title: Borrelia burgdorferi binds to, invades, and colonizes native type I collagen lattices.
abstract: Borrelia burgdorferi binds strongly to the extracellular matrix and cells of the connective tissue, a binding apparently mediated by specific proteins and proteoglycans. We investigated the interactions between B. burgdorferi cells and intact type I collagen using hydrated lattices that reproduce features of in vivo collagen matrices. B. burgdorferi cells of several strains adhered avidly to these acellular matrices by a mechanism that was not mediated by decorin or other proteoglycans. Moreover, following adhesion to these matrices, B. burgdorferi grew and formed microcolonies. The collagen used in these studies was confirmed to lack decorin by immunoblot analysis; B. burgdorferi cells lacking the decorin adhesin bound readily to intact collagen matrices. B. burgdorferi also bound to collagen lattices that incorporated enzymes that degraded glycosaminoglycan chains in any residual proteoglycans. Binding of the bacteria to intact collagen was nonetheless specific, as bacteria did not bind agar and showed only minimal binding to bovine serum albumin, gelatin, pepsinized type I collagen, and intact collagen that had been misassembled under nonphysiological pH and ionic-strength conditions. Proteinase K treatment of B. burgdorferi cells decreased the binding, as did a lack of flagella, suggesting that surface-exposed proteins and motility may be involved in the ability of B. burgdorferi to interact with intact collagen matrices. The high efficiency of binding of B. burgdorferi strains to intact collagen matrices permits replacement of the commonly used isotopic binding assay with visual fluorescent microscopic assays and will facilitate future studies of these interactions.
authors.affiliation: Department of Microbiology and Immunology, New York Medical College, Basic Science Building, Valhalla, NY 10595-1690, USA.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Zambrano
authors.forename: Anastasia A
authors.initials: AA
authors.lastname: Beklemisheva
authors.forename: Anton V
authors.initials: AV
authors.lastname: Bryksin
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Newman
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Cabello
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D025065:Borrelia burgdorferi / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*; D024042:Collagen Type I / Q000378:metabolism*; D058575:Decorin; D019286:Endopeptidase K / Q000378:metabolism; D016326:Extracellular Matrix Proteins; D009068:Movement; D011509:Proteoglycans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D024042:Collagen Type I; D058575:Decorin; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans; D019286:Endopeptidase K