1
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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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Adhikari EH. Update on syphilis in pregnancy: marrying basic science advances and clinical perseverance to solve an ancient public health problem. Curr Opin Obstet Gynecol 2024; 36:67-74. [PMID: 38205786 DOI: 10.1097/gco.0000000000000939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
PURPOSE OF REVIEW While the clinical disease of syphilis, its consequences in pregnancy, and its sensitivity to penicillin treatment have remained relatively unchanged for a century or more, new technologies and basic discoveries in syphilis research have translated into tangible advances in clinical diagnosis, treatment, and prevention. The purpose of this review is to help the reader understand some of the recent relevant scientific publications on syphilis and its causative organism in a clinical obstetric context. RECENT FINDINGS Rates of adult and congenital syphilis have risen dramatically in the last decade despite public health efforts. Penicillin shortages and lack of screening or adequate treatment have all contributed to global disease burden. Advances in genomic and microbiological characterization of this spirochete have led to new developments in serologic and molecular diagnosis as well as evaluation of potential vaccine candidates. Until a syphilis vaccine is available, substance use disorders and lack of screening in pregnancy are associated with increased congenital syphilis, and these challenges will require novel solutions to fully address this public health crisis. SUMMARY Addressing the burden of congenital syphilis demands that obstetricians stay well informed of new tools and resources for diagnosis, treatment, and prevention of syphilis now and in the future.
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Affiliation(s)
- Emily H Adhikari
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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3
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Reid TB, Godornes C, Campbell VL, Laing KJ, Tantalo LC, Gomez A, Pholsena TN, Lieberman NAP, Krause TM, Cegielski VI, Culver LA, Nguyen N, Tong DQ, Hawley KL, Greninger AL, Giacani L, Cameron CE, Dombrowski JC, Wald A, Koelle DM. Treponema pallidum periplasmic and membrane proteins are recognized by circulating and skin CD4+ T cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.581790. [PMID: 38464313 PMCID: PMC10925203 DOI: 10.1101/2024.02.27.581790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Background Histologic and serologic studies suggest the induction of local and systemic Treponema pallidum ( Tp )-specific CD4+ T cell responses to Tp infection. We hypothesized that Tp -specific CD4+ T cells are detectable in blood and in the skin rash of secondary syphilis and persist in both compartments after treatment. Methods PBMC collected from 67 participants were screened by IFNγ ELISPOT response to Tp sonicate. Tp -reactive T cell lines from blood and skin were probed for responses to 88 recombinant Tp antigens. Peptide epitopes and HLA class II restriction were defined for selected antigens. Results We detected CD4+ T cell responses to Tp sonicate ex vivo. Using Tp -reactive T cell lines we observed recognition of 14 discrete proteins, 13 of which localize to bacterial membranes or the periplasmic space. After therapy, Tp -specific T cells persisted for at least 6 months in skin and 10 years in blood. Conclusions Tp infection elicits an antigen-specific CD4+ T cell response in blood and skin. Tp -specific CD4+ T cells persist as memory in both compartments long after curative therapy. The Tp antigenic targets we identified may be high priority vaccine candidates.
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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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5
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Lorenz Z, Rybolt L, Ghanem KG, Shiroky-Kochavi J. A patient with secondary syphilis following incomplete treatment of primary infection. THE LANCET. INFECTIOUS DISEASES 2023; 23:e497-e504. [PMID: 37414065 DOI: 10.1016/s1473-3099(23)00211-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/06/2023] [Accepted: 03/24/2023] [Indexed: 07/08/2023]
Abstract
Syphilis is a bacterial infection caused by Treponema pallidum and is primarily transmitted via skin-to-skin or mucosal contact during sexual encounters, or through vertical transmission during pregnancy. Cases continue to rise globally across various demographic groups despite effective treatment and prevention interventions. We discuss the case of a 28-year-old cisgender man who presented with secondary syphilis 1 month after being inadequately treated for primary syphilis. Individuals can present with symptoms and signs of syphilis to clinicians of various subspecialties due to diverse clinical presentation. All health-care providers should be able to identify the common and less common manifestations of this infection, and adequate treatment and follow-up are crucial to preventing serious sequelae. Novel biomedical prevention interventions, such as doxycycline post-exposure prophylaxis, are on the horizon.
