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Seña AC, Matoga MM, Yang L, Lopez-Medina E, Aghakhanian F, Chen JS, Bettin EB, Caimano MJ, Chen W, Garcia-Luna JA, Hennelly CM, Jere E, Jiang Y, Juliano JJ, Pospíšilová P, Ramirez L, Šmajs D, Tucker JD, Vargas Cely F, Zheng H, Hoffman IF, Yang B, Moody MA, Hawley KL, Salazar JC, Radolf JD, Parr JB. Clinical and genomic diversity of Treponema pallidum subspecies pallidum to inform vaccine research: an international, molecular epidemiology study. THE LANCET. MICROBE 2024; 5:100871. [PMID: 39181152 PMCID: PMC11371664 DOI: 10.1016/s2666-5247(24)00087-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 02/19/2024] [Accepted: 03/25/2024] [Indexed: 08/27/2024]
Abstract
BACKGROUND The increase in syphilis rates worldwide necessitates development of a vaccine with global efficacy. We aimed to explore Treponema pallidum subspecies pallidum (TPA) molecular epidemiology essential for vaccine research by analysing clinical data and specimens from early syphilis patients using whole-genome sequencing (WGS) and publicly available WGS data. METHODS In this multicentre, cross-sectional, molecular epidemiology study, we enrolled patients with primary, secondary, or early latent syphilis from clinics in China, Colombia, Malawi, and the USA between Nov 28, 2019, and May 27, 2022. Participants aged 18 years or older with laboratory confirmation of syphilis by direct detection methods or serological testing, or both, were included. Patients were excluded from enrolment if they were unwilling or unable to give informed consent, did not understand the study purpose or nature of their participation, or received antibiotics active against syphilis in the past 30 days. TPA detection and WGS were conducted on lesion swabs, skin biopsies, skin scrapings, whole blood, or rabbit-passaged isolates. We compared our WGS data to publicly available genomes and analysed TPA populations to identify mutations associated with lineage and geography. FINDINGS We screened 2802 patients and enrolled 233 participants, of whom 77 (33%) had primary syphilis, 154 (66%) had secondary syphilis, and two (1%) had early latent syphilis. The median age of participants was 28 years (IQR 22-35); 154 (66%) participants were cisgender men, 77 (33%) were cisgender women, and two (1%) were transgender women. Of the cisgender men, 66 (43%) identified as gay, bisexual, or other sexuality. Among all participants, 56 (24%) had HIV co-infection. WGS data from 113 participants showed a predominance of SS14-lineage strains with geographical clustering. Phylogenomic analyses confirmed that Nichols-lineage strains were more genetically diverse than SS14-lineage strains and clustered into more distinct subclades. Differences in single nucleotide variants (SNVs) were evident by TPA lineage and geography. Mapping of highly differentiated SNVs to three-dimensional protein models showed population-specific substitutions, some in outer membrane proteins (OMPs) of interest. INTERPRETATION Our study substantiates the global diversity of TPA strains. Additional analyses to explore TPA OMP variability within strains is vital for vaccine development and understanding syphilis pathogenesis on a population level. FUNDING US National Institutes of Health National Institute for Allergy and Infectious Disease, the Bill & Melinda Gates Foundation, Connecticut Children's, and the Czech Republic National Institute of Virology and Bacteriology.
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Affiliation(s)
- Arlene C Seña
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | | | - Ligang Yang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Eduardo Lopez-Medina
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Department of Pediatrics, Universidad del Valle, Cali, Colombia
| | - Farhang Aghakhanian
- Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jane S Chen
- Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Melissa J Caimano
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Wentao Chen
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China; BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research School of Public Health, Southern Medical University, Guangzhou, China
| | - Jonny A Garcia-Luna
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Universidad Icesi, Cali, Colombia; Division of Dermatology, Department of Internal Medicine, School of Medicine, Universidad del Valle, Cali, Colombia
| | - Christopher M Hennelly
- Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Edward Jere
- UNC Project Malawi, Tidziwe Centre, Lilongwe, Malawi
| | - Yinbo Jiang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Jonathan J Juliano
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Lady Ramirez
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia; Universidad Icesi, Cali, Colombia
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Joseph D Tucker
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Fabio Vargas Cely
- Centro Internacional de Entrenamiento e Investigaciones Medicas, Campus de la Universidad Icesi, Cali, Colombia
| | - Heping Zheng
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - Irving F Hoffman
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China
| | - M Anthony Moody
- Department of Pediatrics, Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USA; Department of Integrative Immunology, Duke University Medical Center, Durham, NC, USA; Duke Human Vaccine Institute, Durham, NC, USA
| | - Kelly L Hawley
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Juan C Salazar
- Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, CT, USA; Department of Pediatrics, UConn Health, Farmington, CT, USA; Department of Immunology, UConn Health, Farmington, CT, USA; Connecticut Children's, Hartford, CT, USA
| | - Jonathan B Parr
- Department of Medicine, Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Institute for Global Health and Infectious Diseases, Infectious Diseases Epidemiology and Ecology Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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2
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Grillová L, Romeis E, Lieberman NAP, Tantalo LC, Xu LH, Molini B, Trejos AT, Lacey G, Goulding D, Thomson NR, Greninger AL, Giacani L. Bright New Resources for Syphilis Research: Genetically Encoded Fluorescent Tags for Treponema pallidum and Sf1Ep Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596454. [PMID: 38854070 PMCID: PMC11160695 DOI: 10.1101/2024.05.29.596454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The recently discovered methodologies to cultivate and genetically manipulate Treponema pallidum subsp. pallidum ( T. pallidum ) have significantly helped syphilis research, allowing the in vitro evaluation of antibiotic efficacy, performance of controlled studies to assess differential treponemal gene expression, and generation of loss-of-function mutants to evaluate the contribution of specific genetic loci to T. pallidum virulence. Building on this progress, we engineered the T. pallidum SS14 strain to express a red-shifted Green Fluorescent Protein (GFP) and Sf1Ep cells to express mCherry and blue fluorescent protein (BFP) for enhanced visualization. These new resources improve microscopy- and cell sorting-based applications for T. pallidum , better capturing the physical interaction between the host and pathogen, among other possibilities. Continued efforts to develop and share new tools and resources are required to help our overall knowledge of T. pallidum biology and syphilis pathogenesis reach that of other bacterial pathogens, including spirochetes. Graphical abstract By employing genetic engineering, T. pallidum was modified to express GFP, and Sf1Ep cells to express mCherry on the cytoplasmic membrane and BFP in the nucleus. These new resources for syphilis research will facilitate experimental designs to better define the complex interplay between T. pallidum and the host during infection.
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Houston S, Gomez A, Geppert A, Goodyear MC, Cameron CE. In-Depth Proteome Coverage of In Vitro-Cultured Treponema pallidum and Quantitative Comparison Analyses with In Vivo-Grown Treponemes. J Proteome Res 2024; 23:1725-1743. [PMID: 38636938 PMCID: PMC11077495 DOI: 10.1021/acs.jproteome.3c00891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/14/2024] [Accepted: 03/22/2024] [Indexed: 04/20/2024]
Abstract
Previous mass spectrometry (MS)-based global proteomics studies have detected a combined total of 86% of all Treponema pallidum proteins under infection conditions (in vivo-grown T. pallidum). Recently, a method was developed for the long-term culture of T. pallidum under in vitro conditions (in vitro-cultured T. pallidum). Herein, we used our previously reported optimized MS-based proteomics approach to characterize the T. pallidum global protein expression profile under in vitro culture conditions. These analyses provided a proteome coverage of 94%, which extends the combined T. pallidum proteome coverage from the previously reported 86% to a new combined total of 95%. This study provides a more complete understanding of the protein repertoire of T. pallidum. Further, comparison of the in vitro-expressed proteome with the previously determined in vivo-expressed proteome identifies only a few proteomic changes between the two growth conditions, reinforcing the suitability of in vitro-cultured T. pallidum as an alternative to rabbit-based treponemal growth. The MS proteomics data have been deposited in the MassIVE repository with the data set identifier MSV000093603 (ProteomeXchange identifier PXD047625).
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Affiliation(s)
- Simon Houston
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Alloysius Gomez
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Andrew Geppert
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Mara C. Goodyear
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Caroline E. Cameron
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
- Department
of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington 98195, United States
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Haynes AM, Konda KA, Romeis E, Siebert J, Vargas SK, Reyes Diaz M, Phan A, Caceres CF, Giacani L, Klausner JD. Evaluation of a minimal array of Treponema pallidum antigens as biomarkers for syphilis diagnosis, infection staging, and response to treatment. Microbiol Spectr 2024; 12:e0346623. [PMID: 38095465 PMCID: PMC10782976 DOI: 10.1128/spectrum.03466-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE This manuscript explores the host humoral response to selected antigens of the syphilis agent during infection to evaluate their potential use as diagnostic tests and markers for treatment.
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Affiliation(s)
- Austin M. Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Kelika A. Konda
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Center for Interdisciplinary Studies in Sexuality, AIDS and Society, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | | | - Silver K. Vargas
- Center for Interdisciplinary Studies in Sexuality, AIDS and Society, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Michael Reyes Diaz
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Amber Phan
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Carlos F. Caceres
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
- Department of Global Health, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Jeffrey D. Klausner
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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Knauf S, Hisgen L, Ågren EO, Barlow AM, Faehndrich M, Voigt U, Fischer L, Grillová L, Hallmaier-Wacker LK, Kik MJL, Klink JC, Křenová J, Lavazza A, Lüert S, Nováková M, Čejková D, Pacioni C, Trogu T, Šmajs D, Roos C. High prevalence and genetic diversity of Treponema paraluisleporidarum isolates in European lagomorphs. Microbiol Spectr 2024; 12:e0177423. [PMID: 38095473 PMCID: PMC10783078 DOI: 10.1128/spectrum.01774-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 10/17/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE Syphilis is an ancient disease of humans and lagomorphs caused by two distinct but genetically closely related bacteria (>98% sequence identity based on the whole genome) of the genus Treponema. While human syphilis is well studied, little is known about the disease in the lagomorph host. Yet, comparative studies are needed to understand mechanisms in host-pathogen coevolution in treponematoses. Importantly, Treponema paraluisleporidarum-infected hare populations provide ample opportunity to study the syphilis-causing pathogen in a naturally infected model population without antibiotic treatment, data that cannot be obtained from syphilis infection in humans. We provide data on genetic diversity and are able to highlight various types of repetitions in one of the two hypervariable regions at the tp0548 locus that have not been described in the human syphilis-causing sister bacterium Treponema pallidum subsp. pallidum.
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Affiliation(s)
- Sascha Knauf
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Germany
- Infection Biology Unit, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
- Professorship for International Animal Health/One Health, Faculty of Veterinary Medicine, Justus Liebig University, Giessen, Germany
| | - Linda Hisgen
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Germany
- Infection Biology Unit, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Erik O. Ågren
- Department of Pathology and Wildlife Diseases, National Veterinary Institute, Uppsala, Sweden
| | - Alexander M. Barlow
- Wildlife Network for Disease Surveillance, Bristol Veterinary School, Langford, Somerset, United Kingdom
| | - Marcus Faehndrich
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
| | - Ulrich Voigt
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
| | - Luisa Fischer
- Wildlife Research Institute, State Agency for Nature, Environment and Consumer Protection North Rhine-Westphalia, Bonn, Germany
| | - Linda Grillová
- Department of Biology, Masaryk University, Brno, Czechia
| | - Luisa K. Hallmaier-Wacker
- Infection Biology Unit, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Marja J. L. Kik
- Pathology Division, Department of Biomedical Health Sciences, Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Jana C. Klink
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hanover, Foundation, Hanover, Germany
| | - Jitka Křenová
- Department of Biology, Masaryk University, Brno, Czechia
| | - Antonio Lavazza
- Department of Animal Health and Welfare – Virology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Brescia, Italy
| | - Simone Lüert
- Institute of International Animal Health/One Health, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Germany
- Infection Biology Unit, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
| | | | - Darina Čejková
- Department of Biomedical Engineering, Brno University of Technology, Brno, Czechia
| | - Carlo Pacioni
- Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, Australia
- Environmental and Conservation Sciences, Murdoch University, Murdoch, Australia
| | - Tiziana Trogu
- Department of Animal Health and Welfare – Virology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Brescia, Italy
| | - David Šmajs
- Department of Biology, Masaryk University, Brno, Czechia
| | - Christian Roos
- Primate Genetics Laboratory, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
- Gene Bank of Primates, Deutsches Primatenzentrum GmbH, Leibniz Institute for Primate Research, Göttingen, Germany
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6
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Houston S, Gomez A, Geppert A, Eshghi A, Smith DS, Waugh S, Hardie DB, Goodlett DR, Cameron CE. Deep proteome coverage advances knowledge of Treponema pallidum protein expression profiles during infection. Sci Rep 2023; 13:18259. [PMID: 37880309 PMCID: PMC10600179 DOI: 10.1038/s41598-023-45219-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/17/2023] [Indexed: 10/27/2023] Open
Abstract
Comprehensive proteome-wide analysis of the syphilis spirochete, Treponema pallidum ssp. pallidum, is technically challenging due to high sample complexity, difficulties with obtaining sufficient quantities of bacteria for analysis, and the inherent fragility of the T. pallidum cell envelope which further complicates proteomic identification of rare T. pallidum outer membrane proteins (OMPs). The main aim of the present study was to gain a deeper understanding of the T. pallidum global proteome expression profile under infection conditions. This will corroborate and extend genome annotations, identify protein modifications that are unable to be predicted at the genomic or transcriptomic levels, and provide a foundational knowledge of the T. pallidum protein expression repertoire. Here we describe the optimization of a T. pallidum-specific sample preparation workflow and mass spectrometry-based proteomics pipeline which allowed for the detection of 77% of the T. pallidum protein repertoire under infection conditions. When combined with prior studies, this brings the overall coverage of the T. pallidum proteome to almost 90%. These investigations identified 27 known/predicted OMPs, including potential vaccine candidates, and detected expression of 11 potential OMPs under infection conditions for the first time. The optimized pipeline provides a robust and reproducible workflow for investigating T. pallidum protein expression during infection. Importantly, the combined results provide the deepest coverage of the T. pallidum proteome to date.
