Impact of Single Point Mutations in the SARS-CoV-2 Spike Protein RBD on B-Cell Receptor Diversity and Cross-Reactivity 4525

Abstract Description This study aims to explore how single point mutations in the intrinsically disordered regions of the SARS-CoV-2 spike protein’s receptor-binding domain (RBD) impact B-cell receptor (BCR) diversity and cross-reactivity. This study aims to reveal the implications of these mutations for developing adaptable and broad-spectrum vaccines to address evolving viral strains. Twelve groups of BALB/c mice were immunized with different antigen constructs of the SARS-CoV-2 spike protein, including full-length spikes, the receptor-binding domain (RBD), and short peptides containing key single-point mutations from critical hotspot regions of various variants of the virus. Immunizations were administered subcutaneously, with booster doses given biweekly. Post-immunization, peripheral blood mononuclear cells (PBMCs) and splenocytes were isolated for comprehensive single-cell V(D)J sequencing and gene expression analysis. Preliminary analysis suggests variability in BCR diversity and clonotypic expansions among the different immunization groups. Early transcriptomics data indicates distinct gene expression patterns and adaptations in key signaling pathways and immune-related genes in response to specific viral variants. This study’s investigation into how RBD mutations impact BCR diversity and immune adaptability is expected to give insight into the development of more effective and broad-spectrum vaccines in response to both existing and emerging SARS-CoV-2 variants. Funding Sources NIAID, NIH R01A1169543-0151 DoE DE-SC0025244 Topic Categories Viral Immunology (VIR)