title: Activation of the Caenorhabditis elegans FOXO family transcription factor DAF-16 by pathogenic Bacillus thuringiensis.
abstract: The FOXO family of transcription factors have recently been implicated in innate immunity, especially in case of DAF-16 from the nematode Caenorhabditis elegans. However, previous studies with this nematode proposed that DAF-16 is not directly activated by pathogens. Rather, DAF-16 mediates resistance if activated by some other cue as part of a general stress response. We specifically tested this notion by analysis of DAF-16 nuclear translocation and thus regulatory activity upon exposure to pathogenic Bacillus thuringiensis. Our results demonstrate that DAF-16 nuclear translocation is indeed particularly induced in response to bacterial pathogenicity, whereas infection load alone has little effect. Translocation is strongest at an early time point, suggesting a role during the immediate immune response. The increased DAF-16 availability is associated with higher resistance and a reduction in feeding behaviour. Taken together, our data highlight that a FOXO transcription factor directly responds to pathogens and thus contributes to immune defence.
authors.affiliation: Department of Animal Evolutionary Ecology, Zoological Institute, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Rania
authors.initials: R
authors.lastname: Nakad
authors.forename: Hinrich
authors.initials: H
authors.lastname: Schulenburg
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000472:pathogenicity / Q000502:physiology*; D058491:Bacterial Load; D017173:Caenorhabditis elegans / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D005247:Feeding Behavior; D051858:Forkhead Transcription Factors; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D021381:Protein Transport; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D051858:Forkhead Transcription Factors; D014157:Transcription Factors; C108831:daf-16 protein, C elegans