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Affiliation(s)
- Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Andrew Geppert
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Azad Eshghi
- University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, BC, Canada
| | - Derek S Smith
- University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, BC, Canada
| | - Sean Waugh
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Darryl B Hardie
- University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, BC, Canada
| | - David R Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, BC, Canada
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, USA.
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Yang L, Zhang X, Chen W, Seña AC, Zheng H, Jiang Y, Zhao P, Chen R, Wang L, Ke W, Salazar JC, Parr JB, Tucker JD, Hawley KL, Caimano MJ, Hennelly CM, Aghakanian F, Zhang F, Chen JS, Moody MA, Radolf JD, Yang B. Early syphilis in Guangzhou, China: presentation, molecular detection of Treponema pallidum , and genomic sequences in clinical specimens and isolates obtained by rabbit infectivity testing. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.17.23297169. [PMID: 37905017 PMCID: PMC10614984 DOI: 10.1101/2023.10.17.23297169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Background The global resurgence of syphilis requires novel prevention strategies. Whole genome sequencing (WGS) of Treponema pallidum ( TPA ) using different specimen types is essential for vaccine development. Methods Patients with primary (PS) and secondary (SS) syphilis were recruited in Guangzhou, China. We collected ulcer exudates and blood from PS participants, and skin biopsies and blood from SS participants for TPA polA polymerase chain reaction (PCR); ulcer exudates and blood were also used to isolate TPA strains by rabbit infectivity testing (RIT). TPA WGS was performed on 52 ulcer exudates and biopsy specimens and 25 matched rabbit isolates. Results We enrolled 18 PS and 51 SS participants from December 2019 to March 2022. Among PS participants, TPA DNA was detected in 16 (89%) ulcer exudates and three (17%) blood specimens. Among SS participants, TPA DNA was detected in 50 (98%) skin biopsies and 27 (53%) blood specimens. TP A was isolated from 48 rabbits, with a 71% (12/17) success rate from ulcer exudates and 69% (36/52) from SS bloods. Twenty-three matched SS14 clade genomes were virtually identical, while two Nichols clade pairs had discordant tprK sequences. Forty-two of 52 unique TPA genomes clustered in an SS14 East Asia subgroup, while ten fell into two East Asian Nichols subgroups. Conclusions Our TPA detection rate was high from PS ulcer exudates and SS skin biopsies and over 50% from SS whole blood, with RIT isolation in over two-thirds of samples. Our results support the use of WGS from rabbit isolates to inform vaccine development. Summary We performed Treponema pallidum molecular detection and genome sequencing from multiple specimens collected from early syphilis patients and isolates obtained by rabbit inoculation. Our results support the use of whole genome sequencing from rabbit isolates to inform syphilis vaccine development.
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Waugh S, Ranasinghe A, Gomez A, Houston S, Lithgow KV, Eshghi A, Fleetwood J, Conway KME, Reynolds LA, Cameron CE. Syphilis and the host: multi-omic analysis of host cellular responses to Treponema pallidum provides novel insight into syphilis pathogenesis. Front Microbiol 2023; 14:1254342. [PMID: 37795301 PMCID: PMC10546344 DOI: 10.3389/fmicb.2023.1254342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction Syphilis is a chronic, multi-stage infection caused by the extracellular bacterium Treponema pallidum ssp. pallidum. Treponema pallidum widely disseminates through the vasculature, crosses endothelial, blood-brain and placental barriers, and establishes systemic infection. Although the capacity of T. pallidum to traverse the endothelium is well-described, the response of endothelial cells to T. pallidum exposure, and the contribution of this response to treponemal traversal, is poorly understood. Methods To address this knowledge gap, we used quantitative proteomics and cytokine profiling to characterize endothelial responses to T. pallidum. Results Proteomic analyses detected altered host pathways controlling extracellular matrix organization, necroptosis and cell death, and innate immune signaling. Cytokine analyses of endothelial cells exposed to T. pallidum revealed increased secretion of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF), and decreased secretion of monocyte chemoattractant protein-1 (MCP-1). Discussion This study provides insight into the molecular basis of syphilis disease symptoms and the enhanced susceptibility of individuals infected with syphilis to HIV co-infection. These investigations also enhance understanding of the host response to T. pallidum exposure and the pathogenic strategies used by T. pallidum to disseminate and persist within the host. Furthermore, our findings highlight the critical need for inclusion of appropriate controls when conducting T. pallidum-host cell interactions using in vitro- and in vivo-grown T. pallidum.
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Affiliation(s)
- Sean Waugh
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Akash Ranasinghe
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Karen V. Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Azad Eshghi
- University of Victoria-Genome BC Proteomics Centre, Victoria, BC, Canada
| | - Jenna Fleetwood
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Kate M. E. Conway
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Lisa A. Reynolds
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, United States
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Seña AC, Matoga MM, Yang L, Lopez-Medina E, Aghakanian F, Chen JS, Bettin EB, Caimano MJ, Chen W, Garcia-Luna JA, Hennelly CM, Jiang Y, Juliano JJ, Pospíšilová P, Ramirez L, Šmajs D, Tucker JD, Cely FV, Zheng H, Hoffman IF, Yang B, Moody MA, Hawley KL, Salazar JC, Radolf JD, Parr JB. Clinical and genomic diversity of Treponema pallidum subsp. pallidum: A global, multi-center study of early syphilis to inform vaccine research. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.19.23291250. [PMID: 37546832 PMCID: PMC10402240 DOI: 10.1101/2023.07.19.23291250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Background The continuing increase in syphilis rates worldwide necessitates development of a vaccine with global efficacy. We conducted a multi-center, observational study to explore Treponema pallidum subsp. pallidum ( TPA ) molecular epidemiology essential for vaccine research by analyzing clinical data and specimens from early syphilis patients using whole-genome sequencing (WGS) and publicly available WGS data. Methods We enrolled patients with primary (PS), secondary (SS) or early latent (ELS) syphilis from clinics in China, Colombia, Malawi and the United States between November 2019 - May 2022. Inclusion criteria included age ≥18 years, and syphilis confirmation by direct detection methods and/or serological testing. TPA detection and WGS were conducted on lesion swabs, skin biopsies/scrapings, whole blood, and/or rabbit-passaged isolates. We compared our WGS data to publicly available genomes, and analysed TPA populations to identify mutations associated with lineage and geography. Findings We screened 2,820 patients and enrolled 233 participants - 77 (33%) with PS, 154 (66%) with SS, and two (1%) with ELS. Median age of participants was 28; 66% were cis -gender male, of which 43% reported identifying as "gay", "bisexual", or "other sexuality". Among all participants, 56 (24%) had HIV co-infection. WGS data from 113 participants demonstrated a predominance of SS14-lineage strains with geographic clustering. Phylogenomic analysis confirmed that Nichols-lineage strains are more genetically diverse than SS14-lineage strains and cluster into more distinct subclades. Differences in single nucleotide variants (SNVs) were evident by TPA lineage and geography. Mapping of highly differentiated SNVs to three-dimensional protein models demonstrated population-specific substitutions, some in outer membrane proteins (OMPs) of interest. Interpretation Our study involving participants from four countries substantiates the global diversity of TPA strains. Additional analyses to explore TPA OMP variability within strains will be vital for vaccine development and improved understanding of syphilis pathogenesis on a population level. Funding National Institutes of Health, Bill and Melinda Gates Foundation.
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Ávila-Nieto C, Pedreño-López N, Mitjà O, Clotet B, Blanco J, Carrillo J. Syphilis vaccine: challenges, controversies and opportunities. Front Immunol 2023; 14:1126170. [PMID: 37090699 PMCID: PMC10118025 DOI: 10.3389/fimmu.2023.1126170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
Syphilis is a sexually or vertically (mother to fetus) transmitted disease caused by the infection of Treponema pallidum subspecie pallidum (TPA). The incidence of syphilis has increased over the past years despite the fact that this bacterium is an obligate human pathogen, the infection route is well known, and the disease can be successfully treated with penicillin. As complementary measures to preventive campaigns and early treatment of infected individuals, development of a syphilis vaccine may be crucial for controlling disease spread and/or severity, particularly in countries where the effectiveness of the aforementioned measures is limited. In the last century, several vaccine prototypes have been tested in preclinical studies, mainly in rabbits. While none of them provided protection against infection, some prototypes prevented bacteria from disseminating to distal organs, attenuated lesion development, and accelerated their healing. In spite of these promising results, there is still some controversy regarding the identification of vaccine candidates and the characteristics of a syphilis-protective immune response. In this review, we describe what is known about TPA immune response, and the main mechanisms used by this pathogen to evade it. Moreover, we emphasize the importance of integrating this knowledge, in conjunction with the characterization of outer membrane proteins (OMPs), to expedite the development of a syphilis vaccine that can protect against TPA infection.
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Affiliation(s)
- Carlos Ávila-Nieto
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Autonomous University of Barcelona, Cerdanyola del Vallès, Catalonia, Spain
| | | | - Oriol Mitjà
- Skin Neglected Tropical Diseases and Sexually Transmitted Infections Department, Germans Trias i Pujol Hospital, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
| | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Fight Infections Foundation, Germans Trias i Pujol Hospital, Badalona, Catalonia, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Julià Blanco
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Centre for Health and Social Care Research (CESS), Faculty of Medicine, University of Vic – Central University of Catalonia (UVic – UCC), Vic, Catalonia, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
| | - Jorge Carrillo
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- CIBERINFEC, Instituto de Salut Carlos III (ISCIII), Madrid, Spain
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11
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He Y, Chen D, Fu Y, Huo X, Zhao F, Yao L, Zhou X, Qi P, Yin H, Cao L, Ling H, Zeng T. Immunization with Tp0954, an adhesin of Treponema pallidum, provides protective efficacy in the rabbit model of experimental syphilis. Front Immunol 2023; 14:1130593. [PMID: 36993963 PMCID: PMC10042077 DOI: 10.3389/fimmu.2023.1130593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Syphilis, a chronic multisystemic disease caused by spirochete Treponema pallidum subspecies pallidum infection, continues to be a serious global health problem and congenital syphilis remains a major cause of adverse outcomes in pregnancy in developing countries. The development of an effective vaccine is the most cost-effective way to eliminate syphilis, but so far has been elusive. Here, we evaluated the immunogenicity and protective efficacy of Tp0954, a T. pallidum placental adhesin, as a potential vaccine candidate in a New Zealand White rabbit model of experimental syphilis. Animals immunized with recombinant Tp0954 (rTp0954) produced high titers of Tp0954-specific serum IgG, high levels of IFN-γ from splenocytes and specific splenocyte proliferation response when compared to control animals immunized with PBS and Freund’s adjuvant (FA). Furthermore, rTp0954 immunization significantly delayed the development of cutaneous lesions, promoted inflammatory cellular infiltration at the primary lesion sites, as well as inhibited T. pallidum dissemination to distal tissues or organs when compared with that of the control animals. In addition, the naïve rabbits receiving popliteal lymph nodes from Tp0954-immunized, T. pallidum-challenged animals were not infected by T. pallidum, confirming sterile immunity. These findings suggest that Tp0954 is a potential vaccine candidate against syphilis.
