Quantification of CD95-induced apoptosis and NF-κB activation at the single cell level.

CD95/Fas/APO-1 is a member of the death receptor (DR) family. Stimulation of CD95 leads to the induction of apoptosis as well as to NF-κB signaling. Crosstalk between these two pathways plays a central role in cell fate. Defects in the regulation of apoptosis and of NF-κB are connected to a number of chronic inflammatory diseases and cancer. For a better understanding of the life/death decisions in the cell and their contribution to disease progression, the development of new technologies is required. Using imaging flow cytometry we developed a method that enables a quantitative detection of different CD95 signaling pathways in the single cell. The important advantage of this method compared to other approaches is that it allows quantifying a large number of single cells undergoing apoptosis and NF-κB activation. This technology could provide new insights into the quantitative characterization of apoptosis and NF-κB at the single cell level and could be used for the quantitative network analysis in systems biology studies.