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Liu Z, Zhang X, Xiong S, Huang S, Ding X, Xu M, Yao J, Liu S, Zhao F. Endothelial dysfunction of syphilis: Pathogenesis. J Eur Acad Dermatol Venereol 2024. [PMID: 38376088 DOI: 10.1111/jdv.19899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/19/2024] [Indexed: 02/21/2024]
Abstract
Treponema pallidum is the causative factor of syphilis, a sexually transmitted disease (STD) characterized by perivascular infiltration of inflammatory cells, vascular leakage, swelling and proliferation of endothelial cells (ECs). The endothelium lining blood and lymphatic vessels is a key barrier separating body fluids from host tissues and is a major target of T. pallidum. In this review, we focus on how T. pallidum establish intimate interactions with ECs, triggering endothelial dysfunction such as endothelial inflammation, abnormal repairment and damage of ECs. In addition, we summarize that migration and invasion of T. pallidum across vascular ECs may occur through two pathways. These two mechanisms of transendothelial migration are paracellular and cholesterol-dependent, respectively. Herein, clarifying the relationship between T. pallidum and endothelial dysfunction is of great significance to provide novel strategies for diagnosis and prevention of syphilis, and has a great potential prospect of clinical application.
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Affiliation(s)
- Zhaoping Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Xiaohong Zhang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Shun Xiong
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Shaobin Huang
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Xuan Ding
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Man Xu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Jiangchen Yao
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
| | - Shuangquan Liu
- Institute of Pathogenic Biology and Key Laboratory of Special Pathogen Prevention and Control of Hunan Province, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, 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, Hengyang Medical College, University of South China, Hengyang, China
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital, Hengyang Medical College, University of South China, Hengyang, China
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Waugh S, Ranasinghe A, Gomez A, Houston S, Lithgow KV, Eshghi A, Fleetwood J, Conway KME, Reynolds LA, Cameron CE. Syphilis and the host: multi-omic analysis of host cellular responses to Treponema pallidum provides novel insight into syphilis pathogenesis. Front Microbiol 2023; 14:1254342. [PMID: 37795301 PMCID: PMC10546344 DOI: 10.3389/fmicb.2023.1254342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction Syphilis is a chronic, multi-stage infection caused by the extracellular bacterium Treponema pallidum ssp. pallidum. Treponema pallidum widely disseminates through the vasculature, crosses endothelial, blood-brain and placental barriers, and establishes systemic infection. Although the capacity of T. pallidum to traverse the endothelium is well-described, the response of endothelial cells to T. pallidum exposure, and the contribution of this response to treponemal traversal, is poorly understood. Methods To address this knowledge gap, we used quantitative proteomics and cytokine profiling to characterize endothelial responses to T. pallidum. Results Proteomic analyses detected altered host pathways controlling extracellular matrix organization, necroptosis and cell death, and innate immune signaling. Cytokine analyses of endothelial cells exposed to T. pallidum revealed increased secretion of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF), and decreased secretion of monocyte chemoattractant protein-1 (MCP-1). Discussion This study provides insight into the molecular basis of syphilis disease symptoms and the enhanced susceptibility of individuals infected with syphilis to HIV co-infection. These investigations also enhance understanding of the host response to T. pallidum exposure and the pathogenic strategies used by T. pallidum to disseminate and persist within the host. Furthermore, our findings highlight the critical need for inclusion of appropriate controls when conducting T. pallidum-host cell interactions using in vitro- and in vivo-grown T. pallidum.
