516 Caspase-8 regulated senescence as an immune checkpoint in T lymphocytes for adoptive cell therapy by Valérie Janelle, Mathieu Neault, Marie-Eve Lebel, Dave De Sousa, Salix Boulet, Ludovic Durrieu, Cedric Carli, Sebastien Lemieux, Nathalie Labrecque, Heather Melichar, Frederick Mallette, Jean-Sebastien Delisle