Frequency-potency analysis of IgG+ memory B cells delineates neutralizing antibody responses at single-cell resolution

Identifying individual functional B cell receptors (BCRs) is common, but two-dimensional analysis of B cell frequency versus BCR potency would delineate both quantity and quality of antigen-specific memory B cells. We efficiently determine quantitative BCR neutralizing activities using a single-cell-derived antibody supernatant analysis (SCAN) workflow and develop a frequency-potency algorithm to estimate B cell frequencies at various neutralizing activity or binding affinity cutoffs. In an HIV-1 fusion peptide (FP) immunization study, frequency-potency curves elucidate the quantity and quality of FP-specific immunoglobulin G (IgG)+ memory B cells for different animals, time points, and antibody lineages at single-cell resolution. The BCR neutralizing activities are mainly determined by their affinities to soluble envelope trimer. Frequency analysis definitively demonstrates dominant neutralizing antibody lineages. These findings establish SCAN and frequency-potency analyses as promising approaches for general B cell analysis and monoclonal antibody (mAb) discovery. They also provide specific rationales for HIV-1 FP-directed vaccine optimization. [Display omitted] •Frequency-potency of antigen-specific memory B cells at single-cell resolution•Affinities to soluble trimer dominate vaccine-induced, FP-directed neutralization•96% Ig sequence recovery definitively demonstrates dominant neutralizing lineages•SCAN efficiently identifies cross-neutralizing monoclonal antibodies Tenggara et al. use a single-cell-derived antibody supernatant analysis (SCAN) workflow to efficiently generate quantitative BCR neutralizing IC50 data against HIV-1, on top of which a two-dimensional frequency-potency analysis delineates quantity and quality of IgG+ memory B cells simultaneously at single-cell resolution.