title: Identification of cell-binding adhesins of Leptospira interrogans.
abstract: Leptospirosis is a globally distributed bacterial infectious disease caused by pathogenic members of the genus Leptospira. Infection can lead to illness ranging from mild and non-specific to severe, with jaundice, kidney and liver dysfunction, and widespread endothelial damage. The adhesion of pathogenic Leptospira species (spp.), the causative agent of leptospirosis, to host tissue components is necessary for infection and pathogenesis. While it is well-established that extracellular matrix (ECM) components play a role in the interaction of the pathogen with host molecules, we have shown that pathogenic Leptospira interrogans binds to host cells more efficiently than to ECM components. Using in vitro phage display to select for phage clones that bind to EA.hy926 endothelial cells, we identified the putative lipoproteins LIC10508 and LIC13411, and the conserved hypothetical proteins LIC12341 and LIC11574, as candidate L. interrogans sv. Copenhageni st. Fiocruz L1-130 adhesins. Recombinant LIC11574, but not its L. biflexa homologue LBF1629, exhibited dose-dependent binding to both endothelial and epithelial cells. In addition, LIC11574 and LIC13411 bind to VE-cadherin, an endothelial cell receptor for L. interrogans. Extraction of bacteria with the non-ionic detergent Triton X-114 resulted in partitioning of the candidate adhesins to the detergent fraction, a likely indication that these proteins are outer membrane localized. All candidate adhesins were recognized by sera obtained from leptospirosis patients but not by sera from healthy individuals as assessed by western blot. This work has identified bacterial adhesins that are potentially involved in L. interrogans infection of the mammalian host, and through cadherin binding, may contribute to dissemination and vascular damage. Our findings may be of value in leptospirosis control and prevention, with the bacterial adhesins potentially serving as targets for development of diagnostics, therapeutics, and vaccines.
authors.affiliation: Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America.
authors.forename: Karen V
authors.initials: KV
authors.lastname: Evangelista
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America.
authors.forename: Beth
authors.initials: B
authors.lastname: Hahn
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America.
authors.forename: Elsio A
authors.initials: EA
authors.lastname: Wunder
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America.
authors.forename: Albert I
authors.initials: AI
authors.lastname: Ko
authors.affiliation: Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, California, United States of America; Departments of Medicine, Urology, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America.
authors.forename: David A
authors.initials: DA
authors.lastname: Haake
authors.affiliation: Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America; Division of Infectious Diseases, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America.
authors.forename: Jenifer
authors.initials: J
authors.lastname: Coburn
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion; D015820:Cadherins / Q000378:metabolism; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000382:microbiology; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006801:Humans; D007921:Leptospira interrogans / Q000502:physiology*; D007922:Leptospirosis / Q000276:immunology; D008074:Lipoproteins / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D019151:Peptide Library; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D015820:Cadherins; D008074:Lipoproteins; D019151:Peptide Library; D011994:Recombinant Proteins