Effect of general and class I PI3K isoform–selective inhibitors on S aureus– and E coli–induced ROS formation in neutrophils. (A) Primed human (i,ii) and mouse (iii,iv) neutrophils were preincubated for 10 minutes with wortmannin (■), TGX-221 (), IC87114 (gray diamonds), YM-024 (▴), or AS252424 (), as indicated, in the presence of luminol as described in “Measurement of ROS production.” Cells were added to serum-opsonized S aureus (i,iii) or E coli (ii,iv), and ROS responses measured over 40 minutes, as described in Figure 1. Data (mean ± SEM, n ≥ 3) are accumulated light emission, expressed as a percentage of response in the absence of inhibitor (DMSO control). (B) Primed bone marrow neutrophils, derived from wild-type mice (WT, ■) or mice lacking p110γ (p110γ^−/−, ), or expressing a kinase-dead version of p110δ (p110δ^D910A, ) were prepared and ROS generation in response to S aureus or E coli measured as described in Figure 1. Data are mean plus or minus SEM from at least 2 independent experiments performed in duplicate, and expressed as a percentage of response from neutrophils derived from WT mice. (C) Primed bone marrow neutrophils derived from WT or PI3Kγ^−/− mice were preincubated with either 100 nM wortmannin, 0.1 μM TGX221 (TGX), 3 μM YM-024 (YM), or 3 μM IC87114 (IC) as indicated, alone or in combination, for 10 minutes before addition of serum-opsonized S aureus (■) or E coli). ROS generation was measured as described in panel A. Data are mean plus or minus SEM (n ≥ 6) and are expressed as a percentage of WT untreated responses.