Fig. 3

Epitope mapping of mAbs. a Antibody epitope analysis of Wuhan CoV-2-NP by cell ELISA. HEK293 cells expressing either the full-length (Full), N-terminal domain (NTD) or C-terminal domain (CTD) of myc-tagged Wuhan CoV-2-NP were stained with the indicated mAbs. Representative florescence images are shown. b Epitope mapping of #1 using solid-phase peptide arrays. Solid-phase supports containing synthetic peptides spanning the C-terminus of Wuhan CoV-2-NP were screened for reactivity with #1. Major epitopes were defined as having greater than ten times the reactivity of guinea pig IgG. c Schematic diagram of the CoV-2-NP domain. Each mAb epitope determined by peptide array and/or immunostaining is shown with a red bar. d Epitope residues of #1 on CoV-2-NPs of SARC-CoV-2 variants and NPs of other human coronaviruses. Epitope residues that are conserved are shown in black, and those that are not conserved are shown in red. e Cross-reactivity of mAbs with CoV-2-NPs of SARS-CoV-2 variants. The indicated mAb was reacted with a series of CoV-2-NPs immobilized on plates, and the binding was analyzed by ELISA. The results are expressed as the mean ± SD of four replicates relative to Wuhan CoV-2-NP. f Cross reactivity of #1 and #31 with NPs of human coronaviruses. The indicated mAb was reacted with a series of NPs immobilized on plates, and the binding was analyzed by ELISA. The results are expressed as the mean of two replicates