Fig. 1: Single cell transcriptional signature of ABCs.

Magnetically enriched B cells from PBMCs were analysed through droplet-based single cell RNA sequencing technology (n = 52402). UMAPs of cells from all individuals coloured by (a) annotated Louvain clusters, (b) health condition (HC healthy controls, ICB immune-checkpoint blockade treated cancer patients, IEI CTLA-4/NFKB1, inborn errors of immunity, CTLA-4 and NFKB1 mutants respectively, SLE systemic lupus erythematosus patients), and (c) gender. Dots represent a single cell. d Proportion of total cells from each health condition belonging to each cluster, clusters coloured as indicated. e Expression of 46 genes in each B cell cluster which define the different subpopulations. Dot size represents proportion of cells within a cluster expressing the indicated gene and colours represent the average expression level. f Heatmap representing scaled expression values of genes associated with antigen uptake, processing and class-II presentation in each cluster. g Gene ontology enrichment analysis of biological processes associated with upregulated genes in classical ABCs. GO terms with highest fold enrichments are ranked by -log (P value). Statistical testing via Fisher’s Exact test with correction for false discovery rate. Dot size is proportional to the fold enrichment.