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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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2
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Wu S, Ye F, Wang Y, Li D. Neurosyphilis: insights into its pathogenesis, susceptibility, diagnosis, treatment, and prevention. Front Neurol 2024; 14:1340321. [PMID: 38274871 PMCID: PMC10808744 DOI: 10.3389/fneur.2023.1340321] [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: 11/17/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Background and aim Invasion of the central nervous system by Treponema pallidum can occur at any stage of syphilis. In the event that T. pallidum is not cleared promptly, certain individuals may experience progression to neurosyphilis, which manifests as cognitive and behavioral abnormalities, limb paralysis, and potentially fatal outcomes. Early identification or prevention of neurosyphilis is therefore crucial. The aim of this paper is to conduct a critical and narrative review of the latest information focusing exclusively to the pathogenesis and clinical management of neurosyphilis. Methodology To compile this review, we have conducted electronic literature searches from the PubMed database relating to neurosyphilis. Priority was given to studies published from the past 10 years (from 2013 to 2023) and other studies if they were of significant importance (from 1985 to 2012), including whole genome sequencing results, cell structure of T. pallidum, history of genotyping, and other related topics. These studies are classic or reflect a developmental process. Results Neurosyphilis has garnered global attention, yet susceptibility to and the pathogenesis of this condition remain under investigation. Cerebrospinal fluid examination plays an important role in the diagnosis of neurosyphilis, but lacks the gold standard. Intravenous aqueous crystalline penicillin G continues to be the recommended therapeutic approach for neurosyphilis. Considering its sustained prominence, it is imperative to develop novel public health tactics in order to manage the resurgence of neurosyphilis. Conclusion This review gives an updated narrative description of neurosyphilis with special emphasis on its pathogenesis, susceptibility, diagnosis, treatment, and prevention.
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Affiliation(s)
| | | | | | - Dongdong Li
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, China
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3
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Zhang X, Duan J, Wang Y, Xie B, Zhou J, Zhao S, Yin W, Liu P, Zhao F. Insight into the invasion process and immune-protective evaluation of Tp0971, a membrane lipoprotein from Treponema pallidum. Microbiol Spectr 2023; 11:e0004723. [PMID: 37855609 PMCID: PMC10714829 DOI: 10.1128/spectrum.00047-23] [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: 01/05/2023] [Accepted: 09/01/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum (T. 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." There are many hurdles to studying syphilis pathogenesis, most notably the difficulty of culturing and genetically manipulating T. pallidum, as well as the absence of an effective vaccine for T. pallidum prevention. T. pallidum infection in humans is a complex and lengthy process. In this study, we investigated the invasion process and the function of the infection-dependent antigen Tp0971 as an immunogen to inhibit the dissemination of T. pallidum in an animal infection model. This enables a better understanding of the specific pathogenic mechanism of this pathogen, syphilis pathogenesis, and vaccine research.
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Affiliation(s)
- Xiaohong Zhang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Junxia Duan
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Yali Wang
- Department of Clinical Medicine Undergraduate, Hengyang Medical College, University of South China, Hengyang, China
| | - Bibo Xie
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Jie Zhou
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Sisi Zhao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Weiguo Yin
- Laboratory Department, Qingyuan People’s Hospital, Qingyuan, China
| | - Peng Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Feijun Zhao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Department of Clinical Laboratory Medicine of the First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
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4
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Gökengin D, Noori T, Alemany A, Bienkowski C, Liegon G, İnkaya AÇ, Carrillo J, Stary G, Knapp K, Mitja O, Molina JM. Prevention strategies for sexually transmitted infections, HIV, and viral hepatitis in Europe. THE LANCET REGIONAL HEALTH. EUROPE 2023; 34:100738. [PMID: 37927439 PMCID: PMC10625023 DOI: 10.1016/j.lanepe.2023.100738] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 08/26/2023] [Accepted: 09/12/2023] [Indexed: 11/07/2023]
Abstract
The current prevention efforts for STIs, HIV and viral hepatitis in the WHO European Region, especially in the Central and Eastern subregions, are hindered by healthcare disparities, data gaps, and limited resources. In this comprehensive narrative review, we aim to highlight both achievements and persisting challenges while also exploring new developments that could significantly impact the prevention of these infections in the near future. While pre-exposure prophylaxis (PrEP) for HIV has been broadly approved and implemented in 38 out of 53 countries in the region, challenges remain, including cost, limited licensing, and incomplete adherence. We explore innovative approaches like on-demand PrEP, long-acting injectable cabotegravir, and intravaginal rings that have shown promising results, alongside the use of six-monthly lenacapavir, the outcomes of which are pending. Additionally, the potential of doxycycline post-exposure prophylaxis has been discussed, revealing efficacy in reducing chlamydia and syphilis risk, but effectiveness against gonorrhoea being contingent on tetracycline resistance rates, and the need of further data to determine potential resistance development in other bacteria and its impact on the gut microbiome. We examine successful vaccination campaigns against HBV and HPV, the ongoing development of vaccines for chlamydia, syphilis, herpesvirus, and gonorrhoea, and challenges in HIV vaccine research, including lines of research with significant potential like sequential immunization, T-cell responses, and mRNA technology. This review underscores the research endeavors that pave the way for a more resilient and robust approach to combating STIs, HIV, and viral hepatitis in the region.
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Affiliation(s)
- Deniz Gökengin
- Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Ege University, Izmir, Turkiye
- Ege University HIV/AIDS Practice and Research Center, Izmir, Turkiye
| | - Teymur Noori
- European Centre for Disease Prevention and Control STI, Blood-Borne Viruses and TB DPR, Stockholm, Sweden
| | - Andrea Alemany
- Skin Neglected Tropical Diseases and Sexually Transmitted Infections Section, Fight Infectious Diseases Foundation, University Hospital Germans Trias i Pujol, Badalona, Spain
| | - Carlo Bienkowski
- Department of Adults' Infectious Diseases, Medical University of Warsaw, Poland and Hospital for Infectious Diseases in Warsaw, Poland
| | - Geoffroy Liegon
- Section of Infectious Diseases and Global Health University of Chicago Medicine Chicago, Illinois, United States
| | - Ahmet Çağkan İnkaya
- Hacettepe University Faculty of Medicine Department of Infectious Diseases Ankara, Turkey
| | - Jorge Carrillo
- IrsiCaixa AIDS Research Institute, Campus Can Ruti, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Campus Can Ruti, Badalona, Spain
- CIBERINFEC, Instituto de Salud Carlos IIII, Madrid, Spain
| | - Georg Stary
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Katja Knapp
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Oriol Mitja
- Skin Neglected Tropical Diseases and Sexually Transmitted Infections Section, Fight Infectious Diseases Foundation, University Hospital Germans Trias i Pujol, Badalona, Spain
| | - Jean-Michel Molina
- University of Paris Cité and Department of Infectious Diseases Saint-Louis and Lariboisiére Hospitals, APHP, Paris, France
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5
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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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6
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Liu D, Chen R, Wang YJ, Li W, Liu LL, Lin LR, Yang TC, Tong ML. Insights into the protective immune response by immunization with full-length recombinant TprK protein: cellular and humoral responses. NPJ Vaccines 2023; 8:146. [PMID: 37773233 PMCID: PMC10542339 DOI: 10.1038/s41541-023-00748-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/19/2023] [Indexed: 10/01/2023] Open
Abstract
Syphilis has resurged in many countries, which has called attention to vaccine development. Based on the immunization-based rabbit model of infection with the Nichols strain, this study explored the protective immune response of a controversial syphilis vaccine candidate, TprK, and found that immunization with full-length rTprK was effective in attenuating lesion development and accelerating lesion resolution, which could reduce the probability of the pathogen spreading to distant tissue sites to prevent the progression of the disease to some extent. Furthermore, the results revealed that immunization with rTprK not only rapidly induced a strong Th1-like cellular response but also elicited a humoral immune response to produce opsonic antibodies to enhance macrophage-mediated opsonophagocytosis. Although complete protection against infection was not achieved, the study provided a comprehensive and in-depth exploration of the immunogenicity of TprK and highlighted the importance of TprK as a promising syphilis vaccine component.
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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
| | - Rui Chen
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Yong-Jing Wang
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Wei Li
- Institute of Infectious Disease, 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.
| | - 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.