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Affiliation(s)
- Sean Waugh
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Akash Ranasinghe
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Karen V. Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Azad Eshghi
- University of Victoria-Genome BC Proteomics Centre, Victoria, BC, Canada
| | - Jenna Fleetwood
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Kate M. E. Conway
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Lisa A. Reynolds
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA, United States
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Li S, Li W, Jin Y, Wu B, Wu Y. Advancements in the development of nucleic acid vaccines for syphilis prevention and control. Hum Vaccin Immunother 2023; 19:2234790. [PMID: 37538024 PMCID: PMC10405752 DOI: 10.1080/21645515.2023.2234790] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/12/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023] Open
Abstract
Syphilis, a chronic systemic sexually transmitted disease, is caused by the bacterium Treponema pallidum (T. pallidum). Currently, syphilis remains a widespread infectious disease with significant disease burden in many countries. Despite the absence of identified penicillin-resistant strains, challenges in syphilis treatment persist due to penicillin allergies, supply issues, and the emergence of macrolide-resistant strains. Vaccines represent the most cost-effective strategy to prevent and control the syphilis epidemic. In light of the ongoing global coronavirus disease 2019 (COVID-19) pandemic, nucleic acid vaccines have gained prominence in the field of vaccine research and development, owing to their superior efficiency compared to traditional vaccines. This review summarizes the current state of the syphilis epidemic and the preliminary findings in T. pallidum nucleic acid vaccine research, discusses the challenges associated with the development of T. pallidum nucleic acid vaccines, and proposes strategies and measures for future T. pallidum vaccine development.
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Affiliation(s)
- Sijia Li
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Weiwei Li
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
- Department of Clinical Laboratory, The Second People’s Hospital of Foshan, Foshan, China
| | - Yinqi Jin
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
| | - Bin Wu
- First Affiliated Hospital, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Yimou Wu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, Institution of Pathogenic Biology, University of South China, Hengyang, China
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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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5
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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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6
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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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Courrol DDS, da Silva CCF, Prado LG, Chura-Chambi RM, Morganti L, de Souza GO, Heinemann MB, Isaac L, Conte FP, Portaro FCV, Rodrigues-da-Silva RN, Barbosa AS. Leptolysin, a Leptospira secreted metalloprotease of the pappalysin family with broad-spectrum activity. Front Cell Infect Microbiol 2022; 12:966370. [PMID: 36081769 PMCID: PMC9445424 DOI: 10.3389/fcimb.2022.966370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/03/2022] [Indexed: 11/22/2022] Open
Abstract
Extracellular proteolytic enzymes are produced by a variety of pathogenic microorganisms, and contribute to host colonization by modulating virulence. Here, we present a first characterization of leptolysin, a Leptospira metalloprotease of the pappalysin family identified in a previous exoproteomic study. Comparative molecular analysis of leptolysin with two other pappalysins from prokaryotes, ulilysin and mirolysin, reveals similarities regarding calcium, zinc, and arginine -binding sites conservation within the catalytic domain, but also discloses peculiarities. Variations observed in the primary and tertiary structures may reflect differences in primary specificities. Purified recombinant leptolysin of L. interrogans was obtained as a ~50 kDa protein. The protease exhibited maximal activity at pH 8.0 and 37°C, and hydrolytic activity was observed in the presence of different salts with maximum efficiency in NaCl. Substrate specificity was assessed using a small number of FRET peptides, and showed a marked preference for arginine residues at the P1 position. L. interrogans leptolysin proteolytic activity on proteinaceous substrates such as proteoglycans and plasma fibronectin was also evaluated. All proteins tested were efficiently degraded over time, confirming the protease´s broad-spectrum activity in vitro. In addition, leptolysin induced morphological alterations on HK-2 cells, which may be partially attributed to extracellular matrix (ECM) degradation. Hemorrhagic foci were observed in the dorsal skin of mice intradermally injected with leptolysin, as a plausible consequence of ECM disarray and vascular endothelium glycocalyx damage. Assuming that leptospiral proteases play an important role in all stages of the infectious process, characterizing their functional properties, substrates and mechanisms of action is of great importance for therapeutic purposes.