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Affiliation(s)
- Yuxing He
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Dejun Chen
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yue Fu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Xinzhuo Huo
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Ling Yao
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Xiuping Zhou
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Pengfei Qi
- Department of Clinical Medical undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Haoquan Yin
- Department of Clinical Medical undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Longgu Cao
- College of Medical Imaging and Inspection, Xiangnan University, Chenzhou, China
| | - Hui Ling
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
- Hunan Province Key Laboratory of Tumor Cellular and Molecular Pathology, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, China
- *Correspondence: Tiebing Zeng, ; Hui Ling,
| | - Tiebing Zeng
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
- *Correspondence: Tiebing Zeng, ; Hui Ling,
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12
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Romeis E, Lieberman NAP, Molini B, Tantalo LC, Chung B, Phung Q, Avendaño C, Vorobieva A, Greninger AL, Giacani L. Treponema pallidum subsp. pallidum with an Artificially Impaired TprK Antigenic Variation System is Attenuated in the Rabbit Model of Syphilis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.18.524629. [PMID: 36711914 PMCID: PMC9882362 DOI: 10.1101/2023.01.18.524629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background The TprK protein of the syphilis agent, Treponema pallidum subsp. pallidum ( T. pallidum ), undergoes antigenic variation in seven discrete variable (V) regions via non-reciprocal segmental gene conversion. These recombination events transfer information from a repertoire of 53 silent chromosomal donor cassettes (DCs) into the single tprK expression site to continually generate TprK variants. Several lines of research developed over the last two decades support the theory that this mechanism is central to T. pallidum 's ability for immune avoidance and persistence in the host. Structural and modeling data, for example, identify TprK as an integral outer membrane porin with the V regions exposed on the pathogen's surface. Furthermore, infection-induced antibodies preferentially target the V regions rather than the predicted β-barrel scaffolding, and sequence variation abrogates the binding of antibodies elicited by antigenically different V regions. Here, we engineered a T. pallidum strain to impair its ability to vary TprK and assessed its virulence in the rabbit model of syphilis. Principal findings A suicide vector was transformed into the wild-type (WT) SS14 T. pallidum isolate to eliminate 96% of its tprK DCs. The resulting SS14-DC KO strain exhibited an in vitro growth rate identical to the untransformed strain, supporting that the elimination of the DCs did not affect strain viability in absence of immune pressure. In rabbits injected intradermally with the SS14-DC KO strain, generation of new TprK sequences was impaired, and the animals developed attenuated lesions with a significantly reduced treponemal burden compared to control animals. During infection, clearance of V region variants originally in the inoculum mirrored the generation of antibodies to these variants, although no new variants were generated in the SS14-DC KO strain to overcome immune pressure. Naïve rabbits that received lymph node extracts from animals infected with the SS14-DC KO strain remained uninfected. Conclusion These data further support the critical role of TprK in T. pallidum virulence and persistence during infection. Author Summary Syphilis is still endemic in low- and middle-income countries, and it has been resurgent in high-income nations, including the U.S., for years. In endemic areas, there is still significant morbidity and mortality associated with this disease, particularly when its causative agent, the spirochete Treponema pallidum subsp . pallidum ( T. pallidum ) infects the fetus during pregnancy. Improving our understanding of syphilis pathogenesis and T. pallidum biology could help investigators devise better control strategies for this serious infection. Now that tools to genetically manipulate this pathogen are available, we can engineer T. pallidum strains lacking specific genes or genomic regions known (or believed) to be associated with virulence. This approach can shed light on the role of the ablated genes or sequences in disease development using loss-of-function strains. Here, we derived a knockout (KO) T. pallidum mutant (SS14-DC KO ) impaired in its ability to undergo antigenic variation of TprK, a protein that has long been hypothesized to be central in evasion of the host immune response and pathogen persistence during infection. When compared to the WT isolate, which is still capable of antigenic variation, the SS14-DC KO strain is significantly attenuated in its ability to proliferate and to induce early disease manifestations in infected rabbits. Our results further support the importance of TprK antigenic variation in syphilis pathogenesis and pathogen persistence.
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13
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Transcriptome-wide assessment of N6-methyladenosine modification identifies different gene expression and infection-associated pathways in Treponema pallidum-infected macrophage. J Dermatol Sci 2023; 109:108-116. [PMID: 36841722 DOI: 10.1016/j.jdermsci.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 12/18/2022] [Accepted: 02/16/2023] [Indexed: 02/21/2023]
Abstract
BACKGROUND Treponema pallidum (Tp) is a widespread and destructive pathogen that leads to syphilis. As the acknowledged executor of host immunity, macrophage plays vital roles in combating the invasion and migration of Tp. However, the mechanisms of these processes are largely unknown, especially the critical driver genes and associated modifications. OBJECTIVE We aimed to systematically dissect the global N6-methyladenosine (m6A) RNA modification patterns in Tp-infected macrophages. METHODS The RNA of Tp-infected/non-infected macrophage was extracted, followed by mRNA sequencing and methylated RNA immunoprecipitation (MeRIP) sequencing. Bioinformatics analysis was executed by m6A peaks and motifs identification, Gene ontology and signaling pathways analysis of differentially expressed genes, and comprehensive comparison. The m6A levels were measured by RNA Methylation Assay, and m6A modified genes were determined by qPCR. RESULTS Totally, 2623 unique and 3509 common m6A peaks were proved along with related transcripts in Tp-infected macrophages. The common m6A-related genes were enriched in the signals of oxidative stress, cell differentiation, and angiogenesis, while unique genes in those of metabolism, inflammation, and infection. And differentially expressed transcripts revealed various biological processes and pathways associated with catabolic and infection. They also experienced comprehensive analysis due to hyper-/hypo-methylation. And the m6A level of macrophage was elevated, along with qPCR validation of specific genes. CONCLUSION With a particular m6A transcriptome-wide map, our study provides unprecedented insights into the RNA modification of macrophage stimulated by Tp in vitro, which partially differs from other infections and may provide clues to explore the immune process for syphilis.
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14
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Luo Y, Xie Y, Chen J, Zhou J, Zhao F, Liu S, Zeng T, Xu M, Xiao Y. Treponema pallidum FlaA2 inducing the release of pro-inflammatory cytokines is mediated via TLR2 in keratinocytes. Microb Pathog 2022; 173:105879. [DOI: 10.1016/j.micpath.2022.105879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 11/01/2022] [Accepted: 11/09/2022] [Indexed: 11/14/2022]
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15
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Chen W, Luo H, Zeng L, Pan Y, Parr JB, Jiang Y, Cunningham CH, Hawley KL, Radolf JD, Ke W, Ou J, Yang J, Yang B, Zheng H. A suite of PCR-LwCas13a assays for detection and genotyping of Treponema pallidum in clinical samples. Nat Commun 2022; 13:4671. [PMID: 35945210 PMCID: PMC9362966 DOI: 10.1038/s41467-022-32250-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 07/25/2022] [Indexed: 11/10/2022] Open
Abstract
The performance of commonly used assays for diagnosis of syphilis varies considerably depending on stage of infection and sample type. In response to the need for improved syphilis diagnostics, we develop assays that pair PCR pre-amplification of the tpp47 gene of Treponema pallidum subsp. pallidum with CRISPR-LwCas13a. The PCR-LwCas13a assay achieves an order of magnitude better analytical sensitivity than real-time PCR with equivalent specificity. When applied to a panel of 216 biological specimens, including 135 clinically confirmed primary and secondary syphilis samples, the PCR-LwCas13a assay demonstrates 93.3% clinical sensitivity and 100% specificity, outperforming tpp47 real-time PCR and rabbit-infectivity testing. We further adapt this approach to distinguish Treponema pallidum subsp. pallidum lineages and identify genetic markers of macrolide resistance. Our study demonstrates the potential of CRISPR-based approaches to improve diagnosis and epidemiological surveillance of syphilis.
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Affiliation(s)
- Wentao Chen
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Hao Luo
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Lihong Zeng
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Yuying Pan
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, and Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, NC, USA
| | - Yinbo Jiang
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Clark H Cunningham
- Division of Infectious Diseases, Department of Medicine, and Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, NC, USA
| | - Kelly L Hawley
- Division of Infectious Diseases, Connecticut Children's, Hartford, CT, USA
- Department of Medicine, UConn Health, Farmington, CT, USA
- Department of Pediatrics, UConn Health, Farmington, CT, USA
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, CT, USA
- Department of Pediatrics, UConn Health, Farmington, CT, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA
- Department of Immunology, UConn Health, Farmington, CT, USA
| | - Wujian Ke
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Jiangli Ou
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Jianjiang Yang
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China.
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China.
| | - Heping Zheng
- Dermatology Hospital, Southern Medical University, Guangzhou, P. R. China.
- Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, P. R. China.
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16
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Chen D, Wang S, He Y, Fu Y, Zhao F, Zhou X, Yin H, Wan J, Huang Y, Wu Y, Cao L, Zeng T. Assessment of recombinant antigens Tp0100 and Tp1016 of Treponema pallidum for serological diagnosis of syphilis. J Clin Lab Anal 2022; 36:e24635. [PMID: 35908795 PMCID: PMC9459255 DOI: 10.1002/jcla.24635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 07/08/2022] [Accepted: 07/13/2022] [Indexed: 11/30/2022] Open
Abstract
Objective To discover novel serodiagnostic candidates for the serological diagnosis of syphilis. Methods Two recombinant Treponema pallidum proteins Tp0100 and Tp1016 were expressed, purified, and identified by Western Blotting. A total of 600 clinical serum samples were tested with the Tp0100‐based ELISA, the Tp1016‐based ELISA, and the commercial LICA Syphilis TP kit (ChIVD, Beijing, China). The sensitivities were determined by testing 340 samples from individuals with clinically diagnosed primary, secondary, latent, and tertiary syphilis. The specificities were determined by screening 260 samples from healthy controls and individuals with potentially cross‐reactive infections, including leptospirosis, Lyme disease, hepatitis B, tuberculosis, rheumatoid arthritis, systemic lupus erythematosus. Kappa (κ) values were applied to compare the agreement between clinical syphilis diagnosis and the Tp0100‐based ELISA, the Tp1016‐based ELISA, or the LICA Syphilis TP test. Results Using clinical syphilis diagnosis as the gold standard, Tp0100 exhibited an overall sensitivity of 95.6% and specificity of 98.1% for testing IgG antibody while Tp1016 demonstrated only an overall sensitivity of 75.0% and specificity of 79.6%. In contrast, the LICA Syphilis TP test revealed an overall sensitivity of 97.6% and specificity of 96.2%. In addition, the overall percent agreement and corresponding κ values were 96.7% (95% CI 95.6%–97.8%) and 0.93 for the Tp0100‐based ELISA, 77.0% (95% CI 74.3%–79.7%) and 0.54 for the Tp1016‐based ELISA, and 97.0% (95% CI 96.0%–98.0%) and 0.94 for the LICA Syphilis TP test, respectively. Conclusion The recombinant T. pallidum protein Tp0100 shows promise as a novel diagnostic antigen in the serological tests for syphilis.
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Affiliation(s)
- Dejun Chen
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Siqian Wang
- Clinical laboratory of the First Pepole's Hospital of Changde City, Changde, China
| | - Yuxing He
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yue Fu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Xiuping Zhou
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Haoquan Yin
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Jia Wan
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Yunting Huang
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Longgu Cao
- College of Medical Imaging Laboratory and Rehabilitation, Xiangnan University, Chenzhou, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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17
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Wang J, Lu S, Zheng K, He Z, Li W, Liu J, Guo N, Xie Y, Chen D, Xu M, Wu Y. Treponema pallidum delays the apoptosis of human polymorphonuclear neutrophils through the intrinsic and extrinsic pathways. Mol Immunol 2022; 147:157-169. [PMID: 35597181 DOI: 10.1016/j.molimm.2022.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/26/2022] [Accepted: 04/21/2022] [Indexed: 11/26/2022]
Abstract
Treponema pallidum is a "stealth pathogen" responsible for infectious sexually transmitted diseases. Although neutrophils are usually present in skin lesions of early syphilis, the role of these cells in T. pallidum infection has barely been investigated. Neutrophils are short-lived cells that undergo constitutive apoptosis, and phagocytosis usually accelerates this process. Here, we demonstrated that human polymorphonuclear neutrophils (hPMNs) could phagocytose T. pallidum in vitro. An unexpected discovery was that T. pallidum inhibited hPMNs apoptosis markedly in an opsonin-independent manner. Furthermore, this phenomenon was not affected by bacterial viability, as detected by annexin V, morphology studies, and TUNEL staining. Exploration of the underlying mechanism showed that expression of the cleaved forms of caspase-3, -8, and -9 and effector caspase activity were diminished significantly in T. pallidum-infected hPMNs. T. pallidum also impaired staurosporine- and anti-Fas-induced signaling for neutrophil apoptosis. Of note, these effects were accompanied by inducing the autocrine production of the anti-apoptotic cytokine IL-8. Taken together, our data revealed that T. pallidum could inhibit the apoptosis of hPMNs through intrinsic and extrinsic pathways and provide new insights for understanding the pathogenicity mechanisms of T. pallidum.
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Affiliation(s)
- Jianye Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Simin Lu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Kang Zheng
- Clinical Laboratory, Hengyang Central Hospital, Hengyang, China
| | - Zhangping He
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Weiwei Li
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Jie Liu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Ningyuan Guo
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Yafeng Xie
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China; Department of Clinical Laboratory, the Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Dejun Chen
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Man Xu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China.
| | - Yimou Wu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China.
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18
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Molini B, Fernandez MC, Godornes C, Vorobieva A, Lukehart SA, Giacani L. B-Cell Epitope Mapping of TprC and TprD Variants of Treponema pallidum Subspecies Informs Vaccine Development for Human Treponematoses. Front Immunol 2022; 13:862491. [PMID: 35422800 PMCID: PMC9001972 DOI: 10.3389/fimmu.2022.862491] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/07/2022] [Indexed: 12/02/2022] Open
Abstract
Several recent studies have focused on the identification, functional analysis, and structural characterization of outer membrane proteins (OMPs) of Treponema pallidum (Tp). The Tp species encompasses the highly related pallidum, pertenue, and endemicum subspecies of this pathogen, known to be the causative agents of syphilis, yaws, and bejel, respectively. These studies highlighted the importance of identifying surface-exposed OMP regions and the identification of B-cell epitopes that could be protective and used in vaccine development efforts. We previously reported that the TprC and TprD OMPs of Tp are predicted to contain external loops scattered throughout the entire length of the proteins, several of which show a low degree of sequence variability among strains and subspecies. In this study, these models were corroborated using AlphaFold2, a state-of-the-art protein structure modeling software. Here, we identified B-cell epitopes across the full-length TprC and TprD variants using the Geysan pepscan mapping approach with antisera from rabbits infected with syphilis, yaws, and bejel strains and from animals immunized with refolded recombinant TprC proteins from three syphilis strains. Our results show that the humoral response is primarily directed to sequences predicted to be on surface-exposed loops of TprC and TprD proteins, and that the magnitude of the humoral response to individual epitopes differs among animals infected with various syphilis strains and Tp subspecies. Rather than exhibiting strain-specificity, antisera showed various degrees of cross-reactivity with variant sequences from other strains. The data support the further exploration of TprC and TprD as vaccine candidates.
