Figure 3. IL-27 does not induce cytotoxicity in CD56^dim NK cells, but imparts immunoregulatory function to CD56^bright NK cells.

Degranulation (a) and cytotoxicity (b) of CD56^dim NK cells after stimulation with or without IL-27. Purified CD56^dim NKcells were cultured for 72 hours in the presence or absence of IL-27. Viable cells were re-sorted and cultured with or without the target cell line K562 for 4 hours or were stained for CD107a. One representative experiment is shown of 5–7 experiments. (c) Suppression assay of CD56^bright NK cells activated for 72 hours with IL-27. Live cells were sorted and cultured with autologous purified CD4+ T cells in the presence of anti-CD3 and anti-CD28 coated beads. Cell proliferation was assessed after five days as shown with mean+s.d. in triplicate wells, one of seven experiments is shown. (d) Suppressive activity of NK cells activated in the presence of IL-27 and incubated in contact with responder T cells (Control) or with a transwell (Transwell). (e) Expression of molecules involved in NK cell mediated cytotoxicity in CD56^bright NK cells treated with IL-27 after 72 hours.