Figure 4.

Live imaging reveals that birinapant promotes bystander and TNF-mediated synaptic killing. (a) MC38-Ova cells were seeded in chamber slides, then overlaid with perforin-deficient OT-I T cells. T cells were labeled with cell trace violet (CTV). A cleaved caspase 3/7 reporter and birinapant (1 μM)/DMSO was added to the co-culture media. Representative still images at the indicated time-points are depicted (hr:min). (b) MC38-Ova cells that became caspase 3/7 positive in the absence of an immune synapse with a T-cell within the 8 h time span. (c) MC38-Ova cells that became caspase 3/7 positive during an immune synapse with a T-cell within the 8 h time span. All quantification data are pooled from five separate camera positions across two individual experiments. Error bars represent the mean±S.E.M *P<0.05 by unpaired Student’s t-test