title: The role of VlsE antigenic variation in the Lyme disease spirochete: persistence through a mechanism that differs from other pathogens.
abstract: The linear plasmid, lp28-1, is required for persistent infection by the Lyme disease spirochete, Borrelia burgdorferi. This plasmid contains the vls antigenic variation locus, which has long been thought to be important for immune evasion. However, the role of the vls locus as a virulence factor during mammalian infection has not been clearly defined. We report the successful removal of the vls locus through telomere resolvase-mediated targeted deletion, and demonstrate the absolute requirement of this lp28-1 component for persistence in the mouse host. Moreover, successful infection of C3H/HeN mice with an lp28-1 plasmid in which the left portion was deleted excludes participation of other lp28-1 non-vls genes in spirochete virulence, persistence and the process of recombinational switching at vlsE. Data are also presented that cast doubt on an immune evasion mechanism whereby VlsE directly masks other surface antigens similar to what has been observed for several other pathogens that undergo recombinational antigenic variation.
authors: Department of Biochemistry, University of Calgary, Calgary, Alberta T2N 4 N1, Canada.
authors: Troy
authors: T
authors: Bankhead
authors: George
authors: G
authors: Chaconas
mesh_terms: D000818:Animals; D000940:Antigenic Variation / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D025065:Borrelia burgdorferi / Q000276:immunology* / Q000472:pathogenicity*; D002999:Clone Cells; D017353:Gene Deletion; D007106:Immune Sera; D008074:Lipoproteins / Q000276:immunology*; D008193:Lyme Disease / Q000382:microbiology; D051379:Mice; D050296:Microbial Viability; D016254:Mutagenesis, Insertional; D016615:Telomere
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007106:Immune Sera; D008074:Lipoproteins; C105546:VlsE protein, Borrelia burgdorferi