Fig. 4

(a) Human LPS-primed PBMCs were treated with cytochalasin D in ascending doses and subsequently stimulated with silica crystals, MSU crystals or ATP. IL-1β release was measured by ELISA 6h after stimulation. Data from one representative experiment out of two are depicted. (b) B6-MCLs were stimulated for 2h with silica crystals in the presence or absence of cytochalasin D (2.5 µM). Cells were then membrane stained with fluorescent choleratoxin (red), nuclei stained with Hoechst dye (blue) and analyzed for crystal uptake (green) using confocal microscopy. (c) B6-MCLs were incubated with silica crystals as in (b) and phagocytosed silica crystals was analyzed for their length and the fractional distribution of crystal sizes is shown from phagocytosed crystals of 10 representative cells. (d and e) Bone marrow-derived macrophages of wild-type mice, gp91Phox-deficient mice or IPAF-deficient mice (as a mixed background control) were primed with LPS for 3h and subsequently stimulated with either silica crystals, MSU crystals, ATP or transfected with dAdT. 6h after stimulation, supernatants were analyzed for IL-1β by ELISA (d) and assessed for activated caspase-1 by Western blot (e). Data from one representative experiment out of two are depicted.