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Affiliation(s)
| | | | - Luan Gavião Prado
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rosa Maria Chura-Chambi
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil
- Center of Biotechnology, Energy and Nuclear Research Institute (IPEN)-CNEN/SP), São Paulo, Brazil
| | - Ligia Morganti
- Center of Biotechnology, Energy and Nuclear Research Institute (IPEN)-CNEN/SP), São Paulo, Brazil
| | - Gisele Oliveira de Souza
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Marcos Bryan Heinemann
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Lourdes Isaac
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Fernando Paiva Conte
- Pilot Plant Implementation Project, Immunobiological Technology Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | | | - Angela Silva Barbosa
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil
- *Correspondence: Angela Silva Barbosa,
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8
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Lithgow KV, Tsao E, Schovanek E, Gomez A, Swayne LA, Cameron CE. Treponema pallidum Disrupts VE-Cadherin Intercellular Junctions and Traverses Endothelial Barriers Using a Cholesterol-Dependent Mechanism. Front Microbiol 2021; 12:691731. [PMID: 34354688 PMCID: PMC8329343 DOI: 10.3389/fmicb.2021.691731] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Treponema pallidum subspecies pallidum, the causative agent of syphilis, traverses the vascular endothelium to gain access to underlying tissue sites. Herein, we investigate the mechanisms associated with T. pallidum traversal of endothelial barriers. Immunofluorescence microscopy reveals that a subpopulation of T. pallidum localizes to intercellular junctions and that viable T. pallidum, as well as a T. pallidum vascular adhesin (Tp0751), disrupts the architecture of the main endothelial junctional protein VE-cadherin. Intriguingly, in this study we show that T. pallidum traverses endothelial barriers with no disruption in barrier permeability. Furthermore, barrier traversal by T. pallidum is reduced by pretreatment of endothelial cells with filipin, an inhibitor that blocks cholesterol-mediated endocytosis. Collectively, these results suggest that T. pallidum can use a cholesterol-dependent, lipid raft-mediated endocytosis mechanism to traverse endothelial barriers. Further, treponemal localization to, and disruption of, intercellular junctions suggests that a paracellular route may also be utilized, a dual traversal strategy that has also been observed to occur for leukocytes and other invasive bacteria.
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Affiliation(s)
- Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Emily Tsao
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Ethan Schovanek
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.,Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, United States
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9
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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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10
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Identification of the Neuroinvasive Pathogen Host Target, LamR, as an Endothelial Receptor for the Treponema pallidum Adhesin Tp0751. mSphere 2020; 5:5/2/e00195-20. [PMID: 32238570 PMCID: PMC7113585 DOI: 10.1128/msphere.00195-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Treponema pallidum subsp. pallidum is the causative agent of syphilis, a human-specific sexually transmitted infection that causes a multistage disease with diverse clinical manifestations. Treponema pallidum undergoes rapid vascular dissemination to penetrate tissue, placental, and blood-brain barriers and gain access to distant tissue sites. The rapidity and extent of T. pallidum dissemination are well documented, but the molecular mechanisms have yet to be fully elucidated. One protein that has been shown to play a role in treponemal dissemination is Tp0751, a T. pallidum adhesin that interacts with host components found within the vasculature and mediates bacterial adherence to endothelial cells under shear flow conditions. In this study, we further explore the molecular interactions of Tp0751-mediated adhesion to the vascular endothelium. We demonstrate that recombinant Tp0751 adheres to human endothelial cells of macrovascular and microvascular origin, including a cerebral brain microvascular endothelial cell line. Adhesion assays using recombinant Tp0751 N-terminal truncations reveal that endothelial binding is localized to the lipocalin fold-containing domain of the protein. We also confirm this interaction using live T. pallidum and show that spirochete attachment to endothelial monolayers is disrupted by Tp0751-specific antiserum. Further, we identify the 67-kDa laminin receptor (LamR) as an endothelial receptor for Tp0751 using affinity chromatography, coimmunoprecipitation, and plate-based binding methodologies. Notably, LamR has been identified as a receptor for adhesion of other neurotropic invasive bacterial pathogens to brain endothelial cells, including Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae, suggesting the existence of a common mechanism for extravasation of invasive extracellular bacterial pathogens.IMPORTANCE Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subsp. pallidum. The continued incidence of syphilis demonstrates that screening and treatment strategies are not sufficient to curb this infectious disease, and there is currently no vaccine available. Herein we demonstrate that the T. pallidum adhesin Tp0751 interacts with endothelial cells that line the lumen of human blood vessels through the 67-kDa laminin receptor (LamR). Importantly, LamR is also a receptor for meningitis-causing neuroinvasive bacterial pathogens such as Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae Our findings enhance understanding of the Tp0751 adhesin and present the intriguing possibility that the molecular events of Tp0751-mediated treponemal dissemination may mimic the endothelial interaction strategies of other invasive pathogens.
