scholarly journals Correlation of Immunity in Experimental Syphilis with Serum-Mediated Aggregation of Treponema pallidum Rare Outer Membrane Proteins

1999 ◽  
Vol 67 (7) ◽  
pp. 3631-3636 ◽  
Author(s):  
Michael A. Lewinski ◽  
James N. Miller ◽  
Michael A. Lovett ◽  
David R. Blanco
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum ◽  
Freeze Fracture ◽  
Normal Serum ◽  
Acquired Immunity ◽  
Freeze Fracture Electron Microscopy ◽  
Membrane Spanning ◽  
Number Of Particles

ABSTRACT We have previously shown by freeze-fracture electron microscopy that serum from infection-immune syphilitic rabbits aggregates the low-density membrane-spanning Treponema pallidum rare outer membrane proteins (TROMPs). The purpose of this study was to determine if a relationship could be demonstrated between acquired immunity in experimental rabbit syphilis, serum complement-dependent treponemicidal antibody, and antibody directed against TROMPs as measured by the aggregation of TROMP particles. Three groups of T. pallidum-infected rabbits were treated curatively with penicillin at 9 days, 30 days, and 6 months postinfection to generate various degrees of immunity to challenge reinfection. Sera from rabbits completely susceptible to localized and disseminated reinfection possessed a low titer of treponemicidal antibody (≤1:1 in killing ≥50% of a treponemal suspension) and showed a correspondingly low level of TROMP aggregation (16.5% of the total number of outer membrane particles counted) similar to normal serum controls (13.4%); the number of particles within these aggregates never exceeded three. Sera from partially immune rabbits, which were susceptible to local reinfection but had no evidence of dissemination, showed an increase in the titer of treponemicidal antibody (1:16) compared to the completely susceptible group (≤1:1). Although no significant increase was observed in the total number of TROMP particles aggregated (18.9%) compared to the number in controls (13.4%), approximately 15% of these aggregates did exhibit a significant increase in the number of particles per aggregate (4 to 5 particles) compared to controls (≤3 particles), indicating a measurable increase in anti-TROMP antibody. Finally, sera from rabbits completely immune to both local and disseminated reinfection possessed both high titers of treponemicidal antibody (1:128) and significant aggregation of TROMP (88.6%); approximately 50% of these aggregates contained four to six particles. The results indicate that complete immunity in experimental rabbit syphilis correlates with antibody that kills T. pallidumand aggregates TROMPs, suggesting that TROMPs are molecules which contribute to the development of acquired immunity.

scholarly journals TP0453, a Concealed Outer Membrane Protein of Treponema pallidum, Enhances Membrane Permeability

2005 ◽  
Vol 187 (18) ◽  
pp. 6499-6508 ◽  
Author(s):  
Karsten R. O. Hazlett ◽  
David L. Cox ◽  
Marc Decaffmeyer ◽  
Michael P. Bennett ◽  
Daniel C. Desrosiers ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Nutrient Transport ◽  
Treponema Pallidum ◽  
Protein S ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Membrane Spanning

ABSTRACT The outer membrane of Treponema pallidum, the noncultivable agent of venereal syphilis, contains a paucity of protein(s) which has yet to be definitively identified. In contrast, the outer membranes of gram-negative bacteria contain abundant immunogenic membrane-spanning β-barrel proteins mainly involved in nutrient transport. The absence of orthologs of gram-negative porins and outer membrane nutrient-specific transporters in the T. pallidum genome predicts that nutrient transport across the outer membrane must differ fundamentally in T. pallidum and gram-negative bacteria. Here we describe a T. pallidum outer membrane protein (TP0453) that, in contrast to all integral outer membrane proteins of known structure, lacks extensive β-sheet structure and does not traverse the outer membrane to become surface exposed. TP0453 is a lipoprotein with an amphiphilic polypeptide containing multiple membrane-inserting, amphipathic α-helices. Insertion of the recombinant, nonlipidated protein into artificial membranes results in bilayer destabilization and enhanced permeability. Our findings lead us to hypothesize that TP0453 is a novel type of bacterial outer membrane protein which may render the T. pallidum outer membrane permeable to nutrients while remaining inaccessible to antibody.

scholarly journals Surface Immunolabeling and Consensus Computational Framework To Identify Candidate Rare Outer Membrane Proteins of Treponema pallidum

2010 ◽  
Vol 78 (12) ◽  
pp. 5178-5194 ◽  
Author(s):  
David L. Cox ◽  
Amit Luthra ◽  
Star Dunham-Ems ◽  
Daniel C. Desrosiers ◽  
Juan C. Salazar ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum ◽  
Immunoblot Analysis ◽  
Proteinase K ◽  
Membrane Proteome ◽  
Computational Framework ◽  
Shifting Balance ◽  
Dual Label

