title: Burkholderia cenocepacia O antigen lipopolysaccharide prevents phagocytosis by macrophages and adhesion to epithelial cells.
abstract: Chronic respiratory infections by the Burkholderia cepacia complex (Bcc) are of great concern to patients with cystic fibrosis. Bcc isolates may survive intracellularly within amoebae, respiratory epithelial cells and macrophages. The molecular mechanisms facilitating colonization and pathogenesis remain unclear. Given the importance of bacterial adhesion to host surfaces in microbial pathogenesis, we investigated the role of the O antigen LPS in the interaction of Burkholderia cenocepacia, a member of the Bcc, with macrophages and epithelial cells. Our results demonstrated that the O antigen modulates phagocytosis but does not affect intracellular survival of B. cenocepacia. Internalization of strains that lack O antigen was significantly increased compared to that of their isogenic smooth counterparts. However, no differences between rough and smooth strains were found in their ability to delay phagosomal maturation. We also found that the O antigen interfered with the ability of B. cenocepacia to adhere to bronchial epithelial cells, suggesting that this polysaccharide may mask one or more bacterial surface adhesins.
authors.affiliation: Infectious Diseases Research Group, Siebens-Drake Research Institute, Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada.
authors.forename: M Soledad
authors.initials: MS
authors.lastname: Saldías
authors.affiliation: Infectious Diseases Research Group, Siebens-Drake Research Institute, Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada.
authors.forename: Ximena
authors.initials: X
authors.lastname: Ortega
authors.affiliation: Department of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada.|Infectious Diseases Research Group, Siebens-Drake Research Institute, Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D019117:Burkholderia / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004847:Epithelial Cells / Q000502:physiology*; D008168:Lung / Q000166:cytology; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D009154:Mutation; D019081:O Antigens / Q000378:metabolism*; D010587:Phagocytosis / Q000502:physiology*
chemical_list: D019081:O Antigens