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Affiliation(s)
- Zachary Lorenz
- Division of General Internal Medicine, Johns Hopkins University School of Medicine, Bayview Medical Center, Baltimore, MD, USA
| | - Lauren Rybolt
- Department of Internal Medicine, Division of General Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Khalil G Ghanem
- Department of Internal Medicine, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Bayview Medical Center, Baltimore, MD, USA
| | - Jennifer Shiroky-Kochavi
- Department of Internal Medicine, Division of General Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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6
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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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7
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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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8
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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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9
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He H, Pramanik AS, Swanson SK, Johnson DK, Florens L, Zückert WR. A Borrelia burgdorferi LptD homolog is required for flipping of surface lipoproteins through the spirochetal outer membrane. Mol Microbiol 2023; 119:752-767. [PMID: 37170643 PMCID: PMC10330739 DOI: 10.1111/mmi.15072] [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: 12/21/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023]
Abstract
Borrelia spirochetes are unique among diderm bacteria in their lack of lipopolysaccharide (LPS) in the outer membrane (OM) and their abundance of surface-exposed lipoproteins with major roles in transmission, virulence, and pathogenesis. Despite their importance, little is known about how surface lipoproteins are translocated through the periplasm and the OM. Here, we characterized Borrelia burgdorferi BB0838, a distant homolog of the OM LPS assembly protein LptD. Using a CRISPR interference approach, we showed that BB0838 is required for cell growth and envelope stability. Upon BB0838 knockdown, surface lipoprotein OspA was retained in the inner leaflet of the OM, as determined by its inaccessibility to in situ proteolysis but its presence in OM vesicles. The topology of the OM porin/adhesin P66 remained unaffected. Quantitative mass spectrometry of the B. burgdorferi membrane-associated proteome confirmed the selective periplasmic retention of surface lipoproteins under BB0838 knockdown conditions. Additional analysis identified a single in situ protease-accessible BB0838 peptide that mapped to a predicted β-barrel surface loop. Alphafold Multimer modeled a B. burgdorferi LptB2 FGCAD complex spanning the periplasm. Together, this suggests that BB0838/LptDBb facilitates the essential terminal step in spirochetal surface lipoprotein secretion, using an orthologous OM component of a pathway that secretes LPS in proteobacteria.
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Affiliation(s)
- Huan He
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | - Ankita S. Pramanik
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | | | - David K. Johnson
- University of Kansas, Computational Chemical Biology Core, Lawrence, Kansas, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Wolfram R. Zückert
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
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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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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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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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Kojima N, Konda KA, Klausner JD. Notes on syphilis vaccine development. Front Immunol 2022; 13:952284. [PMID: 35967432 PMCID: PMC9365935 DOI: 10.3389/fimmu.2022.952284] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
The quest for a syphilis vaccine to provide protection from infection or disease began not long after the isolation of the first Treponema pallidum subspecies pallidum (T. pallidum) strain in 1912. Yet, a practical and effective vaccine formulation continues to elude scientists. Over the last few years, however, efforts toward developing a syphilis vaccine have increased thanks to an improved understanding of the repertoire of T. pallidum outer membrane proteins (OMPs), which are the most likely syphilis vaccine candidates. More has been also learned about the molecular mechanisms behind pathogen persistence and immune evasion. Published vaccine formulations based on a subset of the pathogen's OMPs have conferred only partial protection upon challenge of immunized laboratory animals, primarily rabbits. Nonetheless, those experiments have improved our approach to the choice of immunization regimens, adjuvants, and vaccine target selection, although significant knowledge gaps remain. Herein, we provide a brief overview on current technologies and approaches employed in syphilis vaccinology, and possible future directions to develop a vaccine that could be pivotal to future syphilis control and elimination initiatives.