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11
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Zhang R, Wang Q, Yang L. Chemerin induced by
Treponema pallidum
predicted membrane protein Tp0965 mediates the activation of endothelial cell via MAPK signaling pathway. J Cell Biochem 2019; 120:19621-19634. [PMID: 31322756 DOI: 10.1002/jcb.29269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 06/11/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Rui‐Li Zhang
- Department of Dermatology Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University Wuxi China
| | - Qian‐Qiu Wang
- Institute of Dermatology, Chinese Academy of Medical Science & Peking Union Medical College, & National Center for STD Control China Centers for Disease Control and Prevention Nanjing China
| | - Li‐Jia Yang
- Department of Dermatology Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University Wuxi China
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12
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Abstract
The outer membrane (OM) of Treponema pallidum, the uncultivatable agent of venereal syphilis, has long been the subject of misconceptions and controversy. Decades ago, researchers postulated that T. pallidum's poor surface antigenicity is the basis for its ability to cause persistent infection, but they mistakenly attributed this enigmatic property to the presence of a protective outer coat of serum proteins and mucopolysaccharides. Subsequent studies revealed that the OM is the barrier to antibody binding, that it contains a paucity of integral membrane proteins, and that the preponderance of the spirochete's immunogenic lipoproteins is periplasmic. Since the advent of recombinant DNA technology, the fragility of the OM, its low protein content, and the lack of sequence relatedness between T. pallidum and Gram-negative outer membrane proteins (OMPs) have complicated efforts to characterize molecules residing at the host-pathogen interface. We have overcome these hurdles using the genomic sequence in concert with computational tools to identify proteins predicted to form β-barrels, the hallmark conformation of OMPs in double-membrane organisms and evolutionarily related eukaryotic organelles. We also have employed diverse methodologies to confirm that some candidate OMPs do, in fact, form amphiphilic β-barrels and are surface-exposed in T. pallidum. These studies have led to a structural homology model for BamA and established the bipartite topology of the T. pallidum repeat (Tpr) family of proteins. Recent bioinformatics has identified several structural orthologs for well-characterized Gram-negative OMPs, suggesting that the T. pallidum OMP repertoire is more Gram-negative-like than previously supposed. Lipoprotein adhesins and proteases on the spirochete surface also may contribute to disease pathogenesis and protective immunity.
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Affiliation(s)
- Justin D Radolf
- Departments of Medicine, Pediatrics, Molecular Biology and Biophysics, Genetics and Genomic Sciences, and Immunology, UConn Health, Farmington, CT 06030-3715, USA.
| | - Sanjiv Kumar
- Department of Medicine, UConn Health, Farmington, CT 06030-3715, USA
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13
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Zhu XZ, Fan JY, Liu D, Gao ZX, Gao K, Lin Y, Tong ML, Zhang HL, Liu LL, Yang TC, Lin LR, Niu JJ. Assessing effects of different processing procedures on the yield of Treponema pallidum DNA from blood. Anal Biochem 2018; 557:91-96. [PMID: 30040912 DOI: 10.1016/j.ab.2018.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 07/21/2018] [Accepted: 07/21/2018] [Indexed: 02/05/2023]
Abstract
In this work, we employed real-time PCR analysis targeting tp0574 to investigate the effects of different processing procedures on the yield of T. pallidum DNA from blood to improve assay sensitivity. The T. pallidum DNA yields following red blood cell lysis pretreatment were 40.4 times greater from whole blood and 32.4 times greater from residual hematocytes than yields without pretreatment. For the simulated whole-blood experiments, the T. pallidum DNA yields from the lower layer were 2.8, 4.6, 7.3, 12.6, 15.24, 16.7, 65.1 and 73.1 times those from the upper layer following centrifugation at 500×, 1000×, 2000×, 4000×, 5000×, 7000×, 10,000× and 20,000 × g, respectively. However, the T. pallidum DNA yields from blood clots were only 1.0% at different centrifugal forces. The experiment with infected rabbit blood showed results similar to those mentioned above. In addition, sample processing time (within 48 h) and storage temperature (4 °C and 25 °C) did not affect T. pallidum DNA extraction efficiency. The T. pallidum DNA yield can be significantly improved by red blood cell lysis pretreatment and appropriate centrifugation. Furthermore, the T. pallidum DNA extraction yield is greater from whole blood or residual hematocytes from anti-coagulated blood than from plasma, serum or blood clots.
