Figure 6. IFN-γ induces Paneth cell death through a caspase-3/7–dependent pathway.

Still images from time-lapse analysis of caspase-3/7 activity in an enteroid exposed to IFN-γ (from Supplemental Videos 1 and 2). Paneth cells (white arrowheads) are granule-containing and appear white in the differential interference contrast images (top row). Cells containing activated caspase-3/7 have bright green nuclei (red arrowheads), which were detected only in Paneth cells and extruded into the crypt lumen after caspase-3/7 activation (bottom row). Time after addition of 2 ng/ml IFN-γ is indicated in the upper left corner of each image. Representative images from 2 experiments are shown. Scale bars: 20 μm.