The present invention relates to a process for activating natural killer
cells comprising bringing NK cells into contact with dendritic cells in
vitro, ex vivo or in vivo. The invention also relates to cell compositions
comprising activated NK cells, NK cell-dendritic cell co-cultures or
dendritic cells, and to their use to stimulate the cytolytic activity of
NK cells or natural immunity in vivo. The invention also relates to a NK
cell stimulation factor present in the dendritic cell membrane, and to
triggering media and factor(s) for dendritic cells and to their use,
either alone or in combination, to stimulate NK activity, in particular in
vivo. The invention can be used to control NK cell activity in vitro, ex
vivo or in vivo, in particular under pathological conditions.