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7
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Ferguson MR, Delgado KN, McBride S, Orbe IC, La Vake CJ, Caimano MJ, Mendez Q, Moraes TF, Schryvers AB, Moody MA, Radolf JD, Weiner MP, Hawley KL. Use of Epivolve phage display to generate a monoclonal antibody with opsonic activity directed against a subdominant epitope on extracellular loop 4 of Treponema pallidum BamA (TP0326). Front Immunol 2023; 14:1222267. [PMID: 37675118 PMCID: PMC10478084 DOI: 10.3389/fimmu.2023.1222267] [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: 05/14/2023] [Accepted: 07/19/2023] [Indexed: 09/08/2023] Open
Abstract
Introduction Syphilis, a sexually transmitted infection caused by the spirochete Treponema pallidum (Tp), is resurging globally. Tp's repertoire of outer membrane proteins (OMPs) includes BamA (β-barrel assembly machinery subunit A/TP0326), a bipartite protein consisting of a 16-stranded β-barrel with nine extracellular loops (ECLs) and five periplasmic POTRA (polypeptide transport-associated) domains. BamA ECL4 antisera promotes internalization of Tp by rabbit peritoneal macrophages. Methods Three overlapping BamA ECL4 peptides and a two-stage, phage display strategy, termed "Epivolve" (for epitope evolution) were employed to generate single-chain variable fragments (scFvs). Additionally, antisera generated by immunizing mice and rabbits with BamA ECL4 displayed by a Pyrococcus furiosus thioredoxin scaffold (PfTrxBamA/ECL4). MAbs and antisera reactivities were evaluated by immunoblotting and ELISA. A comparison of murine and rabbit opsonophagocytosis assays was conducted to evaluate the functional ability of the Abs (e.g., opsonization) and validate the mouse assay. Sera from Tp-infected mice (MSS) and rabbits (IRS) were evaluated for ECL4-specific Abs using PfTrxBamA/ECL4 and overlapping ECL4 peptides in immunoblotting and ELISA assays. Results Each of the five mAbs demonstrated reactivity by immunoblotting and ELISA to nanogram amounts of PfTrxBamA/ECL4. One mAb, containing a unique amino acid sequence in both the light and heavy chains, showed activity in the murine opsonophagocytosis assay. Mice and rabbits hyperimmunized with PfTrxBamA/ECL4 produced opsonic antisera that strongly recognized the ECL presented in a heterologous scaffold and overlapping ECL4 peptides, including S2. In contrast, Abs generated during Tp infection of mice and rabbits poorly recognized the peptides, indicating that S2 contains a subdominant epitope. Discussion Epivolve produced mAbs target subdominant opsonic epitopes in BamA ECL4, a top syphilis vaccine candidate. The murine opsonophagocytosis assay can serve as an alternative model to investigate the opsonic potential of vaccinogens. Detailed characterization of BamA ECL4-specific Abs provided a means to dissect Ab responses elicited by Tp infection.
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Affiliation(s)
- Mary R. Ferguson
- Department of Molecular Sciences, Abbratech, Branford, CT, United States
| | | | | | - Isabel C. Orbe
- Department of Pediatrics, UConn Health, Farmington, CT, United States
| | - Carson J. La Vake
- Department of Pediatrics, UConn Health, Farmington, CT, United States
| | - Melissa J. Caimano
- Department of Medicine, UConn Health, Farmington, CT, United States
- Department of Pediatrics, UConn Health, Farmington, CT, United States
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Qiana Mendez
- Department of Molecular Sciences, Abbratech, Branford, CT, United States
| | - Trevor F. Moraes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Anthony B. Schryvers
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - M. Anthony Moody
- Duke Human Vaccine Institute, Durham, NC, United States
- Department of Pediatrics, Duke University Medical Center, Durham, NC, United States
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC, United States
| | - Justin D. Radolf
- Department of Medicine, UConn Health, Farmington, CT, United States
- Department of Pediatrics, UConn Health, Farmington, CT, United States
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
- Department of Immunology, UConn Health, Farmington, CT, United States
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, United States
| | - Michael P. Weiner
- Department of Molecular Sciences, Abbratech, Branford, CT, United States
| | - Kelly L. Hawley
- Department of Medicine, UConn Health, Farmington, CT, United States
- Department of Pediatrics, UConn Health, Farmington, CT, United States
- Department of Immunology, UConn Health, Farmington, CT, United States
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, CT, United States
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8
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Liu D, Liu LL, Zheng XQ, Chen R, Lin LR, Yang TC, Tong ML. Genetic Profiling of the Full-Length tprK Gene in Patients with Primary and Secondary Syphilis. Microbiol Spectr 2023; 11:e0493122. [PMID: 37036342 PMCID: PMC10269439 DOI: 10.1128/spectrum.04931-22] [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: 11/30/2022] [Accepted: 03/17/2023] [Indexed: 04/11/2023] Open
Abstract
TprK antigenic variation is acknowledged as an important strategy developed by Treponema pallidum to achieve immune evasion. Previous studies applied short-read sequencing to explore tprK gene sequence diversity in clinical samples; however, due to the limitations of short-read sequencing, it was difficult to determine the linkage between the seven V regions, and crucial information about full-length tprK variants was lost. Although two recent studies explored complete tprK gene profiles in natural human syphilis infection, there are still too few profiled full-length tprK variants among clinical T. pallidum isolates to fully understand the characteristics of TprK coding diversity. Here, Pacific Biosciences (PacBio) long-read sequencing was applied to examine the diversity of full-length tprK variants in 21 clinical T. pallidum isolates from 11 patients with primary syphilis and 10 patients with secondary syphilis. A total of 398 high-confidence full-length sequences, which presented remarkable sequence heterogeneity, were found. However, these full-length tprK variants exhibited limited variation in length and GC content, showing 24 length types and average GC content of 51.5 ± 0.42% and 51.6 ± 0.26% for primary and secondary syphilis samples, respectively. Additionally, the combined patterns of mutated V regions generating new tprK variants were obviously different in primary and secondary syphilis samples. The diversity of tprK gene sequences in primary syphilis samples may represent the underlying variability of the bacterium; conversely, the variability of the tprK gene in secondary syphilis samples may more accurately reflect how T. pallidum escapes host immune clearance. These data highlight the tprK gene as an important coding gene that shows conflicting genetic characteristics but underlies the persistence of spirochete infection. IMPORTANCE The resurgence of syphilis in both low- and high-income countries has attracted attention, and persistent infection by the pathogen has long been a research focus. The tprK gene, encoding the hypervariable outer membrane protein, is thought to be responsible for pathogen immune evasion and persistent infection. Here, PacBio long-read sequencing was applied to examine the diversity of full-length tprK variants in 21 clinical T. pallidum isolates from 11 patients with primary syphilis and 10 patients with secondary syphilis. The results showed that the sequences of the tprK gene were remarkably heterogeneous; however, the sequences presented limited variation in length and GC content. The investigation of the combined patterns of the V regions allowed us to gain insight into the features of the tprK gene generating new variants at different clinical stages. The findings of this study will be helpful for further exploration of the pathogenesis of syphilis.
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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
| | - 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
| | - Xin-Qi Zheng
- Institute of Infectious Disease, School of Medicine, Xiamen University, Xiamen, China
| | - Rui Chen
- 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
| | - 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
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9
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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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10
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Bowen HG, Kenedy MR, Johnson DK, MacKerell AD, Akins DR. Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes. Pathog Dis 2023; 81:ftad014. [PMID: 37385817 PMCID: PMC10353723 DOI: 10.1093/femspd/ftad014] [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: 04/20/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/01/2023] Open
Abstract
Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane.
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Affiliation(s)
- Hannah G Bowen
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
| | - Melisha R Kenedy
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
| | - David K Johnson
- Shenkel Structural Biology Center, Molecular Graphics and Modeling Laboratory and the Computational Biology Core, University of Kansas, 2034 Becker Drive Lawrence, Kansas 66047, United States
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore 20 North Pine Street Baltimore, Maryland 21201, United States
| | - Darrin R Akins
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
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11
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Tang Y, Zhou Y, He B, Cao T, Zhou X, Ning L, Chen E, Li Y, Xie X, Peng B, Hu Y, Liu S. Investigation of the immune escape mechanism of Treponema pallidum. Infection 2022; 51:305-321. [PMID: 36260281 DOI: 10.1007/s15010-022-01939-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Syphilis is a chronic sexually transmitted disease caused by Treponema pallidum subspecies pallidum (T. pallidum), which is a public health problem that seriously affects human health worldwide. T. pallidum is characterized by early transmission and immune escape and is therefore termed an "invisible pathogen". METHODS This review systematically summarizes the host's innate and adaptive immune responses to T. pallidum infection as well as the escape mechanisms of T. pallidum. PURPOSE To lay the foundation for assessing the pathogenic mechanism and the systematic prevention and treatment of syphilis. CONCLUSION The immune escape mechanism of T. pallidum plays an important role in its survival. Exploring the occurrence and development of these mechanisms has laid the foundation for the development of syphilis vaccine.
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Affiliation(s)
- Yun Tang
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yingjie Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Bisha He
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Ting Cao
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiangping Zhou
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Lichang Ning
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - En Chen
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yumeng Li
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Xiaoping Xie
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Binfeng Peng
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Yibao Hu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China
| | - Shuangquan Liu
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, Hengyang Medical School, The First Affiliated Hospital, University of South China, No. 69, Chuanshan Road, Hengyang City, 421000, Hunan, China.
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12
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Characterization of Treponema denticola Major Surface Protein (Msp) by Deletion Analysis and Advanced Molecular Modeling. J Bacteriol 2022; 204:e0022822. [PMID: 35913147 PMCID: PMC9487533 DOI: 10.1128/jb.00228-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Treponema denticola, a keystone pathogen in periodontitis, is a model organism for studying Treponema physiology and host-microbe interactions. Its major surface protein Msp forms an oligomeric outer membrane complex that binds fibronectin, has cytotoxic pore-forming activity, and disrupts several intracellular processes in host cells. T. denticola msp is an ortholog of the Treponema pallidum tprA to -K gene family that includes tprK, whose remarkable in vivo hypervariability is proposed to contribute to T. pallidum immune evasion. We recently identified the primary Msp surface-exposed epitope and proposed a model of the Msp protein as a β-barrel protein similar to Gram-negative bacterial porins. Here, we report fine-scale Msp mutagenesis demonstrating that both the N and C termini as well as the centrally located Msp surface epitope are required for native Msp oligomer expression. Removal of as few as three C-terminal amino acids abrogated Msp detection on the T. denticola cell surface, and deletion of four residues resulted in complete loss of detectable Msp. Substitution of a FLAG tag for either residues 6 to 13 of mature Msp or an 8-residue portion of the central Msp surface epitope resulted in expression of full-length Msp but absence of the oligomer, suggesting roles for both domains in oligomer formation. Consistent with previously reported Msp N-glycosylation, proteinase K treatment of intact cells released a 25 kDa polypeptide containing the Msp surface epitope into culture supernatants. Molecular modeling of Msp using novel metagenome-derived multiple sequence alignment (MSA) algorithms supports the hypothesis that Msp is a large-diameter, trimeric outer membrane porin-like protein whose potential transport substrate remains to be identified. IMPORTANCE The Treponema denticola gene encoding its major surface protein (Msp) is an ortholog of the T. pallidum tprA to -K gene family that includes tprK, whose remarkable in vivo hypervariability is proposed to contribute to T. pallidum immune evasion. Using a combined strategy of fine-scale mutagenesis and advanced predictive molecular modeling, we characterized the Msp protein and present a high-confidence model of its structure as an oligomer embedded in the outer membrane. This work adds to knowledge of Msp-like proteins in oral treponemes and may contribute to understanding the evolutionary and potential functional relationships between T. denticola Msp and the orthologous T. pallidum Tpr proteins.