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Affiliation(s)
- Barbara Molini
- Department of Medicine, University of Washington, Seattle, WA, United States
| | - Mark C. Fernandez
- Department of Medicine, University of Washington, Seattle, WA, United States
| | - Charmie Godornes
- Department of Medicine, University of Washington, Seattle, WA, United States
| | - Anastassia Vorobieva
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Sheila A. Lukehart
- Department of Medicine, University of Washington, Seattle, WA, United States
- Department of Global Health, University of Washington, Seattle, WA, United States
| | - Lorenzo Giacani
- Department of Medicine, University of Washington, Seattle, WA, United States
- Department of Global Health, University of Washington, Seattle, WA, United States
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19
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Xu M, Xie Y, Zheng K, Luo H, Tan M, Zhao F, Zeng T, Wu Y. Two Potential Syphilis Vaccine Candidates Inhibit Dissemination of Treponema pallidum. Front Immunol 2021; 12:759474. [PMID: 34899710 PMCID: PMC8657604 DOI: 10.3389/fimmu.2021.759474] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a major public health problem worldwide. Recent increases in the number of syphilis cases, in addition to the lack of an efficient vaccine against T. pallidum for humans, highlights an urgent need for the design and development of an efficacious syphilis vaccine. Here, we assess the vaccine potential of the adhesion protein Tp0136 and the outer membrane protein Tp0663. Rabbits were subcutaneously immunized with recombinant proteins Tp0136, Tp0663, or control PBS. Immunization with Tp0136 or Tp0663 generated a strong humoral immune response with high titers of IgG, as assessed by ELISA. Moreover, animals immunized with Tp0136 or Tp0663 exhibited attenuated lesion development, increased cellular infiltration at the lesion sites, and inhibition of treponemal dissemination to distant organs compared to the unimmunized animals. These findings indicate that Tp0136 and Tp0663 are promising syphilis vaccine candidates. Furthermore, these results provide novel and important information for not only understanding the pathogenic mechanisms of spirochetes, but also the development of spirochete-specific subunit vaccines.
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Affiliation(s)
- Man Xu
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yafeng Xie
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China.,Department of Clinical Laboratory, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Kang Zheng
- Department of Clinical Laboratory, Hengyang Central Hospital, Hengyang, China
| | - Haodang Luo
- Department of Clinical Laboratory, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Manyi Tan
- Department of Toxicology, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Feijun Zhao
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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20
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Tamrakar P, Bett C, Molano RD, Ayub A, Asher DM, Gregori L. Effect of storage on survival of infectious Treponema pallidum spiked in whole blood and platelets. Transfusion 2021; 61:3181-3189. [PMID: 34534364 DOI: 10.1111/trf.16655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Blood donations must be tested for evidence of syphilis, a transfusion-transmitted infection. Screening blood for syphilis-related antibodies greatly reduced the risk of transfusion-transmitted syphilis (TTS). It is commonly believed that Treponema pallidum (Tp), the bacterium causing syphilis, does not survive in blood during cold storage-suggested as one reason why no cases of TTS have been recognized in the United States for many years. Some have suggested that routine syphilis screening of blood donations is no longer needed. To address the effect of storage, we investigated the survival of Tp experimentally spiked into blood and platelets stored under conventional conditions. STUDY DESIGN AND METHODS We spiked fresh human blood products with high concentrations of Tp and inoculated samples at intervals into rabbits, a sensitive assay detecting infectious Tp. We tested whole blood (WB) stored refrigerated (1-6°C) for 9 days and platelets stored at room temperature for 7 days or refrigerated for 14 days. We assayed sera of the rabbits collected at intervals for seroconversion using two different tests and assessed orchitis. Rabbits were considered infected if one or both serological test results became positive. RESULTS Viable Tp survived 7 days in WB and 6 days in platelets stored at both ambient and cold temperatures. DISCUSSION Tp at concentrations much higher than those possibly present in an infected blood unit survived in cold blood products longer than previously reported and, thus, storage conditions cannot be relied upon to eliminate T. pallidum from blood or platelets. TTS remains a topic of concern for public health.
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Affiliation(s)
- Pratistha Tamrakar
- Division of Emerging and Transfusion-Infected Diseases, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, Maryland, USA
| | - Cyrus Bett
- Division of Emerging and Transfusion-Infected Diseases, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, Maryland, USA
| | - Ruth Damaris Molano
- Division of Veterinary Services, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Management, Silver Spring, Maryland, USA
| | - Amna Ayub
- Division of Emerging and Transfusion-Infected Diseases, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, Maryland, USA
| | - David M Asher
- Division of Emerging and Transfusion-Infected Diseases, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, Maryland, USA
| | - Luisa Gregori
- Division of Emerging and Transfusion-Infected Diseases, US Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, Maryland, USA
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21
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Lithgow KV, Tsao E, Schovanek E, Gomez A, Swayne LA, Cameron CE. Treponema pallidum Disrupts VE-Cadherin Intercellular Junctions and Traverses Endothelial Barriers Using a Cholesterol-Dependent Mechanism. Front Microbiol 2021; 12:691731. [PMID: 34354688 PMCID: PMC8329343 DOI: 10.3389/fmicb.2021.691731] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Treponema pallidum subspecies pallidum, the causative agent of syphilis, traverses the vascular endothelium to gain access to underlying tissue sites. Herein, we investigate the mechanisms associated with T. pallidum traversal of endothelial barriers. Immunofluorescence microscopy reveals that a subpopulation of T. pallidum localizes to intercellular junctions and that viable T. pallidum, as well as a T. pallidum vascular adhesin (Tp0751), disrupts the architecture of the main endothelial junctional protein VE-cadherin. Intriguingly, in this study we show that T. pallidum traverses endothelial barriers with no disruption in barrier permeability. Furthermore, barrier traversal by T. pallidum is reduced by pretreatment of endothelial cells with filipin, an inhibitor that blocks cholesterol-mediated endocytosis. Collectively, these results suggest that T. pallidum can use a cholesterol-dependent, lipid raft-mediated endocytosis mechanism to traverse endothelial barriers. Further, treponemal localization to, and disruption of, intercellular junctions suggests that a paracellular route may also be utilized, a dual traversal strategy that has also been observed to occur for leukocytes and other invasive bacteria.
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Affiliation(s)
- Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Emily Tsao
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Ethan Schovanek
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, United States
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22
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Romeis E, Tantalo L, Lieberman N, Phung Q, Greninger A, Giacani L. Genetic engineering of Treponema pallidum subsp. pallidum, the Syphilis Spirochete. PLoS Pathog 2021; 17:e1009612. [PMID: 34228757 PMCID: PMC8284648 DOI: 10.1371/journal.ppat.1009612] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/16/2021] [Accepted: 06/21/2021] [Indexed: 12/28/2022] Open
Abstract
Despite more than a century of research, genetic manipulation of Treponema pallidum subsp. pallidum (T. pallidum), the causative agent of syphilis, has not been successful. The lack of genetic engineering tools has severely limited understanding of the mechanisms behind T. pallidum success as a pathogen. A recently described method for in vitro cultivation of T. pallidum, however, has made it possible to experiment with transformation and selection protocols in this pathogen. Here, we describe an approach that successfully replaced the tprA (tp0009) pseudogene in the SS14 T. pallidum strain with a kanamycin resistance (kanR) cassette. A suicide vector was constructed using the pUC57 plasmid backbone. In the vector, the kanR gene was cloned downstream of the tp0574 gene promoter. The tp0574prom-kanR cassette was then placed between two 1-kbp homology arms identical to the sequences upstream and downstream of the tprA pseudogene. To induce homologous recombination and integration of the kanR cassette into the T. pallidum chromosome, in vitro-cultured SS14 strain spirochetes were exposed to the engineered vector in a CaCl2-based transformation buffer and let recover for 24 hours before adding kanamycin-containing selective media. Integration of the kanR cassette was demonstrated by qualitative PCR, droplet digital PCR (ddPCR), and whole-genome sequencing (WGS) of transformed treponemes propagated in vitro and/or in vivo. ddPCR analysis of RNA and mass spectrometry confirmed expression of the kanR message and protein in treponemes propagated in vitro. Moreover, tprA knockout (tprAko-SS14) treponemes grew in kanamycin concentrations that were 64 times higher than the MIC for the wild-type SS14 (wt-SS14) strain and in infected rabbits treated with kanamycin. We demonstrated that genetic manipulation of T. pallidum is attainable. This discovery will allow the application of functional genetics techniques to study syphilis pathogenesis and improve syphilis vaccine development. Syphilis is still an endemic disease in many low- and middle-income countries, and it has been resurgent in high-income nations for almost two decades. In endemic areas, syphilis causes significant morbidity and mortality, particularly when its causative agent, the spirochete Treponema pallidum subsp. pallidum (T. pallidum) is transmitted to the fetus during pregnancy. A better understanding of T. pallidum biology and syphilis pathogenesis would help devise better control strategies for this infection. One of the limitations associated with working with T. pallidum was our inability to genetically alter this pathogen to evaluate the function of genes encoding virulence factors or create attenuated strains that could be informative for vaccine development when studied using the rabbit model of the disease. Here, we report a transformation protocol that allowed us to replace a specific region of the T. pallidum genome containing a pseudogene (i.e., a non-functional gene) with a stably integrated kanamycin resistance gene. To our knowledge, this is the first-ever report of a method to achieve a genetically modified T. pallidum strain.
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Affiliation(s)
- Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Lauren Tantalo
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Nicole Lieberman
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Quynh Phung
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Alex Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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23
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Jekl V, Nováková M, Jeklová E, Pospíšilová P, Křenová J, Faldyna M, Škorič M, Šmajs D. Penicillin Treatment Failure in Rabbit Syphilis Due to the Persistence of Treponemes ( Treponema paraluisleporidarum Ecovar Cuniculus) in the Focus of Infection. Front Vet Sci 2021; 8:675631. [PMID: 34222401 PMCID: PMC8245693 DOI: 10.3389/fvets.2021.675631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/25/2021] [Indexed: 11/13/2022] Open
Abstract
Rabbit venereal spirochetosis, a disease caused by Treponema paraluisleporidarum ecovar Cuniculus (TPeC), affects both wild and pet rabbits, and is transmitted sexually and via direct contact among animals. Treatment of syphilis in pet rabbits requires administration of antibiotics, including penicillin G, chloramphenicol, or fluoroquinolones. The aim of this work was to elucidate the cause of penicillin treatment failure in rabbit syphilis in a pet rabbit treated in Brno, Czech Republic, and to assess the phylogenetic relatedness of the agent to previously characterized pathogenic treponemes. Following amputation of the infected digits, the second round of penicillin treatment using the same dosage and application route resulted in the disappearance of clinical symptoms within a period of two weeks. The bacterium was successfully isolated from the claws, propagated in three experimental rabbits, and the resulting TPeC strain was designated as Cz-2020. Analysis of four genetic loci revealed that the Cz-2020 strain was similar but also clearly distinct from the only TPeC strain, which had been characterized in detail to date, i.e., the Cuniculi A strain, which was isolated in North America. The strain Cz-2020 represents the first available viable TPeC strain of European origin. DNA sequences encoding five penicillin-binding proteins of the strain Cz-2020 were compared to those of Cuniculi A, which is known to be sensitive to penicillin. The sequences differed in six nucleotides resulting in single amino acid changes in Penicillin-binding protein 1, 2, and 3. Since the second round of treatment was successful, we conclude that the penicillin treatment failure in the first round resulted from the presence of infection foci in claws where treponemes persisted.
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Affiliation(s)
- Vladimír Jekl
- Jekl and Hauptman Veterinary Clinic, Brno, Czechia.,Department of Pharmacology and Pharmacy, Faculty of Veterinary Medicine, Veterinary University Brno, Brno, Czechia
| | - Markéta Nováková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia.,Department of Botany and Zoology, Faculty of SciencVeterinary University Brnoe, Masaryk University, Brno, Czechia
| | - Edita Jeklová
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czechia
| | - Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Jitka Křenová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Martin Faldyna
- Department of Infectious Diseases and Preventive Medicine, Veterinary Research Institute, Brno, Czechia
| | - Miša Škorič
- Department of Pathological Morphology and Parasitology, Faculty of Veterinary Medicine, Veterinary University Brno, Brno, Czechia
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
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Abstract
For over a century, investigation of Treponema pallidum subsp. pallidum, the spiral-shaped bacterium that causes syphilis, was hindered by an inability to culture the organism in vitro. A recent breakthrough has enabled continuous in vitro growth of this organism in co-culture with mammalian tissue culture cells. This article contains the protocols needed to culture T. pallidum in the standard laboratory environment. In addition, protocols for growing and maintaining the required tissue culture cells, for generating isogenic strains by limiting dilution, and for quantitating T. pallidum by darkfield microscopy are included. © 2021 Wiley Periodicals LLC. Basic Protocol 1: In vitro cultivation of Treponema pallidum Basic Protocol 2: Generation of isogenic strains Support Protocol 1: Alternate harvest procedure Support Protocol 2: Culture of Sf1Ep cells Support Protocol 3: Assessment of T. pallidum number and viability.
