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Campo JJ, Romeis E, Oberai A, Pablo JV, Hung C, Teng AA, Shandling AD, Phan A, Haynes AM, Giacani L. A novel pan-proteome array for high-throughput profiling of the humoral response to Treponema pallidum. iScience 2024; 27:110618. [PMID: 39262771 PMCID: PMC11387709 DOI: 10.1016/j.isci.2024.110618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/08/2024] [Accepted: 07/26/2024] [Indexed: 09/13/2024] Open
Abstract
Given the resurgence of syphilis, research endeavors to improve current assays for serological diagnosis and management of this disease are a priority. A proteome-scale platform for high-throughput profiling of the humoral response to Treponema pallidum (T. pallidum) proteins during infection could identify antigens suitable to ameliorate the performance and capabilities of treponemal tests for syphilis. Additionally, because infection-induced immunity is partially protective, profiling the response to T. pallidum outer membrane proteins (OMPs) could help select vaccine candidates. Therefore, we developed a pan-proteome array (PPA) based on the Nichols and SS14 strain complete proteomes and used it to define the immunoglobulin M (IgM) and IgG humoral response to T. pallidum proteins in sera collected longitudinally from long-term infected rabbits and from rabbits that were infected, treated, and re-infected. We identified antigens that could facilitate early diagnosis and immunity to a core set of OMP that could explain protection upon reinfection.
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Affiliation(s)
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA
| | | | | | | | | | | | - Amber Phan
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Austin M Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA
| | - 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
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2
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Salazar JC, Radolf JD. T-Cell Responses to Treponema pallidum Proteins in Blood and Skin to Advance Syphilis Vaccine Design: Learning From Nature. J Infect Dis 2024; 230:275-277. [PMID: 39147388 PMCID: PMC11326806 DOI: 10.1093/infdis/jiae246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 08/17/2024] Open
Affiliation(s)
- Juan C Salazar
- Departments of Pediatrics
- Immunology, University of Connecticut School of Medicine, Farmington
- Division of Pediatric Infectious Diseases and Immunology, Connecticut Children's, Hartford
| | - Justin D Radolf
- Departments of Pediatrics
- Immunology, University of Connecticut School of Medicine, Farmington
- Departments of Medicine
- Genetics and Genome Sciences
- Molecular Biology and Biophysics, University of Connecticut School of Medicine, Farmington
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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. J Infect Dis 2024; 230:281-292. [PMID: 38932740 PMCID: PMC11326851 DOI: 10.1093/infdis/jiae245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Histologic and serologic studies suggest the induction of local and systemic Treponema pallidum-specific CD4+ T-cell responses to T. pallidum infection. We hypothesized that T. pallidum-specific CD4+ T cells are detectable in blood and in the skin rash of secondary syphilis and persist in both compartments after treatment. METHODS Peripheral blood mononuclear cells collected from 67 participants were screened by interferon-γ (IFN-γ) ELISPOT response to T. pallidum sonicate. T. pallidum-reactive T-cell lines from blood and skin were probed for responses to 89 recombinant T. pallidum antigens. Peptide epitopes and HLA class II restriction were defined for selected antigens. RESULTS We detected CD4+ T-cell responses to T. pallidum sonicate ex vivo. Using T. pallidum-reactive T-cell lines we observed recognition of 14 discrete proteins, 13 of which localize to bacterial membranes or the periplasmic space. After therapy, T. pallidum-specific T cells persisted for at least 6 months in skin and 10 years in blood. CONCLUSIONS T. pallidum infection elicits an antigen-specific CD4+ T-cell response in blood and skin. T. pallidum-specific CD4+ T cells persist as memory in both compartments long after curative therapy. The T. pallidum antigenic targets we identified may be high-priority vaccine candidates.
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Affiliation(s)
- Tara B Reid
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Charmie Godornes
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Victoria L Campbell
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Kerry J Laing
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Lauren C Tantalo
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Alloysius Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Thepthara N Pholsena
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Nicole A P Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Taylor M Krause
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Victoria I Cegielski
- Department of Medicine, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Lauren A Culver
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Nhi Nguyen
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Denise Q Tong
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Kelly L Hawley
- Department of Medicine and Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases, Connecticut Children's, Hartford, Connecticut, USA
| | - Alexander L Greninger
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Lorenzo Giacani
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Caroline E Cameron
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Julia C Dombrowski
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Epidemiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anna Wald
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
- Department of Epidemiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - David M Koelle
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
- Center for Translational Immunology, Benaroya Research Institute, Seattle, Washington, USA
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4
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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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Silva ÂAO, Lima AA, Vasconcelos LCM, Almeida RA, Freitas NEM, Oliva TA, de Carvalho Ribeiro da Silva MF, Marchini FK, Zanchin NIT, de Siqueira IC, Santos FLN. Evaluating the diagnostic accuracy of TpN17 and TmpA recombinant proteins in syphilis detection: a phase II study. Front Microbiol 2024; 15:1348437. [PMID: 38476951 PMCID: PMC10929016 DOI: 10.3389/fmicb.2024.1348437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 02/06/2024] [Indexed: 03/14/2024] Open
Abstract
Syphilis is a sexually transmitted infection (STI) caused by the spiral bacterium Treponema pallidum. Diagnosis is based on epidemiology, clinical and serology, but serodiagnosis is challenging because distinct clinical forms of the infection may influence serological performance. Several recombinant Treponema pallidum-proteins have already been tested for syphilis diagnosis and they are critical to achieve high accuracy in serological testing. A total of 647 samples were included in the study: 180 T. pallidum-positive samples, 191 T. pallidum-negative samples and 276 sera from individuals infected with unrelated diseases. The diagnostic potential was validated by analysis of ROC curves. For the indirect ELISA, TpN17 (100%) and TmpA (99%) showed excellent AUC values. Sensitivity values were 97.2% for TpN17 and 90.6% for TmpA, while specificity was 100% for both molecules. According to the clinical phase, TmpA ranged from 84% to 97%, with the highest value for secondary syphilis. TpN17 was 100% sensitive for the primary and secondary stages and 93.2% for recent latent syphilis. All clinical phases achieved 100% specificity. Accuracy values showed that TmpA (> 95%) and TpN17 (> 98%) presented high diagnostic accuracy for all clinical stages of syphilis. Cross-reactivity was only observed in one sample positive for Chagas disease (1.5%), when TpN17 was evaluated. On the other hand, TmpA showed reactivity for two samples positive for Chagas disease (3.1%), one sample positive for HBV (1.25%), two samples positive for HIV (9.5%) and one sample positive for HTLV (1.6%). The TmpA antigen's performance was evaluated in multiple studies for syphilis diagnosis, corroborating our findings. However, TpN17 sensitivity values have ranged in other studies. According to clinical stages of the infection, our findings obtained close performance values.
