IL-4 pretreatment and N meningitidis challenge inhibit Akt phosphorylation, but stimulate p42/p44 and p38 pathways. (A) Phagocytosis of N meningitidis by ThioMΦs is dependent on the p38 and PI3K pathway. ThioMΦs were treated with a kinase inhibitor (PD98059, 50μM; wortmannin, 100nM; SB202190, 50μM) for 1 hour before and during challenge (2 hours at 37°C) with RdGnX-N.m. (Nm; 100 bacteria/cell), and phagocytosis was determined by flow cytometry. (Right) FACS profile of RdGnX-N.m. uptake after treatments. The mean fluorescence of 1 experiment representative of 3 is shown as a bar diagram (left). (B) Proinflammatory cytokine secretion is dependent on the p38 pathway. ThioMΦs were treated with a kinase inhibitor (PD98059, 50μM; wortmannin, 100nM; or SB202190, 50μM) for 1 hour before and during challenge (24 hours at 37°C) with N meningitidis (100 bacteria/cell), and cytokine production was determined by ELISA. Results from 1 experiment of 2 are presented. (C) ThioMΦs were stimulated for 48 hours in the presence or absence of IL-4 and challenged with N meningitidis (100 bacteria/cell) for different periods. Expression of total protein levels and of the phosphorylated forms of p38, p42/p44, and Akt was determined by Western blotting. The results of 1 experiment, representative of 2, are presented. A vertical line has been inserted to indicate a repositioned gel lane.