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Affiliation(s)
- Diane G. Edmondson
- Department of Pathology and Laboratory Medicine, McGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTexas
| | - Steven J. Norris
- Department of Pathology and Laboratory Medicine, McGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTexas
- Department of Microbiology and Molecular Genetics, McGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTexas
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25
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Haynes AM, Fernandez M, Romeis E, Mitjà O, Konda KA, Vargas SK, Eguiluz M, Caceres CF, Klausner JD, Giacani L. Transcriptional and immunological analysis of the putative outer membrane protein and vaccine candidate TprL of Treponema pallidum. PLoS Negl Trop Dis 2021; 15:e0008812. [PMID: 33497377 PMCID: PMC7864442 DOI: 10.1371/journal.pntd.0008812] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 02/05/2021] [Accepted: 01/09/2021] [Indexed: 11/29/2022] Open
Abstract
Background An effective syphilis vaccine should elicit antibodies to Treponema pallidum subsp. pallidum (T. p. pallidum) surface antigens to induce pathogen clearance through opsonophagocytosis. Although the combination of bioinformatics, structural, and functional analyses of T. p. pallidum genes to identify putative outer membrane proteins (OMPs) resulted in a list of potential vaccine candidates, still very little is known about whether and how transcription of these genes is regulated during infection. This knowledge gap is a limitation to vaccine design, as immunity generated to an antigen that can be down-regulated or even silenced at the transcriptional level without affecting virulence would not induce clearance of the pathogen, hence allowing disease progression. Principal findings We report here that tp1031, the T. p. pallidum gene encoding the putative OMP and vaccine candidate TprL is differentially expressed in several T. p. pallidum strains, suggesting transcriptional regulation. Experimental identification of the tprL transcriptional start site revealed that a homopolymeric G sequence of varying length resides within the tprL promoter and that its length affects promoter activity compatible with phase variation. Conversely, in the closely related pathogen T. p. subsp. pertenue, the agent of yaws, where a naturally-occurring deletion has eliminated the tprL promoter region, elements necessary for protein synthesis, and part of the gene ORF, tprL transcription level are negligible compared to T. p. pallidum strains. Accordingly, the humoral response to TprL is absent in yaws-infected laboratory animals and patients compared to syphilis-infected subjects. Conclusion The ability of T. p. pallidum to stochastically vary tprL expression should be considered in any vaccine development effort that includes this antigen. The role of phase variation in contributing to T. p. pallidum antigenic diversity should be further studied. Syphilis is still an endemic disease in many low- and middle-income countries and has been resurgent in high-income nations for almost two decades now. In endemic areas, syphilis still causes significant morbidity and mortality in patients, particularly when its causative agent, the bacterium Treponema pallidum subsp. pallidum is transmitted to the fetus during pregnancy. Although there are significant ongoing efforts to identify an effective syphilis vaccine to bring into clinical trials within the decade in the U.S., such efforts are partially hindered by the lack of knowledge on transcriptional regulation of many genes encoding vaccine candidates. Here, we start addressing this knowledge gap for the putative outer membrane protein (OMP) and vaccine candidates TprL, encoded by the tp1031 gene. As we previously reported for other putative OMP-encoding genes of the syphilis agent, tprL transcription level appears to be affected by the length of a homopolymeric sequence of guanosines (Gs) located within the gene promoter. This is a mechanism known as phase variation and often involved in altering the surface antigenic profile of a bacterial pathogen to facilitate immune evasion and/or adaptation to the host milieu.
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Affiliation(s)
- Austin M. Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Mark Fernandez
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Oriol Mitjà
- Fight Aids and Infectious Diseases Foundation, Hospital Germans Trias I Pujol, Badalona, Barcelona, Spain
- Lihir Medical Centre-International SOS, Newcrest Mining, Lihir Island, Papua New Guinea
| | - Kelika A. Konda
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
- David Geffen School of Medicine, Division of Infectious Diseases, University of California Los Angeles, Los Angeles, United States of America
| | - Silver K. Vargas
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
- School of Public Health and Administration “Carlos Vidal Layseca”, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Maria Eguiluz
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Carlos F. Caceres
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Jeffrey D. Klausner
- David Geffen School of Medicine, Division of Infectious Diseases, University of California Los Angeles, Los Angeles, United States of America
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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26
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Lu S, Zheng K, Wang J, Xu M, Xie Y, Yuan S, Wang C, Wu Y. Characterization of Treponema pallidum Dissemination in C57BL/6 Mice. Front Immunol 2021; 11:577129. [PMID: 33488577 PMCID: PMC7819853 DOI: 10.3389/fimmu.2020.577129] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 11/20/2020] [Indexed: 11/13/2022] Open
Abstract
The spirochetal pathogen Treponema pallidum causes 5 million new cases of venereal syphilis worldwide each year. One major obstacle to syphilis prevention and treatment is the lack of suitable experimental animal models to study its pathogenesis. Accordingly, in this study, we further evaluated the responses of mice to Treponema pallidum. Quantitative polymerase chain reaction showed that Treponema pallidum could colonize the heart, liver, spleen, kidneys, and testicles of C57BL/6 mice, and the organism may be able to rapidly penetrate the blood-brain barrier in mice by 24 h after infection. In subsequent rabbit infectivity tests, we observed evident signs of the microorganism in the mouse lymph node suspension. After infection, bacterial loads were higher in the tissues than in the blood of C57BL/6 mice. Moreover, a significant Th1 immune response was recorded by cytokine assays. Flow cytometric analysis suggested an obvious increase in the proportion of CD3+ T and CD4+ T cells in the spleen cells in the infected mice. Thus, improving our understanding of the response of C57BL/6 mice for Treponema pallidum will help to comprehensive elucidate the pathogenic mechanisms of this bacterium and lay the foundation for the development of a new research model of Treponema pallidum.
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Affiliation(s)
- Simin Lu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Kang Zheng
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Jianye Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Man Xu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Yafeng Xie
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
- Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Shuai Yuan
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Chuan Wang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Yimou Wu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
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Luthra A, Montezuma-Rusca JM, La Vake CJ, LeDoyt M, Delgado KN, Davenport TC, Fiel-Gan M, Caimano MJ, Radolf JD, Hawley KL. Evidence that immunization with TP0751, a bipartite Treponema pallidum lipoprotein with an intrinsically disordered region and lipocalin fold, fails to protect in the rabbit model of experimental syphilis. PLoS Pathog 2020; 16:e1008871. [PMID: 32936831 PMCID: PMC7521688 DOI: 10.1371/journal.ppat.1008871] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/28/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
Deconvolution of syphilis pathogenesis and selection of candidate syphilis vaccinogens requires detailed knowledge of the molecular architecture of the Treponema pallidum outer membrane (OM). The T. pallidum OM contains a low density of integral OM proteins, while the spirochete's many lipoprotein immunogens are periplasmic. TP0751, a lipoprotein with a lipocalin fold, is reportedly a surface-exposed protease/adhesin and protective antigen. The rapid expansion of calycin/lipocalin structures in the RCSB PDB database prompted a comprehensive reassessment of TP0751. Small angle X-ray scattering analysis of full-length protein revealed a bipartite topology consisting of an N-terminal, intrinsically disordered region (IDR) and the previously characterized C-terminal lipocalin domain. A DALI server query using the lipocalin domain yielded 97 hits, 52 belonging to the calycin superfamily, including 15 bacterial lipocalins, but no Gram-negative surface proteins. Surprisingly, Tpp17 (TP0435) was identified as a structural ortholog of TP0751. In silico docking predicted that TP0751 can bind diverse ligands along the rim of its eight-stranded β-barrel; high affinity binding of one predicted ligand, heme, to the lipocalin domain was demonstrated. qRT-PCR and immunoblotting revealed very low expression of TP0751 compared to other T. pallidum lipoproteins. Immunoblot analysis of immune rabbit serum failed to detect TP0751 antibodies, while only one of five patients with secondary syphilis mounted a discernible TP0751-specific antibody response. In opsonophagocytosis assays, neither TP0751 nor Tpp17 antibodies promoted uptake of T. pallidum by rabbit peritoneal macrophages. Rabbits immunized with intact, full-length TP0751 showed no protection against local or disseminated infection following intradermal challenge with T. pallidum. Our data argue that, like other lipoprotein lipocalins in dual-membrane bacteria, TP0751 is periplasmic and binds small molecules, and we propose that its IDR facilitates ligand binding by and offloading from the lipocalin domain. The inability of TP0751 to elicit opsonic or protective antibodies is consistent with a subsurface location.
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Affiliation(s)
- Amit Luthra
- Department of Medicine, UConn Health, Farmington, United States of America
| | - Jairo M. Montezuma-Rusca
- Department of Medicine, UConn Health, Farmington, United States of America
- Division of Infectious Diseases, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
| | - Carson J. La Vake
- Department of Pediatrics, UConn Health, Farmington, United States of America
| | - Morgan LeDoyt
- Department of Medicine, UConn Health, Farmington, United States of America
| | | | | | - Mary Fiel-Gan
- Department of Pathology, Hartford Hospital, Hartford, United States of America
| | - Melissa J. Caimano
- Department of Medicine, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, United States of America
| | - Justin D. Radolf
- Department of Medicine, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, United States of America
- Department of Genetics and Genome Sciences, UConn Health, Farmington, United States of America
- Department of Immunology, UConn Health, Farmington, United States of America
| | - Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, United States of America
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Identification of the Neuroinvasive Pathogen Host Target, LamR, as an Endothelial Receptor for the Treponema pallidum Adhesin Tp0751. mSphere 2020; 5:5/2/e00195-20. [PMID: 32238570 PMCID: PMC7113585 DOI: 10.1128/msphere.00195-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Treponema pallidum subsp. pallidum is the causative agent of syphilis, a human-specific sexually transmitted infection that causes a multistage disease with diverse clinical manifestations. Treponema pallidum undergoes rapid vascular dissemination to penetrate tissue, placental, and blood-brain barriers and gain access to distant tissue sites. The rapidity and extent of T. pallidum dissemination are well documented, but the molecular mechanisms have yet to be fully elucidated. One protein that has been shown to play a role in treponemal dissemination is Tp0751, a T. pallidum adhesin that interacts with host components found within the vasculature and mediates bacterial adherence to endothelial cells under shear flow conditions. In this study, we further explore the molecular interactions of Tp0751-mediated adhesion to the vascular endothelium. We demonstrate that recombinant Tp0751 adheres to human endothelial cells of macrovascular and microvascular origin, including a cerebral brain microvascular endothelial cell line. Adhesion assays using recombinant Tp0751 N-terminal truncations reveal that endothelial binding is localized to the lipocalin fold-containing domain of the protein. We also confirm this interaction using live T. pallidum and show that spirochete attachment to endothelial monolayers is disrupted by Tp0751-specific antiserum. Further, we identify the 67-kDa laminin receptor (LamR) as an endothelial receptor for Tp0751 using affinity chromatography, coimmunoprecipitation, and plate-based binding methodologies. Notably, LamR has been identified as a receptor for adhesion of other neurotropic invasive bacterial pathogens to brain endothelial cells, including Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae, suggesting the existence of a common mechanism for extravasation of invasive extracellular bacterial pathogens.IMPORTANCE Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subsp. pallidum. The continued incidence of syphilis demonstrates that screening and treatment strategies are not sufficient to curb this infectious disease, and there is currently no vaccine available. Herein we demonstrate that the T. pallidum adhesin Tp0751 interacts with endothelial cells that line the lumen of human blood vessels through the 67-kDa laminin receptor (LamR). Importantly, LamR is also a receptor for meningitis-causing neuroinvasive bacterial pathogens such as Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae Our findings enhance understanding of the Tp0751 adhesin and present the intriguing possibility that the molecular events of Tp0751-mediated treponemal dissemination may mimic the endothelial interaction strategies of other invasive pathogens.
