title: Gut immunity in a protochordate involves a secreted immunoglobulin-type mediator binding host chitin and bacteria.
abstract: Protochordate variable region-containing chitin-binding proteins (VCBPs) consist of immunoglobulin-type V domains and a chitin-binding domain (CBD). VCBP V domains facilitate phagocytosis of bacteria by granulocytic amoebocytes; the function of the CBD is not understood. Here we show that the gut mucosa of Ciona intestinalis contains an extensive matrix of chitin fibrils to which VCBPs bind early in gut development, before feeding. Later in development, VCBPs and bacteria colocalize to chitin-rich mucus along the intestinal wall. VCBP-C influences biofilm formation in vitro and, collectively, the findings of this study suggest that VCBP-C may influence the overall settlement and colonization of bacteria in the Ciona gut. Basic relationships between soluble immunoglobulin-type molecules, endogenous chitin and bacteria arose early in chordate evolution and are integral to the overall function of the gut barrier.
authors.affiliation: Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Dishaw
authors.affiliation: College of Marine Sciences, University of South Florida St Petersburg, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: Brittany
authors.initials: B
authors.lastname: Leigh
authors.affiliation: Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Cannon
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Liberti
authors.affiliation: Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.|Department of Molecular Genetics, All Children's Hospital Johns Hopkins Medicine, 501 6th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: M Gail
authors.initials: MG
authors.lastname: Mueller
authors.affiliation: Department of Molecular Genetics, All Children's Hospital Johns Hopkins Medicine, 501 6th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: Diana P
authors.initials: DP
authors.lastname: Skapura
authors.affiliation: Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Karrer
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy.
authors.forename: Maria R
authors.initials: MR
authors.lastname: Pinto
authors.affiliation: Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy.
authors.forename: Rosaria
authors.initials: R
authors.lastname: De Santis
authors.affiliation: Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.|Department of Molecular Genetics, All Children's Hospital Johns Hopkins Medicine, 501 6th Avenue South, St Petersburg, Florida 33701, USA.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Litman
mesh_terms: D000818:Animals; D018441:Biofilms; D002352:Carrier Proteins / Q000276:immunology* / Q000378:metabolism; D002686:Chitin / Q000378:metabolism*; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism; D002938:Ciona intestinalis / Q000276:immunology*; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D018928:Immunity, Mucosal / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000276:immunology*; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007413:Intestinal Mucosa / Q000276:immunology*; D009093:Mucus
chemical_list: D002352:Carrier Proteins; D007135:Immunoglobulin Variable Region; D002686:Chitin; D002687:Chitin Synthase