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Affiliation(s)
- Noah Kojima
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Kelika A. Konda
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, United States
- Centro de Investigación Interdisciplinaria en Sexualidad Sida y Sociedad, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jeffrey D. Klausner
- Departments of Medicine and Population and Public Health Sciences, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States
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Lian T, Zhang B, Giacani L, Kou C, Yang X, Zhang R, Wang Q. Full-length TprK of Treponema pallidum subsp. pallidum in lipid nanodiscs is a monomeric porin. Enzyme Microb Technol 2022; 153:109897. [PMID: 34670182 PMCID: PMC10929906 DOI: 10.1016/j.enzmictec.2021.109897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/27/2021] [Accepted: 08/23/2021] [Indexed: 11/22/2022]
Abstract
TprK is a key virulence factor of Treponema pallidum subsp. pallidum (T. pallidum) due to its ability to undergo intra-strain antigenic variation through gene conversion. This mechanism can generate millions of tprK gene and protein variants to allow immune evasion and pathogen persistence during infection. In silico structural modeling supports that TprK is an outer membrane β-barrel with porin function and with several surface-exposed loops, seven of which corresponding to the variable regions. No definitive structural of functional data, however, exist for this protein aside from its role in immune evasion. Studies to elucidate TprK biological function as a porin, are hindered by the evidence that TprK is not abundant on T. pallidum outer membrane, and by the fragility of T. pallidum envelope. To gain insight onto TprK structure and possible function as a porin, we used an Escherichia coli - based expression system that yielded highly pure full-length TprK without any intermediate denaturation step, and proceeded to reconstitute it in detergents and lipid nanodiscs. Visualization of TprK in nanodiscs using negative staining electron microscopy supported that TprK is a monomeric porin in an artificial lipid environment mimicking T. pallidum membrane. Our work provided evidence that TprK is a possible porin transporter of T. pallidum, a biological function compatible with its structural models. These results bring us closer to a comprehensive understanding of the function of this important virulence factor in syphilis pathogenesis and T. pallidum biology.
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Affiliation(s)
- Tingting Lian
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
| | - Bing Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 200120, China.
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA.
| | - Caixia Kou
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 200120, China.
| | - Ruili Zhang
- Department of Dermatology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210042, China.
| | - Qianqiu Wang
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
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Tiecco G, Degli Antoni M, Storti S, Marchese V, Focà E, Torti C, Castelli F, Quiros-Roldan E. A 2021 Update on Syphilis: Taking Stock from Pathogenesis to Vaccines. Pathogens 2021; 10:pathogens10111364. [PMID: 34832520 PMCID: PMC8620723 DOI: 10.3390/pathogens10111364] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/14/2021] [Accepted: 10/19/2021] [Indexed: 12/22/2022] Open
Abstract
In 2021 the scientific community’s efforts have been focused on solving the back-breaking challenge of the COVID-19 pandemic, but sexually transmitted infections (STI) are still one of the most common global health problems. Syphilis is a systemic disease caused by the spirochaete Treponema pallidum (TP) and is one of the oldest known diseases. Its incidence has increased in the last few years and syphilis still remains a contemporary plague that continues to afflict millions of people worldwide. Despite research improvements, syphilis pathogenesis is not completely clear; clinical presentation is very heterogeneous and the diagnosis can sometimes be difficult. Furthermore, few therapeutic options are available, and a vaccine has not been found yet. In this review, we describe the most recent evidence concerning the clinical manifestation, diagnosis, treatment and vaccine prospectives for this disease.
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Affiliation(s)
- Giorgio Tiecco
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Melania Degli Antoni
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Samuele Storti
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Valentina Marchese
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Emanuele Focà
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Carlo Torti
- Infectious and Tropical Disease Unit, Department of Medical and Surgical Sciences, “Magna Graecia” University of Catanzaro, 88100 Catanzaro, Italy;
| | - Francesco Castelli
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
| | - Eugenia Quiros-Roldan
- Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, ASST Spedali di Brescia, University of Brescia, 25123 Brescia, Italy; (G.T.); (M.D.A.); (S.S.); (V.M.); (E.F.); (F.C.)
- Correspondence: ; Tel.: +39-(030)-399-5677
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