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Affiliation(s)
- Ângelo Antônio Oliveira Silva
- Advanced Public Health Laboratory, Gonçalo Moniz Institute (IGM) Foundation Oswaldo Cruz (Fiocruz-BA), Salvador, Brazil
- Salvador University (UNIFACS), Salvador, Brazil
| | - Ayla Araújo Lima
- Advanced Public Health Laboratory, Gonçalo Moniz Institute (IGM) Foundation Oswaldo Cruz (Fiocruz-BA), Salvador, Brazil
| | | | - Rosângela Andrade Almeida
- Advanced Public Health Laboratory, Gonçalo Moniz Institute (IGM) Foundation Oswaldo Cruz (Fiocruz-BA), Salvador, Brazil
| | - Natália Erdens Maron Freitas
- Advanced Public Health Laboratory, Gonçalo Moniz Institute (IGM) Foundation Oswaldo Cruz (Fiocruz-BA), Salvador, Brazil
| | | | | | - Fabricio Klerynton Marchini
- Molecular Biology Institute of Paraná, Curitiba, Brazil
- Laboratory for Applied Science and Technology in Health, Carlos Chagas Institute (ICC) Oswaldo Cruz Foundation (Fiocruz-PR), Curitiba, Brazil
| | - Nilson Ivo Tonin Zanchin
- Structural Biology and Protein Engineering Laboratory, Carlos Chagas Institute (ICC) Oswaldo Cruz Foundation (Fiocruz-PR), Curitiba, Brazil
- Integrated Translational Program in Chagas Disease from Fiocruz (Fio-Chagas), Oswaldo Cruz Foundation (Fiocruz-RJ), Rio de Janeiro, Brazil
| | - Isadora Cristina de Siqueira
- Integrated Translational Program in Chagas Disease from Fiocruz (Fio-Chagas), Oswaldo Cruz Foundation (Fiocruz-RJ), Rio de Janeiro, Brazil
- Laboratory of Investigation in Global Health and Neglected Diseases, Gonçalo Moniz Institute (IGM) Oswaldo Cruz Foundation (FIOCRUZ-BA), Salvador, Brazil
| | - Fred Luciano Neves Santos
- Advanced Public Health Laboratory, Gonçalo Moniz Institute (IGM) Foundation Oswaldo Cruz (Fiocruz-BA), Salvador, Brazil
- Integrated Translational Program in Chagas Disease from Fiocruz (Fio-Chagas), Oswaldo Cruz Foundation (Fiocruz-RJ), Rio de Janeiro, Brazil
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Haynes AM, Konda KA, Romeis E, Siebert J, Vargas SK, Reyes Diaz M, Phan A, Caceres CF, Giacani L, Klausner JD. Evaluation of a minimal array of Treponema pallidum antigens as biomarkers for syphilis diagnosis, infection staging, and response to treatment. Microbiol Spectr 2024; 12:e0346623. [PMID: 38095465 PMCID: PMC10782976 DOI: 10.1128/spectrum.03466-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE This manuscript explores the host humoral response to selected antigens of the syphilis agent during infection to evaluate their potential use as diagnostic tests and markers for treatment.
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Affiliation(s)
- Austin M. Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Kelika A. Konda
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Center for Interdisciplinary Studies in Sexuality, AIDS and Society, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | | | - Silver K. Vargas
- Center for Interdisciplinary Studies in Sexuality, AIDS and Society, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Michael Reyes Diaz
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Amber Phan
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Carlos F. Caceres
- Division of Infectious Disease, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, Harborview Medical Center, University of Washington, Seattle, Washington, USA
- Department of Global Health, Harborview Medical Center, University of Washington, Seattle, Washington, USA
| | - Jeffrey D. Klausner
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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7
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He Y, Chen D, Fu Y, Huo X, Zhao F, Yao L, Zhou X, Qi P, Yin H, Cao L, Ling H, Zeng T. Immunization with Tp0954, an adhesin of Treponema pallidum, provides protective efficacy in the rabbit model of experimental syphilis. Front Immunol 2023; 14:1130593. [PMID: 36993963 PMCID: PMC10042077 DOI: 10.3389/fimmu.2023.1130593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Syphilis, a chronic multisystemic disease caused by spirochete Treponema pallidum subspecies pallidum infection, continues to be a serious global health problem and congenital syphilis remains a major cause of adverse outcomes in pregnancy in developing countries. The development of an effective vaccine is the most cost-effective way to eliminate syphilis, but so far has been elusive. Here, we evaluated the immunogenicity and protective efficacy of Tp0954, a T. pallidum placental adhesin, as a potential vaccine candidate in a New Zealand White rabbit model of experimental syphilis. Animals immunized with recombinant Tp0954 (rTp0954) produced high titers of Tp0954-specific serum IgG, high levels of IFN-γ from splenocytes and specific splenocyte proliferation response when compared to control animals immunized with PBS and Freund’s adjuvant (FA). Furthermore, rTp0954 immunization significantly delayed the development of cutaneous lesions, promoted inflammatory cellular infiltration at the primary lesion sites, as well as inhibited T. pallidum dissemination to distal tissues or organs when compared with that of the control animals. In addition, the naïve rabbits receiving popliteal lymph nodes from Tp0954-immunized, T. pallidum-challenged animals were not infected by T. pallidum, confirming sterile immunity. These findings suggest that Tp0954 is a potential vaccine candidate against syphilis.
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Affiliation(s)
- Yuxing He
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Dejun Chen
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yue Fu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Xinzhuo Huo
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Ling Yao
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Xiuping Zhou
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Pengfei Qi
- Department of Clinical Medical undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Haoquan Yin
- Department of Clinical Medical undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Longgu Cao
- College of Medical Imaging and Inspection, Xiangnan University, Chenzhou, China
| | - Hui Ling
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
- Hunan Province Key Laboratory of Tumor Cellular and Molecular Pathology, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, China
- *Correspondence: Tiebing Zeng, ; Hui Ling,
| | - Tiebing Zeng
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
- *Correspondence: Tiebing Zeng, ; Hui Ling,
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8
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Lieberman NAP, Armstrong TD, Chung B, Pfalmer D, Hennelly CM, Haynes A, Romeis E, Wang QQ, Zhang RL, Kou CX, Ciccarese G, Conte ID, Cusini M, Drago F, Nakayama SI, Lee K, Ohnishi M, Konda KA, Vargas SK, Eguiluz M, Caceres CF, Klausner JD, Mitja O, Rompalo A, Mulcahy F, Hook EW, Hoffman IF, Matoga MM, Zheng H, Yang B, Lopez-Medina E, Ramirez LG, Radolf JD, Hawley KL, Salazar JC, Lukehart SA, Seña AC, Parr JB, Giacani L, Greninger AL. High-throughput nanopore sequencing of Treponema pallidum tandem repeat genes arp and tp0470 reveals clade-specific patterns and recapitulates global whole genome phylogeny. Front Microbiol 2022; 13:1007056. [PMID: 36204625 PMCID: PMC9531955 DOI: 10.3389/fmicb.2022.1007056] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/22/2022] [Indexed: 11/23/2022] Open
Abstract
Sequencing of most Treponema pallidum genomes excludes repeat regions in tp0470 and the tp0433 gene, encoding the acidic repeat protein (arp). As a first step to understanding the evolution and function of these genes and the proteins they encode, we developed a protocol to nanopore sequence tp0470 and arp genes from 212 clinical samples collected from ten countries on six continents. Both tp0470 and arp repeat structures recapitulate the whole genome phylogeny, with subclade-specific patterns emerging. The number of tp0470 repeats is on average appears to be higher in Nichols-like clade strains than in SS14-like clade strains. Consistent with previous studies, we found that 14-repeat arp sequences predominate across both major clades, but the combination and order of repeat type varies among subclades, with many arp sequence variants limited to a single subclade. Although strains that were closely related by whole genome sequencing frequently had the same arp repeat length, this was not always the case. Structural modeling of TP0470 suggested that the eight residue repeats form an extended α-helix, predicted to be periplasmic. Modeling of the ARP revealed a C-terminal sporulation-related repeat (SPOR) domain, predicted to bind denuded peptidoglycan, with repeat regions possibly incorporated into a highly charged β-sheet. Outside of the repeats, all TP0470 and ARP amino acid sequences were identical. Together, our data, along with functional considerations, suggests that both TP0470 and ARP proteins may be involved in T. pallidum cell envelope remodeling and homeostasis, with their highly plastic repeat regions playing as-yet-undetermined roles.
