B Cell‐Activating Factor Enhances Interleukin‐6 and Interleukin‐10 Production by ODN‐Activated Human B Cells

We aim to investigate the additive value of B cell‐activating factor (BAFF) when added to oligodeoxynucleotides (ODN)‐activated B cells with respect to TLR‐9, CD69, MHC‐II expression, IL‐6 and IL‐10 secretion and B cell cycling. Therefore, B cells from healthy individuals were incubated under the following conditions: (1) B cells with medium, (2) B cells with ODN 0.5 μ m , (3) B cells with BAFF 20 μ m and (4) B cells with both ODN 0.5 μ m and BAFF 20 μ m . We found that addition of BAFF did not enhance the expression of TLR‐9, CD69 and MHC‐II in ODN‐activated B cells. Incubation of B cells with BAFF and ODN together leads to a marked elevation of IL‐6 and IL‐10 levels compared to ODN alone. Synthesis and mitosis were higher in B cells stimulated by BAFF than in B cells stimulated by ODN. These findings suggest that both BAFF and TLR‐9 contribute independently to B cell function.