CD56^brightCD16⁻ Cells from Blood, Tonsil, and Spleen Limit EBV-mediated B Cell Transformation after Activation by DCs

(A and B) B cells were infected with EBV and cultured for 12 d with peripheral blood NK cells and DC1s at the indicated NK cell to B cell ratios. Total NK cells were compared to sorted CD56^brightCD16⁻ and CD56^dimCD16⁺ NK cells in their ability to limit EBV-mediated B cell transformation. Total transformed B cell numbers for one representative experiment (A) and restriction of B cell transformation for all experiments (B) were compared after addition of unseparated bulk NK cells (total NK), CD56^dimCD16⁺ NK cells (90% of the bulk NK cell number) or CD56^brightCD16⁻ NK cells (10% of the bulk NK cell number, to respect the NK subset distribution in peripheral blood) (*, p < 0.01).

(C and D) Tonsilar B cells were infected with EBV and cultured for 12 d alone or with autologous tonsilar NK cell subsets at 2 ratios (NK, 5,000 and 5-fold NK, 25,000) in the absence or presence of allogeneic iDCs or DC1s (*, p < 0.01). Total transformed B cell numbers for one representative experiment (C), and restriction of B cell transformation for all experiments are shown (D).

(E and F) Splenic B cells were infected with EBV and cultured for 12 d alone or with autologous splenic NK cell subsets in the absence or presence of autologous splenic DCs matured with polyI:C, TNF-α, IL-1β, IFN-α and IFN-γ (*, p < 0.01). Total transformed B cell numbers for one representative experiment (E), and restriction of B cell transformation for all experiments are shown (F). Data in (A–F) represent results from three independent experiments (mean ± standard error of the mean).