Fig. 1: Isolation and characterization of novel fully human single-domain antibodies (UdAbs) that bind to the NiV or HeV G protein.

a Neutralizing mAbs (m102.4 (PDB ID: 6CMG), HENV-26 (PDB ID: 6VY6), HENV-32 (PDB ID: 6VY4), hAH1.3 (PDB ID: 7SYY), and nAH1.3 (PDB ID: 7TXZ)) representing four different antigenic binding sites are mapped onto the surface of the HeV-RBP or NiV-RBP head domain surfaces. The surfaces of the HeV-RBP or NiV-RBP head domain are colored gray, with nonconserved amino acids between NiV and HeV highlighted in red based on the sequence alignment in Supplementary Fig. 1. b Schematic illustration of the antibody panning process for the NiV or HeV G protein. The schemes were created with BioRender.com under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license. c Identification of G protein binders. Using a high-throughput screening ELISA, the binding activity of 1000 randomly selected sequences from the output libraries after 4 rounds of selection was calculated. d Binding kinetics of UdAb n425 to the immobilized NiV-G head domain determined by biolayer interferometry. The n425 concentrations used were 100 nM (red), 33 nM (green), 11 nM (blue), 3.7 nM (purple), and 1.2 nM (orange). The vertical dashed line corresponds to the transition between the association and dissociation phases. Curve fitting was performed to extrapolate equilibrium dissociation constant values using a 1:1 global model. e Binding and neutralizing activity of n425 against NiV or HeV pseudoviruses. The negative control (gray) is a neutralizing UdAb against the SARS-CoV-2 RBD. The data are presented as the mean ± standard deviation (S.D.); n = 2 biologically independent experiments for ELISA binding, n = 3 biologically independent experiments for henipavirus pseudovirus neutralization. Source data are provided as a Source Data File.