Fig. 4.

B7-H1 expression and signal transduction inhibitors. a B7-H1 mRNA levels (relative to rRNA) in THP-1 (left panel) and U937 (right panel) cells measured by RQ-PCR following 24 h incubation with IFN-γ with or without 1-h pre-treatment with signal transduction inhibitors. Inhibitors included the following: 20 μM UO126 (MEK1/2), 25 μM PD98059 (MEK1), 25 μM SP600125 (JNK), 25 μM AG490 (JAK2), 25 μM LY294002 (PI3K), 3 μM SB203850 (p38MAPK) and 10 nM rapamycin (mTOR). *indicates significant differences from cells treated with IFN-γ alone (Student’s t test). b B7-H1 expression in 60 blast samples with or without incubation with 25 μM of the PI3K inhibitor LY294002. c Same as in (b), but with incubation with the mTOR inhibitor rapamycin