Fig. 1. Identification of broadly neutralizing antibodies against SARS-CoV-2 variants.

(A) A pipeline of antibody identification and characterization. Splenocytes from mice immunized with the RBD or the ectodomain of spike protein (S-ecto) were stained with biotinylated antigens that were labeled with DNA oligonucleotide barcodes. IgG+ antigen+ cells were sorted and processed for scRNA-seq to obtain the antigen-specific BCR sequences. Each antibody was analyzed by ELISA and neutralization assays using pseudoviruses displaying the spike proteins from SARS-CoV-2 variants. (B) Analyses of antibody binding to the spike protein and RBD. The heatmap shows the area under the curve (AUC) values measured by ELISA assay. The unit of AUC is (μg/mL) * OD450. The y-axis indicates the antigens used to coat the ELISA plates, and the labels on the top indicate the antigens used to immunize the mice. (C) IC₅₀ values from the neutralization assays of seven selected antibodies using pseudotyped viruses displaying the spike proteins from indicated SARS-CoV-2 variants. The heatmap shows the -log(IC₅₀), and the numbers in the plot represent the IC₅₀ values in ng/mL (representative data from three independent experiments).