Cullen Lori M, Schmidt Madelyn R, Torres Gretel M, Capoferri Adam A, Morrison Trudy G
Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Program of Immunology and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Vaccines (Basel). 2019 Feb 15;7(1):21. doi: 10.3390/vaccines7010021.
Efforts to develop a vaccine for respiratory syncytial virus (RSV) have primarily focused on the RSV fusion protein. The pre-fusion conformation of this protein induces the most potent neutralizing antibodies and is the focus of recent efforts in vaccine development. Following the first identification of mutations in the RSV F protein (DS-Cav1 mutant protein) that stabilized the pre-fusion conformation, other mutant stabilized pre-fusion F proteins have been described. To determine if there are differences in alternate versions of stabilized pre-fusion F proteins, we explored the use, as vaccine candidates, of virus-like particles (VLPs) containing five different pre-fusion F proteins, including the DS-Cav1 protein. The expression of these five pre-F proteins, their assembly into VLPs, their pre-fusion conformation stability in VLPs, their reactivity with anti-F monoclonal antibodies, and their induction of immune responses after the immunization of mice, were characterized, comparing VLPs containing the DS-Cav1 pre-F protein with VLPs containing four alternative pre-fusion F proteins. The concentrations of anti-F IgG induced by each VLP that blocked the binding of prototype monoclonal antibodies using two different soluble pre-fusion F proteins as targets were measured. Our results indicate that both the conformation and immunogenicity of alternative VLP associated stabilized pre-fusion RSV F proteins are different from those of DS-Cav1 VLPs.
研发呼吸道合胞病毒（RSV）疫苗的工作主要集中在RSV融合蛋白上。该蛋白的前融合构象可诱导产生最有效的中和抗体，也是近期疫苗研发工作的重点。在首次鉴定出稳定前融合构象的RSV F蛋白突变（DS-Cav1突变蛋白）后，又描述了其他稳定前融合F蛋白的突变体。为了确定稳定前融合F蛋白的不同变体之间是否存在差异，我们探索了使用包含五种不同前融合F蛋白（包括DS-Cav1蛋白）的病毒样颗粒（VLP）作为候选疫苗。对这五种前F蛋白的表达、它们组装成VLP的情况、它们在VLP中的前融合构象稳定性、它们与抗F单克隆抗体的反应性以及在小鼠免疫后诱导的免疫反应进行了表征，将包含DS-Cav1前F蛋白的VLP与包含四种替代前融合F蛋白的VLP进行了比较。测量了每种VLP诱导的抗F IgG浓度，这些抗F IgG使用两种不同的可溶性前融合F蛋白作为靶标来阻断原型单克隆抗体的结合。我们的结果表明，替代VLP相关的稳定前融合RSV F蛋白的构象和免疫原性均与DS-Cav1 VLP不同。