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Affiliation(s)
- Nicole A. P. Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Thaddeus D. Armstrong
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Benjamin Chung
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Daniel Pfalmer
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Christopher M. Hennelly
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Austin Haynes
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Emily Romeis
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Qian-Qiu Wang
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- National Center for STD Control, China Centers for Disease Control and Prevention, Nanjing, China
| | - Rui-Li Zhang
- Department of Dermatology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Cai-Xia Kou
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- National Center for STD Control, China Centers for Disease Control and Prevention, Nanjing, China
| | - Giulia Ciccarese
- Section of Dermatology, Department of Health Sciences, San Martino University Hospital, Genoa, Italy
| | - Ivano Dal Conte
- Sexual Health Center, Department of Prevention, ASL Città di Torino, Turin, Italy
| | - Marco Cusini
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Drago
- Section of Dermatology, Department of Health Sciences, San Martino University Hospital, Genoa, Italy
| | - Shu-ichi Nakayama
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenichi Lee
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kelika A. Konda
- Unit of Health, Sexuality and Human Development, Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Silver K. Vargas
- Unit of Health, Sexuality and Human Development, Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
- School of Public Health and Administration “Carlos Vidal Layseca”, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Maria Eguiluz
- Unit of Health, Sexuality and Human Development, Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Carlos F. Caceres
- Unit of Health, Sexuality and Human Development, Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Jeffrey D. Klausner
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Oriol Mitja
- Fight Aids and Infectious Diseases Foundation, Hospital Germans Trias i Pujol, Barcelona, Spain
- Lihir Medical Centre, International SOS, Londolovit, Papua New Guinea
| | - Anne Rompalo
- Department of Infectious Diseases, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Fiona Mulcahy
- Department of Genito Urinary Medicine and Infectious Diseases, St. James’s Hospital, Dublin, Ireland
| | - Edward W. Hook
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Irving F. Hoffman
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC Project-Malawi, Lilongwe, Malawi
| | - Mitch M. Matoga
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC Project-Malawi, Lilongwe, Malawi
| | - Heping Zheng
- Dermatology Hospital of Southern Medical University, Guangzhou, China
- Institute for Global Health and Sexually Transmitted Infections, Guangzhou, China
| | - Bin Yang
- Dermatology Hospital of Southern Medical University, Guangzhou, China
- Institute for Global Health and Sexually Transmitted Infections, Guangzhou, China
| | - Eduardo Lopez-Medina
- Centro Internacional de Entrenamiento e Investigaciones Medicas (CIDEIM), Cali, Colombia
- Centro de Estudios en Infectología Pediátrica (CEIP), Cali, Colombia
| | - Lady G. Ramirez
- Centro Internacional de Entrenamiento e Investigaciones Medicas (CIDEIM), Cali, Colombia
- Universidad ICESI, Cali, Colombia
| | - 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
| | - 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 Medical Center, Hartford, CT, United States
| | - Juan C. Salazar
- 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 Medical Center, Hartford, CT, United States
| | - Sheila A. Lukehart
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
- Department of Global Health, University of Washington School of Medicine, Seattle, WA, United States
| | - Arlene C. Seña
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jonathan B. Parr
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lorenzo Giacani
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
- Department of Global Health, University of Washington School of Medicine, Seattle, WA, United States
| | - Alexander L. Greninger
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
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9
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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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10
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Chen D, Wang S, He Y, Fu Y, Zhao F, Zhou X, Yin H, Wan J, Huang Y, Wu Y, Cao L, Zeng T. Assessment of recombinant antigens Tp0100 and Tp1016 of Treponema pallidum for serological diagnosis of syphilis. J Clin Lab Anal 2022; 36:e24635. [PMID: 35908795 PMCID: PMC9459255 DOI: 10.1002/jcla.24635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 07/08/2022] [Accepted: 07/13/2022] [Indexed: 11/30/2022] Open
Abstract
Objective To discover novel serodiagnostic candidates for the serological diagnosis of syphilis. Methods Two recombinant Treponema pallidum proteins Tp0100 and Tp1016 were expressed, purified, and identified by Western Blotting. A total of 600 clinical serum samples were tested with the Tp0100‐based ELISA, the Tp1016‐based ELISA, and the commercial LICA Syphilis TP kit (ChIVD, Beijing, China). The sensitivities were determined by testing 340 samples from individuals with clinically diagnosed primary, secondary, latent, and tertiary syphilis. The specificities were determined by screening 260 samples from healthy controls and individuals with potentially cross‐reactive infections, including leptospirosis, Lyme disease, hepatitis B, tuberculosis, rheumatoid arthritis, systemic lupus erythematosus. Kappa (κ) values were applied to compare the agreement between clinical syphilis diagnosis and the Tp0100‐based ELISA, the Tp1016‐based ELISA, or the LICA Syphilis TP test. Results Using clinical syphilis diagnosis as the gold standard, Tp0100 exhibited an overall sensitivity of 95.6% and specificity of 98.1% for testing IgG antibody while Tp1016 demonstrated only an overall sensitivity of 75.0% and specificity of 79.6%. In contrast, the LICA Syphilis TP test revealed an overall sensitivity of 97.6% and specificity of 96.2%. In addition, the overall percent agreement and corresponding κ values were 96.7% (95% CI 95.6%–97.8%) and 0.93 for the Tp0100‐based ELISA, 77.0% (95% CI 74.3%–79.7%) and 0.54 for the Tp1016‐based ELISA, and 97.0% (95% CI 96.0%–98.0%) and 0.94 for the LICA Syphilis TP test, respectively. Conclusion The recombinant T. pallidum protein Tp0100 shows promise as a novel diagnostic antigen in the serological tests for syphilis.
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Affiliation(s)
- Dejun Chen
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Siqian Wang
- Clinical laboratory of the First Pepole's Hospital of Changde City, Changde, China
| | - Yuxing He
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yue Fu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Xiuping Zhou
- Department of Laboratory Medicine, Changsha Health Vocational College, Changsha, China
| | - Haoquan Yin
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Jia Wan
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Yunting Huang
- Department of Clinical Medical Undergraduates, Hengyang Medical School, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Longgu Cao
- College of Medical Imaging Laboratory and Rehabilitation, Xiangnan University, Chenzhou, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology and Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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11
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Chen J, Huang J, Liu Z, Xie Y. Treponema pallidum outer membrane proteins: current status and prospects. Pathog Dis 2022; 80:6649208. [PMID: 35869970 DOI: 10.1093/femspd/ftac023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/30/2022] [Accepted: 07/20/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
The outer membrane proteins (OMPs) of Treponema pallidum subsp. Pallidum (T. pallidum), the etiological agent of the sexually transmitted disease syphilis, has long been a hot research topic. Despite many hurdles to studying the pathogen, especially the inability to manipulate T. pallidum in vitro genetically1, considerable progress has been made in elucidating the structure, pathogenesis, and functions of T. pallidum OMPs. In this review, we integrate this information to garner fresh insights into the role of OMPs in the diagnosis, pathogenicity, and vaccine development of T. pallidum. Collectively, the essential scientific discussions herein should provide a framework for understanding the current status and prospects of T. pallidum OMPs.
