title: Lcl of Legionella pneumophila is an immunogenic GAG binding adhesin that promotes interactions with lung epithelial cells and plays a crucial role in biofilm formation.
abstract: Legionellosis is mostly caused by Legionella pneumophila and is defined by a severe respiratory illness with a case fatality rate ranging from 5 to 80%. In vitro and in vivo, interactions of L. pneumophila with lung epithelial cells are mediated by the sulfated glycosaminoglycans (GAGs) of the host extracellular matrix. In this study, we have identified several Legionella heparin binding proteins. We have shown that one of these proteins, designated Lcl, is a polymorphic adhesin of L. pneumophila that is produced during legionellosis. Homologues of Lcl are ubiquitous in L. pneumophila serogroups but are undetected in other Legionella species. Recombinant Lcl binds to GAGs, and a Δlpg2644 mutant demonstrated reduced binding to GAGs and human lung epithelial cells. Importantly, we showed that the Δlpg2644 strain is dramatically impaired in biofilm formation. These data delineate the role of Lcl in the GAG binding properties of L. pneumophila and provide molecular evidence regarding its role in L. pneumophila adherence and biofilm formation.
authors.affiliation: Ontario Agency for Health Protection and Promotion, 81 Resources Road, Toronto, ON M9P 3T1, Canada.
authors.forename: Carla
authors.initials: C
authors.lastname: Duncan
authors.forename: Akriti
authors.initials: A
authors.lastname: Prashar
authors.forename: Jannice
authors.initials: J
authors.lastname: So
authors.forename: Patrick
authors.initials: P
authors.lastname: Tang
authors.forename: Donald E
authors.initials: DE
authors.lastname: Low
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terebiznik
authors.forename: Cyril
authors.initials: C
authors.lastname: Guyard
mesh_terms: D018829:Adhesins, Bacterial / Q000502:physiology*; D000595:Amino Acid Sequence; D018441:Biofilms / Q000254:growth & development*; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000502:physiology; D006025:Glycosaminoglycans / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism; D006801:Humans; D016952:Legionella pneumophila / Q000502:physiology*; D007877:Legionnaires' Disease / Q000382:microbiology* / Q000503:physiopathology; D008168:Lung / Q000382:microbiology* / Q000503:physiopathology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D020545:Respiratory Mucosa / Q000382:microbiology* / Q000503:physiopathology
chemical_list: D018829:Adhesins, Bacterial; D006025:Glycosaminoglycans; D006493:Heparin