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Pereira LE, Katz SS, Sun Y, Mills P, Taylor W, Atkins P, Thurlow CM, Chi KH, Danavall D, Cook N, Ahmed T, Debra A, Philip S, Cohen S, Workowski KA, Kersh E, Fakile Y, Chen CY, Pillay A. Successful isolation of Treponema pallidum strains from patients' cryopreserved ulcer exudate using the rabbit model. PLoS One 2020; 15:e0227769. [PMID: 31929602 PMCID: PMC6957173 DOI: 10.1371/journal.pone.0227769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/27/2019] [Indexed: 02/07/2023] Open
Abstract
Clinical isolates of Treponema pallidum subspecies pallidum (T. pallidum) would facilitate study of prevalent strains. We describe the first successful rabbit propagation of T. pallidum from cryopreserved ulcer specimens. Fresh ulcer exudates were collected and cryopreserved with consent from syphilis-diagnosed patients (N = 8). Each of eight age-matched adult male rabbits were later inoculated with a thawed specimen, with two rabbits receiving 1.3 ml intratesticularly (IT), and six receiving 0.6 ml intravenously (IV) and IT. Monitoring of serology, blood PCR and orchitis showed that T. pallidum grew in 2/8 rabbits that were inoculated IV and IT with either a penile primary lesion specimen (CDC-SF003) or a perianal secondary lesion specimen (CDC-SF007). Rabbit CDC-SF003 was seroreactive by T. pallidum Particle Agglutination (TP-PA) and Rapid Plasma Reagin (RPR) testing, PCR+, and showed orchitis by week 6. Euthanasia was performed in week 7, with treponemal growth in the testes confirmed and quantified by qPCR and darkfield microscopy (DF). Serial passage of the extract in a second age-matched rabbit also yielded treponemes. Similarly, rabbit CDC-SF007 showed negligible orchitis, but was seroreactive and PCR+ by week 4 and euthanized in week 6 to yield T. pallidum, which was further propagated by second passage. Using the 4-component molecular typing system for syphilis, 3 propagated strains (CDC-SF003, CDC-SF007, CDC-SF008) were typed as 14d9f, 14d9g, and 14d10c, respectively. All 3 isolates including strain CDC-SF011, which was not successfully propagated, had the A2058G mutation associated with azithromycin resistance. Our results show that immediate cryopreservation of syphilitic ulcer exudate can maintain T. pallidum viability for rabbit propagation.
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Affiliation(s)
- Lara E. Pereira
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
- * E-mail:
| | - Samantha S. Katz
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Yongcheng Sun
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Patrick Mills
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Willie Taylor
- Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Patricia Atkins
- Charles River Laboratories, Wilmington, MA, United States of America
| | - Charles M. Thurlow
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Kai-Hua Chi
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Damien Danavall
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Nicholas Cook
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Tamanna Ahmed
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Alyssa Debra
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Susan Philip
- San Francisco Department of Public Health, San Francisco, CA, United States of America
| | - Stephanie Cohen
- San Francisco Department of Public Health, San Francisco, CA, United States of America
| | - Kimberly A. Workowski
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
- Emory University Department of Medicine, Atlanta, GA, United States of America
| | - Ellen Kersh
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Yetunde Fakile
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Cheng Y. Chen
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Allan Pillay
- Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
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Evaluation of the Protective Ability of the Treponema pallidum subsp. pallidum Tp0126 OmpW Homolog in the Rabbit Model of Syphilis. Infect Immun 2019; 87:IAI.00323-19. [PMID: 31182617 DOI: 10.1128/iai.00323-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 05/30/2019] [Indexed: 12/16/2022] Open
Abstract
In silico analyses of Treponema pallidum subsp. pallidum genomes and predicted proteomes to search for homologs of known bacterial outer membrane proteins (OMPs) led to the identification of tp0126 as a gene encoding a putative member of the OmpW family of porins/virulence factors. Our previous investigations on the role of Tp0126 in T. pallidum biology and syphilis pathogenesis showed that Tp0126 is fully conserved among T. pallidum strains and that transcription of tp0126 is driven by σ70 These initial results pointed to a housekeeping function for this protein. We also demonstrated that a guanosine homopolymer of various lengths located between the -10 and -35 consensus sequences in the tp0126 promoter modulates transcription consistently with phase variation, a mechanism that we also previously described for other T. pallidum genes encoding putative OMPs/virulence factors and that is often employed as a strategy for immune evasion. Circular dichroism spectra of recombinant Tp0126 also supported its structural homology with OmpW. Here we further investigated the humoral and cellular responses to Tp0126 during experimental and natural syphilis and the ability of Tp0126 to confer protection against syphilis in immunized rabbits. B-cell epitope mapping showed that compared to sera from experimentally infected animals, immunizations enhanced humoral immunity to sequences located in the putative Tp0126 surface-exposed loops, while phagocytosis assays showed that postimmunization sera opsonized T. pallidum Despite such promising results, no significant protection was seen following infectious challenge in immunized animals versus controls. Functional redundancy and phase variation might explain the lack of effectiveness of this vaccine candidate and/or design.
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Liu D, Tong ML, Lin Y, Liu LL, Lin LR, Yang TC. Insights into the genetic variation profile of tprK in Treponema pallidum during the development of natural human syphilis infection. PLoS Negl Trop Dis 2019; 13:e0007621. [PMID: 31329597 PMCID: PMC6675121 DOI: 10.1371/journal.pntd.0007621] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 08/01/2019] [Accepted: 07/09/2019] [Indexed: 01/25/2023] Open
Abstract
Background Although the tprK gene of Treponema pallidum are thought to play a critical role in the pathogenesis of syphilis, the profile of variations in tprK during the development of human syphilis infection have remained unclear. Methods/Principal findings Through next-generation sequencing, we compared the tprK gene of 14 secondary syphilis patients with that of 14 primary syphilis patients, and the results showed an increased number of variants within the seven V regions of the tprK gene in the secondary syphilis samples. The length of the sequences within each V region also presented a 3-bp changing pattern. Interestingly, the frequencies of predominant sequences within the V regions in the secondary syphilis samples were generally decreased compared with those found in the primary syphilis samples, particularly in the V7 region, where a frequency below 60% was found in up to 57% (8/14) of all secondary samples compared with 7% (1/14) of all primary samples. Moreover, the number of minor variants distributed between frequencies of 10 and 49.9% was increased. The alignment of all amino acid sequences within each V region of the primary and secondary syphilis samples revealed that some amino acid sequences, particularly the amino acid sequences IASDGGAIKH and IASEDGSAGNLKH in V1, were highly stable. Additionally, the amino acid sequences in V6 also exhibited notable intrastrain heterogeneity and were likely to form a strain-specific pattern at the interstrain level. Conclusions The identification of different profiles of the tprK gene in primary and secondary syphilis patients indicated that the tprK gene of T. pallidum undergoes constant variation to result in the best adaptation to the host. The highly stable peptides found in V1 are likely promising potential vaccine components. The highly heterogenetic regions (e.g., V6) could help to understand the role of tprK in immune evasion. Antigenic variation of the TprK antigen has been acknowledged to explain the persistence of Treponema pallidum in the host, however, the profile of variations in tprK during the development of human syphilis infection has not been well characterized. Here, we performed next-generation sequencing to compare the variations in tprK between primary and secondary syphilis samples. The profiles of tprK in the samples at different stages showed differences. A higher amount of pool variants within seven V regions was found in the secondary syphilis samples, and the frequencies of their predominant sequences generally decreased with increases in the number of minor variants with frequencies in the range of 10 to 49.9%. However, the length of variable sequences within the V regions of tprK in the secondary syphilis samples also presented a 3-bp changing pattern. Notably, the amino acid sequences IASDGGAIKH and IASEDGSAGNLKH in V1 not only presented a high proportion of interstrain sharing but also were found at a relatively high frequency (above 80%) in the populations. The sequences in V6 of the samples demonstrated substantial variability at the intra- and interstrain levels. These findings could provide insights into the potential syphilis vaccine components and the role of TprK in immune evasion.
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Affiliation(s)
- Dan Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Man-Li Tong
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Yong Lin
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Li Liu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Li-Rong Lin
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Tian-Ci Yang
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, China
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
- * E-mail:
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Beale MA, Marks M, Sahi SK, Tantalo LC, Nori AV, French P, Lukehart SA, Marra CM, Thomson NR. Genomic epidemiology of syphilis reveals independent emergence of macrolide resistance across multiple circulating lineages. Nat Commun 2019; 10:3255. [PMID: 31332179 PMCID: PMC6646400 DOI: 10.1038/s41467-019-11216-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 07/01/2019] [Indexed: 11/09/2022] Open
Abstract
Syphilis is a sexually transmitted infection caused by Treponema pallidum subspecies pallidum and may lead to severe complications. Recent years have seen striking increases in syphilis in many countries. Previous analyses have suggested one lineage of syphilis, SS14, may have expanded recently, indicating emergence of a single pandemic azithromycin-resistant cluster. Here we use direct sequencing of T. pallidum combined with phylogenomic analyses to show that both SS14- and Nichols-lineages are simultaneously circulating in clinically relevant populations in multiple countries. We correlate the appearance of genotypic macrolide resistance with multiple independently evolved SS14 sub-lineages and show that genotypically resistant and sensitive sub-lineages are spreading contemporaneously. These findings inform our understanding of the current syphilis epidemic by demonstrating how macrolide resistance evolves in Treponema subspecies and provide a warning on broader issues of antimicrobial resistance.
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Affiliation(s)
- Mathew A Beale
- Parasites and Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
| | - Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Hospital for Tropical Diseases, London, UK
| | - Sharon K Sahi
- Department of Neurology, University of Washington, Seattle, WA, 98195, USA
| | - Lauren C Tantalo
- Department of Neurology, University of Washington, Seattle, WA, 98195, USA
| | | | - Patrick French
- The Mortimer Market Centre CNWL, Camden Provider Services, London, UK
| | - Sheila A Lukehart
- Departments of Medicine and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Christina M Marra
- Department of Neurology, University of Washington, Seattle, WA, 98195, USA
| | - Nicholas R Thomson
- Parasites and Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
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Parveen N, Fernandez MC, Haynes AM, Zhang RL, Godornes BC, Centurion-Lara A, Giacani L. Non-pathogenic Borrelia burgdorferi expressing Treponema pallidum TprK and Tp0435 antigens as a novel approach to evaluate syphilis vaccine candidates. Vaccine 2019; 37:1807-1818. [PMID: 30797635 DOI: 10.1016/j.vaccine.2019.02.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/16/2019] [Accepted: 02/04/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND Syphilis is resurgent in many developed countries and still prevalent in developing nations. Current and future control campaigns would benefit from the development of a vaccine, but although promising vaccine candidates were identified among the putative surface-exposed integral outer membrane proteins of the syphilis spirochete, immunization experiments in the rabbit model using recombinant antigens have failed to fully protect animals upon infectious challenge. We speculated that such recombinant immunogens, purified under denaturing conditions from Escherichia coli prior to immunization might not necessarily harbor their original structure, and hypothesized that enhanced protection would result from performing similar immunization/challenge experiments with native antigens. METHODS To test our hypothesis, we engineered non-infectious Borrelia burgdorferi strains to express the tp0897 (tprK) and tp0435 genes of Treponema pallidum subsp. pallidum and immunized two groups of rabbits by injecting recombinant strains intramuscularly with no adjuvant. TprK is a putative integral outer membrane protein of the syphilis agent, while tp0435 encodes the highly immunogenic T. pallidum 17-kDa lipoprotein, a periplasmic antigen that was also shown on the pathogen surface. Following development of a specific host immune response to these antigens as the result of immunization, animals were challenged by intradermal inoculation of T. pallidum. Cutaneous lesion development was monitored and treponemal burden within lesions were assessed by dark-field microscopy and RT-qPCR, in comparison to control rabbits. RESULTS Partial protection was observed in rabbits immunized with B. burgdorferi expressing TprK while immunity to Tp0435 was not protective. Analysis of the humoral response to TprK antigen suggested reactivity to conformational epitopes. CONCLUSIONS Immunization with native antigens might not be sufficient to obtain complete protection to infection. Nonetheless we showed that non-infectious B. burgdorferi can be an effective carrier to deliver and elicit a specific host response to T. pallidum antigens to assess the efficacy of syphilis vaccine candidates.
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Affiliation(s)
- Nikhat Parveen
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, Newark, NJ 07103, United States
| | - Mark C Fernandez
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, Seattle, WA 98104, United States
| | - Austin M Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, Seattle, WA 98104, United States
| | - Rui-Li Zhang
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, Seattle, WA 98104, United States; Department of Dermatology, Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, 214002 Wuxi, China
| | - B Charmie Godornes
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, Seattle, WA 98104, United States
| | | | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Harborview Medical Center, Seattle, WA 98104, United States; Department of Global Health, University of Washington, Seattle, WA 98104, United States.
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Church B, Wall E, Webb JR, Cameron CE. Interaction of Treponema pallidum, the syphilis spirochete, with human platelets. PLoS One 2019; 14:e0210902. [PMID: 30657796 PMCID: PMC6338379 DOI: 10.1371/journal.pone.0210902] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/03/2019] [Indexed: 02/06/2023] Open
Abstract
Extracellular bacteria that spread via the vasculature employ invasive mechanisms that mirror those of metastatic tumor cells, including intravasation into the bloodstream and survival during hematogenous dissemination, arrestation despite blood flow, and extravasation into distant tissue sites. Several invasive bacteria have been shown to exploit normal platelet function during infection. Due to their inherent ability to interact with and influence other cell types, platelets play a critical role in alteration of endothelial barrier permeability, and their role in cancer metastasis has been well established. The highly invasive bacterium and causative agent of syphilis, Treponema pallidum subspecies pallidum, readily crosses the endothelial, blood-brain and placental barriers. However, the mechanisms underlying this unusual and important aspect of T. pallidum pathogenesis are incompletely understood. In this study we use darkfield microscopy in combination with flow cytometry to establish that T. pallidum interacts with platelets. We also investigate the dynamics of this interaction and show T. pallidum is able to activate platelets and preferentially interacts with activated platelets. Platelet-interacting treponemes consistently exhibit altered kinematic (movement) parameters compared to free treponemes, and T. pallidum-platelet interactions are reversible. This study provides insight into host cell interactions at play during T. pallidum infection and suggests that T. pallidum may exploit platelet function to aid in establishment of disseminated infection.
