title: Treponema pallidum major sheath protein homologue Tpr K is a target of opsonic antibody and the protective immune response.
abstract: We have identified a family of genes that code for targets for opsonic antibody and protective immunity in T. pallidum subspecies pallidum using two different approaches, subtraction hybridization and differential immunologic screening of a T. pallidum genomic library. Both approaches led to the identification of a polymorphic multicopy gene family with predicted amino acid homology to the major sheath protein of Treponema denticola. One of the members of this gene family, tpr K, codes for a protein that is predicted to have a cleavable signal peptide and be located in the outer membrane of the bacterium. Reverse transcription polymerase chain reaction analysis of T. pallidum reveals that Tpr K is preferentially transcribed in the Nichols strain of T. pallidum. Antibodies directed to purified recombinant variable domain of Tpr K can opsonize T. pallidum, Nichols strain, for phagocytosis, supporting the hypothesis that this portion of the protein is exposed at the surface of the treponeme. Immunization of rabbits with the purified recombinant variable domain of Tpr K provides significant protection against infection with the Nichols strain of T. pallidum. This gene family is hypothesized to be central to pathogenesis and immunity during syphilis infection.
authors.affiliation: Department of Medicine, University of Washington, Seattle, Washington 98195, USA. acentur@u.washington.edu
authors.forename: A
authors.initials: A
authors.lastname: Centurion-Lara
authors.forename: C
authors.initials: C
authors.lastname: Castro
authors.forename: L
authors.initials: L
authors.lastname: Barrett
authors.forename: C
authors.initials: C
authors.lastname: Cameron
authors.forename: M
authors.initials: M
authors.lastname: Mostowfi
authors.forename: W C
authors.initials: WC
authors.lastname: Van Voorhis
authors.forename: S A
authors.initials: SA
authors.lastname: Lukehart
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000940:Antigenic Variation / Q000235:genetics; D001426:Bacterial Proteins; D017125:Genes, Protozoan; D007114:Immunization; D008969:Molecular Sequence Data; D009895:Opsonin Proteins / Q000276:immunology*; D018272:Porins / Q000235:genetics / Q000276:immunology*; D021382:Protein Sorting Signals / Q000235:genetics; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013382:Subtraction Technique; D014210:Treponema pallidum / Q000235:genetics / Q000276:immunology*