Decades ago, researchers postulated that the poor surface antigenicity of T. pallidum is the basis for its ability to cause persistent infection. Still, they believed that the mysterious properties of T. pallidum should not be attributed to the presence of the outer membrane proteins (OMPs). Subsequent studies revealed that the OM, which lacks integral membrane proteins, prevents antibody binding2. Since the advent of recombinant DNA technology, the fragility of the OM, low protein content, and the lack of sequence relatedness between T. pallidum and Gram-negative OMPs have complicated efforts to characterize molecules residing at the host-pathogen interface. These hurdles have been overcome by using the genomic sequence with computational tools to identify proteins predicted to form beta barrels, the hallmark conformation of OMPs in many organisms. Diverse methodologies have also confirmed that some candidate OMPs from amphiphilic β-barrels 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 OMPs are 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)
- Jinlin Chen
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China , Hengyang 421001 , China
| | - Jielite Huang
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China , Hengyang 421001 , China
| | - Zhuoran Liu
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China , Hengyang 421001 , China
| | - Yafeng Xie
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China , Hengyang 421001 , China
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12
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Xu M, Xie Y, Zheng K, Luo H, Tan M, Zhao F, Zeng T, Wu Y. Two Potential Syphilis Vaccine Candidates Inhibit Dissemination of Treponema pallidum. Front Immunol 2021; 12:759474. [PMID: 34899710 PMCID: PMC8657604 DOI: 10.3389/fimmu.2021.759474] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a major public health problem worldwide. Recent increases in the number of syphilis cases, in addition to the lack of an efficient vaccine against T. pallidum for humans, highlights an urgent need for the design and development of an efficacious syphilis vaccine. Here, we assess the vaccine potential of the adhesion protein Tp0136 and the outer membrane protein Tp0663. Rabbits were subcutaneously immunized with recombinant proteins Tp0136, Tp0663, or control PBS. Immunization with Tp0136 or Tp0663 generated a strong humoral immune response with high titers of IgG, as assessed by ELISA. Moreover, animals immunized with Tp0136 or Tp0663 exhibited attenuated lesion development, increased cellular infiltration at the lesion sites, and inhibition of treponemal dissemination to distant organs compared to the unimmunized animals. These findings indicate that Tp0136 and Tp0663 are promising syphilis vaccine candidates. Furthermore, these results provide novel and important information for not only understanding the pathogenic mechanisms of spirochetes, but also the development of spirochete-specific subunit vaccines.
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Affiliation(s)
- Man Xu
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yafeng Xie
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China.,Department of Clinical Laboratory, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Kang Zheng
- Department of Clinical Laboratory, Hengyang Central Hospital, Hengyang, China
| | - Haodang Luo
- Department of Clinical Laboratory, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Manyi Tan
- Department of Toxicology, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Feijun Zhao
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology, Hengyang Medical School, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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13
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Lieberman NAP, Lin MJ, Xie H, Shrestha L, Nguyen T, Huang ML, Haynes AM, Romeis E, Wang QQ, Zhang RL, Kou CX, Ciccarese G, Dal Conte I, Cusini M, Drago F, Nakayama SI, Lee K, Ohnishi M, Konda KA, Vargas SK, Eguiluz M, Caceres CF, Klausner JD, Mitjà O, Rompalo A, Mulcahy F, Hook EW, Lukehart SA, Casto AM, Roychoudhury P, DiMaio F, Giacani L, Greninger AL. Treponema pallidum genome sequencing from six continents reveals variability in vaccine candidate genes and dominance of Nichols clade strains in Madagascar. PLoS Negl Trop Dis 2021; 15:e0010063. [PMID: 34936652 PMCID: PMC8735616 DOI: 10.1371/journal.pntd.0010063] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/06/2022] [Accepted: 12/06/2021] [Indexed: 11/19/2022] Open
Abstract
In spite of its immutable susceptibility to penicillin, Treponema pallidum (T. pallidum) subsp. pallidum continues to cause millions of cases of syphilis each year worldwide, resulting in significant morbidity and mortality and underscoring the urgency of developing an effective vaccine to curtail the spread of the infection. Several technical challenges, including absence of an in vitro culture system until very recently, have hampered efforts to catalog the diversity of strains collected worldwide. Here, we provide near-complete genomes from 196 T. pallidum strains-including 191 T. pallidum subsp. pallidum-sequenced directly from patient samples collected from 8 countries and 6 continents. Maximum likelihood phylogeny revealed that samples from most sites were predominantly SS14 clade. However, 99% (84/85) of the samples from Madagascar formed two of the five distinct Nichols subclades. Although recombination was uncommon in the evolution of modern circulating strains, we found multiple putative recombination events between T. pallidum subsp. pallidum and subsp. endemicum, shaping the genomes of several subclades. Temporal analysis dated the most recent common ancestor of Nichols and SS14 clades to 1717 (95% HPD: 1543-1869), in agreement with other recent studies. Rates of SNP accumulation varied significantly among subclades, particularly among different Nichols subclades, and was associated in the Nichols A subclade with a C394F substitution in TP0380, a ERCC3-like DNA repair helicase. Our data highlight the role played by variation in genes encoding putative surface-exposed outer membrane proteins in defining separate lineages, and provide a critical resource for the design of broadly protective syphilis vaccines targeting surface antigens.
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Affiliation(s)
- Nicole A. P. Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Michelle J. Lin
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Hong Xie
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Lasata Shrestha
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Tien Nguyen
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Meei-Li Huang
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Austin M. Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Emily Romeis
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
| | - Qian-Qiu Wang
- Institute of Dermatology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
- National Center for STD Control, China Centers for Disease Control and Prevention, Nanjing, China
| | - Rui-Li Zhang
- Department of Dermatology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Cai-Xia Kou
- Institute of Dermatology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
- National Center for STD Control, China Centers for Disease Control and Prevention, Nanjing, China
| | - Giulia Ciccarese
- Health Sciences Department, Section of Dermatology, San Martino University Hospital, Genoa, Italy
| | - Ivano Dal Conte
- STI Clinic, Infectious Diseases Unit, University of Turin, Turin, Italy
| | - Marco Cusini
- Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesco Drago
- Health Sciences Department, Section of Dermatology, San Martino University Hospital, Genoa, Italy
| | - Shu-ichi Nakayama
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenichi Lee
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kelika A. Konda
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
- Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Silver K. Vargas
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Maria Eguiluz
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Carlos F. Caceres
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano-Heredia, Lima, Peru
| | - Jeffrey D. Klausner
- Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Oriol Mitjà
- Fight Aids and Infectious Diseases Foundation, Hospital Germans Trias i Pujol, Barcelona, Spain
- Lihir Medical Centre-International SOS, Newcrest Mining, Lihir Island, Papua New Guinea
| | - Anne Rompalo
- Department of Infectious Diseases, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Fiona Mulcahy
- Department of Genito Urinary Medicine and Infectious Diseases, St James’s Hospital, Dublin, Ireland
| | - Edward W. Hook
- Department of Medicine, University of Alabama, Birmingham, Birmingham, Alabama, United States of America
| | - Sheila A. Lukehart
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Amanda M. Casto
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Pavitra Roychoudhury
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Alexander L. Greninger
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
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14
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Runina AV, Shpilevaya MV, Katunin GL, Kubanov AA. Differential Serodiagnostics of Latent Stages of Syphilis Based on Measuring IgG and IgM Levels towards Extended Panel of Recombinant Antigens of T. pallidum. Bull Exp Biol Med 2020; 169:470-473. [PMID: 32910381 DOI: 10.1007/s10517-020-04911-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Indexed: 10/23/2022]
Abstract
Immunochips containing 12 recombinant antigens of T. pallidum (Тр15, Тр17, Тр47, TmpA, Тр0163, Тр0277, Тр0319, Тр0453, Тр0684, Тр0965, Тр0971, and Тр1038) were prepared to assay for IgG and IgM in serum samples (n=68) of healthy individuals and patients with the latent stages of syphilis. The linear discriminant analysis of detected IgG and IgM differentiated three groups of serum samples as 1) early latent syphilis; 2) seroresistant early latent syphilis; and 3) late latent syphilis with overall differentiation potency of 95.6% (88.9-100%). The samples of all syphilis patients were differentiated from the samples of healthy individuals with 100% specificity.
