Neutrophils potentiate the production of slanDC-derived IL-12p70 in coculture. NK cell/slanDC cocultures were incubated either alone or with neutrophils and then treated with LPS + either IL-2 or IL-15/IL-18 in the absence (A) or presence (B) of αIFNγ mAbs. After 18 hours, GM-CSF (A) and IL-12p70 (B) were measured in culture supernatants. (A) *P < .001 by Student t test using a 2-tail distribution of paired samples (n = 20). (B) The percentage of inhibition of IL-12p70 release by αIFNγ mAbs (n = 3) was calculated as described in “Analysis of cytokine production.” (C-D) slanDCs were cultured alone or together with neutrophils either in contact or on top of a transwell (PMNtw) in the absence or presence of LPS (C) or LPS + IFNγ (C-D) for 18 hours. IL-12p70 secretion was then measured either in culture supernatants (n = 4; C), or by flow cytometry (D). (D) IL-12p70 secretion was evaluated in slanDC cultures (middle panel) and neutrophil/slanDC cocultures (upper and lower panels) as described in “Analysis of cytokine production,” and is depicted in an overlay graph. (C) *P < .001 by 2-way ANOVA of paired samples.