Differentiation into plasma cells of CD38-positive B-CLL cells after treatment with Gaδ-ab and rIL2.

CD38-positive B-CLL cells were cultured in the presence of NGI, Gaδ-ab (10 μg/mL) plus rIL2 (100 U/mL), or rIL2 alone for 5 days. Cells were recovered, stained, and analyzed by flow cytometry. (top) Double staining for CD19 and CD38 of the cells cultured with the indicated stimuli. Gates 1 and 2 show CD19-bright, CD38-bright, and CD19-dim/CD38-bright cells, respectively, together with their percentages. (middle) FSC and SSC parameters of the cultured cells. Large cells with substantial cytoplasmic granularity were gated, and their fluorescence relative to the CD138, CD38, CD3, and CD11b stainings was recorded (bottom histograms). These cells were present only in Gaδ-ab-stimulated cultures. Cytospin preparations from Gaδ-ab rIL2–cultured cells (left) or rIL2 cultured cells (right) were fixed and stained with FITC-conjugated anti-IgM mAb. Results are from 1 representative experiment (patient B) of the 3 performed (patients B, E, F).