ABSTRACT Treponema pallidum reacts poorly with the antibodies present in rabbit and human syphilitic sera, a property attributed to the paucity of proteins in its outer membrane. To better understand the basis for the syphilis spirochete's “stealth pathogenicity,” we used a dual-label, 3-step amplified assay in which treponemes encapsulated in gel microdroplets were probed with syphilitic sera in parallel with anti-FlaA antibodies. A small (approximately 5 to 10%) but reproducible fraction of intact treponemes bound IgG and/or IgM antibodies. Three lines of evidence supported the notion that the surface antigens were likely β-barrel-forming outer membrane proteins (OMPs): (i) surface labeling with anti-lipoidal (VDRL) antibodies was not observed, (ii) immunoblot analysis confirmed prior results showing that T. pallidum glycolipids are not immunoreactive, and (iii) labeling of intact organisms was not appreciably affected by proteinase K (PK) treatment. With this method, we also demonstrate that TprK (TP0897), an extensively studied candidate OMP, and TP0136, a lipoprotein recently reported to be surface exposed, are both periplasmic. Consistent with the immunolabeling studies, TprK was also found to lack amphiphilicity, a characteristic property of β-barrel-forming proteins. Using a consensus computational framework that combined subcellular localization and β-barrel structural prediction tools, we generated ranked groups of candidate rare OMPs, the predicted T. pallidum outer membrane proteome (OMPeome), which we postulate includes the surface-exposed molecules detected by our enhanced gel microdroplet assay. In addition to underscoring the syphilis spirochete's remarkably poor surface antigenicity, our findings help to explain the complex and shifting balance between pathogen and host defenses that characterizes syphilitic infection.

scholarly journals Assessment of cell-surface exposure and vaccinogenic potentials of Treponema pallidum candidate outer membrane proteins

2007 ◽  
Vol 9 (11) ◽  
pp. 1267-1275 ◽  
Author(s):  
Farol L. Tomson ◽  
Patrick G. Conley ◽  
Michael V. Norgard ◽  
Kayla E. Hagman
Keyword(s):  
Membrane Proteins ◽  
Cell Surface ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum

scholarly journals Isolation and Characterization of the Outer Membrane ofBorrelia hermsii

1998 ◽  
Vol 66 (3) ◽  
pp. 1082-1091 ◽  
Author(s):  
Ellen S. Shang ◽  
Jonathan T. Skare ◽  
Maurice M. Exner ◽  
David R. Blanco ◽  
Bruce L. Kagan ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Gradient Centrifugation ◽  
Outer Membrane Proteins ◽  
Freeze Fracture ◽  
Outer Membrane Vesicles ◽  
Proteinase K ◽  
Blue Staining ◽  
Isolation And Characterization

ABSTRACT The outer membrane of Borrelia hermsii has been shown by freeze-fracture analysis to contain a low density of membrane-spanning outer membrane proteins which have not yet been isolated or identified. In this study, we report the purification of outer membrane vesicles (OMV) from B. hermsii HS-1 and the subsequent identification of their constituent outer membrane proteins. The B. hermsii outer membranes were released by vigorous vortexing of whole organisms in low-pH, hypotonic citrate buffer and isolated by isopycnic sucrose gradient centrifugation. The isolated OMV exhibited porin activities ranging from 0.2 to 7.2 nS, consistent with their outer membrane origin. Purified OMV were shown to be relatively free of inner membrane contamination by the absence of measurable β-NADH oxidase activity and the absence of protoplasmic cylinder-associated proteins observed by Coomassie blue staining. Approximately 60 protein spots (some of which are putative isoelectric isomers) with 25 distinct molecular weights were identified as constituents of the OMV enrichment. The majority of these proteins were also shown to be antigenic with sera from B. hermsii-infected mice. Seven of these antigenic proteins were labeled with [3H]palmitate, including the surface-exposed glycerophosphodiester phosphodiesterase, the variable major proteins 7 and 33, and proteins of 15, 17, 38, 42, and 67 kDa, indicating that they are lipoprotein constituents of the outer membrane. In addition, immunoblot analysis of the OMV probed with antiserum to the Borrelia garinii surface-exposed p66/Oms66 porin protein demonstrated the presence of a p66 (Oms66) outer membrane homolog. Treatment of intact B. hermsii with proteinase K resulted in the partial proteolysis of the Oms66/p66 homolog, indicating that it is surface exposed. This identification and characterization of the OMV proteins should aid in further studies of pathogenesis and immunity of tick-borne relapsing fever.

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