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Affiliation(s)
- Brigette Church
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Erika Wall
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - John R. Webb
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Trev and Joyce Deeley Research Centre, British Columbia Cancer Agency, Victoria, BC, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
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Topical treatment with gallium maltolate reduces Treponema pallidum subsp. pertenue burden in primary experimental lesions in a rabbit model of yaws. PLoS Negl Trop Dis 2019; 13:e0007076. [PMID: 30601824 PMCID: PMC6331133 DOI: 10.1371/journal.pntd.0007076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/14/2019] [Accepted: 12/12/2018] [Indexed: 12/22/2022] Open
Abstract
Background Gallium is a semi-metallic element known since the 1930s to have antimicrobial activity. This activity stems primarily from gallium's ability to mimic trivalent iron and disrupt specific Fe(III)-dependent pathways, particularly DNA synthesis (due to inhibition of ribonucleotide reductase). Because of its novel mechanism of action, gallium is currently being investigated as a new antibacterial agent, particularly in light of the increasing resistance of many pathogenic bacteria to existing antibiotics. Gallium maltolate (GaM) is being developed as an orally and topically administrable form of gallium. Yaws is a neglected tropical disease affecting mainly the skin and skeletal system of children in underprivileged settings. It is currently the object of a WHO-promoted eradication campaign using mass administration of the macrolide azithromycin, an antibiotic to which the yaws agent Treponema pallidum subsp. pertenue has slowly begun to develop genetic resistance. Methods Because yaws transmission is mainly due to direct skin contact with an infectious skin lesion, we evaluated the treponemicidal activity of GaM applied topically to skin lesions in a rabbit model of yaws. Treatment efficacy was evaluated by measuring lesion diameter, treponemal burden in lesion aspirates as determined by dark field microscopy and amplification of treponemal RNA, serology, and immunohistochemistry of biopsied tissue samples. Results Our results show that topical GaM was effective in reducing treponemal burden in yaws experimental lesions, particularly when applied at the first sign of lesion appearance but, as expected, did not prevent pathogen dissemination. Conclusion Early administration of GaM to yaws lesions could reduce the infectivity of the lesions and thus yaws transmission, potentially contributing to current and future yaws control campaigns. Yaws is a neglected tropical disease affecting children in underprivileged countries, transmitted through direct skin contact with an active lesion. This infection, although rarely fatal, can lead to disfigurement and serious disability. The World Health Organization is currently conducting a yaws eradication effort that employs mass administration of azithromycin, an antibiotic against which the yaws pathogen has slowly begun to develop genetic resistance. Because this phenomenon has the potential to undermine the eradication effort, we investigated the antimicrobial activity of gallium maltolate, which has a novel mechanism of action, against the yaws pathogen. Our initial results show that topical application of gallium maltolate has significant treponemicidal activity, and suggest that this compound might find an application in the effort to eradicate yaws. Future studies will evaluate whether oral administration of gallium maltolate is as effective as the antibiotics currently approved for yaws treatment to clear systemic infection.
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Liu W, Zhang X, Zhao T, Zhou C, Duan J, Zhao F. Data on the generation of rabbit infections and RPR titre changes in serum samples from syphilis patients at follow-up. Data Brief 2018; 21:2237-2241. [PMID: 30555861 PMCID: PMC6276544 DOI: 10.1016/j.dib.2018.10.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/19/2018] [Accepted: 10/23/2018] [Indexed: 11/25/2022] Open
Abstract
The data presented in this article are related to the research article entitled “Performance of novel infection phase-dependent antigens in syphilis serodiagnosis and treatment efficacy determination”. The rabbit model [1], [2] is an appropriate animal model for studying syphilis, a classic sexually transmitted disease (STD). Live Treponema pallidum (T. pallidum, Tp) and inactivated T. pallidum were inoculated in the backs of New Zealand rabbits. RT-PCR was performed to determine whether T. pallidum DNA could be detected in different groups. Sixty paired serum samples from patients at follow-up were tested by RPR and recombinant Tp0971-, Tp0768-, Tp0462- and Tp92-based ELISA.
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Affiliation(s)
- Wen Liu
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China
| | - Xiaohong Zhang
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China.,Department of Histology and Embryology, Hengyang Medical College, University of South China, Hengyang 421001, China
| | - Tie Zhao
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China
| | - Chenglong Zhou
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China
| | - Junxia Duan
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China
| | - Feijun Zhao
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Pathogentic Biology Institute, University of South China, Hengyang 421001, China
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Luo X, Zhang X, Gan L, Zhou C, Zhao T, Zeng T, Liu S, Xiao Y, Yu J, Zhao F. The outer membrane protein Tp92 of Treponema pallidum induces human mononuclear cell death and IL-8 secretion. J Cell Mol Med 2018; 22:6039-6054. [PMID: 30596396 PMCID: PMC6237608 DOI: 10.1111/jcmm.13879] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/30/2018] [Indexed: 12/19/2022] Open
Abstract
Treponema pallidum is the pathogen that causes syphilis, a sexually transmitted disease; however, the pathogenic mechanism of this organism remains unclear. Tp92 is the only T. pallidum outer membrane protein that has structural features similar to the outer membrane proteins of other Gram-negative bacteria, but the exact functions of this protein remain unknown. In the present study, we demonstrated that the recombinant Tp92 protein can induce human mononuclear cell death. Tp92 mediated the human monocytic cell line derived from an acute monicytic leukemia patient (THP-1) cell death by recognizing CD14 and/or TLR2 on cell surfaces. After the stimulation of THP-1 cells by the Tp92 protein, Tp92 may induce atypical pyroptosis of THP-1 cells via the pro-caspase-1 pathway. Meanwhile, this protein caused the apoptosis of THP-1 cells via the receptor-interacting protein kinase 1/caspase-8/aspase-3 pathway. Tp92 reduced the number of monocytes among peripheral blood mononuclear cells. Interestingly, further research showed that Tp92 failed to increase the tumour necrosis factor-α, interleukin (IL)-1β, IL-6, IL-10, IL-18 and monocyte chemotactic protein 1 (MCP)-1 levels but slightly elevated the IL-8 levels via the Nuclear Factor (NF)-κB pathway in THP-1 cells. The data suggest that Tp92 recognizes CD14 and TLR2, transfers the signal to a downstream pathway, and activates NF-κB to mediate the production of IL-8. This mechanism may help T. pallidum escape recognition and elimination by the host innate immune system.
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MESH Headings
- Antigens, Surface/genetics
- Bacterial Proteins/genetics
- Caspase 1/genetics
- Cell Death/genetics
- Cell Line, Tumor
- Cytokines/genetics
- Host-Pathogen Interactions/genetics
- Humans
- Interleukin-8/genetics
- Leukemia, Monocytic, Acute/genetics
- Leukemia, Monocytic, Acute/microbiology
- Leukemia, Monocytic, Acute/pathology
- Leukocytes, Mononuclear/microbiology
- Leukocytes, Mononuclear/pathology
- Lipopolysaccharide Receptors/genetics
- NF-kappa B/genetics
- Recombinant Proteins/genetics
- Signal Transduction/genetics
- Syphilis/genetics
- Syphilis/microbiology
- Syphilis/pathology
- Toll-Like Receptor 2/genetics
- Treponema pallidum/genetics
- Treponema pallidum/pathogenicity
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Affiliation(s)
- Xi Luo
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Xiaohong Zhang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
- Department of Histology and EmbryologySchool of MedicineUniversity of South ChinaHengyangChina
| | - Lin Gan
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Chenglong Zhou
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Tie Zhao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Tiebing Zeng
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Shuangquan Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
- Department of Clinical LaboratoryThe First Affiliated Hospital of University of South ChinaHengyangChina
| | - Yongjian Xiao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
- Department of Clinical LaboratoryThe Second Affiliated Hospital of University of South ChinaHengyangChina
| | - Jian Yu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
| | - Feijun Zhao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan ProvinceCollaborative Innovation Center for New Molecular Drug ResearchUniversity of South ChinaHengyangChina
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Immunogenicity and protective efficacy against Treponema pallidum in New Zealand rabbits immunized with plasmid DNA encoding flagellin. Emerg Microbes Infect 2018; 7:177. [PMID: 30405111 PMCID: PMC6220273 DOI: 10.1038/s41426-018-0176-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 09/10/2018] [Accepted: 09/13/2018] [Indexed: 11/08/2022]
Abstract
Plasmid DNA encoding flagellin FlaB3 was used as a vaccination candidate for the evaluation of immunogenicity and protection against Treponema pallidum subsp. pallidum dissemination. First, intramuscular injection of the flagellin encoded by the plasmid DNA into New Zealand rabbits elicited both humoral and cellular immune responses. Total IgG production increased in response to flagellin. In addition, serum IFN-γ secretion and CD8+ cells were substantially greater in the rabbits immunized with the plasmid encoding flagellin FlaB3 than those in the rabbits immunized with recombinant flagellin. The flagellin encoded by the plasmid DNA induced significant upregulation of serum IL-6 and IL-8 compared to that of the control rabbits. Subsequently, intradermal challenge of the vaccinated New Zealand rabbits with 1 × 107T. pallidum resulted in a significant reduction of the bacterial organ burden in the blood, liver, spleen, and testicles in the flagellin plasmid DNA-vaccinated rabbits. Furthermore, the histopathological analysis demonstrated that the rabbits immunized with the plasmid DNA-encoded flagellin (FlaB3) showed better immune protection. These findings provide evidence that plasmid DNA-encoded flagellin (FlaB3) may be useful as a potential immunization route for future development of a vaccine to inhibit T. pallidum dissemination in related animals.
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Van Raemdonck GA, Osbak KK, Van Ostade X, Kenyon CR. Needle lost in the haystack: multiple reaction monitoring fails to detect Treponema pallidum candidate protein biomarkers in plasma and urine samples from individuals with syphilis. F1000Res 2018; 7:336. [PMID: 30519456 PMCID: PMC6248270 DOI: 10.12688/f1000research.13964.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2018] [Indexed: 12/13/2022] Open
Abstract
Background: Current syphilis diagnostic strategies are lacking a sensitive manner of directly detecting
Treponema pallidum antigens. A diagnostic test that could directly detect
T. pallidum antigens in individuals with syphilis would be of considerable clinical utility, especially for the diagnosis of reinfections and for post-treatment serological follow-up. Methods: In this study, 11 candidate
T. pallidum biomarker proteins were chosen according to their physiochemical characteristics,
T. pallidum specificity and predicted abundance. Thirty isotopically labelled proteotypic surrogate peptides (hPTPs) were synthesized and incorporated into a scheduled multiple reaction monitoring assay. Protein extracts from undepleted/unenriched plasma (N = 18) and urine (N = 4) samples from 18 individuals with syphilis in various clinical stages were tryptically digested, spiked with the hPTP mixture and analysed with a triple quadruple mass spectrometer. Results: No endogenous PTPs corresponding to the eleven candidate biomarkers were detected in any samples analysed. To estimate the Limit of Detection (LOD) of a comparably sensitive mass spectrometer (LTQ-Orbitrap), two dilution series of rabbit cultured purified
T. pallidum were prepared in PBS. Polyclonal anti-
T. pallidum antibodies coupled to magnetic Dynabeads were used to enrich one sample series; no LOD improvement was found compared to the unenriched series. The estimated LOD of MS instruments is 300
T. pallidum/ml in PBS. Conclusions: Biomarker protein detection likely failed due to the low (femtomoles/liter) predicted concentration of
T. pallidum proteins. Alternative sample preparation strategies may improve the detectability of
T. pallidum proteins in biofluids.
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Affiliation(s)
- Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium.,Laboratory for Protein Science, Proteomics and Epigenetic Signalling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, 2610, Belgium
| | - Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics and Epigenetic Signalling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, 2610, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, 7925, South Africa
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Sun J, Meng Z, Wu K, Liu B, Zhang S, Liu Y, Wang Y, Zheng H, Huang J, Zhou P. Tracing the origin of Treponema pallidum in China using next-generation sequencing. Oncotarget 2018; 7:42904-42918. [PMID: 27344187 PMCID: PMC5189996 DOI: 10.18632/oncotarget.10154] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 06/01/2016] [Indexed: 12/29/2022] Open
Abstract
Syphilis is a systemic sexually transmitted disease caused by Treponema pallidum ssp. pallidum (TPA). The origin and genetic background of Chinese TPA strains remain unclear. We identified a total of 329 single-nucleotide variants (SNVs) in eight Chinese TPA strains using next-generation sequencing. All of the TPA strains were clustered into three lineages, and Chinese TPA strains were grouped in Lineage 2 based on phylogenetic analysis. The phylogeographical data showed that TPA strains originated earlier than did T. pallidum ssp. pertenue (TPE) and T. pallidum ssp. endemicum (TPN) strains and that Chinese TPA strains might be derived from recombination between Lineage 1 and Lineage 3. Moreover, we found through a homology modeling analysis that a nonsynonymous substitution (I415F) in the PBP3 protein might affect the structural flexibility of PBP3 and the binding constant for substrates based on its possible association with penicillin resistance in T. pallidum. Our findings provide new insight into the molecular foundation of the evolutionary origin of TPA and support the development of novel diagnostic/therapeutic technology for syphilis.
