Rapid isolation and immune profiling of SARS-CoV-2 specific memory B cell in convalescent COVID-19 patients via LIBRA-seq

B cell response plays a critical role against SARS-CoV-2 infection.However,little is known about the diversity and frequency of the paired SARS-CoV-2 antigen-specific BCR repertoire after SARS-CoV-2 infection.Here,we performed single-cell RNA sequencing and VDJ sequencing using the memory and plasma B cells isolated from five convalescent COVID-19 patients,and analyzed the spectrum and transcriptional heterogeneity of antibody immune responses.Via linking BCR to antigen specificity through sequencing(LIBRA-seq),we identified a distinct activated memory B cell subgroup(CD11c^(high) CD95^(high))had a higher proportion of SARS-CoV-2 antigen-labeled cells compared with memory B cells.Our results revealed the diversity of paired BCR repertoire and the non-stochastic pairing of SARS-CoV-2 antigen-specific immunoglobulin heavy and light chains after SARS-CoV-2 infection.The public antibody clonotypes were shared by distinct convalescent individuals.Moreover,several antibodies isolated by LIBRA-seq showed high binding affinity against SARS-CoV-2 receptor-binding domain(RBD)or nucleoprotein(NP)via ELISA assay.Two RBD-reactive antibodies C14646P3S and C2767P3S isolated by LIBRA-seq exhibited high neutralizing activities against both pseudotyped and authentic SARS-CoV-2 viruses in vitro.Our study provides fundamental insights into B cell response following SARS-CoV-2 infection at the single-cell level.