title: Heterologous expression of the Treponema pallidum laminin-binding adhesin Tp0751 in the culturable spirochete Treponema phagedenis.
abstract: Treponema pallidum subsp. pallidum, the causative agent of syphilis, is an unculturable, genetically intractable bacterium. Here we report the use of the shuttle vector pKMR4PEMCS for the expression of a previously identified T. pallidum laminin-binding adhesin, Tp0751, in the nonadherent, culturable spirochete Treponema phagedenis. Heterologous expression of Tp0751 in T. phagedenis was confirmed via reverse transcriptase PCR analysis with tp0751 gene-specific primers and immunofluorescence analysis with Tp0751-specific antibodies; the latter assay verified the expression of the laminin-binding adhesin on the treponemal surface. Expression of Tp0751 within T. phagedenis was functionally confirmed via laminin attachment assays, in which heterologous Tp0751 expression conferred upon T. phagedenis the capacity to attach to laminin. Further, specific inhibition of the attachment of T. phagedenis heterologously expressing Tp0751 to laminin was achieved by using purified antibodies raised against recombinant T. pallidum Tp0751. This is the first report of heterologous expression of a gene from an unculturable treponeme in T. phagedenis. This novel methodology will significantly advance the field of syphilis research by allowing targeted investigations of T. pallidum proteins purported to play a role in pathogenesis, and specifically host cell attachment, in the nonadherent spirochete T. phagedenis.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, BC, Canada V8W 3P6. caroc@uvic.ca
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Cameron
authors.forename: Janelle M Y
authors.initials: JM
authors.lastname: Kuroiwa
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Yamada
authors.forename: Teresa
authors.initials: T
authors.lastname: Francescutti
authors.forename: Bo
authors.initials: B
authors.lastname: Chi
authors.forename: Howard K
authors.initials: HK
authors.lastname: Kuramitsu
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007797:Laminin / Q000378:metabolism*; D008957:Models, Genetic; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014208:Treponema / Q000235:genetics*; D014210:Treponema pallidum / Q000235:genetics / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D007797:Laminin; D011994:Recombinant Proteins; C049192:adhesin, Treponema pallidum