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Affiliation(s)
- A V Runina
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia.
| | - M V Shpilevaya
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - G L Katunin
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - A A Kubanov
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
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15
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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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16
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Osias E, Hung P, Giacani L, Stafylis C, Konda KA, Vargas SK, Reyes-Díaz EM, Comulada WS, Haake DA, Haynes AM, Caceres CF, Klausner JD. Investigation of syphilis immunology and Treponema pallidum subsp. pallidum biology to improve clinical management and design a broadly protective vaccine: study protocol. BMC Infect Dis 2020; 20:444. [PMID: 32576149 PMCID: PMC7309211 DOI: 10.1186/s12879-020-05141-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/08/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The syphilis epidemic continues to cause substantial morbidity and mortality worldwide, particularly in low- and middle-income countries, despite several recent disease control initiatives. Though our understanding of the pathogenesis of this disease and the biology of the syphilis agent, Treponema pallidum subsp. pallidum has improved over the last two decades, further research is necessary to improve clinical diagnosis and disease management protocols. Additionally, such research efforts could contribute to the identification of possible targets for the development of an effective vaccine to stem syphilis spread. METHODS This study will recruit two cohorts of participants with active syphilis infection, one with de novo infection, one with repeat infection. Whole blood specimens will be collected from each study participant at baseline, 4, 12, 24, 36, and 48 weeks, to track specific markers of their immunological response, as well as to compare humoral reactivity to Treponema pallidum antigens between the two groups. Additionally, we will use serum specimens to look for unique cytokine patterns in participants with early syphilis. Oral and blood samples, as well as samples from any syphilitic lesions present, will also be collected to sequence any Treponema pallidum DNA found. DISCUSSION By furthering our understanding of syphilis pathogenesis and human host immune response to Treponema pallidum, we will provide important data that will help in development of new point-of-care tests that could better identify active infection, leading to improved syphilis diagnosis and management. Findings could also contribute to vaccine development efforts.
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Affiliation(s)
- Ethan Osias
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Phoebe Hung
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - Lorenzo Giacani
- Department of Medicine, Division of Allergy and Infectious Diseases, and Department of Global Health, University of Washington, Seattle, WA, USA
| | - Chrysovalantis Stafylis
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - Kelika A Konda
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Silver K Vargas
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - E Michael Reyes-Díaz
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - W Scott Comulada
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - David A Haake
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Austin M Haynes
- Department of Medicine, Division of Allergy and Infectious Diseases, and Department of Global Health, University of Washington, Seattle, WA, USA
| | - Carlos F Caceres
- Unit of Health, Sexuality and Human Development and Laboratory of Sexual Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jeffrey D Klausner
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
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17
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Addetia A, Tantalo LC, Lin MJ, Xie H, Huang ML, Marra CM, Greninger AL. Comparative genomics and full-length Tprk profiling of Treponema pallidum subsp. pallidum reinfection. PLoS Negl Trop Dis 2020; 14:e0007921. [PMID: 32251462 PMCID: PMC7162541 DOI: 10.1371/journal.pntd.0007921] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/16/2020] [Accepted: 02/08/2020] [Indexed: 12/25/2022] Open
Abstract
Developing a vaccine against Treponema pallidum subspecies pallidum, the causative agent of syphilis, remains a public health priority. Syphilis vaccine design efforts have been complicated by lack of an in vitro T. pallidum culture system, prolific antigenic variation in outer membrane protein TprK, and lack of functional annotation for nearly half of the genes. Understanding the genetic basis of T. pallidum reinfection can provide insights into variation among strains that escape cross-protective immunity. Here, we present comparative genomic sequencing and deep, full-length tprK profiling of two T. pallidum isolates from blood from the same patient that were collected six years apart. Notably, this patient was diagnosed with syphilis four times, with two of these episodes meeting the definition of neurosyphilis, during this interval. Outside of the highly variable tprK gene, we identified 14 coding changes in 13 genes. Nine of these genes putatively localized to the periplasmic or outer membrane spaces, consistent with a potential role in serological immunoevasion. Using a newly developed full-length tprK deep sequencing protocol, we profiled the diversity of this gene that far outpaces the rest of the genome. Intriguingly, we found that the reinfecting isolate demonstrated less diversity across each tprK variable region compared to the isolate from the first infection. Notably, the two isolates did not share any full-length TprK sequences. Our results are consistent with an immunodominant-evasion model in which the diversity of TprK explains the ability of T. pallidum to successfully reinfect individuals, even when they have been infected with the organism multiple times.
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Affiliation(s)
- Amin Addetia
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Lauren C. Tantalo
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Michelle J. Lin
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Hong Xie
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Meei-Li Huang
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Christina M. Marra
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Alexander L. Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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18
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Runina AV, Katunin GL, Filippova MA, Zatevalov AM, Kubanov AA, Deryabin DG. Immunochip for Syphilis Serodiagnostics with the Use of Extended Array of Treponema pallidum Recombinant Antigens. Bull Exp Biol Med 2018; 165:767-771. [PMID: 30353336 DOI: 10.1007/s10517-018-4261-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Indexed: 10/28/2022]
Abstract
An immunochip for multiple parallel detection of specific serum IgG in serological screening for syphilis is based on the use of an extended array of Treponema pallidum recombinant proteins and includes traditionally used immunodominant antigens (Tp15, Tp17, Tp47, and TmpA) and new synthetic proteins (Tp0277, Tp0319, Tp0453, Tp0684, Tp0965, and Tp1038). The use of individual antigens has demonstrated high analytical value of Tp0277 (periplasmatic C-terminal protease), Tp0319 (cytoplasmic membrane-associated lipoprotein TmpC), and external membrane-associated protein Tp0453 with transporting function, all of them improving significantly the efficiency of screening for syphilis in comparison with the traditional array of antigens. Multiparametric analysis of the results obtained on the immunochip with the use of linear discriminant analysis confirmed the efficiency of extended array of T. pallidum diagnostic antigens. Due to proposed modification, the "positive" and "negative" sera are clearly differentiated: the serological study showed 94.1% sensitivity and 100% specificity.
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Affiliation(s)
- A V Runina
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - G L Katunin
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - M A Filippova
- V. A. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - A M Zatevalov
- G. N. Ga-brichevsky Moscow Research Institute of Epidemiology and Microbiology, Moscow, Russia
| | - A A Kubanov
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - D G Deryabin
- State Research Center of Dermatovenereology and Cosmetology, Ministry of Health of the Russian Federation, Moscow, Russia.
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19
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Osbak KK, Van Raemdonck GA, Dom M, Cameron CE, Meehan CJ, Deforce D, Ostade XV, Kenyon CR, Dhaenens M. Candidate Treponema pallidum biomarkers uncovered in urine from individuals with syphilis using mass spectrometry. Future Microbiol 2018; 13:1497-1510. [PMID: 30311792 DOI: 10.2217/fmb-2018-0182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AIM A diagnostic test that could detect Treponema pallidum antigens in urine would facilitate the prompt diagnosis of syphilis. MATERIALS & METHODS Urine from 54 individuals with various clinical stages of syphilis and 6 controls were pooled according to disease stage and interrogated with complementary mass spectrometry techniques to uncover potential syphilis biomarkers. RESULTS & CONCLUSION In total, 26 unique peptides were uncovered corresponding to four unique T. pallidum proteins that have low genetic sequence similarity to other prokaryotes and human proteins. This is the first account of direct T. pallidum protein detection in human clinical samples using mass spectrometry. The implications of these findings for future diagnostic test development is discussed. Data are available via ProteomeXchange with identifier PXD009707.
