Activation of the Caenorhabditis elegans FOXO family transcription factor DAF-16 by pathogenic Bacillus thuringiensis

► The role of FOXO transcription factors in innate immunity is tested with C. elegans. ► C. elegans FOXO DAF-16 is directly activated by pathogenic Bacillus thuringiensis. ► DAF-16 activation mainly depends on pathogenicity but not infection load alone. ► Increased DAF-16 levels associate with increased host defence. ► FOXO transcription factors can thus be part of a direct immune response to pathogens.