title: In silico mining and characterization of bifidobacterial lipoprotein with CHAP domain secreted in an aggregated form.
abstract: Bifidobacterium breve C50 secretes a lipoprotein associated with glucose, acting in an aggregating form (>600kDa) as an agonist of TLR2/6. Similar lipoproteins were sought for in bifidobacteria. In silico, the closest homology was shown with a Bifidobacterium longum protein containing CHAP and lipobox domains. Two strains secreted aggregates whose peptides sequences aligned with the mined protein. C16:0 and C18:0 fatty acids detected in the aggregates further supported a lipoprotein structure. Glucose and mannose detected by gas chromatography were likely ligands of the lipoprotein. The binding of aggregates to galectin-1 indicated that hexosamines and galactose surrounded them. However, unlike B. breve C50, aggregate secreted by B. longum CBi0703 was unable to bind TLR2/6 likely because of a more hydrophobic structure. In gnotobiotic mice, the intake of B. longum aggregate induced, in splenic dendritic cells, the expression of genes involved in antigen presentation. A positive correlation between the number of dendritic cells and CD4(+)CD25(+) cells was observed in mice receiving these aggregates. In conclusion, B. longum secretes a lipoprotein forming aggregates which may influence dendritic and CD4(+)CD25(+) cell interactions independently of the TLR2/6 pathway.
authors.affiliation: EA 3610, Laboratoire de Bactériologie, Faculté des Sciences Pharmaceutiques et Biologiques, Université de Lille 2, 3 rue du Pr. Laguesse, 59006 Lille Cedex, France; Bifinove SAS, 99 rue du jardin des plantes, 59000 Lille, France. Electronic address: angelo.scuotto@live.fr.
authors.forename: Angelo
authors.initials: A
authors.lastname: Scuotto
authors.affiliation: CIDAM, ERT18, Université d'Auvergne, France. Electronic address: p-charles.romond@udamail.fr.
authors.forename: Pierre-Charles
authors.initials: PC
authors.lastname: Romond
authors.affiliation: CIDAM, ERT18, Université d'Auvergne, France. Electronic address: djorie2000@yahoo.fr.
authors.forename: Serge
authors.initials: S
authors.lastname: Djorie
authors.affiliation: CIDAM, ERT18, Université d'Auvergne, France. Electronic address: monique.alric@udamail.fr.
authors.forename: Monique
authors.initials: M
authors.lastname: Alric
authors.affiliation: EA 3610, Laboratoire de Bactériologie, Faculté des Sciences Pharmaceutiques et Biologiques, Université de Lille 2, 3 rue du Pr. Laguesse, 59006 Lille Cedex, France. Electronic address: marie-benedicte.romond@univ-lille2.fr.
authors.forename: Marie-Bénédicte
authors.initials: MB
authors.lastname: Romond
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D001644:Bifidobacterium / Q000276:immunology / Q000378:metabolism*; D002241:Carbohydrates / Q000737:chemistry; D019295:Computational Biology; D003198:Computer Simulation; D057225:Data Mining; D030562:Databases, Protein; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D037483:Galectin 1 / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D008055:Lipids / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry; D066329:Protein Aggregates / Q000276:immunology; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051216:Toll-Like Receptor 6 / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002241:Carbohydrates; D037483:Galectin 1; D008055:Lipids; D008074:Lipoproteins; D010455:Peptides; D066329:Protein Aggregates; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6
keywords: Aggregates; Bifidobacteria; Dendritic cells; Galectin-1; Gnotobiotic mice; Lipoprotein; Rheumatoid arthritis; TLRs