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Affiliation(s)
- Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Laboratory for Protein Science, Proteomics & Epigenetic Signalling & Centre for Proteomics, University of Antwerp, Wilrijk, Belgium
| | - Martin Dom
- Laboratory for Protein Science, Proteomics & Epigenetic Signalling & Centre for Proteomics, University of Antwerp, Wilrijk, Belgium
| | - Caroline E Cameron
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Conor J Meehan
- Department of Biomedical Sciences, Institute for Tropical Medicine, Antwerp, Belgium
| | - Dieter Deforce
- Laboratory for Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics & Epigenetic Signalling & Centre for Proteomics, University of Antwerp, Wilrijk, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases & HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Maarten Dhaenens
- Laboratory for Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium
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20
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Van Raemdonck GA, Osbak KK, Van Ostade X, Kenyon CR. Needle lost in the haystack: multiple reaction monitoring fails to detect Treponema pallidum candidate protein biomarkers in plasma and urine samples from individuals with syphilis. F1000Res 2018; 7:336. [PMID: 30519456 PMCID: PMC6248270 DOI: 10.12688/f1000research.13964.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2018] [Indexed: 12/13/2022] Open
Abstract
Background: Current syphilis diagnostic strategies are lacking a sensitive manner of directly detecting
Treponema pallidum antigens. A diagnostic test that could directly detect
T. pallidum antigens in individuals with syphilis would be of considerable clinical utility, especially for the diagnosis of reinfections and for post-treatment serological follow-up. Methods: In this study, 11 candidate
T. pallidum biomarker proteins were chosen according to their physiochemical characteristics,
T. pallidum specificity and predicted abundance. Thirty isotopically labelled proteotypic surrogate peptides (hPTPs) were synthesized and incorporated into a scheduled multiple reaction monitoring assay. Protein extracts from undepleted/unenriched plasma (N = 18) and urine (N = 4) samples from 18 individuals with syphilis in various clinical stages were tryptically digested, spiked with the hPTP mixture and analysed with a triple quadruple mass spectrometer. Results: No endogenous PTPs corresponding to the eleven candidate biomarkers were detected in any samples analysed. To estimate the Limit of Detection (LOD) of a comparably sensitive mass spectrometer (LTQ-Orbitrap), two dilution series of rabbit cultured purified
T. pallidum were prepared in PBS. Polyclonal anti-
T. pallidum antibodies coupled to magnetic Dynabeads were used to enrich one sample series; no LOD improvement was found compared to the unenriched series. The estimated LOD of MS instruments is 300
T. pallidum/ml in PBS. Conclusions: Biomarker protein detection likely failed due to the low (femtomoles/liter) predicted concentration of
T. pallidum proteins. Alternative sample preparation strategies may improve the detectability of
T. pallidum proteins in biofluids.
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Affiliation(s)
- Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium.,Laboratory for Protein Science, Proteomics and Epigenetic Signalling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, 2610, Belgium
| | - Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics and Epigenetic Signalling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, 2610, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, 2000, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, 7925, South Africa
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21
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Xiao Y, Xie Y, Xu M, Liu S, Jiang C, Zhao F, Zeng T, Liu Z, Yu J, Wu Y. Development and Evaluation of a Loop-Mediated Isothermal Amplification Assay for the Detection of Treponema pallidum DNA in the Peripheral Blood of Secondary Syphilis Patients. Am J Trop Med Hyg 2017; 97:1673-1678. [PMID: 29016285 DOI: 10.4269/ajtmh.17-0051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Secondary syphilis (SS) has always been puzzling for the clinicians because of the similarity of the appearance of skin rashes with other dermatoses. Serological assays are useful, but less sensitive at an early stage of SS or when patients are immunodeficient. Therefore, there is an urgent need to develop a rapid and effective tool for the diagnosis of SS, which may play an important role in the control of epidemic syphilis outbreaks. In this study, we evaluated a loop-mediated isothermal amplification (LAMP) assay, targeting gene encoding the basic membrane protein of Treponema pallidum, to detect the presence of circulating T. pallidum DNA in the blood of SS patients. The specificity of LAMP was validated using three strains of Spirochaetales and six common clinical bacteria. The clinical applicability of LAMP assay was assessed using 642 blood samples from clinically suspected SS patients and 80 samples from healthy blood donors, showing a sensitivity of 82.1% and a specificity of 100.0% in the diagnosis of SS. Thus, our results indicate that the LAMP can be used as a supplementary method for the diagnosis of SS.
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Affiliation(s)
- Yongjian Xiao
- Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China.,Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China
| | - Yafeng Xie
- Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China.,Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Man Xu
- Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China
| | - Shuangquan Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang, China
| | - Chuanhao Jiang
- Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China
| | - Feijun Zhao
- Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China
| | - Tiebing Zeng
- Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China
| | - Zhuoran Liu
- Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Jian Yu
- Department of Experimental Zoology, Medical College, University of South China, Hengyang, China
| | - Yimou Wu
- Hunan Provincial Key Laboratory for Special Pathogen Prevention and Control, Hengyang, China.,Institute of Pathogenic Biology Institute, Medical College, University of South China, Hengyang, China.,Hunan Province Cooperative Innovation Center for Molecular Targeted New Drug Study, Hengyang, China
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22
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Wu N, Li N, Hu L, He J, Li J, Zhao F, Wu Y. Immunogenicity and immunoreactivity of Tp0821 recombinant protein from Treponema pallidum. Mol Med Rep 2017; 16:851-856. [PMID: 28586013 DOI: 10.3892/mmr.2017.6675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 02/13/2017] [Indexed: 11/05/2022] Open
Abstract
Treponema pallidum (Tp) is responsible for invading reproductive organs and the skin in early stages, and involves almost all organs/systems at advanced stages. In the present study, screening of the dominant epitope fragment of the Tp outer membrane protein, Tp0821, was performed and the prokaryotic expression vector pQE32/Tp0821 was constructed. The denaturation and dialysis of rTp0821 were achieved through ultrasound, inclusion body washing and dissolution. Experiments in purified rTp0821‑immune New Zealand rabbits indicated that the recombinant proteins were of high immunogenicity, and the irritation led a marked humoral immune response in the New Zealand rabbits. Western blot analysis showed that the purified recombinant proteins reacted with the Tp‑positive infected serum, confirming the high level of immunoreactivity. The delayed type hypersensitivity of rTp0821 recombinant proteins was positive, indicating that rTp0821 induced a specific cell immune response and was selected as a Tp vaccine candidate protein. The findings of the present study provided novel evidence, which provided information for further investigations on the pathogenic mechanism of Tp and the development of diagnostic reagents.
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Affiliation(s)
- Ning Wu
- Department of Clinical Laboratory, The First People's Hospital of Hengyang, Hengyang, Hunan 421001, P.R. China
| | - Ni Li
- Emergency Department, Second Affiliated Hospital, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Liping Hu
- Department of Clinical Laboratory, The First People's Hospital of Hengyang, Hengyang, Hunan 421001, P.R. China
| | - Jun He
- Department of Clinical Laboratory, Nanhua Affiliated Hospital, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Junhong Li
- Changzhou Center for Disease Control and Prevention, Changzhou, Jiangsu 213022, P.R. China
| | - Feijun Zhao
- Pathogenic Biology Institute, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Yimou Wu
- Pathogenic Biology Institute, University of South China, Hengyang, Hunan 421001, P.R. China
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23
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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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24
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Xie Y, Xu M, Wang C, Xiao J, Xiao Y, Jiang C, You X, Zhao F, Zeng T, Liu S, Kuang X, Wu Y. Diagnostic value of recombinant Tp0821 protein in serodiagnosis for syphilis. Lett Appl Microbiol 2016; 62:336-43. [PMID: 26853900 DOI: 10.1111/lam.12554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/31/2016] [Accepted: 02/01/2016] [Indexed: 12/15/2022]
Abstract
UNLABELLED Syphilis is a multistage sexually transmitted disease that remains a serious public health concern worldwide. The coexistence of Treponema pallidum with other closely related members of spirochaeta, such as Leptospira spp. and Borrelia burgdorferi, has complicated the serodiagnosis due to cross-reactive antigens. In this study, recombinant Tp0821 protein was expressed in Escherichia coli and purified by metal affinity chromatography. Then enzyme-linked immunosorbent assays (ELISAs) based on Tp0821 for the detection of specific antibodies were established. The relative positive rates of the IgM ELISA and the IgG ELISA were found to be 91·0 and 98·3%, respectively, when screening 578 syphilis specimens. The specificities were 94·3 and 100%, respectively, when cross-checking with serum samples obtained from 30 patients with Lyme disease, five patients with leptospirosis, and 52 uninfected controls. In addition, relative positive rates and specificities of Tp0821 for human sera were all 100% in Western blotting. When compared to the syphilis diagnostic tests commonly used in clinical settings, we found that the results of Tp0821-based ELISAs correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, these findings identify Tp0821 as a novel serodiagnostic candidate for syphilis. SIGNIFICANCE AND IMPACT OF THE STUDY In this study, we expressed and purified the Treponema pallidum protein Tp0821 and developed Tp0821-based enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies. The serodiagnostic performance of the recombinant protein was then evaluated. When compared to the results of syphilis diagnostic tests commonly used in clinical settings, we found that the reactivities of syphilitic sera with the recombinant antigen correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, the recombinant protein shows promise as a new diagnostic antigen in the ELISAs.
