FIGURE 6.

AgNP₁₅ induce activation of the inflammasome in human monocyte THP-1 cells. Cells were treated or not with 100 ng/ml LPS for 4 h and then were incubated for 1 h with the indicated concentrations of AgNP₁₅, 2 mm ATP, or buffer (Ctrl). A and B, after treatment, the pellets were lysed in Laemmli buffer for Western blot experiments (A) or caspase-1 (Casp-1) lysis buffer for caspase-1 assay (B), as described under “Experimental Procedures.” MW, molecular weight markers. C and D, for IL-1β quantification, cells were primed 4 h with 100 ng/ml LPS. Cells were then incubated with cytochalasin D (10 μg/ml), Dynasore (80 μm), or the equivalent volume of diluent (dimethyl sulfoxide (DMSO)) for 30 min before the addition of the indicated agonists for 1 h (D). Supernatants were harvested to quantify IL-1β by ELISA. Results are from one representative experiment out of three (A) are expressed as means ± S.E. of three independent experiments (B–D). Differences were considered statistically significant as follows: *, p ≤ 0.05, **, p ≤ 0.01, and ***, p ≤ 0.005 versus control or appropriate diluent.