Neutrophils potentiate the release of IL-12p70 and IFNγ by slanDCs and NK cells, respectively, via CD18-mediated interactions. slanDCs were cultured in the presence of LPS + IFNγ (A-B), with (A) or without (B) αCD18 (IB4) mAbs for 18 hours alone or with neutrophils, which were either left untreated (A-B) or pre-incubated with IB4 or the isotype-matched control mAbs (B). IL-12p70 secretion was then measured in culture supernatants (A-B; n = 4). (C) NK cell/slanDC cocultures were incubated either alone or with neutrophils and then treated with LPS + IL-15/IL-18 in the absence or presence of IB4 mAbs. After 18 hours, both IFNγ and IL-12p70 were measured in culture supernatants (n = 5). ***P < .001 and *P < 0.05 by 1-way ANOVA of paired samples.