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Affiliation(s)
- Y Xie
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - M Xu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - C Wang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - J Xiao
- Clinical Laboratory Department, Hunan Provincial People's Hospital, Changsha, Hunan, China
| | - Y Xiao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China.,Clinical Laboratory Department, The Second Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - C Jiang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - X You
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - F Zhao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - T Zeng
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - S Liu
- Clinical Laboratory Department, The First Affiliated Hospital of University of South China, Hengyang, Hunan, China
| | - X Kuang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
| | - Y Wu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang, Hunan, China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.,Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, Hunan, China
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Radolf JD, Deka RK, Anand A, Šmajs D, Norgard MV, Yang XF. Treponema pallidum, the syphilis spirochete: making a living as a stealth pathogen. Nat Rev Microbiol 2016; 14:744-759. [PMID: 27721440 DOI: 10.1038/nrmicro.2016.141] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The past two decades have seen a worldwide resurgence in infections caused by Treponema pallidum subsp. pallidum, the syphilis spirochete. The well-recognized capacity of the syphilis spirochete for early dissemination and immune evasion has earned it the designation 'the stealth pathogen'. Despite the many hurdles to studying syphilis pathogenesis, most notably the inability to culture and to genetically manipulate T. pallidum, in recent years, considerable progress has been made in elucidating the structural, physiological, and regulatory facets of T. pallidum pathogenicity. In this Review, we integrate this eclectic body of information to garner fresh insights into the highly successful parasitic lifestyles of the syphilis spirochete and related pathogenic treponemes.
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Affiliation(s)
- Justin D Radolf
- Departments of Medicine, Pediatrics, Genetics and Genomic Science, Molecular Biology and Biophysics, and Immunology, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - Ranjit K Deka
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - Arvind Anand
- Department of Medicine, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030-3715, USA
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Michael V Norgard
- Department of Microbiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9048, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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Osbak KK, Houston S, Lithgow KV, Meehan CJ, Strouhal M, Šmajs D, Cameron CE, Van Ostade X, Kenyon CR, Van Raemdonck GA. Characterizing the Syphilis-Causing Treponema pallidum ssp. pallidum Proteome Using Complementary Mass Spectrometry. PLoS Negl Trop Dis 2016; 10:e0004988. [PMID: 27606673 PMCID: PMC5015957 DOI: 10.1371/journal.pntd.0004988] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/19/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The spirochete bacterium Treponema pallidum ssp. pallidum is the etiological agent of syphilis, a chronic multistage disease. Little is known about the global T. pallidum proteome, therefore mass spectrometry studies are needed to bring insights into pathogenicity and protein expression profiles during infection. METHODOLOGY/PRINCIPAL FINDINGS To better understand the T. pallidum proteome profile during infection, we studied T. pallidum ssp. pallidum DAL-1 strain bacteria isolated from rabbits using complementary mass spectrometry techniques, including multidimensional peptide separation and protein identification via matrix-assisted laser desorption ionization-time of flight (MALDI-TOF/TOF) and electrospray ionization (ESI-LTQ-Orbitrap) tandem mass spectrometry. A total of 6033 peptides were detected, corresponding to 557 unique T. pallidum proteins at a high level of confidence, representing 54% of the predicted proteome. A previous gel-based T. pallidum MS proteome study detected 58 of these proteins. One hundred fourteen of the detected proteins were previously annotated as hypothetical or uncharacterized proteins; this is the first account of 106 of these proteins at the protein level. Detected proteins were characterized according to their predicted biological function and localization; half were allocated into a wide range of functional categories. Proteins annotated as potential membrane proteins and proteins with unclear functional annotations were subjected to an additional bioinformatics pipeline analysis to facilitate further characterization. A total of 116 potential membrane proteins were identified, of which 16 have evidence supporting outer membrane localization. We found 8/12 proteins related to the paralogous tpr gene family: TprB, TprC/D, TprE, TprG, TprH, TprI and TprJ. Protein abundance was semi-quantified using label-free spectral counting methods. A low correlation (r = 0.26) was found between previous microarray signal data and protein abundance. CONCLUSIONS This is the most comprehensive description of the global T. pallidum proteome to date. These data provide valuable insights into in vivo T. pallidum protein expression, paving the way for improved understanding of the pathogenicity of this enigmatic organism.
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Affiliation(s)
- Kara K Osbak
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Karen V Lithgow
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Conor J Meehan
- Unit of Mycobacteriology, Institute of Tropical Medicine, Antwerp, Belgium
| | - Michal Strouhal
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Xaveer Van Ostade
- Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
| | - Chris R Kenyon
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
| | - Geert A Van Raemdonck
- HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.,Laboratory for Protein Science, Proteomics and Epigenetic Signaling (PPES) and Centre for Proteomics (CFP), University of Antwerp, Wilrijk, Belgium
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Xu M, Xie Y, Jiang C, Xiao Y, Kuang X, Zhao F, Zeng T, Liu S, Liang M, Li L, Wang C, Wu Y. A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis. Int J Infect Dis 2015; 43:51-57. [PMID: 26747418 DOI: 10.1016/j.ijid.2015.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging. METHODS A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG). RESULTS Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96). CONCLUSION These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.
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Affiliation(s)
- Man Xu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yafeng Xie
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Chuanhao Jiang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yongjian Xiao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China; Department of Clinical Laboratory, The Second Affiliated Hospital of University of South China, Hengyang, China
| | - Xingxing Kuang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Feijun Zhao
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Tiebing Zeng
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Shuangquan Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of University of South China, Hengyang, China
| | - Mingxing Liang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Li Li
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Chuan Wang
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China
| | - Yimou Wu
- Institution of Pathogenic Biology, Medical College, University of South China, Hengyang 421001, China; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, China.
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Evaluation of FlaB1, FlaB2, FlaB3, and Tp0463 of Treponema pallidum for serodiagnosis of syphilis. Diagn Microbiol Infect Dis 2015; 84:105-11. [PMID: 26607421 DOI: 10.1016/j.diagmicrobio.2015.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 09/30/2015] [Accepted: 10/04/2015] [Indexed: 10/22/2022]
Abstract
Syphilis is a multistage disease caused by the invasive spirochete Treponema pallidum subsp. pallidum, and accurate diagnosis is important for the prevention and treatment of syphilis. Here, to identify appropriate diagnostic antigens for serodiagnosis of syphilis, 6 recombinant proteins were expressed in Escherichia coli and purified, including flagellins (FlaB1 [Tp0868], FlaB2 [Tp0792], and FlaB3 [Tp0870]), Tp0463, Tp0751, and Tp1038. The sensitivities were determined by screening sera from individuals with primary (n=82), secondary (n=115), latent (n=105), and congenital (n=65) syphilis. The specificities were determined by screening sera from uninfected controls (n=30) and potentially cross-reactive infections including Lyme disease (n=30), leptospirosis (n=5), and hepatitis B (n=30). Our data showed that FlaB1, FlaB2, FlaB3, Tp0463, and Tp1038 exhibited higher overall sensitivities and specificities for detecting IgG antibody, with 95.4% and 98.9%, 92.6% and 95.8%, 95.1% and 95.8%, 92.6% and 97.9%, and 95.9% and 98.9%, respectively. In contrast, Tp0751 demonstrated only an overall sensitivity of 39.2%. For comparison, the sensitivity and specificity of Architect Syphilis TP were determined to be 98.1% and 93.7%, respectively. In addition, FlaB1, FlaB2, FlaB3, and Tp0463 demonstrated excellent performance for detecting IgM antibody in primary and congenital syphilis, with sensitivities of 76.8% and 83.1%, 72.0% and 87.7%, 74.4% and 89.2%, and 64.6% and 75.3%, respectively. These results indicate that FlaB1, FlaB2, FlaB3, and Tp0463 could be as novel diagnostic candidates for serodiagnosis of syphilis.
