Figure 2. Caspase-1 activation by aluminium adjuvants requires Nalp3 and ASC.

a, b, LPS-primed or unprimed macrophages from WT mice (a, b), Nalp3-deficient mice and caspase-1-deficient (Casp1) mice (a) and from ASC-deficient mice (b) were stimulated with Imject alum (500 µg ml⁻¹) for the indicated durations, and cell lysates were immunoblotted with antibodies against the p10 subunit of caspase-1. Macrophages from caspase-1 knockout mice were stimulated as indicated to provide a reference for some of the non-specific bands seen with this antibody. Indeed, the band at 15 kDa in the Nalp3 knockout samples in a and in all samples in b is distinct from the p10 band representing active caspase-1. c, LPS-primed macrophages from WT or Nalp3-deficient mice were stimulated with Imject alum (500 µg ml⁻¹) for the indicated durations, and the IL-1β released into culture supernatants was measured by ELISA. Results are shown as means ± s.d. from one of three independent experiments.