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Affiliation(s)
- Xiao-Zhen Zhu
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Jin-Yi Fan
- Department of Clinical Laboratory, Shaanxi Provincial People's Hospital, Xi'an, 710068, China
| | - Dan Liu
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Zheng-Xiang Gao
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China
| | - Kun Gao
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Yong Lin
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Man-Li Tong
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Hui-Lin Zhang
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Li-Li Liu
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Tian-Ci Yang
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China
| | - Li-Rong Lin
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China.
| | - Jian-Jun Niu
- Zhongshan Hospital, Medical College of Xiamen University, Xiamen, 361004, China; Institute of Infectious Disease, Medical College of Xiamen University, Xiamen, 361004, China.
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14
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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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15
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da Silva LB, Menezes MC, Kitano ES, Oliveira AK, Abreu AG, Souza GO, Heinemann MB, Isaac L, Fraga TR, Serrano SMT, Barbosa AS. Leptospira interrogans Secreted Proteases Degrade Extracellular Matrix and Plasma Proteins From the Host. Front Cell Infect Microbiol 2018; 8:92. [PMID: 29637048 PMCID: PMC5881292 DOI: 10.3389/fcimb.2018.00092] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 03/07/2018] [Indexed: 12/30/2022] Open
Abstract
Leptospires are highly motile spirochetes equipped with strategies for efficient invasion and dissemination within the host. Our group previously demonstrated that pathogenic leptospires secrete proteases capable of cleaving and inactivating key molecules of the complement system, allowing these bacteria to circumvent host's innate immune defense mechanisms. Given the successful dissemination of leptospires during infection, we wondered if such proteases would target a broader range of host molecules. In the present study, the proteolytic activity of secreted leptospiral proteases against a panel of extracellular matrix (ECM) and plasma proteins was assessed. The culture supernatant of the virulent L. interrogans serovar Kennewicki strain Fromm (LPF) degraded human fibrinogen, plasma fibronectin, gelatin, and the proteoglycans decorin, biglycan, and lumican. Interestingly, human plasminogen was not cleaved by proteases present in the supernatants. Proteolytic activity was inhibited by 1,10-phenanthroline, suggesting the participation of metalloproteases. Moreover, production of proteases might be an important virulence determinant since culture-attenuated or saprophytic Leptospira did not display proteolytic activity against ECM or plasma components. Exoproteomic analysis allowed the identification of three metalloproteases that could be involved in the degradation of host components. The ability to cleave conjunctive tissue molecules and coagulation cascade proteins may certainly contribute to invasion and tissue destruction observed upon infection with Leptospira.
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Affiliation(s)
| | - Milene C Menezes
- Special Laboratory of Applied Toxinology, Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, Brazil
| | - Eduardo S Kitano
- Special Laboratory of Applied Toxinology, Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, Brazil
| | - Ana K Oliveira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Afonso G Abreu
- Postgraduation Program in Parasitic Biology, CEUMA University, São Luís, Brazil.,Postgraduation Program in Health Sciences, Federal University of Maranhão, São Luís, Brazil
| | - Gisele O Souza
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Marcos B Heinemann
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Lourdes Isaac
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Tatiana R Fraga
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Solange M T Serrano
- Special Laboratory of Applied Toxinology, Center of Toxins, Immune-Response and Cell Signaling, Butantan Institute, São Paulo, Brazil
| | - Angela S Barbosa
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil
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16
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Abstract
Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.
