α-Hemolysin-Aided Oligomerization of the Spike Protein RBD Resulted in Improved Immunogenicity and Neutralization Against SARS-CoV-2 Variants.
α-Hemolysin-Aided Oligomerization of the Spike Protein RBD Resulted in Improved Immunogenicity and Neutralization Against SARS-CoV-2 Variants.
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DOI：
10.3389/fimmu.2021.757691
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发表时间：
2021
影响因子：
7.3
通讯作者：
Zhang J
中科院分区：
文献类型：
--
作者：
Zou J;Jing H;Zhang X;Liu Y;Zhao Z;Duan L;Yuan Y;Chen Z;Gou Q;Xiong Q;Li S;Yang F;Zeng H;Zou Q;Zhang J
COVID-19确诊病例和SARS-CoV-2变体的增加要求开发安全和广泛的交叉保护疫苗。刺突蛋白的RBD被认为是一种安全有效的候选抗原。但其免疫原性较低，限制了其在疫苗开发中的应用。在此，我们设计并获得了基于载体蛋白辅助组装策略的RBD七聚体（mHla-RBD）。mHla-RBD的分子量高达450 kDa，约为RBD单体的10倍。当与明矾佐剂配制时，mHla-RBD免疫显著提高了RBD的免疫原性，与RBD单体相比，RBD特异性抗体、中和抗体、Th2细胞免疫反应和假病毒中和活性的滴度增加。此外，我们证实了rbd特异性抗体主要靶向构象表位，大约是靶向线性表位的200倍。最后，假病毒中和实验显示，mHla-RBD诱导的针对不同SARS-CoV-2变体的中和抗体与针对野生型病毒的中和抗体相当，并且对不同SARS-CoV-2变体表现出广谱中和活性。研究结果表明，mHla- rbd是开发SARS-CoV-2疫苗的一个有希望的候选抗原，mHla可以作为抗原设计的通用载体蛋白。
The increase in confirmed COVID-19 cases and SARS-CoV-2 variants calls for the development of safe and broad cross-protective vaccines. The RBD of the spike protein was considered to be a safe and effective candidate antigen. However, the low immunogenicity limited its application in vaccine development. Herein, we designed and obtained an RBD heptamer (mHla-RBD) based on a carrier protein-aided assembly strategy. The molecular weight of mHla-RBD is up to 450 kDa, approximately 10 times higher than that of the RBD monomer. When formulated with alum adjuvant, mHla-RBD immunization significantly increased the immunogenicity of RBD, as indicated by increased titers of RBD-specific antibodies, neutralizing antibodies, Th2 cellular immune response, and pseudovirus neutralization activity, when compared to RBD monomer. Furthermore, we confirmed that RBD-specific antibodies predominantly target conformational epitopes, which was approximately 200 times that targeting linear epitopes. Finally, a pseudovirus neutralization assay revealed that neutralizing antibodies induced by mHla-RBD against different SARS-CoV-2 variants were comparable to those against the wild-type virus and showed broad-spectrum neutralizing activity toward different SARS-CoV-2 variants. Our results demonstrated that mHla-RBD is a promising candidate antigen for development of SARS-CoV-2 vaccines and the mHla could serve as a universal carrier protein for antigen design.