep 11;16:6099-6110. doi: 10.2147/IDR.S426039. eCollection 2023.
Heterologous virus-like particle (VLP) assembly involving influenza or the Newcastle disease virus matrix protein (M) has been extensively used to explore the efficacies of VLP vaccines against the respiratory syncytial virus (RSV). Here, we attempted to generate homologous RSV VLPs by expressing the pre-fusion (pre-F) or the glycoprotein (G) on the RSV M protein and evaluated their protective efficacy in mice.
We generated VLPs using the baculovirus expression system in (Sf9) insect cells. Recombinant baculoviruses expressing the RSV pre-F, G, and M antigens were inoculated into Sf9 cells, and particles were self-assembled. Mice were immunized with either pre-F or G-expressing VLPs, and immune parameters were assessed to determine protection.
Our findings show that successful VLP assembly can be achieved by utilizing recombinant baculoviruses expressing the RSV pre-F or G proteins with the native matrix protein. Mice immunized with either pre-F or the G antigen-expressing VLPs elicited robust serum-mediated virus neutralization. VLP immunization evoked Th1-biased RSV-specific antibody responses in the sera of mice. Following challenge infection with the RSV A2 strain, immunized mice experienced lesser eosinophil and IL-4 accumulation in the lungs, though a substantial increase in TNF-α secretion was observed from CD4+ T cells. Interestingly, splenic antibody-secreting cell responses were substantially enhanced against RSV F antigen, but not against the RSV G antigen following immunization and challenge infection. Immunizing mice with the VLPs significantly inhibited pulmonary histopathology development, as indicated by the diminished inflammatory immune cell influx and mucin secretion.
Combined, these vaccine-induced immune responses contributed to successfully inhibiting the RSV replication in the lungs of mice and demonstrated that RSV VLP assembly using insect cell-derived homologous RSV matrix protein is a feasible approach.
涉及流感病毒或新城疫病毒基质蛋白（M）的异源病毒样颗粒（VLP）组装已被广泛用于探索VLP疫苗抗呼吸道合胞病毒（RSV）的效果。在此，我们试图通过在RSV M蛋白上表达融合前（pre-F）或糖蛋白（G）来生成同源RSV VLP，并评估它们在小鼠中的保护效果。
我们在（Sf9）昆虫细胞中使用杆状病毒表达系统生成VLP。将表达RSV pre-F、G和M抗原的重组杆状病毒接种到Sf9细胞中，颗粒自行组装。用表达pre-F或G的VLP免疫小鼠，并评估免疫参数以确定保护作用。
我们的研究结果表明，利用表达RSV pre-F或G蛋白与天然基质蛋白的重组杆状病毒可以成功实现VLP组装。用表达pre-F或G抗原的VLP免疫的小鼠引发了强大的血清介导的病毒中和作用。VLP免疫在小鼠血清中引发了以Th1为主的RSV特异性抗体反应。在用RSV A2株进行攻击感染后，免疫小鼠肺部的嗜酸性粒细胞和IL-4积累较少，尽管观察到CD4+ T细胞分泌的TNF-α大幅增加。有趣的是，免疫和攻击感染后，脾脏抗体分泌细胞对RSV F抗原的反应显著增强，但对RSV G抗原的反应没有增强。用VLP免疫小鼠显著抑制了肺部组织病理学的发展，表现为炎症免疫细胞浸润和粘蛋白分泌减少。
综合来看，这些疫苗诱导的免疫反应有助于成功抑制小鼠肺部的RSV复制，并表明使用昆虫细胞衍生的同源RSV基质蛋白进行RSV VLP组装是一种可行的方法。