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13
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de Sá Queiroz JHF, dos Santos Barbosa M, Miranda LGO, de Oliveira NR, Dellagostin OA, Marchioro SB, Simionatto S. Tp0684, Tp0750, and Tp0792 Recombinant Proteins as Antigens for the Serodiagnosis of Syphilis. Indian J Microbiol 2022; 62:419-427. [PMID: 35974924 PMCID: PMC9375814 DOI: 10.1007/s12088-022-01017-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/20/2022] [Indexed: 11/28/2022] Open
Abstract
The incidence of syphilis has increased alarmingly over the years. Its diagnosis continues to be a challenge, leading to the search for new alternative and effective methods. The objective of this study was to select and evaluate three Treponema pallidum recombinant proteins for potential use in syphilis serodiagnosis. Bioinformatics analysis was performed with three T. pallidum antigens (Tp0684, Tp0750, and Tp0792) to assess their physical, antigenic, and structural characteristics. The antigens were chemically synthesized, recombinant plasmids were expressed in Escherichia coli BL21 Star™ (DE3), and the recombinant proteins were purified by nickel affinity chromatography. The antigenicity of the recombinant proteins was evaluated by western blotting and enzyme-linked immunosorbent assay (ELISA), using the sera from patients with primary and latent syphilis. In silico analysis indicated the antigenic potential once the exposed B cell epitopes were detected in the evaluated proteins. Sera from patients with primary and latent syphilis specifically recognized rTp0684, rTp0750, and rTp0792 recombinant antigens. Moreover, the rTp0684-ELISA receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.99, indicating high diagnostic efficacy with 97.62% specificity and 95% sensitivity. In conclusion, rTp0684 showed better potential as an antigen for the development of syphilis serodiagnosis. Thus, bioinformatic analysis can be an important tool to guide the selection of antigens for serological diagnosis. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-022-01017-w.
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Affiliation(s)
- Júlio Henrique Ferreira de Sá Queiroz
- Laboratório de Pesquisa em Ciências da Saúde, Universidade Federal da Grande Dourados - UFGD, Rodovia Dourados - Itahum, km 12, Cidade Universitária, Dourados, MS 79804970 Brazil
| | - Marcelo dos Santos Barbosa
- Laboratório de Pesquisa em Ciências da Saúde, Universidade Federal da Grande Dourados - UFGD, Rodovia Dourados - Itahum, km 12, Cidade Universitária, Dourados, MS 79804970 Brazil
| | - Lais Gonçalves Ortolani Miranda
- Laboratório de Pesquisa em Ciências da Saúde, Universidade Federal da Grande Dourados - UFGD, Rodovia Dourados - Itahum, km 12, Cidade Universitária, Dourados, MS 79804970 Brazil
| | | | | | - Silvana Beutinger Marchioro
- Laboratório de Pesquisa em Ciências da Saúde, Universidade Federal da Grande Dourados - UFGD, Rodovia Dourados - Itahum, km 12, Cidade Universitária, Dourados, MS 79804970 Brazil
- Laboratório de Imunologia e Biologia Molecular, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, BA Brazil
| | - Simone Simionatto
- Laboratório de Pesquisa em Ciências da Saúde, Universidade Federal da Grande Dourados - UFGD, Rodovia Dourados - Itahum, km 12, Cidade Universitária, Dourados, MS 79804970 Brazil
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14
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Delgado KN, Montezuma-Rusca JM, Orbe IC, Caimano MJ, La Vake CJ, Luthra A, Hennelly CM, Nindo FN, Meyer JW, Jones LD, Parr JB, Salazar JC, Moody MA, Radolf JD, Hawley KL. Extracellular Loops of the Treponema pallidum FadL Orthologs TP0856 and TP0858 Elicit IgG Antibodies and IgG +-Specific B-Cells in the Rabbit Model of Experimental Syphilis. mBio 2022; 13:e0163922. [PMID: 35862766 PMCID: PMC9426418 DOI: 10.1128/mbio.01639-22] [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: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 12/03/2022] Open
Abstract
The resurgence of syphilis in the new millennium has called attention to the importance of a vaccine for global containment strategies. Studies with immune rabbit serum (IRS) indicate that a syphilis vaccine should elicit antibodies (Abs) that promote opsonophagocytosis of treponemes by activated macrophages. The availability of three-dimensional models for Treponema pallidum's (Tp) repertoire of outer membrane proteins (OMPs) provides an architectural framework for identification of candidate vaccinogens with extracellular loops (ECLs) as the targets for protective Abs. Herein, we used Pyrococcus furiosus thioredoxin (PfTrx) as a scaffold to display Tp OMP ECLs to interrogate sera and peripheral blood mononuclear cells (PBMCs) from immune rabbits for ECL-specific Abs and B cells. We validated this approach using a PfTrx scaffold presenting ECL4 from BamA, a known opsonic target. Using scaffolds displaying ECLs of the FadL orthologs TP0856 and TP0858, we determined that ECL2 and ECL4 of both proteins are strongly antigenic. Comparison of ELISA and immunoblot results suggested that the PfTrx scaffolds present conformational and linear epitopes. We then used the FadL ECL2 and ECL4 PfTrx constructs as "hooks" to confirm the presence of ECL-specific B cells in PBMCs from immune rabbits. Our results pinpoint immunogenic ECLs of two newly discovered OMPs, while advancing the utility of the rabbit model for circumventing bottlenecks in vaccine development associated with large-scale production of folded OMPs. They also lay the groundwork for production of rabbit monoclonal Abs (MAbs) to characterize potentially protective ECL epitopes at the atomic level. IMPORTANCE Recent identification and structural modeling of Treponema pallidum's (Tp) repertoire of outer membrane proteins (OMPs) represent a critical breakthrough in the decades long quest for a syphilis vaccine. However, little is known about the antigenic nature of these β-barrel-forming OMPs and, more specifically, their surface exposed regions, the extracellular loops (ECLs). In this study, using Pyrococcus furiosus thioredoxin (PfTrx) as a scaffold to display Tp OMP ECLs, we interrogated immune rabbit sera and peripheral blood mononuclear cells for the presence of antibodies (Abs) and circulating rare antigen-specific B cells. Our results pinpoint immunogenic ECLs of two newly discovered OMPs, while advancing the utility of the rabbit model for surveying the entire Tp OMPeome for promising OMP vaccinogens. This work represents a major advancement toward characterizing potentially protective OMP ECLs and future vaccine studies. Additionally, this strategy could be applied to OMPs of nonspirochetal bacterial pathogens.
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Affiliation(s)
| | - Jairo M Montezuma-Rusca
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
| | - Isabel C Orbe
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
| | - Melissa J Caimano
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Carson J La Vake
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
| | - Amit Luthra
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Christopher M Hennelly
- Division of Infectious Diseases, Department of Medicine, and Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Fredrick N Nindo
- Division of Infectious Diseases, Department of Medicine, and Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jacob W Meyer
- Duke Human Vaccine Institute, Durham, North Carolina, USA
| | | | - Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, and Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Juan C Salazar
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases and Immunology, Connecticut Children's, Hartford, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Durham, North Carolina, USA
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
- Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA
| | - Kelly L Hawley
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases and Immunology, Connecticut Children's, Hartford, Connecticut, USA
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15
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Gomes LGR, Rodrigues TCV, Jaiswal AK, Santos RG, Kato RB, Barh D, Alzahrani KJ, Banjer HJ, Soares SDC, Azevedo V, Tiwari S. In Silico Designed Multi-Epitope Immunogen “Tpme-VAC/LGCM-2022” May Induce Both Cellular and Humoral Immunity against Treponema pallidum Infection. Vaccines (Basel) 2022; 10:vaccines10071019. [PMID: 35891183 PMCID: PMC9320004 DOI: 10.3390/vaccines10071019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 01/16/2023] Open
Abstract
Syphilis, a sexually transmitted infection caused by the spirochete Treponema pallidum, has seen a resurgence over the past years. T. pallidum is capable of early dissemination and immune evasion, and the disease continues to be a global healthcare burden. The purpose of this study was to design a multi-epitope immunogen through an immunoinformatics-based approach. Multi-epitope immunogens constitute carefully selected epitopes belonging to conserved and essential bacterial proteins. Several physico-chemical characteristics, such as antigenicity, allergenicity, and stability, were determined. Further, molecular docking and dynamics simulations were performed, ensuring binding affinity and stability between the immunogen and TLR-2. An in silico cloning was performed using the pET-28a(+) vector and codon adaptation for E. coli. Finally, an in silico immune simulation was performed. The in silico predictions obtained in this work indicate that this construct would be capable of inducing the requisite immune response to elicit protection against T. pallidum. Through this methodology we have designed a promising potential vaccine candidate for syphilis, namely Tpme-VAC/LGCM-2022. However, it is necessary to validate these findings in in vitro and in vivo assays.