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Affiliation(s)
- Rosanna W Peeling
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David Mabey
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Mary L Kamb
- Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xiang-Sheng Chen
- National Center for STD Control, Chinese Academy of Medical Sciences and Peking Union Medical College Institute of Dermatology, Nanjing, China
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Adele S Benzaken
- Department of Surveillance, Prevention and Control of STI, HIV/AIDS and Viral Hepatitis, Ministry of Health, Brasília, Brazil
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17
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Kao WCA, Pětrošová H, Ebady R, Lithgow KV, Rojas P, Zhang Y, Kim YE, Kim YR, Odisho T, Gupta N, Moter A, Cameron CE, Moriarty TJ. Identification of Tp0751 (Pallilysin) as a Treponema pallidum Vascular Adhesin by Heterologous Expression in the Lyme disease Spirochete. Sci Rep 2017; 7:1538. [PMID: 28484210 PMCID: PMC5431505 DOI: 10.1038/s41598-017-01589-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/29/2017] [Indexed: 11/25/2022] Open
Abstract
Treponema pallidum subsp. pallidum, the causative agent of syphilis, is a highly invasive spirochete pathogen that uses the vasculature to disseminate throughout the body. Identification of bacterial factors promoting dissemination is crucial for syphilis vaccine development. An important step in dissemination is bacterial adhesion to blood vessel surfaces, a process mediated by bacterial proteins that can withstand forces imposed on adhesive bonds by blood flow (vascular adhesins). The study of T. pallidum vascular adhesins is hindered by the uncultivable nature of this pathogen. We overcame these limitations by expressing T. pallidum adhesin Tp0751 (pallilysin) in an adhesion-attenuated strain of the cultivable spirochete Borrelia burgdorferi. Under fluid shear stress representative of conditions in postcapillary venules, Tp0751 restored bacterial-vascular interactions to levels similar to those observed for infectious B. burgdorferi and a gain-of-function strain expressing B. burgdorferi vascular adhesin BBK32. The strength and stability of Tp0751- and BBK32-dependent endothelial interactions under physiological shear stress were similar, although the mechanisms stabilizing these interactions were distinct. Tp0751 expression also permitted bacteria to interact with postcapillary venules in live mice as effectively as BBK32-expressing strains. These results demonstrate that Tp0751 can function as a vascular adhesin.
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Affiliation(s)
- Wei-Chien Andrew Kao
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Helena Pětrošová
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Rhodaba Ebady
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Pablo Rojas
- Charité University Medicine Berlin, Berlin, Germany
| | - Yang Zhang
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Yae-Eun Kim
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Yae-Ram Kim
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Tanya Odisho
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Nupur Gupta
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Annette Moter
- Biofilmcenter, German Heart Center Berlin, Berlin, Germany
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.
| | - Tara J Moriarty
- Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada. .,Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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18
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Novel Treponema pallidum Recombinant Antigens for Syphilis Diagnostics: Current Status and Future Prospects. BIOMED RESEARCH INTERNATIONAL 2017; 2017:1436080. [PMID: 28523273 PMCID: PMC5421087 DOI: 10.1155/2017/1436080] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/21/2017] [Indexed: 11/18/2022]
Abstract
The recombinant protein technology considerably promoted the development of rapid and accurate treponema-specific laboratory diagnostics of syphilis infection. For the last ten years, the immunodominant recombinant inner membrane lipoproteins are proved to be sensitive and specific antigens for syphilis screening. However, the development of an enlarged T. pallidum antigen panel for diagnostics of early and late syphilis and differentiation of syphilis stages or cured syphilis remains as actual goal of multidisciplinary expertise. Current review revealed novel recombinant antigens: surface-exposed proteins, adhesins, and periplasmic and flagellar proteins, which are promising candidates for the improved syphilis serological diagnostics. The opportunities and limitations of diagnostic usage of these antigens are discussed and the criteria for selection of optimal antigens panel summarized.
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19
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Radolf JD, Deka RK, Anand A, Šmajs D, Norgard MV, Yang XF. Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen. Nat Rev Microbiol 2016; 14:744-759. [PMID: 27721440 DOI: 10.1038/nrmicro.2016.141] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation 'the stealth pathogen'. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiological, and regulatory facets of T. pallidum pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes.
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Affiliation(s)
- Justin D Radolf
- Departments of Medicine, Pediatrics, Genetics and Genomic Science, Molecular Biology and Biophysics, and Immunology, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - Ranjit K Deka
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - Arvind Anand
- Department of Medicine, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Michael V Norgard
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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20
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Abstract
INTRODUCTION Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a globally prevalent disease despite remaining susceptible to penicillin treatment. Syphilis vaccine development is a viable preventative approach that will serve to complement public health-oriented syphilis prevention, screening and treatment initiatives to deliver a two-pronged approach to stemming disease spread worldwide. Areas covered: This article provides an overview of the need for development of a syphilis vaccine, summarizes significant information that has been garnered from prior syphilis vaccine studies, discusses the critical aspects of infection that would have to be targeted by a syphilis vaccine, and presents the current understanding within the field of the correlates of protection needed to be achieved through vaccination. Expert commentary: Syphilis vaccine development should be considered a priority by industry, regulatory and funding agencies, and should be appropriately promoted and supported.
