CASP1 and infection: C57BL/6J mice were injected intradermally with 5448, 5448AP or saline and euthanised at 6 or 24 hours post-infection, with neutrophil populations (CD45+/CD11b+/Ly-6G+), caspase-1 activation and CD16 expression characterised by flow cytometry (Figures 5A–C, E and S4A–F).