Our data indicated that NKDC were expanded from a culture of
splenic CD11c+ with IL-21. In order to show that these expanded
NKDCs directly kill the tumor cells we used an in vitro CFSE-based
cytotoxic assay with B16F10 tumor cells line as a target. As shown
in Fig. 3A there was a reduction in B16F10 CFSE+ cells when they
were incubated with NKDC expanded with IL-21, and even though
there was no significant difference between cells treated with
10 ng or 20 ng of IL-21, a slight reduction with the higher dose of
IL-21 was observed.