Thesis (M.S.P.H.)--University of Michigan, 1939.

Thesis (M.S.P.H.)--University of Michigan, 1939.

No description available.

Two-dimensional electrophoretic protein profiles of in vivo and in vitro propagated T.pallidum subsps. pallidum Nichols strain were analyzed and compared. This comparative analysis revealed two in vitro synthesized, cytoplasmic cylinder-associated polypeptides with molecular masses 29.5 and 34.7 kDa, pI 5.62, and one in vitro "lost" polypeptide with molecular mass 34.7 kDa, pI 5.34. integral membrane proteins of in vitro and in vivo propagated T. pallidum was identified by phase partitioning with the nonionic Triton X-114, and twelve outer membrane-associated, antigenic proteins were identified in western blots probed with pooled human secondary syphilitic sera. The solubilization of the outer membrane of T. pallidum with Triton X-114 were monitored by electron microscopy. Treatment of freshly harvested 35S labeled T. pallidum with 1% Triton X-114 resulted in solubilization of the outer membrane and reduction of the diameter of the treponemes from .14 +/- .02 micrometers to .095 +/- .003 micrometers. Examination of thin sections of untreated organisms showed integrity of outer and cytoplasmic membranes. In contrast, thin sections of Triton X-114-treated trponemes showed integrity of the cytoplasmic membrane but the loss of the outer membrane. The cytoplasmic cylinders generated by detergent treatment retained their periplasmic flagella, as judged by electron microscopy and immunoblotting. Integral membrane proteins of Treponema phagedenis were also identified by phase partitioning with Triton X-114, and sizteen cross-reactive, outer membrane-associated, outer membrane-associated, antigenic polypeptides were identified in western blots probed with pooled human secondary syphilitic sera. The results of this study indicate that tow-dimensional protein profiles of in vivo and in vitro propagated T.pallidum are almost identical except for the differences mentioned. This results also indicate that 1% Triton X-114 selectively solubilizes the outer membrane, and the antigenic hydrophobic proteins present in the detergent phrase are located exclusively in the outer membrane.

Yes / Background. The spirochete bacterium Treponema pallidum ssp. pallidum is the etiological agent of syphilis, a chronic multistage disease. Little is known about the global T. pallidum proteome, therefore mass spectrometry studies are needed to bring insights into pathogenicity and protein expression profiles during infection. Methodology/Principal Findings. To better understand the T. pallidum proteome profile during infection, we studied T. pallidum ssp. pallidum DAL-1 strain bacteria isolated from rabbits using complementary mass spectrometry techniques, including multidimensional peptide separation and protein identification via matrix-assisted laser desorption ionization-time of flight (MALDI-TOF/TOF) and electrospray ionization (ESI-LTQ-Orbitrap) tandem mass spectrometry. A total of 6033 peptides were detected, corresponding to 557 unique T. pallidum proteins at a high level of confidence, representing 54% of the predicted proteome. A previous gel-based T. pallidum MS proteome study detected 58 of these proteins. One hundred fourteen of the detected proteins were previously annotated as hypothetical or uncharacterized proteins; this is the first account of 106 of these proteins at the protein level. Detected proteins were characterized according to their predicted biological function and localization; half were allocated into a wide range of functional categories. Proteins annotated as potential membrane proteins and proteins with unclear functional annotations were subjected to an additional bioinformatics pipeline analysis to facilitate further characterization. A total of 116 potential membrane proteins were identified, of which 16 have evidence supporting outer membrane localization. We found 8/12 proteins related to the paralogous tpr gene family: TprB, TprC/D, TprE, TprG, TprH, TprI and TprJ. Protein abundance was semi-quantified using label-free spectral counting methods. A low correlation (r = 0.26) was found between previous microarray signal data and protein abundance. Conclusions. This is the most comprehensive description of the global T. pallidum proteome to date. These data provide valuable insights into in vivo T. pallidum protein expression, paving the way for improved understanding of the pathogenicity of this enigmatic organism. / This work was supported by the grants from the Flanders Research Foundation, SOFI-B Grant to CRK, http://www.fwo.be/, a Public Health Service Grant from the National Institutes of Health to CEC, (grant # AI-051334), https://www.nih.gov/ and a grant from the Grant Agency of the Czech Republic to DS and MS (P302/12/0574, GP14-29596P), https:// gacr.cz/.

Thesis (doctoral)--Albert-Ludwigs-Universität Freiburg im Breisgau, 2005.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Treponema pallidum ssp. pallidum is the causative agent of syphilis, a multi-stage bacterial infection, transmitted sexually or from mother-to-child, with an unparalleled range of symptoms arising from the ability of treponemes to penetrate any tissue and cross immune privileged endothelial barriers to access the brain, the eye, and the fetus. Further, without treatment T. pallidum evades immune clearance and persists within the host to establish a chronic infection. These characteristics suggest that T. pallidum may have evolved unique mechanisms for immune escape and to mediate host-cell interactions. The findings presented in this dissertation contribute to our knowledge of T. pallidum pathogenesis by investigating a previously unexplored host-cell interaction, between T. pallidum and human platelets. These results validate the hypothesis that, as a pathogen which successfully utilizes vascular dissemination, T. pallidum would not only encounter, but interact with human platelets, complex cells now viewed as vascular sentinels that participate in many host-pathogen interactions. This is the first study to demonstrate that T. pallidum interacts with human platelets and to characterize and quantify these interactions using high resolution microscope imaging techniques (video and frame analysis). These interactions were shown to be complex, reversible and mediated by motile treponemes localizing to stationary, (slide-adhered) activated platelets, versus to free-floating, inactive platelets. In addition, it was found that T. pallidum discriminates between the level of platelet activation and preferentially localized to the most activated platelet. Treponema pallidum was also able to induce platelet activation following an extended lag period. Modified chemotaxis assays quantified by flow cytometry, were used to investigate the migration of T. pallidum in response to the plasma of platelets differentially activated with infection-relevant host components (thrombin, collagen). The results herein reveal that T. pallidum discriminates between different mechanisms of platelet activation, with a significant preference towards the secretions of collagen-activated platelets (under these experimental conditions), compared with that of inactive or thrombin-activated platelets. Previously, T. pallidum chemotaxis had been investigated through genomic characterization and molecular interaction studies with recombinant proteins. This investigation is the first time live T. pallidum was utilized for in vitro chemotaxis assays and is also the first study of pathogen chemotaxis in response to the secretions of differentially activated platelets. The body of work in this dissertation provides a foundation to further investigate the role of T. pallidum-platelet interactions during infection, adding a new host-cell interaction to our understanding of T. pallidum pathogenesis. The evidence that the molecular gradients of host components can affect T. pallidum migration suggests an important role for chemotaxis during T. pallidum infection. Together, the characterization of platelet-interactions and treponeme chemotaxis in response to host components, adds to our knowledge of T. pallidum-host interactions, and eludes to additional pathogenic strategies that may facilitate T. pallidum dissemination and immune evasion. / Graduate / 2022-01-14

No description available.

No description available.