M-CSF–, but not GM-CSF–derived human macrophages, upregulate components of the Ado and PGE₂pathways after LPS stimulation. Human monocytes were cultured in M-CSF (light blue bars/points) or GM-CSF (red bars/points) for 7 days and then stimulated with LPS (10 ng/mL) on day 7. Relative messenger RNA (mRNA) expression (2^-ΔCT) of the surface receptors for PGE₂: PTGER2 (n = 6 donors) (A) and PTGER4 (B) were analyzed by real-time quantitative polymerase chain reaction (qPCR) after LPS stimulation for 4 hours (n = 6 donors). mRNA expression for components of the PGE₂ synthesis pathway: COX2 (n = 7 donors) (C) and MPGES1 (D) were analyzed by real-time qPCR after LPS stimulation for 4 hours (n = 7 donors). (E) PGE₂ levels in the supernatants of M-CSF and GM-CSF macrophages stimulated with LPS for 24 hours were measured by competitive ELISA (n = 10 donors). (F) ATP (picomoles) was degraded by resting M-CSF (light blue) and GM-CSF (red) macrophages over time and expressed per microgram of protein (n = 3 donors). mRNA expression of the surface receptors for Ado: A2AR (n = 6 donors) (G) and A2BR (n = 6 donors) (H) were analyzed by real-time qPCR after LPS stimulation for 4 hours. Error bars represent standard error of the mean (SEM). *P ≤ .05; **P ≤ .01; ***P ≤ .001; ****P ≤ .0001. ns, not significant.