title: Salmonella-induced mucosal lectin RegIIIβ kills competing gut microbiota.
abstract: Intestinal inflammation induces alterations of the gut microbiota and promotes overgrowth of the enteric pathogen Salmonella enterica by largely unknown mechanisms. Here, we identified a host factor involved in this process. Specifically, the C-type lectin RegIIIβ is strongly upregulated during mucosal infection and released into the gut lumen. In vitro, RegIIIβ kills diverse commensal gut bacteria but not Salmonella enterica subspecies I serovar Typhimurium (S. Typhimurium). Protection of the pathogen was attributable to its specific cell envelope structure. Co-infection experiments with an avirulent S. Typhimurium mutant and a RegIIIβ-sensitive commensal E. coli strain demonstrated that feeding of RegIIIβ was sufficient for suppressing commensals in the absence of all other changes inflicted by mucosal disease. These data suggest that RegIIIβ production by the host can promote S. Typhimurium infection by eliminating inhibitory gut microbiota.
authors.affiliation: Junior Group, Mucosal Infections, Institute of Immunology, Hannover Medical School, Hannover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stelter
authors.forename: Rina
authors.initials: R
authors.lastname: Käppeli
authors.forename: Claudia
authors.initials: C
authors.lastname: König
authors.forename: Alexander
authors.initials: A
authors.lastname: Krah
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Hardt
authors.forename: Bärbel
authors.initials: B
authors.lastname: Stecher
authors.forename: Dirk
authors.initials: D
authors.lastname: Bumann
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000254:growth & development; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000382:microbiology*; D054892:Metagenome; D051379:Mice; D050296:Microbial Viability; D008954:Models, Biological; D000073718:Pancreatitis-Associated Proteins; D011506:Proteins / Q000378:metabolism*; D012480:Salmonella Infections / Q000382:microbiology; D012486:Salmonella typhimurium / Q000276:immunology / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D000073718:Pancreatitis-Associated Proteins; D011506:Proteins; C490253:Reg3b protein, mouse