Role of sortase-dependent pili of Bifidobacterium bifidum PRL2010 in modulating bacterium–host interactions

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. 27; pp. 11151 - 11156
• Main Authors: Turroni, Francesca, Serafini, Fausta, Foroni, Elena, Duranti, Sabrina, Motherway, Mary O'Connell, Taverniti, Valentina, Mangifesta, Marta, Milani, Christian, Viappiani, Alice, Roversi, Tommaso, Sánchez, Borja, Santoni, Andrea, Gioiosa, Laura, Ferrarini, Alberto, Delledonne, Massimo, Margolles, Abelardo, Piazza, Laura, Palanza, Paola, Bolchi, Angelo, Guglielmetti, Simone, van Sinderen, Douwe, Ventura, Marco
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 02.07.2013; National Acad Sciences
• Subjects: Aminoacyltransferases - genetics; Aminoacyltransferases - metabolism; Animals; appendages; Bacteria; Bacterial adhesion; Bacterial Adhesion - genetics; Bacterial Adhesion - immunology; Bacterial proteins; Bacterial Proteins - genetics; Bacterial Proteins - physiology; Bifidobacterium; Bifidobacterium - genetics; Bifidobacterium - immunology; Bifidobacterium - physiology; Bifidobacterium bifidum; Binding sites; Biological Sciences; Caco 2 cells; Cell Line; Cell lines; Commensals; Cysteine Endopeptidases - genetics; Cysteine Endopeptidases - metabolism; Cytokines - biosynthesis; enterocytes; Epithelial cells; Eukaryotes; extracellular matrix; Female; fimbriae; Fimbriae, Bacterial - genetics; Fimbriae, Bacterial - immunology; Fimbriae, Bacterial - physiology; Gene expression; Genes; Genes, Bacterial; Genomics; Gram-positive bacteria; host-pathogen relationships; HT29 cells; Humans; immunomodulation; Infant; Infants; Intestinal Mucosa - immunology; Intestinal Mucosa - microbiology; Lactococcus lactis; Lactococcus lactis - genetics; Lactococcus lactis - physiology; Mice; Mice, Inbred BALB C; Microorganisms; Probiotics; receptors; TNF inhibitors; Transcriptome - immunology; tumor necrosis factor-alpha; host–microbe interaction; transcriptomics; genomics; probiotics
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1303897110

Bifidobacteria represent one of the dominant groups of microorganisms colonizing the human infant intestine. Commensal bacteria that interact with a eukaryotic host are believed to express adhesive molecules on their cell surface that bind to specific host cell receptors or soluble macromolecules. Whole-genome transcription profiling of Bifidobacterium bifidum PRL2010, a strain isolated from infant stool, revealed a small number of commonly expressed extracellular proteins, among which were genes that specify sortase-dependent pili. Expression of the coding sequences of these B. bifidum PRL2010 appendages in nonpiliated Lactococcus lactis enhanced adherence to human enterocytes through extracellular matrix protein and bacterial aggregation. Furthermore, such piliated L. lactis cells evoked a higher TNF-α response during murine colonization compared with their nonpiliated parent, suggesting that bifidobacterial sortase-dependent pili not only contribute to adherence but also display immunomodulatory activity.