Fig. 1: In vitro and in vivo activities of R1-32.
a, Binding of R1-32 to wild-type, variant SARS-CoV-2, animal-origin SARS-related CoV and SARS-CoV-1 RBDs. b, Binding of R1-32 to wild-type and selected variant SARS-CoV-2 spikes. BLI binding assays used 2-fold RBD or spike dilution series (200 nM to 3.125 nM); fitted kinetic parameters are summarized in Supplementary Table 1. c, Top: plaque reduction neutralization activities of R1-32 (mean ± s.e.m.) towards selected variant viruses compared to neutralization towards the wild-type virus. n = 3, except for neutralization of wild-type pseudovirus, n = 2. Representative data are shown from at least 2 independent experiments. Bottom: summary of IC90 and IC50 values. d, Top left: animal protection experiment design, created with BioRender.com. R1-32 (4 mg kg−1 or 20 mg kg−1 of body weight) was intraperitoneally (i.p.) injected into hACE2 transgenic mice 1 h after SARS-CoV-2 infection. PBS injections were used for the control group. Top right: virus titres in lung tissues were determined at 3 dpi by RT-qPCR (n = 5). Data are presented as mean ± s.d. The P values were determined by two-sided unpaired t-test. *P < 0.05, ***P < 0.001; NS, not significant. Bottom: histopathology analysis of lung tissues at 3 dpi. The images and areas of interest are ×10 (scale bar, 500 µm) and ×40 (scale bar, 100 µm). Dotted lines represent limits of detection.
