Nanobody targeting glycan cap confers broad orthoebolavirus neutralization

Xinhui Zhang; Yi Liao; Xiuying Liu; Jingya Zhou; Peixiang Gao; Xuemeng Dong; Shengnan Pan; Huarui Duan; Junyu Liu; Xiaojing Chi; Wei Yang

doi:10.1016/j.virs.2026.03.018

April 2026

Citation: Xinhui Zhang, Yi Liao, Xiuying Liu, Jingya Zhou, Peixiang Gao, Xuemeng Dong, Shengnan Pan, Huarui Duan, Junyu Liu, Xiaojing Chi, Wei Yang. Nanobody targeting glycan cap confers broad orthoebolavirus neutralization .VIROLOGICA SINICA, 2026, 41(2) : 413-422. http://dx.doi.org/10.1016/j.virs.2026.03.018

Nanobody targeting glycan cap confers broad orthoebolavirus neutralization

Xinhui Zhang ^a,b ,
Yi Liao ^a,b ,
Xiuying Liu ^a,b ,
Jingya Zhou ^a,b ,
Peixiang Gao ^a,b ,
Xuemeng Dong ^a,b ,
Shengnan Pan ^a,b ,
Huarui Duan ^a,b ,
Junyu Liu ^a,b ,
Xiaojing Chi ^{a,b
,,} ,
Wei Yang ^{a,b,c
,,}

a. Key Laboratory of Pathogen Infection Prevention and Control (Ministry of Education), National Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 102629, China;
b. NHC Key Laboratory of Systems Biology of Pathogens, National Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 102629, China;
c. State Key Laboratory of Respiratory Health and Multimorbidity, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China

Corresponding author: Xiaojing Chi, chixiaojing@ipbcams.ac.cn
Wei Yang, wyang@ipb.pumc.edu.cn
Received Date: 15 September 2025
Accepted Date: 31 March 2026
Available online: 08 April 2026

Abstract

The Zaire Ebola virus (EBOV) and Bundibugyo virus (BDBV) cause severe hemorrhagic fever with high mortality, highlighting the urgent need for broad-spectrum antiviral therapies. Neutralizing nanobodies, with their small size, structural stability, and ability to access sterically restricted epitopes, represent a promising antiviral modality. Here, we identified a high-affinity nanobody, BDBV-Nb02, from a fully synthetic phage display library targeting the glycan cap of BDBV glycoprotein (GP1). BDBV-Nb02 demonstrated strong binding kinetics (KD ≈ 1 nM) and potent neutralizing activity against both BDBV and EBOV pseudoviruses, with half-maximal inhibitory concentration (IC₅₀) values in the nanomolar range. Engineering a bivalent format significantly enhanced neutralization potency, achieving up to a 56-fold reduction in the 90% inhibitory concentration (IC₉₀) compared with the monovalent form. Epitope competition assays and molecular docking revealed that BDBV-Nb02 targets a conserved glycan cleft, with residues F248 and NP278/279 identified as critical neutralization sites. In contrast, Fc-fusion constructs impaired the nanobody's efficacy, highlighting the importance of preserving the structural features that enable access to glycan-shielded epitopes. Our findings demonstrate that BDBV-Nb02 is a promising candidate for broad-spectrum orthoebolavirus therapy and may serve as a valuable component in future antiviral cocktail formulations.
- Nanobody
- , Orthoebolavirus
- , Neutralizing antibody
- , Glycan cap
- , Broad-spectrum

Electronic Supplementary Material

10.1016j.virs.2026.03.018-ESM.docx
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