Supplementary Figure 3: PBMCs from four healthy controls (WT/WT), two heterozygous carriers (WT/M) and three patients (M/M) were studied.

a) Gating strategy to identify B cell subsets. b) Representative data from FACS analysis for B cell subsets obtained with CD19, CD20, CD10 and CD27 Abs, in WT and SPPL2a-deficient patients. c) Percentages of memory B cells from healthy controls (WT/WT), a healthy WT/WT family member, heterozygous carriers (WT/M) and patients with AR SPPL2a deficiency (M/M) expressing IgG (left panel) or IgA (right panel). Means are indicated with a black line. d). Whiskers (5-95 percentile) graph of the ex vivo IgM, IgG and IgA production by naive and memory B cells from healthy controls, patients and heterozygous carriers following stimulation with CD40L and IL-21. e) BAFF-R expression (upper panel) on naive and memory B cells and HLA-DR expression on monocytes and B cells (lower panel) were assessed by FACS and are presented relative to the results for healthy controls; there were no significant differences between healthy donors, heterozygous carriers and patients. In both graphs means are indicated with a black line.