Cellular responses after activation with 100 nM fMLP. A concentration of 10–7 M chemoattractant was chosen. (A) Rate of pseudopod extension (top row), relative cellular F-actin (middle row), and total cellular PtdIns(3,4,5)P3 (bottom row) were performed as detailed in “Materials and methods.” The presence and absence of chemoattractant (fMLP), wortmannin (WTM), and PI3K-SH2-OMT (SH2) is denoted with (+) and (–). The wortmannin concentration was 1 μM, and the PI3K-SH2-OMT concentration was 50 μM. On the graph for the total F-actin content, open circles show the control (fMLP only); closed squares show the data for incubation with wortmannin; closed circles are the data for incubation with PI3K-SH2-OMT; and closed triangles are the data for simultaneous incubation with wortmannin and PI3K-SH2-OMT. (B) Data for the same neutrophil responses as in panel A for cells pretreated for 30 minutes with 30 pM GM-CSF. (C) Data for the same neutrophil responses as in panel A for cells pretreated for 30 minutes with 320 μU/mL insulin. The data points for pseudopod extension are expressed as the mean ± SD of at least 10 cells. For total cellular F-actin content and total PtdIns(3,4,5)P3, the samples were run in triplicate, and the data are expressed as the mean ± SD. *P < .01.