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Affiliation(s)
- Lucas Gabriel Rodrigues Gomes
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
| | - Thaís Cristina Vilela Rodrigues
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
| | - Arun Kumar Jaiswal
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
| | - Roselane Gonçalves Santos
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
| | - Rodrigo Bentes Kato
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
| | - Debmalya Barh
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur 721172, West Bengal, India
| | - Khalid J. Alzahrani
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (K.J.A.); (H.J.B.)
| | - Hamsa Jameel Banjer
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (K.J.A.); (H.J.B.)
| | - Siomar de Castro Soares
- Department of Immunology, Microbiology, and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro (UFTM), Uberaba 38025-180, Brazil;
| | - Vasco Azevedo
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
- Correspondence: (V.A.); (S.T.)
| | - Sandeep Tiwari
- Laboratory of Cellular and Molecular Genetics (LGCM), PG Program in Bioinformatics, Department of Genetics, Ecology, and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (L.G.R.G.); (T.C.V.R.); (A.K.J.); (R.G.S.); (R.B.K.); (D.B.)
- Correspondence: (V.A.); (S.T.)
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16
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Lipoproteome screening of the Lyme disease agent identifies inhibitors of antibody-mediated complement killing. Proc Natl Acad Sci U S A 2022; 119:e2117770119. [PMID: 35312359 PMCID: PMC9060444 DOI: 10.1073/pnas.2117770119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Spirochetal pathogens encode an abundance of lipoproteins that can provide a critical interface with the host environment. Borrelia burgdorferi, the model species for spirochetal biology, must survive an enzootic life cycle defined by fluctuations between vector (tick) and vertebrate host. While B. burgdorferi expresses over 80 surface lipoproteins—many of which likely contribute to host survival—the B. burgdorferi lipoproteome is poorly characterized. Here, we generated a platform to rapidly identify targets of B. burgdorferi surface lipoproteins and identified two paralogs that confer resistance to antibody-initiated complement killing that may promote survival in immunocompetent hosts. This work expands our understanding of complement evasion mechanisms and points toward a discovery approach for identifying host–pathogen interactions central to spirochete pathogenesis. Spirochetal pathogens, such as the causative agent of Lyme disease, Borrelia burgdorferi sensu lato, encode an abundance of lipoproteins; however, due in part to their evolutionary distance from more well-studied bacteria, such as Proteobacteria and Firmicutes, few spirochetal lipoproteins have assigned functions. Indeed, B. burgdorferi devotes almost 8% of its genome to lipoprotein genes and interacts with its environment primarily through the production of at least 80 surface-exposed lipoproteins throughout its tick vector–vertebrate host lifecycle. Several B. burgdorferi lipoproteins have been shown to serve roles in cellular adherence or immune evasion, but the functions for most B. burgdorferi surface lipoproteins remain unknown. In this study, we developed a B. burgdorferi lipoproteome screening platform utilizing intact spirochetes that enables the identification of previously unrecognized host interactions. As spirochetal survival in the bloodstream is essential for dissemination, we targeted our screen to C1, the first component of the classical (antibody-initiated) complement pathway. We identified two high-affinity C1 interactions by the paralogous lipoproteins, ElpB and ElpQ (also termed ErpB and ErpQ, respectively). Using biochemical, microbiological, and biophysical approaches, we demonstrate that ElpB and ElpQ bind the activated forms of the C1 proteases, C1r and C1s, and represent a distinct mechanistic class of C1 inhibitors that protect the spirochete from antibody-mediated complement killing. In addition to identifying a mode of complement inhibition, our study establishes a lipoproteome screening methodology as a discovery platform for identifying direct host–pathogen interactions that are central to the pathogenesis of spirochetes, such as the Lyme disease agent.
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17
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Megli CJ, Coyne CB. Infections at the maternal-fetal interface: an overview of pathogenesis and defence. Nat Rev Microbiol 2021; 20:67-82. [PMID: 34433930 PMCID: PMC8386341 DOI: 10.1038/s41579-021-00610-y] [Citation(s) in RCA: 148] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2021] [Indexed: 02/08/2023]
Abstract
Infections are a major threat to human reproductive health, and infections in pregnancy can cause prematurity or stillbirth, or can be vertically transmitted to the fetus leading to congenital infection and severe disease. The acronym ‘TORCH’ (Toxoplasma gondii, other, rubella virus, cytomegalovirus, herpes simplex virus) refers to pathogens directly associated with the development of congenital disease and includes diverse bacteria, viruses and parasites. The placenta restricts vertical transmission during pregnancy and has evolved robust mechanisms of microbial defence. However, microorganisms that cause congenital disease have likely evolved diverse mechanisms to bypass these defences. In this Review, we discuss how TORCH pathogens access the intra-amniotic space and overcome the placental defences that protect against microbial vertical transmission. Infections during pregnancy can be associated with devastating outcomes for the pregnant mother and developing fetus. In this Review, Megli and Coyne discuss placental defences and provide an overview of how various viral, bacterial and parasitic pathogens traverse the maternal–fetal interface and cause disease.
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Affiliation(s)
- Christina J Megli
- Division of Maternal-Fetal Medicine, Division of Reproductive Infectious Disease, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine and the Magee Womens Research Institute, Pittsburgh, PA, USA.
| | - Carolyn B Coyne
- Department of Molecular Genetics and Microbiology and the Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA.
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18
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Hawley KL, Montezuma-Rusca JM, Delgado KN, Singh N, Uversky VN, Caimano MJ, Radolf JD, Luthra A. Structural Modeling of the Treponema pallidum Outer Membrane Protein Repertoire: a Road Map for Deconvolution of Syphilis Pathogenesis and Development of a Syphilis Vaccine. J Bacteriol 2021; 203:e0008221. [PMID: 33972353 PMCID: PMC8407342 DOI: 10.1128/jb.00082-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/27/2021] [Indexed: 01/11/2023] Open
Abstract
Treponema pallidum, an obligate human pathogen, has an outer membrane (OM) whose physical properties, ultrastructure, and composition differ markedly from those of phylogenetically distant Gram-negative bacteria. We developed structural models for the outer membrane protein (OMP) repertoire (OMPeome) of T. pallidum Nichols using solved Gram-negative structures, computational tools, and small-angle X-ray scattering (SAXS) of selected recombinant periplasmic domains. The T. pallidum "OMPeome" harbors two "stand-alone" proteins (BamA and LptD) involved in OM biogenesis and four paralogous families involved in the influx/efflux of small molecules: 8-stranded β-barrels, long-chain-fatty-acid transporters (FadLs), OM factors (OMFs) for efflux pumps, and T. pallidum repeat proteins (Tprs). BamA (TP0326), the central component of a β-barrel assembly machine (BAM)/translocation and assembly module (TAM) hybrid, possesses a highly flexible polypeptide-transport-associated (POTRA) 1-5 arm predicted to interact with TamB (TP0325). TP0515, an LptD ortholog, contains a novel, unstructured C-terminal domain that models inside the β-barrel. T. pallidum has four 8-stranded β-barrels, each containing positively charged extracellular loops that could contribute to pathogenesis. Three of five FadL-like orthologs have a novel α-helical, presumptively periplasmic C-terminal extension. SAXS and structural modeling further supported the bipartite membrane topology and tridomain architecture of full-length members of the Tpr family. T. pallidum's two efflux pumps presumably extrude noxious small molecules via four coexpressed OMFs with variably charged tunnels. For BamA, LptD, and OMFs, we modeled the molecular machines that deliver their substrates into the OM or external milieu. The spirochete's extended families of OM transporters collectively confer a broad capacity for nutrient uptake. The models also furnish a structural road map for vaccine development. IMPORTANCE The unusual outer membrane (OM) of T. pallidum, the syphilis spirochete, is the ultrastructural basis for its well-recognized capacity for invasiveness, immune evasion, and persistence. In recent years, we have made considerable progress in identifying T. pallidum's repertoire of OMPs. Here, we developed three-dimensional (3D) models for the T. pallidum Nichols OMPeome using structural modeling, bioinformatics, and solution scattering. The OM contains three families of OMP transporters, an OMP family involved in the extrusion of noxious molecules, and two "stand-alone" proteins involved in OM biogenesis. This work represents a major advance toward elucidating host-pathogen interactions during syphilis; understanding how T. pallidum, an extreme auxotroph, obtains a wide array of biomolecules from its obligate human host; and developing a vaccine with global efficacy.
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Affiliation(s)
- Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, Connecticut, USA
| | - Jairo M. Montezuma-Rusca
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases, UConn Health, Farmington, Connecticut, USA
| | | | - Navreeta Singh
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Melissa J. Caimano
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Justin D. Radolf
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
- Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
| | - Amit Luthra
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
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19
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Jiang R, Meng H, Raddassi K, Fleming I, Hoehn KB, Dardick KR, Belperron AA, Montgomery RR, Shalek AK, Hafler DA, Kleinstein SH, Bockenstedt LK. Single-cell immunophenotyping of the skin lesion erythema migrans identifies IgM memory B cells. JCI Insight 2021; 6:148035. [PMID: 34061047 PMCID: PMC8262471 DOI: 10.1172/jci.insight.148035] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/19/2021] [Indexed: 11/17/2022] Open
Abstract
The skin lesion erythema migrans (EM) is an initial sign of the Ixodes tick-transmitted Borreliella spirochetal infection known as Lyme disease. T cells and innate immune cells have previously been shown to predominate the EM lesion and promote the reaction. Despite the established importance of B cells and antibodies in preventing infection, the role of B cells in the skin immune response to Borreliella is unknown. Here, we used single-cell RNA-Seq in conjunction with B cell receptor (BCR) sequencing to immunophenotype EM lesions and their associated B cells and BCR repertoires. We found that B cells were more abundant in EM in comparison with autologous uninvolved skin; many were clonally expanded and had circulating relatives. EM-associated B cells upregulated the expression of MHC class II genes and exhibited preferential IgM isotype usage. A subset also exhibited low levels of somatic hypermutation despite a gene expression profile consistent with memory B cells. Our study demonstrates that single-cell gene expression with paired BCR sequencing can be used to interrogate the sparse B cell populations in human skin and reveals that B cells in the skin infection site in early Lyme disease expressed a phenotype consistent with local antigen presentation and antibody production.