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Affiliation(s)
- Jun Sun
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, China
| | - Zhefeng Meng
- Oncology Bioinformatics Center, Minhang Hospital, Fudan University, Shanghai, China
| | - Kaiqi Wu
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Biao Liu
- School of Laboratory Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Sufang Zhang
- Shanghai Skin Disease Hospital, Clinical School of Anhui Medical University, Shanghai, China
| | - Yudan Liu
- Shanghai Skin Disease Hospital, Clinical School of Anhui Medical University, Shanghai, China
| | - Yuezhu Wang
- Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center and National Engineering Center for Biochip at Shanghai, Shanghai, China
| | - Huajun Zheng
- Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center and National Engineering Center for Biochip at Shanghai, Shanghai, China
| | - Jian Huang
- Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center and National Engineering Center for Biochip at Shanghai, Shanghai, China.,Key Laboratory of Systems Biomedicine (Ministry of Education) and Collaborative Innovation Center of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Pingyu Zhou
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, China.,Shanghai Skin Disease Hospital, Clinical School of Anhui Medical University, Shanghai, China
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41
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Godornes C, Giacani L, Barry AE, Mitja O, Lukehart SA. Development of a Multilocus Sequence Typing (MLST) scheme for Treponema pallidum subsp. pertenue: Application to yaws in Lihir Island, Papua New Guinea. PLoS Negl Trop Dis 2017; 11:e0006113. [PMID: 29281641 PMCID: PMC5760108 DOI: 10.1371/journal.pntd.0006113] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/09/2018] [Accepted: 11/14/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Yaws is a neglected tropical disease, caused by Treponema pallidum subsp. pertenue. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes. METHODS AND PRINCIPAL FINDINGS Published genome sequences of strains of T. pallidum subsp. pertenue and pallidum were compared to identify polymorphic genetic loci among the strains. DNA from a number of existing historical Treponema isolates, as well as a subset of samples from yaws patients collected in Lihir Island, Papua New Guinea, were analyzed using these targets. From these data, three genes (tp0548, tp0136 and tp0326) were ultimately selected to give a high discriminating capability among the T. pallidum subsp. pertenue samples tested. Intragenic regions of these three target genes were then selected to enhance the discriminating capability of the typing scheme using short readily amplifiable loci. This 3-gene multilocus sequence typing (MLST) method was applied to existing historical human yaws strains, the Fribourg-Blanc simian isolate, and DNA from 194 lesion swabs from yaws patients on Lihir Island, Papua New Guinea. Among all samples tested, fourteen molecular types were identified, seven of which were found in patient samples and seven among historical isolates or DNA. Three types (JG8, TD6, and SE7) were predominant on Lihir Island. CONCLUSIONS This MLST approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed.
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Affiliation(s)
- Charmie Godornes
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lorenzo Giacani
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Alyssa E. Barry
- Division of Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Oriol Mitja
- Barcelona Institute for Global Health, Hospital Clinic-Universitat de Barcelona, Barcelona, Spain
- Division of Public Health, School of Medicine and Health Sciences, University of Papua New Guinea, Port Moresby, Papua New Guinea
- Lihir Medical Center, International SOS-Newcrest Mining, Lihir Island, Papua New Guinea
| | - Sheila A. Lukehart
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
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42
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Abstract
Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.
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Affiliation(s)
- Rosanna W Peeling
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David Mabey
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Mary L Kamb
- Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xiang-Sheng Chen
- National Center for STD Control, Chinese Academy of Medical Sciences and Peking Union Medical College Institute of Dermatology, Nanjing, China
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Adele S Benzaken
- Department of Surveillance, Prevention and Control of STI, HIV/AIDS and Viral Hepatitis, Ministry of Health, Brasília, Brazil
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43
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Lithgow KV, Hof R, Wetherell C, Phillips D, Houston S, Cameron CE. A defined syphilis vaccine candidate inhibits dissemination of Treponema pallidum subspecies pallidum. Nat Commun 2017; 8:14273. [PMID: 28145405 PMCID: PMC5296639 DOI: 10.1038/ncomms14273] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/14/2016] [Indexed: 12/15/2022] Open
Abstract
Syphilis is a prominent disease in low- and middle-income countries, and a re-emerging public health threat in high-income countries. Syphilis elimination will require development of an effective vaccine that has thus far remained elusive. Here we assess the vaccine potential of Tp0751, a vascular adhesin from the causative agent of syphilis, Treponema pallidum subsp. pallidum. Tp0751-immunized animals exhibit a significantly reduced bacterial organ burden upon T. pallidum challenge compared with unimmunized animals. Introduction of lymph nodes from Tp0751-immunized, T. pallidum-challenged animals to naive animals fails to induce infection, confirming sterile protection. These findings provide evidence that Tp0751 is a promising syphilis vaccine candidate. There are no vaccines for the prevention of syphilis, a disease caused by the bacterium Treponema pallidum subsp. pallidum. Here, the authors use an animal model of infection to show that immunization with the Tp0751 bacterial protein inhibits the pathogen's spread within the body.
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Affiliation(s)
- Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Rebecca Hof
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Charmaine Wetherell
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Drew Phillips
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
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Treponema pallidum flagellin FlaA2 induces IL-6 secretion in THP-1 cells via the Toll-like receptor 2 signaling pathway. Mol Immunol 2017; 81:42-51. [DOI: 10.1016/j.molimm.2016.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 10/07/2016] [Accepted: 11/14/2016] [Indexed: 12/23/2022]
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The Structure of Treponema pallidum Tp0624 Reveals a Modular Assembly of Divergently Functionalized and Previously Uncharacterized Domains. PLoS One 2016; 11:e0166274. [PMID: 27832149 PMCID: PMC5104382 DOI: 10.1371/journal.pone.0166274] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/25/2016] [Indexed: 02/03/2023] Open
Abstract
Treponema pallidum subspecies pallidum is the causative agent of syphilis, a chronic, multistage, systemic infection that remains a major global health concern. The molecular mechanisms underlying T. pallidum pathogenesis are incompletely understood, partially due to the phylogenetic divergence of T. pallidum. One aspect of T. pallidum that differentiates it from conventional Gram-negative bacteria, and is believed to play an important role in pathogenesis, is its unusual cell envelope ultrastructure; in particular, the T. pallidum peptidoglycan layer is chemically distinct, thinner and more distal to the outer membrane. Established functional roles for peptidoglycan include contributing to the structural integrity of the cell envelope and stabilization of the flagellar motor complex, which are typically mediated by the OmpA domain-containing family of proteins. To gain insight into the molecular mechanisms that govern peptidoglycan binding and cell envelope biogenesis in T. pallidum we report here the structural characterization of the putative OmpA-like domain-containing protein, Tp0624. Analysis of the 1.70 Å resolution Tp0624 crystal structure reveals a multi-modular architecture comprised of three distinct domains including a C-terminal divergent OmpA-like domain, which we show is unable to bind the conventional peptidoglycan component diaminopimelic acid, and a previously uncharacterized tandem domain unit. Intriguingly, bioinformatic analysis indicates that the three domains together are found in all orthologs from pathogenic treponemes, but are not observed together in genera outside Treponema. These findings provide the first structural insight into a multi-modular treponemal protein containing an OmpA-like domain and its potential role in peptidoglycan coordination and stabilization of the T. pallidum cell envelope.
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Radolf JD, Deka RK, Anand A, Šmajs D, Norgard MV, Yang XF. Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen. Nat Rev Microbiol 2016; 14:744-759. [PMID: 27721440 DOI: 10.1038/nrmicro.2016.141] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation 'the stealth pathogen'. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiological, and regulatory facets of T. pallidum pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes.
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Affiliation(s)
- Justin D Radolf
- Departments of Medicine, Pediatrics, Genetics and Genomic Science, Molecular Biology and Biophysics, and Immunology, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - Ranjit K Deka
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - Arvind Anand
- Department of Medicine, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Michael V Norgard
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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47
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Osbak KK, Houston S, Lithgow KV, Meehan CJ, Strouhal M, Šmajs D, Cameron CE, Van Ostade X, Kenyon CR, Van Raemdonck GA. Characterizing the Syphilis-Causing Treponema pallidum ssp. pallidum Proteome Using Complementary Mass Spectrometry. PLoS Negl Trop Dis 2016; 10:e0004988. [PMID: 27606673 PMCID: PMC5015957 DOI: 10.1371/journal.pntd.0004988] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/19/2016] [Indexed: 12/28/2022] Open
Abstract
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.
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Affiliation(s)
- Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Conor J Meehan
- Unit of Mycobacteriology, Institute of Tropical Medicine, Antwerp, Belgium
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
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Molini BJ, Tantalo LC, Sahi SK, Rodriguez VI, Brandt SL, Fernandez MC, Godornes CB, Marra CM, Lukehart SA. Macrolide Resistance in Treponema pallidum Correlates With 23S rDNA Mutations in Recently Isolated Clinical Strains. Sex Transm Dis 2016; 43:579-83. [PMID: 27513385 PMCID: PMC4982755 DOI: 10.1097/olq.0000000000000486] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/26/2016] [Indexed: 01/07/2023]
Abstract
BACKGROUND High rates of 23S rDNA mutations implicated in macrolide resistance have been identified in Treponema pallidum samples from syphilis patients in many countries. Nonetheless, some clinicians have been reluctant to abandon azithromycin as a treatment for syphilis, citing the lack of a causal association between these mutations and clinical evidence of drug resistance. Although azithromycin resistance has been demonstrated in vivo for the historical Street 14 strain, no recent T. pallidum isolates have been tested. We used the well-established rabbit model of syphilis to determine the in vivo efficacy of azithromycin against 23S rDNA mutant strains collected in 2004 to 2005 from patients with syphilis in Seattle, Wash. METHODS Groups of 9 rabbits were each infected with a strain containing 23S rDNA mutation A2058G (strains UW074B, UW189B, UW391B) or A2059G (strains UW228B, UW254B, and UW330B), or with 1 wild type strain (Chicago, Bal 3, and Mexico A). After documentation of infection, 3 animals per strain were treated with azithromycin, 3 were treated with benzathine penicillin G, and 3 served as untreated control groups. Treatment efficacy was documented by darkfield microscopic evidence of T. pallidum, serological response, and rabbit infectivity test. RESULTS Azithromycin uniformly failed to cure rabbits infected with strains harboring either 23S rDNA mutation, although benzathine penicillin G was effective. Infections caused by wild type strains were successfully treated by either azithromycin or benzathine penicillin G. CONCLUSIONS A macrolide resistant phenotype was demonstrated for all strains harboring a 23S rDNA mutation, demonstrating that either A2058G or A2059G mutation confers in vivo drug resistance.
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Affiliation(s)
- Barbara J. Molini
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Lauren C. Tantalo
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Sharon K. Sahi
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Veronica I. Rodriguez
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Stephanie L. Brandt
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Mark C. Fernandez
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Charmie B. Godornes
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Christina M. Marra
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
| | - Sheila A. Lukehart
- From the *Department of Medicine, †Department of Neurology, and ‡Department of Global Health, University of Washington, Seattle, WA
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Xu M, Xie Y, Jiang C, Xiao Y, Kuang X, Zhao F, Zeng T, Liu S, Liang M, Li L, Wang C, Wu Y. A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis. Int J Infect Dis 2015; 43:51-57. [PMID: 26747418 DOI: 10.1016/j.ijid.2015.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging. METHODS A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG). RESULTS Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96). CONCLUSION These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.
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Affiliation(s)
- Man Xu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yafeng Xie
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Chuanhao Jiang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yongjian Xiao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China; Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Xingxing Kuang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Shuangquan Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang, China
| | - Mingxing Liang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Li Li
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Chuan Wang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
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Marra CM, Tantalo LC, Sahi SK, Dunaway SB, Lukehart SA. Reduced Treponema pallidum-Specific Opsonic Antibody Activity in HIV-Infected Patients With Syphilis. J Infect Dis 2015; 213:1348-54. [PMID: 26655298 DOI: 10.1093/infdis/jiv591] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 11/30/2015] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV)-infected individuals may have poorer serological responses to syphilis treatment and may be more likely to experience neurosyphilis. Treponema pallidum is cleared from sites of infection by opsonization, ingestion, and killing by macrophages. METHODS Serum samples from 235 individuals with syphilis were tested for T. pallidum-specific opsonic activity. Blood T. pallidum concentrations were determined by real-time polymerase chain reaction amplification of the tp0574 gene, and T. pallidum was detected in cerebrospinal fluid (CSF) by reverse-transcriptase polymerase chain reaction of 16S ribosomal RNA. RESULTS Opsonic activity was higher with higher serum rapid plasma reagin titers (P < .001), and in those treated for uncomplicated syphilis before serum collection (P < .001). Opsonic activity was lower in HIV-infected than in HIV-uninfected individuals even after the above factors were taken into account (P = .006). In participants in whom blood T. pallidum was detectable, those with the highest opsonic activity had lower blood T. pallidum concentrations. In multivariable analyses, there was not a significant relationship between opsonic activity and detection of T. pallidum in CSF or CSF-VDRL reactivity. CONCLUSIONS Serum T. pallidum-specific opsonic activity is significantly lower in HIV-infected individuals. Impaired T. pallidum-specific immune responses could contribute to differences in the course of disease or treatment response.
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Affiliation(s)
| | | | | | | | - Sheila A Lukehart
- Department Medicine (Infectious Diseases) Department Global Health, Harborview Medical Center, University of Washington, Seattle
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