(a) NEK7-NLRP3 interaction during mitosis. HEK293T cells were transfected as indicated (above lanes in right panel) and then treated with RO-3306 for 20 h before release in fresh media for the indicated times. Flow cytometric analysis of phosphorylated histone H3-positive mitotic cells (left); the percentage of mitotic cells is indicated. The interaction between NEK7 and NLRP3 was analyzed by immunoprecipitation and immunoblot (right). (b) ELISA analysis of IL-1b secretion by peritoneal macrophages primed with LPS and treated with lysates of non-synchronized cycling HEK293T cells (cytosol extract), or lysates of mitotic HEK293T cells (mitotic cell extract) (mean and s.d. of n = 4 mice per genotype). Results are representative of two independent experiments.