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Affiliation(s)
| | | | - Khadir Raddassi
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ira Fleming
- Broad Institute of MIT and Harvard University, Cambridge, Massachusetts, USA
| | | | | | - Alexia A. Belperron
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ruth R. Montgomery
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Alex K. Shalek
- Broad Institute of MIT and Harvard University, Cambridge, Massachusetts, USA
- The Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
- Institute for Medical Engineering & Science, Department of Chemistry, and Koch Institute for Integrative Cancer Research, MIT, Cambridge, Massachusetts, USA
| | - David A. Hafler
- Department of Immunobiology
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
- Broad Institute of MIT and Harvard University, Cambridge, Massachusetts, USA
| | - Steven H. Kleinstein
- Department of Immunobiology
- Department of Pathology, and
- Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut, USA
| | - Linda K. Bockenstedt
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
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20
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Singh T, Otero CE, Li K, Valencia SM, Nelson AN, Permar SR. Vaccines for Perinatal and Congenital Infections-How Close Are We? Front Pediatr 2020; 8:569. [PMID: 33384972 PMCID: PMC7769834 DOI: 10.3389/fped.2020.00569] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 08/04/2020] [Indexed: 12/26/2022] Open
Abstract
Congenital and perinatal infections are transmitted from mother to infant during pregnancy across the placenta or during delivery. These infections not only cause pregnancy complications and still birth, but also result in an array of pediatric morbidities caused by physical deformities, neurodevelopmental delays, and impaired vision, mobility and hearing. Due to the burden of these conditions, congenital and perinatal infections may result in lifelong disability and profoundly impact an individual's ability to live to their fullest capacity. While there are vaccines to prevent congenital and perinatal rubella, varicella, and hepatitis B infections, many more are currently in development at various stages of progress. The spectrum of our efforts to understand and address these infections includes observational studies of natural history of disease, epidemiological evaluation of risk factors, immunogen design, preclinical research of protective immunity in animal models, and evaluation of promising candidates in vaccine trials. In this review we summarize this progress in vaccine development research for Cytomegalovirus, Group B Streptococcus, Herpes simplex virus, Human Immunodeficiency Virus, Toxoplasma, Syphilis, and Zika virus congenital and perinatal infections. We then synthesize this evidence to examine how close we are to developing a vaccine for these infections, and highlight areas where research is still needed.
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Affiliation(s)
- Tulika Singh
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - Claire E. Otero
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Katherine Li
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Sarah M. Valencia
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Ashley N. Nelson
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
| | - Sallie R. Permar
- Duke University Medical Center, Duke Human Vaccine Institute, Durham, NC, United States
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
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21
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Kesserwani H. Decomplexifying Serum and Cerebrospinal Fluid (CSF) Serologic Testing of Neurosyphilis: A Case Report of Ocular Syphilis and Highlights of the Principles of Serologic Testing. Cureus 2020; 12:e11533. [PMID: 33354477 PMCID: PMC7746323 DOI: 10.7759/cureus.11533] [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] [Accepted: 11/17/2020] [Indexed: 11/30/2022] Open
Abstract
Serologic tests for syphilis can be quite complex. The screening and confirmatory tests, which number at least eight, are mathematically interpreted as a total of 16 possible combinations, if we choose one test from each of two sets of four. However, this bewildering complexity is simplified if we apply certain principles. We reiterate and propose four axioms. First, we distinguish between treponemal versus non-treponemal tests. The former, the treponemal test, is specific for the spirochete, treponema pallidum, and is used as a confirmatory test. It rarely declines over time. The latter, the non-treponemal test, is a screening test and reflects treponemal or tissue damage, is reported as a titer, and is used to monitor disease activity. We usually need both for screening and confirmatory diagnostic testing. Secondly, for rapid plasma reagin (RPR) tests, a non-treponemal serology test titer of at least 1:8 is suggestive of syphilis, but not necessarily neurosyphilis. A false-negative test usually registers below this dilution level and may be due to the "prozone phenomenon". Serum RPR titers are usually greater than 1:32. Thirdly, a negative treponemal test in the cerebrospinal fluid excludes neurosyphilis and a positive test is highly sensitive but lacks specificity, usually due to blood contamination. Most patients with neurosyphilis will have a positive non-treponemal test in the cerebrospinal fluid (CSF) with elevated protein and pleocytosis. Fourthly, a serological cure is defined as at least a four-fold decline in a non-treponemal test titer at three and six months, or a persistently low titer after treatment. Patients who do not fulfill these criteria are known as "serofast". We describe the case of a 38-year-old man with human immunodeficiency virus-type 1 who developed bilateral optic disc edema with photopsias and transient visual obscurations.
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22
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Galvis AE, Arrieta A. Congenital Syphilis: A U.S. Perspective. CHILDREN-BASEL 2020; 7:children7110203. [PMID: 33137962 PMCID: PMC7692780 DOI: 10.3390/children7110203] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 11/16/2022]
Abstract
Congenital syphilis still represents a worldwide public health problem. If left untreated, it can lead to fetal demise and high neonatal morbidity and mortality. Unfortunately, in the last decade, there has been a resurgence of cases in the U.S. This review discusses the ongoing problem of this preventable congenital infection, vertical transmission and clinical manifestations while providing a guidance for the evaluation and management of infants born to mothers with reactive serologic tests for syphilis.
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Affiliation(s)
- Alvaro E. Galvis
- Department of Infectious Diseases, Children’s Hospital of Orange County, Orange, CA 92868, USA;
- School of Medicine, University of California, Irvine, CA 92697, USA
| | - Antonio Arrieta
- Department of Infectious Diseases, Children’s Hospital of Orange County, Orange, CA 92868, USA;
- School of Medicine, University of California, Irvine, CA 92697, USA
- Correspondence:
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23
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Lundstedt E, Kahne D, Ruiz N. Assembly and Maintenance of Lipids at the Bacterial Outer Membrane. Chem Rev 2020; 121:5098-5123. [PMID: 32955879 DOI: 10.1021/acs.chemrev.0c00587] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The outer membrane of Gram-negative bacteria is essential for their survival in harsh environments and provides intrinsic resistance to many antibiotics. This membrane is remarkable; it is a highly asymmetric lipid bilayer. The inner leaflet of the outer membrane contains phospholipids, whereas the fatty acyl chains attached to lipopolysaccharide (LPS) comprise the hydrophobic portion of the outer leaflet. This lipid asymmetry, and in particular the exclusion of phospholipids from the outer leaflet, is key to creating an almost impenetrable barrier to hydrophobic molecules that can otherwise pass through phospholipid bilayers. It has long been known that these lipids are not made in the outer membrane. It is now believed that conserved multisubunit protein machines extract these lipids after their synthesis is completed at the inner membrane and transport them to the outer membrane. A longstanding question is how the cell builds and maintains this asymmetric lipid bilayer in coordination with the assembly of the other components of the cell envelope. This Review describes the trans-envelope lipid transport systems that have been identified to participate in outer-membrane biogenesis: LPS transport via the Lpt machine, and phospholipid transport via the Mla pathway and several recently proposed transporters.
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Affiliation(s)
- Emily Lundstedt
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Natividad Ruiz
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
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24
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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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25
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Chen W, Šmajs D, Hu Y, Ke W, Pospíšilová P, Hawley KL, Caimano MJ, Radolf JD, Sena A, Tucker JD, Yang B, Juliano JJ, Zheng H, Parr JB. Analysis of Treponema pallidum Strains From China Using Improved Methods for Whole-Genome Sequencing From Primary Syphilis Chancres. J Infect Dis 2020; 223:848-853. [PMID: 32710788 DOI: 10.1093/infdis/jiaa449] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Whole-genome sequencing (WGS) of Treponema pallidum subspecies pallidum (TPA) has been constrained by the lack of in vitro cultivation methods for isolating spirochetes from patient samples. METHODS We built upon recently developed enrichment methods to sequence TPA directly from primary syphilis chancre swabs collected in Guangzhou, China. RESULTS By combining parallel, pooled whole-genome amplification with hybrid selection, we generated high-quality genomes from 4 of 8 chancre-swab samples and 2 of 2 rabbit-passaged isolates, all subjected to challenging storage conditions. CONCLUSIONS This approach enabled the first WGS of Chinese samples without rabbit passage and provided insights into TPA genetic diversity in China.
