Differential recognition of CLL and healthy B cells by iNKT cells. (A) CD1d expression by flow cytometry in primary CLL cells and B cells from 4 patients and 4 healthy donors, respectively, used in pairs for iNKT cell activation. (B) The same paired cells were cultured for 48 hours at the indicated numbers with 2 × 10⁴ iNKT cells from healthy donors with or without anti-CD1d (α-CD1d) mAb. IFN-γ release by iNKT cells was measured by ELISA and expressed as mean ± SD. (C) Ex vivo CD127 expression determined by flow cytometry in patients with CD1d^neg/low stable CLL vs patients with CD1d^high progressive CLL. The percentage of CD127-expressing iNKT and T cells is indicated. (D) Frequency of CD127 iNKT and T cells from patients with stable or progressive disease. Graph symbols show single individual values ± SD. ***P < .0005 1-way ANOVA.