Expression of BCMA, TACI, and BAFF-R in CLL B cells.

(A) Surface expression of TACI and soluble BLyS binding was determined by FACS. CD19⁺ B-CLL, CD19⁺ normal B cells, or BLyS-Jurkat cells were incubated with biotin-conjugated anti-TACI or Flag-BLyS (gray histograms) for 30 minutes on ice, washed, and incubated with the respective secondary antibodies, Red 670-streptavidin, or anti–Flag-FITC. Isotype and fluorochrome controls were done for each sample (open histograms). The cells were analyzed for immunofluorescence on a FACS Vantage (Becton Dickinson). Collected data were analyzed using CellQuest software. (B) Expression of BCMA and BAFF-R mRNA was analyzed by RT-PCR in CD19⁺B-CLL and CD19⁺ normal B cells.