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Affiliation(s)
- Karen V Lithgow
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , Canada
| | - Caroline E Cameron
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , Canada
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Houston S, Taylor JS, Denchev Y, Hof R, Zuerner RL, Cameron CE. Conservation of the Host-Interacting Proteins Tp0750 and Pallilysin among Treponemes and Restriction of Proteolytic Capacity to Treponema pallidum. Infect Immun 2015; 83:4204-16. [PMID: 26283341 PMCID: PMC4598410 DOI: 10.1128/iai.00643-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/06/2015] [Indexed: 12/13/2022] Open
Abstract
The spirochete Treponema pallidum subsp. pallidum is the causative agent of syphilis, a chronic, sexually transmitted infection characterized by multiple symptomatic and asymptomatic stages. Although several other species in the genus are able to cause or contribute to disease, T. pallidum differs in that it is able to rapidly disseminate via the bloodstream to tissue sites distant from the site of initial infection. It is also the only Treponema species able to cross both the blood-brain and placental barriers. Previously, the T. pallidum proteins, Tp0750 and Tp0751 (also called pallilysin), were shown to degrade host proteins central to blood coagulation and basement membrane integrity, suggesting a role for these proteins in T. pallidum dissemination and tissue invasion. In the present study, we characterized Tp0750 and Tp0751 sequence variation in a diversity of pathogenic and nonpathogenic treponemes. We also determined the proteolytic potential of the orthologs from the less invasive species Treponema denticola and Treponema phagedenis. These analyses showed high levels of sequence similarity among Tp0750 orthologs from pathogenic species. For pallilysin, lower levels of sequence conservation were observed between this protein and orthologs from other treponemes, except for the ortholog from the highly invasive rabbit venereal syphilis-causing Treponema paraluiscuniculi. In vitro host component binding and degradation assays demonstrated that pallilysin and Tp0750 orthologs from the less invasive treponemes tested were not capable of binding or degrading host proteins. The results show that pallilysin and Tp0750 host protein binding and degradative capability is positively correlated with treponemal invasiveness.
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Affiliation(s)
- Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - John S Taylor
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Yavor Denchev
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Rebecca Hof
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Richard L Zuerner
- Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, USA Department of Biomedicine and Veterinary Public Health, Swedish University of Agricultural Research, Uppsala, Sweden
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
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Abstract
Thiamine pyrophosphate (TPP), the biologically active form of thiamine (also known as vitamin B1), is an essential cofactor for several important enzymes involved in carbohydrate metabolism, and therefore, it is required for all living organisms. We recently found that a thiamine-binding protein (TDE_0143) is essential for the survival of Treponema denticola, an important bacterial pathogen that is associated with human periodontitis. In this report, we provide experimental evidence showing that TP_0144, a homolog of TDE_0143 from the syphilis spirochete Treponema pallidum, is a thiamine-binding protein that has biochemical features and functions that are similar to those of TDE_0143. First, structural modeling analysis reveal that both TDE_0143 and TP_0144 contain a conserved TPP-binding site and share similar structures to the thiamine-binding protein of Escherichia coli. Second, biochemical analysis shows that these two proteins bind to TPP with similar dissociation constant (Kd) values (TDE_0143, Kd of 36.50 nM; TP_0144, Kd of 32.62 nM). Finally, heterologous expression of TP_0144 in a ΔTDE_0143 strain, a previously constructed TDE_0143 mutant of T. denticola, fully restores its growth and TPP uptake when exogenous thiamine is limited. Collectively, these results indicate that TP_0144 is a thiamine-binding protein that is indispensable for T. pallidum to acquire exogenous thiamine, a key nutrient for bacterial survival. In addition, the studies shown in this report further underscore the feasibility of using T. denticola as a platform to study the biology and pathogenicity of T. pallidum and probably other uncultivable treponemal species as well.
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