Mutating a flexible region of the RSV F protein can stabilize the prefusion conformation

Affiliations

• The Sixth Laboratory, National Vaccine and Serum Institute (NVSI), Beijing 101111, China.
• National Engineering Center for New Vaccine Research, Beijing 101111, China.

PMID:  39325881  DOI: 10.1126/science.adp2362

Abstract

The respiratory syncytial virus (RSV) fusion (F) glycoprotein is highly immunogenic in its prefusion (pre-F) conformation. However, the protein is unstable, and its conformation must be stabilized for it to function effectively as an immunogen in vaccines. We present a mutagenesis strategy to arrest the RSV F protein in its pre-F state by blocking localized changes in protein structure that accompany large-scale conformational rearrangements. We generated a series of mutants and screened them in vitro to assess their potential for forming a stable pre-F. In animals, the immunogenicity of a representative mutant F protein, with a conformation confirmed by cryo-electron microscopy, elicited levels of neutralizing antibodies and protection against RSV-induced lung damage that were comparable to those of DS-Cav1, a pre-F used in a licensed vaccine.

呼吸道合胞病毒（RSV）融合（F）糖蛋白的融合前（pre-F）构象具有很强的免疫原性。然而，这种蛋白质并不稳定，必须稳定其构象才能使其在疫苗中有效发挥免疫原的作用。我们提出了一种诱变策略，通过阻断伴随大规模构象重排的蛋白质结构局部变化，将 RSV F 蛋白阻滞在前 F 状态。我们产生了一系列突变体，并对它们进行了体外筛选，以评估它们形成稳定pre-F状态的潜力。在动物体内，具有代表性的突变 F 蛋白的免疫原性（其构象经冷冻电子显微镜确认）激发的中和抗体水平和对 RSV 引起的肺损伤的保护作用与 DS-Cav1 相当，DS-Cav1 是一种已上市的RSV pre-F疫苗。