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Affiliation(s)
- Wentao Chen
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Yongfei Hu
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Wujian Ke
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Kelly L Hawley
- Division of Infectious Diseases and Department of Pediatrics, Connecticut Children's Medical Center, Hartford, Connecticut, USA
| | - Melissa J Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Justin D Radolf
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA.,Departments of Genetics and Genome Sciences, and Immunology, UConn Health, Farmington, Connecticut, USA
| | - Arlene Sena
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Joseph D Tucker
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Bin Yang
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Jonathan J Juliano
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Heping Zheng
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
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26
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Addetia A, Tantalo LC, Lin MJ, Xie H, Huang ML, Marra CM, Greninger AL. Comparative genomics and full-length Tprk profiling of Treponema pallidum subsp. pallidum reinfection. PLoS Negl Trop Dis 2020; 14:e0007921. [PMID: 32251462 PMCID: PMC7162541 DOI: 10.1371/journal.pntd.0007921] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/16/2020] [Accepted: 02/08/2020] [Indexed: 12/25/2022] Open
Abstract
Developing a vaccine against Treponema pallidum subspecies pallidum, the causative agent of syphilis, remains a public health priority. Syphilis vaccine design efforts have been complicated by lack of an in vitro T. pallidum culture system, prolific antigenic variation in outer membrane protein TprK, and lack of functional annotation for nearly half of the genes. Understanding the genetic basis of T. pallidum reinfection can provide insights into variation among strains that escape cross-protective immunity. Here, we present comparative genomic sequencing and deep, full-length tprK profiling of two T. pallidum isolates from blood from the same patient that were collected six years apart. Notably, this patient was diagnosed with syphilis four times, with two of these episodes meeting the definition of neurosyphilis, during this interval. Outside of the highly variable tprK gene, we identified 14 coding changes in 13 genes. Nine of these genes putatively localized to the periplasmic or outer membrane spaces, consistent with a potential role in serological immunoevasion. Using a newly developed full-length tprK deep sequencing protocol, we profiled the diversity of this gene that far outpaces the rest of the genome. Intriguingly, we found that the reinfecting isolate demonstrated less diversity across each tprK variable region compared to the isolate from the first infection. Notably, the two isolates did not share any full-length TprK sequences. Our results are consistent with an immunodominant-evasion model in which the diversity of TprK explains the ability of T. pallidum to successfully reinfect individuals, even when they have been infected with the organism multiple times.
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Affiliation(s)
- Amin Addetia
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lauren C. Tantalo
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Michelle J. Lin
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Hong Xie
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Meei-Li Huang
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Christina M. Marra
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Alexander L. Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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27
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Mikalová L, Janečková K, Nováková M, Strouhal M, Čejková D, Harper KN, Šmajs D. Whole genome sequence of the Treponema pallidum subsp. endemicum strain Iraq B: A subpopulation of bejel treponemes contains full-length tprF and tprG genes similar to those present in T. p. subsp. pertenue strains. PLoS One 2020; 15:e0230926. [PMID: 32236138 PMCID: PMC7112178 DOI: 10.1371/journal.pone.0230926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 03/11/2020] [Indexed: 11/25/2022] Open
Abstract
Treponema pallidum subsp. endemicum (TEN) is the causative agent of endemic syphilis (bejel). Until now, only a single TEN strain, Bosnia A, has been completely sequenced. The only other laboratory TEN strain available, Iraq B, was isolated in Iraq in 1951 by researchers from the US Centers for Disease Control and Prevention. In this study, the complete genome of the Iraq B strain was amplified as overlapping PCR products and sequenced using the pooled segment genome sequencing method and Illumina sequencing. Total average genome sequencing coverage reached 3469×, with a total genome size of 1,137,653 bp. Compared to the genome sequence of Bosnia A, a set of 37 single nucleotide differences, 4 indels, 2 differences in the number of tandem repetitions, and 18 differences in the length of homopolymeric regions were found in the Iraq B genome. Moreover, the tprF and tprG genes that were previously found deleted in the genome of the TEN Bosnia A strain (spanning 2.3 kb in length) were present in a subpopulation of TEN Iraq B and Bosnia A microbes, and their sequence was highly similar to those found in T. p. subsp. pertenue strains, which cause the disease yaws. The genome sequence of TEN Iraq B revealed close genetic relatedness between both available bejel-causing laboratory strains (i.e., Iraq B and Bosnia A) and also genetic variability within the bejel treponemes comparable to that found within yaws- or syphilis-causing strains. In addition, genetic relatedness to TPE strains was demonstrated by the sequence of the tprF and tprG genes found in subpopulations of both TEN Iraq B and Bosnia A. The loss of the tprF and tprG genes in most TEN microbes suggest that TEN genomes have been evolving via the loss of genomic regions, a phenomenon previously found among the treponemes causing both syphilis and rabbit syphilis.
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Affiliation(s)
- Lenka Mikalová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Klára Janečková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Markéta Nováková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Darina Čejková
- Department of Immunology, Veterinary Research Institute, Brno, Czech Republic
| | - Kristin N. Harper
- Department of Population Biology, Ecology, and Evolution, Emory University, Atlanta, Georgia, United States of America
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- * E-mail:
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Strain diversity of Treponema pallidum subsp. pertenue suggests rare interspecies transmission in African nonhuman primates. Sci Rep 2019; 9:14243. [PMID: 31578447 PMCID: PMC6775232 DOI: 10.1038/s41598-019-50779-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 09/19/2019] [Indexed: 11/09/2022] Open
Abstract
In our most recent study, we found that in Tanzania infection with Treponema pallidum (TP) subsp. pertenue (TPE) is present in four different monkey species. In order to gain information on the diversity and epidemiological spread of the infection in Tanzanian nonhuman primates (NHP), we identified two suitable candidate genes for multi-locus sequence typing (MLST). We demonstrate the functionality of the MLST system in invasively and non-invasively collected samples. While we were not able to demonstrate frequent interspecies transmission of TPE in Tanzanian monkeys, our results show a clustering of TPE strains according to geography and not host species, which is suggestive for rare transmission events between different NHP species. In addition to the geographic stability, we describe the relative temporal stability of the strains infecting NHPs and identified multi-strain infection. Differences between TPE strains of NHP and human origin are highlighted. Our results show that antibiotic resistance does not occur in Tanzanian TPE strains of NHP origin.
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Maděránková D, Mikalová L, Strouhal M, Vadják Š, Kuklová I, Pospíšilová P, Krbková L, Koščová P, Provazník I, Šmajs D. Identification of positively selected genes in human pathogenic treponemes: Syphilis-, yaws-, and bejel-causing strains differ in sets of genes showing adaptive evolution. PLoS Negl Trop Dis 2019; 13:e0007463. [PMID: 31216284 PMCID: PMC6602244 DOI: 10.1371/journal.pntd.0007463] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 07/01/2019] [Accepted: 05/14/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Pathogenic treponemes related to Treponema pallidum are both human (causing syphilis, yaws, bejel) and animal pathogens (infections of primates, venereal spirochetosis in rabbits). A set of 11 treponemal genome sequences including those of five Treponema pallidum ssp. pallidum (TPA) strains (Nichols, DAL-1, Mexico A, SS14, Chicago), four T. p. ssp. pertenue (TPE) strains (CDC-2, Gauthier, Samoa D, Fribourg-Blanc), one T. p. ssp. endemicum (TEN) strain (Bosnia A) and one strain (Cuniculi A) of Treponema paraluisleporidarum ecovar Cuniculus (TPeC) were tested for the presence of positively selected genes. METHODOLOGY/PRINCIPAL FINDINGS A total of 1068 orthologous genes annotated in all 11 genomes were tested for the presence of positively selected genes using both site and branch-site models with CODEML (PAML package). Subsequent analyses with sequences obtained from 62 treponemal draft genomes were used for the identification of positively selected amino acid positions. Synthetic biotinylated peptides were designed to cover positively selected protein regions and these peptides were tested for reactivity with the patient's syphilis sera. Altogether, 22 positively selected genes were identified in the TP genomes and TPA sets of positively selected genes differed from TPE genes. While genetic variability among TPA strains was predominantly present in a number of genetic loci, genetic variability within TPE and TEN strains was distributed more equally along the chromosome. Several syphilitic sera were shown to react with some peptides derived from the protein sequences evolving under positive selection. CONCLUSIONS/SIGNIFICANCE The syphilis-, yaws-, and bejel-causing strains differed relative to sets of positively selected genes. Most of the positively selected chromosomal loci were identified among the TPA treponemes. The local accumulation of genetic variability suggests that the diversification of TPA strains took place predominantly in a limited number of genomic regions compared to the more dispersed genetic diversity differentiating TPE and TEN strains. The identification of positively selected sites in tpr genes and genes encoding outer membrane proteins suggests their role during infection of human and animal hosts. The driving force for adaptive evolution at these loci thus appears to be the host immune response as supported by observed reactivity of syphilitic sera with some peptides derived from protein sequences showing adaptive evolution.
