Effect of CsA on NK cells and DCs generated in vitro from CD34⁺ progenitors. (A) NK-cell generation in the absence or presence of the increasing concentrations of CsA for 5 weeks. CD56⁺CD3^– NK-cell content was determined weekly by FACS. A summary of 3 independent experiments performed in duplicate is shown (mean ± SEM). (B) Cytotoxicity of in vitro–generated NK cells against K562 target cells. NK cells generated after 5 weeks of the culture as in panel A were isolated and their cytotoxicity at increasing effector-target (E/T) ratio was measured as LDH released from lysed cells. CD56^– (non-NK) cells obtained from the control culture after NK-cell purification were used as a negative control. A summary of 4 independent experiments is shown (mean ± SEM). (C) Proliferative response of naive T cells stimulated with DCs generated in vitro in the presence of increasing concentrations of CsA. DCs were used in allogeneic mixed lymphocyte reaction and a proliferative response of naive CD4⁺ T cells was measured by ³H-thymidine uptake (cpm). A summary of 3 independent experiments is shown (mean ± SEM). (D) Naive T-cell polarization by in vitro generated DCs. DCs obtained as in panel C were cocultured with naive CD4⁺CD45RA⁺ T cells, and intracellular staining with IL-4– and IFN-γ–specific mAbs was performed. Representative FACS results of 1 of 3 experiments are shown.