State Key Laboratory of Virology, Institute for Vaccine Research and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, 430072, Hubei Province, China.
Anhui Zhifei Longcom Biopharmaceutical, Hefei, China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 3):126874. doi: 10.1016/j.ijbiomac.2023.126874. Epub 2023 Sep 12.
The SARS-CoV-2 spike protein receptor-binding domain (RBD), which is a key target for the development of SARS-CoV-2 neutralizing antibodies and vaccines, mediates the binding of the host receptor angiotensin-converting enzyme 2 (ACE2). However, the high heterogeneity of RBD glycoforms may lead to an incomplete neutralization effect and impact the immunogenicity of RBD-based vaccines (Ye et al., 2021). Here, our data suggested that the glycosylation significantly affected the humoral immunogenicity and immunoreactivity of the RBD-dimer-based Covid-19 vaccine (ZF2001) (Yang et al., 2021). Several deglycosylated types of ZF2001 (with sialic acid removed (ZF2001-ΔSA), sialic acid & O-glycans removed (ZF2001-ΔSA&O), N-glycans removed (ZF2001-ΔN), N- & O-glycans removed (ZF2001-ΔN&O)) were obtained by treatment with glycosidases. The binding affinity between deglycosylated types of ZF2001 and ACE2 was slightly weakened and that between deglycosylated types of ZF2001 and several monoclonal antibodies (mAbs) were also changed compared with ZF2001. The results of pseudovirus neutralization assay and binding affinity assay of all ZF2001 types revealed that the antigens with complex glycosylation had better humoral immunogenicity and immunoreactivity. Molecular dynamics simulation indicated that the more complex glycosylation of RBD corresponded to more hydrogen bonds formed between helper T-cell epitopes of RBD and major histocompatibility complex II (MHC-II). In summary, these results demonstrated that the glycosylation of RBD affects antigen presentation, humoral immunogenicity and immunoreactivity, which may be an important consideration for vaccine design and production technology.
SARS-CoV-2 刺突蛋白受体结合域（RBD）是开发 SARS-CoV-2 中和抗体和疫苗的关键靶点，介导宿主受体血管紧张素转换酶 2（ACE2）的结合。然而，RBD 糖型的高度异质性可能导致不完全的中和效果，并影响基于 RBD 的疫苗的免疫原性（Ye 等人，2021 年）。在这里，我们的数据表明，糖基化显著影响了基于 RBD 二聚体的 COVID-19 疫苗（ZF2001）的体液免疫原性和反应原性（Yang 等人，2021 年）。通过糖苷酶处理获得了几种去糖基化的 ZF2001 类型（去除唾液酸（ZF2001-ΔSA）、去除唾液酸和 O-聚糖（ZF2001-ΔSA&O）、去除 N-聚糖（ZF2001-ΔN）、去除 N-和 O-聚糖（ZF2001-ΔN&O））。与 ZF2001 相比，去糖基化 ZF2001 类型与 ACE2 之间的结合亲和力略有减弱，与几种单克隆抗体（mAbs）之间的结合亲和力也发生了变化。假病毒中和试验和所有 ZF2001 类型的结合亲和力试验的结果表明，具有复杂糖基化的抗原具有更好的体液免疫原性和反应原性。分子动力学模拟表明，RBD 中更复杂的糖基化对应于 RBD 的辅助 T 细胞表位与主要组织相容性复合物 II（MHC-II）之间形成的更多氢键。总之，这些结果表明，RBD 的糖基化影响抗原呈递、体液免疫原性和反应原性，这可能是疫苗设计和生产技术的一个重要考虑因素。
