tetano
Editor, Senior Moderator
Signal Transduct Target Ther
. 2026 Oct 28;11(1):496.
doi: 10.1038/s41392-026-02939-3.
Dandan Peng # 1 , Zimin Chen # 1 , Minyang Fu # 1 , Weiqi Hong # 1 , Mengzhe Dai # 1 , Hao Zeng # 1 , Sheng Lin 1 , Hong Lei 1 , Jingyun Yang 1 , Jie Shi 1 , Xiya Huang 1 , Chunjun Ye 1 , Furong Qin 1 , Yu Zhang 1 , Ying Hao 1 , Binhan Wang 1 , Wenyan Ren 1 , Li Chen 1 , Jian Liu 1 , Aqu Alu 1 , Yishan Lu 1 , Xinyi Du 1 , Jiong Li 1 , Huashan Shi 1 , Yuquan Wei 1 , Yi Chen 2 3 , Shuaiyao Lu 4 , Cai He 5 , Guangwen Lu 6 , Xiawei Wei 7
Affiliations Expand
The recurrent emergence of the F456L substitution in SARS-CoV-2 Omicron sublineages has been associated with immune evasion, yet its impact on vaccine-induced immune responses remains poorly understood. Using a trimeric RBD-HR subunit vaccine platform, we investigated how residue 456 influences the functional immunogenicity of the receptor-binding domain (RBD). We found that the F456L substitution markedly reduced neutralizing antibody responses against multiple SARS-CoV-2 variants, despite maintaining comparable levels of total antigen-specific IgG, indicating a selective impairment of functional immunogenicity rather than overall antigenicity. Single-cell RNA sequencing and B-cell receptor (BCR) repertoire analyses further revealed that the F456L mutation weakened germinal center responses, reduced clonal expansion, and impaired repertoire remodeling of antigen-specific B cells. Structural modeling, biolayer interferometry, and calcium flux assays demonstrated that aromatic residues at position 456 promote effective germline BCR recognition and activation. Importantly, replacing the non-aromatic leucine residue with aromatic amino acids, including tyrosine or tryptophan, restored the neutralizing antibody-eliciting capacity of the antigen. Together, these findings identify aromaticity at residue 456 as a critical determinant of RBD functional immunogenicity and demonstrate how a single amino acid substitution can reshape B-cell responses and antibody quality. This work provides important insights for rational vaccine antigen design and advances our understanding of how site-specific mutations regulate antiviral immunity.
. 2026 Oct 28;11(1):496.
doi: 10.1038/s41392-026-02939-3.
Aromaticity at spike position 456 affects functional immunogenicity of SARS-CoV-2 Omicron variant receptor-binding domain
Dandan Peng # 1 , Zimin Chen # 1 , Minyang Fu # 1 , Weiqi Hong # 1 , Mengzhe Dai # 1 , Hao Zeng # 1 , Sheng Lin 1 , Hong Lei 1 , Jingyun Yang 1 , Jie Shi 1 , Xiya Huang 1 , Chunjun Ye 1 , Furong Qin 1 , Yu Zhang 1 , Ying Hao 1 , Binhan Wang 1 , Wenyan Ren 1 , Li Chen 1 , Jian Liu 1 , Aqu Alu 1 , Yishan Lu 1 , Xinyi Du 1 , Jiong Li 1 , Huashan Shi 1 , Yuquan Wei 1 , Yi Chen 2 3 , Shuaiyao Lu 4 , Cai He 5 , Guangwen Lu 6 , Xiawei Wei 7
Affiliations Expand
- PMID: 42957648
- PMCID: PMC13720146
- DOI: 10.1038/s41392-026-02939-3
Abstract
The recurrent emergence of the F456L substitution in SARS-CoV-2 Omicron sublineages has been associated with immune evasion, yet its impact on vaccine-induced immune responses remains poorly understood. Using a trimeric RBD-HR subunit vaccine platform, we investigated how residue 456 influences the functional immunogenicity of the receptor-binding domain (RBD). We found that the F456L substitution markedly reduced neutralizing antibody responses against multiple SARS-CoV-2 variants, despite maintaining comparable levels of total antigen-specific IgG, indicating a selective impairment of functional immunogenicity rather than overall antigenicity. Single-cell RNA sequencing and B-cell receptor (BCR) repertoire analyses further revealed that the F456L mutation weakened germinal center responses, reduced clonal expansion, and impaired repertoire remodeling of antigen-specific B cells. Structural modeling, biolayer interferometry, and calcium flux assays demonstrated that aromatic residues at position 456 promote effective germline BCR recognition and activation. Importantly, replacing the non-aromatic leucine residue with aromatic amino acids, including tyrosine or tryptophan, restored the neutralizing antibody-eliciting capacity of the antigen. Together, these findings identify aromaticity at residue 456 as a critical determinant of RBD functional immunogenicity and demonstrate how a single amino acid substitution can reshape B-cell responses and antibody quality. This work provides important insights for rational vaccine antigen design and advances our understanding of how site-specific mutations regulate antiviral immunity.