Marie Vétizou, Jonathan M Pitt, Romain Daillère, Patricia Lepage, Nadine Waldschmitt, Caroline Flament, Sylvie Rusakiewicz, Bertrand Routy, Maria P Roberti, Connie P M Duong, Vichnou Poirier-Colame, Antoine Roux, Sonia Becharef, Silvia Formenti, Encouse Golden, Sascha Cording, Gerard Eberl, Andreas Schlitzer, Florent Ginhoux, Sridhar Mani, Takahiro Yamazaki, Nicolas Jacquelot, David P Enot, Marion Bérard, Jérôme Nigou, Paule Opolon, Alexander Eggermont, Paul-Louis Woerther, Elisabeth Chachaty, Nathalie Chaput, Caroline Robert, Christina Mateus, Guido Kroemer, Didier Raoult, Ivo Gomperts Boneca, Franck Carbonnel, Mathias Chamaillard, Laurence Zitvogel
Antibodies targeting CTLA-4 have been successfully used as cancer immunotherapy. We find that the antitumor effects of CTLA-4 blockade depend on distinct Bacteroides species. In mice and patients, T cell responses specific for B. thetaiotaomicron or B. fragilis were associated with the efficacy of CTLA-4 blockade. Tumors in antibiotic-treated or germ-free mice did not respond to CTLA blockade. This defect was overcome by gavage with B. fragilis, by immunization with B. fragilis polysaccharides, or by adoptive transfer of B...
November 27, 2015: Science