Neutrophils potentiate the release of IFNγ, IL-12p70, and TNFα by NK cells/slanDCs in cocultures. NK cell/slanDC (A-F) or NK cell/CD1c⁺ DC (A-C) cocultures were incubated either alone or with neutrophils either in direct contact (A-E) or separated by transwells (F). Cocultures were treated with LPS alone (A-C,E) or in combination with either IL-2 (A-F) or IL-15/IL-18 (A-E) in the absence (A-C,E-F) or presence (D) of αIL-12p70 or αTNFα mAbs. After 18 hours, extracellular IFNγ (A,D,F), IL-12p70 (B, F), and TNFα (C) were measured by ELISA. (A-C) ***P < .001 or **P < .01 by Student t test using a 2-tail distribution of paired samples (n = 13-30 for slanDCs; n = 3 for CD1c⁺ DCs). Inhibition of IFNγ release by αIL-12p70 or αTNFα mAbs (D; n = 3), and inhibition of IL-12p70 and IFNγ release by transwells (F; n = 5) were calculated as described in “Analysis of cytokine production.” (E) The 3 cell populations (depicted in an overlay graph: slanDCs in green, neutrophils in red, NK cells in blue) were analyzed for IL-12p70 secretion by a specific cytokine secretion assay after 14 hours of culture.