title: A role for variable region-containing chitin-binding proteins (VCBPs) in host gut-bacteria interactions.
abstract: A number of different classes of molecules function as structural matrices for effecting innate and adaptive immunity. The most extensively characterized mediators of adaptive immunity are the immunoglobulins and T-cell antigen receptors found in jawed vertebrates. In both classes of molecules, unique receptor specificity is effected through somatic variation in the variable (V) structural domain. V region-containing chitin-binding proteins (VCBPs) consist of two tandem Ig V domains as well as a chitin-binding domain. VCBPs are encoded at four loci (i.e., VCBPA-VCBPD) in Ciona, a urochordate, and are expressed by distinct epithelial cells of the stomach and intestine, as well as by granular amoebocytes present in the lamina propria of the gut and in circulating blood. VCBPs are secreted into the gut lumen, and direct binding to bacterial surfaces can be detected by immunogold analysis. Affinity-purified native and recombinant VCBP-C, as well as a construct consisting only of the tandem V domains, enhance bacterial phagocytosis by granular amoebocytes in vitro. Various aspects of VCBP expression and function suggest an early origin for the key elements that are central to the dialogue between the immune system of the host and gut microflora.
authors.affiliation: Department of Pediatrics, University of South Florida College of Medicine and University of South Florida/All Children's Hospital Children's Research Institute, St Petersburg, FL 33701, USA.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Dishaw
authors.forename: Stefano
authors.initials: S
authors.lastname: Giacomelli
authors.forename: Daniela
authors.initials: D
authors.lastname: Melillo
authors.forename: Ivana
authors.initials: I
authors.lastname: Zucchetti
authors.forename: Robert N
authors.initials: RN
authors.lastname: Haire
authors.forename: Lenina
authors.initials: L
authors.lastname: Natale
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Russo
authors.forename: Rosaria
authors.initials: R
authors.lastname: De Santis
authors.forename: Gary W
authors.initials: GW
authors.lastname: Litman
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Pinto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism*; D002938:Ciona intestinalis / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D041981:Gastrointestinal Tract / Q000378:metabolism* / Q000382:microbiology*; D040461:Gene Components; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007150:Immunohistochemistry; D007558:Italy; D008404:Massachusetts; D008969:Molecular Sequence Data; D010587:Phagocytosis / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D007135:Immunoglobulin Variable Region; D002686:Chitin