Fig. 3: In vitro biological activity of H11-H4.
From: Neutralizing nanobodies bind SARS-CoV-2 spike RBD and block interaction with ACE2
a, Schematic of H11-H4-Fc, the IgG1 Fc (blue) fusion used in in vitro assays. b, Biotinylated RBD was mixed with analytes at various ratios and then added to MDCK-SIAT1 cells stably expressing human ACE2. The amount of biotinylated RBD bound was measured. Experiments were performed in duplicates with mean ± s.d. shown. c, Biotinylated ACE2-Fc was mixed with analytes at various ratios and then added to MDCK-SIAT1 cells stably expressing RBD. The amount of biotinylated ACE2-Fc bound was measured. Experiments were performed in duplicate with the mean ± s.d. shown. d, H11-H4-Fc (ND50 = 6 nM, 95% confidence interval (CI) 3–9 nM) and H11-D4-Fc (ND50 = 18 nM, 95% CI 9–68 nM) show potent neutralization of live wild-type virus. The 95% CIs are shown as dashed lines. Detailed data plots are provided in Extended Data Fig. 3a,b and an experimental plate in Extended Data Fig. 3c. e, H11-H4-Fc shows similar neutralization (ND50 = 4 nM) of live wild-type virus in a Vero cell-based assay in Oxford. CR3022 is shown as a positive control for this assay system and is similar to a previous report18. Data are presented as mean and s.d. of n = 2 technical replicates. Experimental plates are shown in Extended Data Fig. 4a–c.
