Although much has been learned about venereal syphilis in the nearly one hundred years since the discovery of its etiologic agent, Treponema pallidum subsp. pallidum, the disease remains highly enigmatic. Our limited understanding of this chronic, systemic, sexually transmitted infection reflects the many peculiarities of the syphilis spirochete, which include the fragility and unusual molecular architecture of its outer membrane, an extremely narrow mammalian host range, and its inability to replicate continuously in artificial medium. A central theme of our research program has been and will continue to be the identification and characterization of rare outer membrane proteins. There are two principal reasons why we believe that this arduous search is about to reach a successful conclusion. First, using a lipophilic photoactivatable probe, we have identified what appears to be an authentic rare outer membrane protein, designate p30.5. Second, we now have at our disposal the T. pallidum genomic sequence, an extremely powerful too which now enables us to survey in silico the entire treponemal chromosome for additional candidate outer membrane proteins. Equally important, the T. pallidum genomic sequence has provided an invaluable platform for our investigations of physiological processes (i.e., trace metal acquisition and resistance to oxidative stress) which are fundamental to host- pathogen relations during syphilitic infection. Though clearly departures from our traditional areas of concentration, these new avenues of investigation are, nonetheless, outgrowths of our longstanding commitment to delineating in molecular terms the interface between the spirochete and its obligate human host. During the current funding interval, we have made substantial progress towards our long term objective of relating T. pallidum membrane biology to syphilis pathogenesis. In the present proposal, we hope to extend this process by integrating molecular, ultrastructural, and physiological information into a more complete picture of how the parasite sustains itself within the hostile host milieu. To achieve this end, we will molecularly characterize T. pallidum rare outer membrane proteins (Specific Aim One); define the roles of the Tro and TP0034 transporters in trace metal acquisition by T. pallidum (Specific Aim Two); and characterize key components of T. pallidum's defense against oxidative stress (Specific Aim Three).

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AI026756-19
Application #
7089885
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Hiltke, Thomas J
Project Start
1992-07-01
Project End
2007-12-31
Budget Start
2006-07-01
Budget End
2007-12-31
Support Year
19
Fiscal Year
2006
Total Cost
$353,981
Indirect Cost
Name
University of Connecticut
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
022254226
City
Farmington
State
CT
Country
United States
Zip Code
06030
Hawley, Kelly L; Cruz, Adriana R; Benjamin, Sarah J et al. (2017) IFN? Enhances CD64-Potentiated Phagocytosis of Treponema pallidum Opsonized with Human Syphilitic Serum by Human Macrophages. Front Immunol 8:1227
Puthenveetil, Robbins; Kumar, Sanjiv; Caimano, Melissa J et al. (2017) The major outer sheath protein forms distinct conformers and multimeric complexes in the outer membrane and periplasm of Treponema denticola. Sci Rep 7:13260
Groshong, Ashley M; Dey, Abhishek; Bezsonova, Irina et al. (2017) Peptide Uptake Is Essential for Borrelia burgdorferi Viability and Involves Structural and Regulatory Complexity of its Oligopeptide Transporter. MBio 8:
Radolf, Justin D; Deka, Ranjit K; Anand, Arvind et al. (2016) Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen. Nat Rev Microbiol 14:744-759
Luthra, Amit; Anand, Arvind; Hawley, Kelly L et al. (2015) A Homology Model Reveals Novel Structural Features and an Immunodominant Surface Loop/Opsonic Target in the Treponema pallidum BamA Ortholog TP_0326. J Bacteriol 197:1906-20
Luthra, Amit; Anand, Arvind; Radolf, Justin D (2015) Treponema pallidum in Gel Microdroplets: A Method for Topological Analysis of BamA (TP0326) and Localization of Rare Outer Membrane Proteins. Methods Mol Biol 1329:67-75
Anand, Arvind; LeDoyt, Morgan; Karanian, Carson et al. (2015) Bipartite Topology of Treponema pallidum Repeat Proteins C/D and I: OUTER MEMBRANE INSERTION, TRIMERIZATION, AND PORIN FUNCTION REQUIRE A C-TERMINAL ?-BARREL DOMAIN. J Biol Chem 290:12313-31
Kenedy, Melisha R; Luthra, Amit; Anand, Arvind et al. (2014) Structural modeling and physicochemical characterization provide evidence that P66 forms a ?-barrel in the Borrelia burgdorferi outer membrane. J Bacteriol 196:859-72
Anand, Arvind; Luthra, Amit; Edmond, Maxwell E et al. (2013) The major outer sheath protein (Msp) of Treponema denticola has a bipartite domain architecture and exists as periplasmic and outer membrane-spanning conformers. J Bacteriol 195:2060-71
Silver, Adam C; Dunne, Dana W; Zeiss, Caroline J et al. (2013) MyD88 deficiency markedly worsens tissue inflammation and bacterial clearance in mice infected with Treponema pallidum, the agent of syphilis. PLoS One 8:e71388

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