Figure 6. SOX5 modulates in vitro terminal B cell differentiation.

(A) Proliferation measured as the ratio of absolute numbers of GFP⁺ cells in the samples. Absolute cell counts of GFP⁺ cells on day 0 are taken as 1.0 and the data are expressed as mean ± SD. Summary of three independent experiments are depicted. (B) Frequencies of GFP⁺ DAPI⁺ cells within GFP (control) and SOX5-GFP-transduced peripheral blood B cells cultivated in vitro. (C) Plasma cell differentiation analyzed by FACS in peripheral blood B cells stably transduced either with GFP (control) or SOX5-GFP fusion construct upon in vitro stimulation with IL4+CD40L+IL21. DAPI-negative GFP⁺ gated cells were analyzed by FACS for the plasma cell markers CD138 and CD38 at days 3, 6 and 9. Gates indicate the frequencies of CD138⁺CD38^hi plasmablasts in each FACS plot. Representative FACS plots of three independent experiments are shown. (D) Numbers of CD138⁺CD38^hi plasmablasts in GFP (control) and SOX5-GFP-transduced B cells at days 3, 6 and 9 referring to CD38^hi CD138⁺ cells per 1000 GFP⁺ cells at day 0. Cell numbers are depicted as mean ± SD and t-test p-values indicate the significant differences. Summary of three independent experiments are shown.