mRNA levels and processing of IL-1β in monocytes versus macrophages. (A) Steady-state levels of IL-1β and TNF-α in freshly isolated PBMCs or monocyte-derived macrophages after 4 hours of incubation with, LPS (100 ng/mL), Pam3Cys (10 μg/mL), or S epidermidis (106 organisms/mL). (B) Intracellular levels of precursor IL-1β in monocyte-derived macrophages stimulated for 24 hours with the various stimuli as in panel A. (C) Western blot of caspase-1 peptides in monocytes (Mo), macrophages (Mf), or THP-1 cells after 2 hours with and without LPS (100 ng/mL). (D) Western blot of the active p10 fragment of caspase-1 (sc515 antibody from Santa Cruz Biotechnology) in freshly isolated monocytes (column 1) and in monocytes that have adhered for 2 hours in polystyrene plates (column 2). (E) IL-1β and pro-interleukin-1β (proIL-1β) Western blots of lysates of monocyte-derived macrophages before and after stimulation for 24 hours with 100 ng/mL LPS.
