Figure 2.

Transient expression of SipB in BMDPM from caspase-1 ^−/− mice results in cell death. Plasmids expressing either SipB, SipC, or SipD fused to YFP were introduced into BMDPM from caspase-1^−/− mice as indicated in the Materials and methods section. Macrophages were then fixed, stained with DAPI (to visualize chromatin), and observed under a fluorescence microscope. Cells expressing SipC or SipD do not show any signs of cytotoxicity. In contrast, cells expressing SipB show clear signs of cytotoxicity and chromatin condensation. Arrows indicate the nucleus of transfected cells.