The role of cell-cell contact during NK cell-stimulation by monocytes and PstS-1. Purified NK cells (5 x 105 cells/well) were stimulated with monocytes (1:1 cell ratio) with or without PstS-1 (10 μg/ml) for three days. Experiments were performed in presence or absence of a 0,4μm porous membrane (transwell, TW) separating monocytes from NK cells during the stimulation period. CD69-expression on NK cells (a), IFN-γ-secretion (b) and natural cytotoxicity (c) against A2780-cells were determined on day three. Recombinant cytokines (IL-12, IL-15 and IL-18) served as a positive control of IFN-γ-induction (b). Means + SE of three to four experiments are shown. Statistical analysis was performed by unpaired t-test, statistical significance was assumed at p ≤ 0.05.
Gottschalk et al. BMC Cancer 2012 12:451 doi:10.1186/1471-2407-12-451