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Affiliation(s)
- Denisa Maděránková
- Department of Biomedical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Lenka Mikalová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Šimon Vadják
- Department of Biomedical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Ivana Kuklová
- Department of Dermatology, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Krbková
- Department of Children's Infectious Diseases, Faculty of Medicine and University Hospital, Masaryk University, Brno, Czech Republic
| | - Pavlína Koščová
- Department of Biomedical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Ivo Provazník
- Department of Biomedical Engineering, Brno University of Technology, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- * E-mail:
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Strouhal M, Mikalová L, Haviernik J, Knauf S, Bruisten S, Noordhoek GT, Oppelt J, Čejková D, Šmajs D. Complete genome sequences of two strains of Treponema pallidum subsp. pertenue from Indonesia: Modular structure of several treponemal genes. PLoS Negl Trop Dis 2018; 12:e0006867. [PMID: 30303967 PMCID: PMC6197692 DOI: 10.1371/journal.pntd.0006867] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/22/2018] [Accepted: 09/24/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Treponema pallidum subsp. pertenue (TPE) is the causative agent of yaws, a multistage disease endemic in tropical regions in Africa, Asia, Oceania, and South America. To date, seven TPE strains have been completely sequenced and analyzed including five TPE strains of human origin (CDC-2, CDC 2575, Gauthier, Ghana-051, and Samoa D) and two TPE strains isolated from the baboons (Fribourg-Blanc and LMNP-1). This study revealed the complete genome sequences of two TPE strains, Kampung Dalan K363 and Sei Geringging K403, isolated in 1990 from villages in the Pariaman region of Sumatra, Indonesia and compared these genome sequences with other known TPE genomes. METHODOLOGY/PRINCIPAL FINDINGS The genomes were determined using the pooled segment genome sequencing method combined with the Illumina sequencing platform resulting in an average coverage depth of 1,021x and 644x for the TPE Kampung Dalan K363 and TPE Sei Geringging K403 genomes, respectively. Both Indonesian TPE strains were genetically related to each other and were more distantly related to other, previously characterized TPE strains. The modular character of several genes, including TP0136 and TP0858 gene orthologs, was identified by analysis of the corresponding sequences. To systematically detect genes potentially having a modular genetic structure, we performed a whole genome analysis-of-occurrence of direct or inverted repeats of 17 or more nucleotides in length. Besides in tpr genes, a frequent presence of repeats was found in the genetic regions spanning TP0126-TP0136, TP0856-TP0858, and TP0896 genes. CONCLUSIONS/SIGNIFICANCE Comparisons of genome sequences of TPE Kampung Dalan K363 and Sei Geringging K403 with other TPE strains revealed a modular structure of several genomic loci including the TP0136, TP0856, and TP0858 genes. Diversification of TPE genomes appears to be facilitated by intra-strain genome recombination events.
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Affiliation(s)
- Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Mikalová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jan Haviernik
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Sascha Knauf
- Work Group Neglected Tropical Diseases, Infection Biology Unit, German Primate Center, Leibniz Institute for Primate Research, Goettingen, Germany
| | - Sylvia Bruisten
- Public Health Laboratory, Department of Infectious Diseases GGD Amsterdam, WT Amsterdam, the Netherlands
| | - Gerda T. Noordhoek
- Izore, Centrum Infectieziekten Friesland, EN Leeuwarden, the Netherlands
| | - Jan Oppelt
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Darina Čejková
- Department of Immunology, Veterinary Research Institute, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Pospíšilová P, Grange PA, Grillová L, Mikalová L, Martinet P, Janier M, Vermersch A, Benhaddou N, Del Giudice P, Alcaraz I, Truchetet F, Dupin N, Šmajs D. Multi-locus sequence typing of Treponema pallidum subsp. pallidum present in clinical samples from France: Infecting treponemes are genetically diverse and belong to 18 allelic profiles. PLoS One 2018; 13:e0201068. [PMID: 30024965 PMCID: PMC6053231 DOI: 10.1371/journal.pone.0201068] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/07/2018] [Indexed: 11/19/2022] Open
Abstract
Treponema pallidum subsp. pallidum, the causative agent of sexually transmitted syphilis, detected in clinical samples from France, was subjected to molecular typing using the recently developed Multilocus Sequence Typing system. The samples (n = 133) used in this study were collected from 2010-2016 from patients with diagnosed primary or secondary syphilis attending outpatient centers or hospitals in several locations in France. Altogether, 18 different allelic profiles were found among the fully typed samples (n = 112). There were five allelic variants identified for TP0136, 12 for TP0548, and eight for TP0705. Out of the identified alleles, one, seven, and three novel alleles were identified in TP0136, TP0548, and TP0705, respectively. Partial allelic profiles were obtained from 6 samples. The majority of samples (n = 110) belonged to the SS14-like cluster of TPA isolates while 7 clustered with Nichols-like isolates. Patients infected with Nichols-like samples were more often older (p = 0.041) and more often diagnosed with secondary syphilis (p = 0.033) compared to patients infected with SS14-like samples. In addition, macrolide resistance caused by the A2058G mutation was found to be associated with allelic profile 1.3.1 or with strains belonging to the 1.3.1 lineage (p<0.001). The genetic diversity among TPA strains infecting the European population was surprisingly high, which suggests that additional studies are needed to reveal the full genetic diversity of TPA pathogens infecting humans.
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Affiliation(s)
- Petra Pospíšilová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Philippe Alain Grange
- Institut Cochin U1016 Equipe Batteux, Laboratoire de Dermatologie–CNR Syphilis, Faculté de Médecine, Université Sorbonne Paris Descartes, Paris, France
| | - Linda Grillová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Mikalová
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Pervenche Martinet
- Service Prévention Santé Conseil Départemental des Bouches du Rhône, Marseille, France
| | - Michel Janier
- Centre des MST, Hôpital Saint-Louis, AP-HP, Paris, France
| | - Annie Vermersch
- Service de Dermatologie, Hôpital Jean Bernard, Valenciennes, France
| | - Nadjet Benhaddou
- Institut Cochin U1016 Equipe Batteux, Laboratoire de Dermatologie–CNR Syphilis, Faculté de Médecine, Université Sorbonne Paris Descartes, Paris, France
- Service de Bactériologie, Groupe Hospitalier Paris Centre Cochin-Hôtel Dieu-Broca, Paris, France
| | - Pascal Del Giudice
- Service de Dermatologie-Infectiologie, Centre Hospitalier Inter régional, Fréjus, France
| | - Isabelle Alcaraz
- Service Universitaire des Maladies Infectieuses et du Voyageur, Hôpital Dron, Tourcoing, France
| | | | - Nicolas Dupin
- Institut Cochin U1016 Equipe Batteux, Laboratoire de Dermatologie–CNR Syphilis, Faculté de Médecine, Université Sorbonne Paris Descartes, Paris, France
- Service de Dermatologie-Vénéréologie, Hôpital Cochin–Pavillon Tarnier, AP-HP, Paris, France
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Kumar S, Caimano MJ, Anand A, Dey A, Hawley KL, LeDoyt ME, La Vake CJ, Cruz AR, Ramirez LG, Paštěková L, Bezsonova I, Šmajs D, Salazar JC, Radolf JD. Sequence Variation of Rare Outer Membrane Protein β-Barrel Domains in Clinical Strains Provides Insights into the Evolution of Treponema pallidum subsp. pallidum, the Syphilis Spirochete. mBio 2018; 9:e01006-18. [PMID: 29895642 PMCID: PMC6016234 DOI: 10.1128/mbio.01006-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/10/2018] [Indexed: 02/07/2023] Open
Abstract
In recent years, considerable progress has been made in topologically and functionally characterizing integral outer membrane proteins (OMPs) of Treponema pallidum subspecies pallidum, the syphilis spirochete, and identifying its surface-exposed β-barrel domains. Extracellular loops in OMPs of Gram-negative bacteria are known to be highly variable. We examined the sequence diversity of β-barrel-encoding regions of tprC, tprD, and bamA in 31 specimens from Cali, Colombia; San Francisco, California; and the Czech Republic and compared them to allelic variants in the 41 reference genomes in the NCBI database. To establish a phylogenetic framework, we used T. pallidum 0548 (tp0548) genotyping and tp0558 sequences to assign strains to the Nichols or SS14 clades. We found that (i) β-barrels in clinical strains could be grouped according to allelic variants in T. pallidum subsp. pallidum reference genomes; (ii) for all three OMP loci, clinical strains within the Nichols or SS14 clades often harbored β-barrel variants that differed from the Nichols and SS14 reference strains; and (iii) OMP variable regions often reside in predicted extracellular loops containing B-cell epitopes. On the basis of structural models, nonconservative amino acid substitutions in predicted transmembrane β-strands of T. pallidum repeat C (TprC) and TprD2 could give rise to functional differences in their porin channels. OMP profiles of some clinical strains were mosaics of different reference strains and did not correlate with results from enhanced molecular typing. Our observations suggest that human host selection pressures drive T. pallidum subsp. pallidum OMP diversity and that genetic exchange contributes to the evolutionary biology of T. pallidum subsp. pallidum They also set the stage for topology-based analysis of antibody responses to OMPs and help frame strategies for syphilis vaccine development.IMPORTANCE Despite recent progress characterizing outer membrane proteins (OMPs) of Treponema pallidum, little is known about how their surface-exposed, β-barrel-forming domains vary among strains circulating within high-risk populations. In this study, sequences for the β-barrel-encoding regions of three OMP loci, tprC, tprD, and bamA, in T. pallidum subsp. pallidum isolates from a large number of patient specimens from geographically disparate sites were examined. Structural models predict that sequence variation within β-barrel domains occurs predominantly within predicted extracellular loops. Amino acid substitutions in predicted transmembrane strands that could potentially affect porin channel function were also noted. Our findings suggest that selection pressures exerted within human populations drive T. pallidum subsp. pallidum OMP diversity and that recombination at OMP loci contributes to the evolutionary biology of syphilis spirochetes. These results also set the stage for topology-based analysis of antibody responses that promote clearance of T. pallidum subsp. pallidum and frame strategies for vaccine development based upon conserved OMP extracellular loops.
