Combined use of radioimagers and radioactive 3 ' OH DNA nick end labellingto quantify apoptosis in cell lines and tissue sections: applications to virus-induced apoptosis

DNA fragmentation is a key feature of the degradation phase of apoptosis. I n this work we have developed an assay, based on radioimager (beta-IMAGER a nd mu-IMAGER) quantification of radioactive nick end labelling (RANEL), whi ch is quantitative, rapid and sensitive to study in vitro and in vivo induc ed apoptosis. To establish the technique, in vitro apoptosis of T cell line s was induced by stimulation of the Fas receptor; cells were labelled using TdT-mediated [alpha-P-33] dCTP nick end labelling, after which then radioa ctivity was quantified using a beta-IMAGER. We have also shown that the RAN EL method can be applied to the quantification and visualisation, by mu-IMA GER analysis, of liver tissue sections from mouse Fas-induced fulminant hep atitis or from Dengue-1 virus infected individuals. Finally, this system ha s also been used to detect apoptosis induced by rabies virus in Jurkat T ce lls. These data have established a large field of application for the RANEL assay.