Figure 5.

Severe defect in generation of antibody secreting cells in E2A/TACI-deficient cells. (a–c) Summary graphs from in vitro proliferation of naïve B cells stimulated as indicated with CD40L (100 ng ml⁻¹), IL-4 (50 ng ml⁻¹), IL-21 (50 ng ml⁻¹), CpG (1 μg ml⁻¹) and APRIL (500 ng ml⁻¹) as indicated. Isolated cells were collected after 5 days of culture, cell surface stained and analysed by flow cytometry for the (a) proportion of antibody secreting cells (ASC, CD27^hiCD38⁺) and (b) total number of ASC and (c) total lymphocyte number. Cell counts and proportion of ASC are shown for the proband, with both TNFRSF13B/TACI and TCF3 mutations in white; her son (III.1), expressing TCF3 T168fsX191 mutant B cells only (blue); TACI-deficient individuals (II.3, II.4, gray); and wild-type (III.2 and HD, black). Summary graphs of the proportions and total number of differentiated cells for all family members and healthy donors (HD, n=4) was performed in two independent experiments.