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Affiliation(s)
- Sanjiv Kumar
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Melissa J Caimano
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Arvind Anand
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Abhishek Dey
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Kelly L Hawley
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Pediatric Infectious Diseases, Connecticut Children's Medical Center, Hartford, Connecticut, USA
| | - Morgan E LeDoyt
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Carson J La Vake
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
| | - Adriana R Cruz
- Centro Internacional de Entrenamiento e Investigaciones Medicas (CIDEIM), Cali, Colombia
| | - Lady G Ramirez
- Centro Internacional de Entrenamiento e Investigaciones Medicas (CIDEIM), Cali, Colombia
| | - Lenka Paštěková
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Juan C Salazar
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Pediatric Infectious Diseases, Connecticut Children's Medical Center, Hartford, Connecticut, USA
- Centro Internacional de Entrenamiento e Investigaciones Medicas (CIDEIM), Cali, Colombia
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
- Department of Genetic and Genome Sciences, UConn Health, Farmington, Connecticut, USA
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Schuenemann VJ, Kumar Lankapalli A, Barquera R, Nelson EA, Iraíz Hernández D, Acuña Alonzo V, Bos KI, Márquez Morfín L, Herbig A, Krause J. Historic Treponema pallidum genomes from Colonial Mexico retrieved from archaeological remains. PLoS Negl Trop Dis 2018; 12:e0006447. [PMID: 29927932 PMCID: PMC6013024 DOI: 10.1371/journal.pntd.0006447] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/12/2018] [Indexed: 12/20/2022] Open
Abstract
Treponema pallidum infections occur worldwide causing, among other diseases, syphilis and yaws. In particular sexually transmitted syphilis is regarded as a re-emerging infectious disease with millions of new infections annually. Here we present three historic T. pallidum genomes (two from T. pallidum ssp. pallidum and one from T. pallidum ssp. pertenue) that have been reconstructed from skeletons recovered from the Convent of Santa Isabel in Mexico City, operational between the 17th and 19th century. Our analyses indicate that different T. pallidum subspecies caused similar diagnostic presentations that are normally associated with syphilis in infants, and potential evidence of a congenital infection of T. pallidum ssp. pertenue, the causative agent of yaws. This first reconstruction of T. pallidum genomes from archaeological material opens the possibility of studying its evolutionary history at a resolution previously assumed to be out of reach.
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Affiliation(s)
- Verena J. Schuenemann
- Institute for Archaeological Sciences, University of Tübingen, Tübingen, Germany
- Senckenberg Center for Human Evolution and Paleoenvironment, University of Tübingen, Tübingen, Germany
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
| | - Aditya Kumar Lankapalli
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Rodrigo Barquera
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
- Molecular Genetics Laboratory, National School of Anthropology and History, Mexico City, Mexico
| | - Elizabeth A. Nelson
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Diana Iraíz Hernández
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
- Molecular Genetics Laboratory, National School of Anthropology and History, Mexico City, Mexico
| | - Víctor Acuña Alonzo
- Molecular Genetics Laboratory, National School of Anthropology and History, Mexico City, Mexico
| | - Kirsten I. Bos
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | | | - Alexander Herbig
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Johannes Krause
- Institute for Archaeological Sciences, University of Tübingen, Tübingen, Germany
- Senckenberg Center for Human Evolution and Paleoenvironment, University of Tübingen, Tübingen, Germany
- Department for Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
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Houston S, Lithgow KV, Osbak KK, Kenyon CR, Cameron CE. Functional insights from proteome-wide structural modeling of Treponema pallidum subspecies pallidum, the causative agent of syphilis. BMC STRUCTURAL BIOLOGY 2018; 18:7. [PMID: 29769048 PMCID: PMC5956850 DOI: 10.1186/s12900-018-0086-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/27/2018] [Indexed: 12/21/2022]
Abstract
Background Syphilis continues to be a major global health threat with 11 million new infections each year, and a global burden of 36 million cases. The causative agent of syphilis, Treponema pallidum subspecies pallidum, is a highly virulent bacterium, however the molecular mechanisms underlying T. pallidum pathogenesis remain to be definitively identified. This is due to the fact that T. pallidum is currently uncultivatable, inherently fragile and thus difficult to work with, and phylogenetically distinct with no conventional virulence factor homologs found in other pathogens. In fact, approximately 30% of its predicted protein-coding genes have no known orthologs or assigned functions. Here we employed a structural bioinformatics approach using Phyre2-based tertiary structure modeling to improve our understanding of T. pallidum protein function on a proteome-wide scale. Results Phyre2-based tertiary structure modeling generated high-confidence predictions for 80% of the T. pallidum proteome (780/978 predicted proteins). Tertiary structure modeling also inferred the same function as primary structure-based annotations from genome sequencing pipelines for 525/605 proteins (87%), which represents 54% (525/978) of all T. pallidum proteins. Of the 175 T. pallidum proteins modeled with high confidence that were not assigned functions in the previously annotated published proteome, 167 (95%) were able to be assigned predicted functions. Twenty-one of the 175 hypothetical proteins modeled with high confidence were also predicted to exhibit significant structural similarity with proteins experimentally confirmed to be required for virulence in other pathogens. Conclusions Phyre2-based structural modeling is a powerful bioinformatics tool that has provided insight into the potential structure and function of the majority of T. pallidum proteins and helped validate the primary structure-based annotation of more than 50% of all T. pallidum proteins with high confidence. This work represents the first T. pallidum proteome-wide structural modeling study and is one of few studies to apply this approach for the functional annotation of a whole proteome. Electronic supplementary material The online version of this article (10.1186/s12900-018-0086-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen Vivien Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | | | - Chris Richard 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
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
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Hawley KL, Cruz AR, Benjamin SJ, La Vake CJ, Cervantes JL, LeDoyt M, Ramirez LG, Mandich D, Fiel-Gan M, Caimano MJ, Radolf JD, Salazar JC. IFNγ Enhances CD64-Potentiated Phagocytosis of Treponema pallidum Opsonized with Human Syphilitic Serum by Human Macrophages. Front Immunol 2017; 8:1227. [PMID: 29051759 PMCID: PMC5633599 DOI: 10.3389/fimmu.2017.01227] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 09/15/2017] [Indexed: 12/23/2022] Open
Abstract
Syphilis is a multi-stage, sexually transmitted disease caused by the spirochete Treponema pallidum (Tp). Considered broadly, syphilis can be conceptualized as a dualistic process in which spirochete-driven inflammation, the cause of clinical manifestations, coexists to varying extents with bacterial persistence. Inflammation is elicited in the tissues, along with the persistence of spirochetes to keep driving a robust immune response while evading host defenses; this duality is best exemplified during the florid, disseminated stage called secondary syphilis (SS). SS lesions typically contain copious amounts of spirochetes along with a mixed cellular infiltrate consisting of CD4+ T cells, CD8+ T cells, NK cells, plasma cells, and macrophages. In the rabbit model, Tp are cleared by macrophages via antibody-mediated opsonophagocytosis. Previously, we demonstrated that human syphilitic serum (HSS) promotes efficient uptake of Tp by human monocytes and that opsonophagocytosis of Tp markedly enhances cytokine production. Herein, we used monocyte-derived macrophages to study Tp–macrophage interactions ex vivo. In the absence of HSS, monocyte-derived macrophages internalized low numbers of Tp and secreted little cytokine (e.g., TNF). By contrast, these same macrophages internalized large numbers of unopsonized Borrelia burgdorferi and secreted robust levels of cytokines. Maturation of macrophages with M-CSF and IFNγ resulted in a macrophage phenotype with increased expression of HLA-DR, CD14, inducible nitric oxide synthase, TLR2, TLR8, and the Fcγ receptors (FcγR) CD64 and CD16, even in the absence of LPS. Importantly, IFNγ-polarized macrophages resulted in a statistically significant increase in opsonophagocytosis of Tp accompanied by enhanced production of cytokines, macrophage activation markers (CD40, CD80), TLRs (TLR2, TLR7, TLR8), chemokines (CCL19, CXCL10, CXCL11), and TH1-promoting cytokines (IL-12, IL-15). Finally, the blockade of FcγRs, primarily CD64, significantly diminished spirochetal uptake and proinflammatory cytokine secretion by IFNγ-stimulated macrophages. Our ex vivo studies demonstrate the importance of CD64-potentiated uptake of opsonized Tp and suggest that IFNγ-activated macrophages have an important role in the context of early syphilis. Our study results also provide an ex vivo surrogate system for use in future syphilis vaccine studies.
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Affiliation(s)
- Kelly L Hawley
- Department of Pediatrics, UConn Health, Farmington, CT, United States.,Division of Infectious Diseases, Connecticut Children's Medical Center, Hartford, CT, United States
| | - Adriana R Cruz
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
| | - Sarah J Benjamin
- Department of Pediatrics, UConn Health, Farmington, CT, United States.,Division of Infectious Diseases, Connecticut Children's Medical Center, Hartford, CT, United States.,Department of Immunology, UConn Health, Farmington, CT, United States
| | - Carson J La Vake
- Department of Pediatrics, UConn Health, Farmington, CT, United States
| | - Jorge L Cervantes
- Department of Pediatrics, UConn Health, Farmington, CT, United States.,Division of Infectious Diseases, Connecticut Children's Medical Center, Hartford, CT, United States
| | - Morgan LeDoyt
- Department of Medicine, UConn Health, Farmington, CT, United States
| | - Lady G Ramirez
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
| | - Daniza Mandich
- Department of Pathology, Hartford Hospital, Hartford, CT, United States
| | - Mary Fiel-Gan
- Department of Pathology, Hartford Hospital, Hartford, CT, United States
| | | | - Justin D Radolf
- Department of Pediatrics, UConn Health, Farmington, CT, United States.,Division of Infectious Diseases, Connecticut Children's Medical Center, Hartford, CT, United States.,Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia.,Department of Immunology, UConn Health, Farmington, CT, United States.,Department of Medicine, UConn Health, Farmington, CT, United States.,Department of Genetics and Developmental Biology, UConn Health, Farmington, CT, United States
| | - Juan C Salazar
- Department of Pediatrics, UConn Health, Farmington, CT, United States.,Division of Infectious Diseases, Connecticut Children's Medical Center, Hartford, CT, United States.,Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia.,Department of Immunology, UConn Health, Farmington, CT, United States
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