We would like to thank M. Nussenzweig (Rockefeller University) and H. Wardemann (German Cancer Research Center) for providing reagents for antibody cloning and expression. This work was supported in part by the Swiss Vaccine Research Institute, by the European Research Council (grant no. 670955 BROADimmune) and by the Fondazione Aldo e Cele Daccò. J.T. is funded by the Wellcome Trust (grant no. 204689/Z/16/Z). B.S. is funded by the National Institutes of Health (grant no. F32 AI 114113).