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29
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Huang NL, Ye L, Schneider ME, Du YX, Xu YH, Fan LB, Du WD. Development of a novel protein biochip enabling validation of immunological assays and detection of serum IgG and IgM antibodies against Treponema pallidum pathogens in the patients with syphilis. Biosens Bioelectron 2015; 75:465-71. [PMID: 26364122 DOI: 10.1016/j.bios.2015.08.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/05/2015] [Accepted: 08/18/2015] [Indexed: 01/03/2023]
Abstract
In this study, we developed a novel protein biochip methodology that was characterized by dithiobis (succinimidyl undecanoate) (DSU) and specialized for detection of serum IgG and IgM antibodies against Treponema pallidum pathogens in the patients with syphilis, respectively. The biochips were validated by a dimension of atomic force microscope (AFM). The visualized detection limit of IgG antibody on the biochip was 0.39μg/ml. Finally, 286 serum samples from the patients with syphilis were simultaneously tested on the rTpN15-17-47 coated biochips. The results were evaluated in comparison with the assays of T. pallidum particle agglutination (TPPA) and the toluidine red unheated serum test (TRUST). The result demonstrated that the relative positive rate in the 286 patients by biochip was 99.0%, similar to that by TPPA (97.9%, P>0.05) and higher than that by TRUST, (76.2%, P<0.01). The detection specificities were 100% for the biochip and the TPPA and 97.0% for the TRUST. Thus, the protein biochip would provide a useful platform not only for enabling concurrent detection of the infectious antibodies directed against T. pallidum on a larger scale, but also for monitoring therapy modality of the disease.
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Affiliation(s)
- Na-Li Huang
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Lei Ye
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Marion E Schneider
- Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany
| | - Yi-Xin Du
- Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany
| | - Yuan-Hong Xu
- Clinical Laboratory, the First Affiliated Hospital, Anhui Medical University, Hefei 230032, China
| | - Li-Bin Fan
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Wei-Dong Du
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China; Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany; Department of Pathology, Anhui Medical University, Hefei 230032, China.
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A Homology Model Reveals Novel Structural Features and an Immunodominant Surface Loop/Opsonic Target in the Treponema pallidum BamA Ortholog TP_0326. J Bacteriol 2015; 197:1906-20. [PMID: 25825429 DOI: 10.1128/jb.00086-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/18/2015] [Indexed: 12/29/2022] Open
Abstract
UNLABELLED We recently demonstrated that TP_0326 is a bona fide rare outer membrane protein (OMP) in Treponema pallidum and that it possesses characteristic BamA bipartite topology. Herein, we used immunofluorescence analysis (IFA) to show that only the β-barrel domain of TP_0326 contains surface-exposed epitopes in intact T. pallidum. Using the solved structure of Neisseria gonorrhoeae BamA, we generated a homology model of full-length TP_0326. Although the model predicts a typical BamA fold, the β-barrel harbors features not described in other BamAs. Structural modeling predicted that a dome comprised of three large extracellular loops, loop 4 (L4), L6, and L7, covers the barrel's extracellular opening. L4, the dome's major surface-accessible loop, contains mainly charged residues, while L7 is largely neutral and contains a polyserine tract in a two-tiered conformation. L6 projects into the β-barrel but lacks the VRGF/Y motif that anchors L6 within other BamAs. IFA and opsonophagocytosis assay revealed that L4 is surface exposed and an opsonic target. Consistent with B cell epitope predictions, immunoblotting and enzyme-linked immunosorbent assay (ELISA) confirmed that L4 is an immunodominant loop in T. pallidum-infected rabbits and humans with secondary syphilis. Antibody capture experiments using Escherichia coli expressing OM-localized TP_0326 as a T. pallidum surrogate further established the surface accessibility of L4. Lastly, we found that a naturally occurring substitution (Leu(593) → Gln(593)) in the L4 sequences of T. pallidum strains affects antibody binding in sera from syphilitic patients. Ours is the first study to employ a "structure-to-pathogenesis" approach to map the surface topology of a T. pallidum OMP within the context of syphilitic infection. IMPORTANCE Previously, we reported that TP_0326 is a bona fide rare outer membrane protein (OMP) in Treponema pallidum and that it possesses the bipartite topology characteristic of a BamA ortholog. Using a homology model as a guide, we found that TP_0326 displays unique features which presumably relate to its function(s) in the biogenesis of T. pallidum's unorthodox OM. The model also enabled us to identify an immunodominant epitope in a large extracellular loop that is both an opsonic target and subject to immune pressure in a human population. Ours is the first study to follow a structure-to-pathogenesis approach to map the surface topology of a T. pallidum rare OMP within the context of syphilitic infection.
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Runina AV, Rog KV, Vasilev MM. ТрF1 - a new potential antigen for serological diagnostics of latent forms of syphilis. VESTNIK DERMATOLOGII I VENEROLOGII 2014. [DOI: 10.25208/0042-4609-2014-90-6-86-92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The current diagnostics of sexually transmitted diseases is focused on the search for new diagnostically important antigens, especially antigens of T. pallidum that causes syphilis. This article describes the recovery of the recombinant protein TpF1, a cytoplasmic bacterioferritin of T. pallidum, and a study of its immunogenicity in blood serum samples taken from patients with different forms of syphilis and from healthy volunteers. The authors performed a heterologous expression of the TpF1 protein in E. coli cells and purified the recovered TpF1 by means of metal-chelate affinity chromatography. The recombinant TpF1 was further used as an antigen for the determination of specific IgG for this protein in serum samples taken from patients suffering from primary, secondary and early/late latent forms of syphilis. According to the study results, anti-TpF1 antibodies are present at all stages of syphilis yet the level of such antibodies revealed in the groups of patients suffering from secondary, early and late latent forms of syphilis was statistically significantly different from the level of antibodies in the group of healthy volunteers. The greatest difference was observed in the groups of latent syphilis. These data characterize the TpF1 protein as a promising antigen for the diagnostics of syphilis, and TpF1 can also be considered as a potential antigen for the differential diagnostics of latent forms of syphilis.
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Rotanov SV, Ermatova FA. Determination of class M and G antibodies to T.pallidum antigens in patients with primary syphilis. VESTNIK DERMATOLOGII I VENEROLOGII 2013. [DOI: 10.25208/vdv615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The authors present the results of a study of blood serum samples obtained from patients with clinically diagnosed primary syphilis by the linear immunoblotting method to determine IgM and IgG antibodies to T. pallidum antigens, which enabled the authors to study the intensity of the humoral immune response to individual T. pallidum antigens at early stages of the infection. The humoral response by means of the synthesis of specific class M antibodies in case of primary syphilis was accompanied by the formation of Class G antibodies in most cases; the frequency of revealing Class M and G antibodies was as follows: TmpA antigen 100 and 98.68%; TpN47 90.79 and 97.37%; TpN17 90.79 and 89.47%; TpN 15 72.37 and 73.69% of all cases, respectively; the content of class G antibodies to each of the four T. pallidum antigens exceeded the levels of Class M antibodies by more than twice. Different profiles of the humoral immune response with the involvement of IgM and IgG antibodies distinguished by a more expressed synthesis of antibodies to any or several of T. pallidum antigens were discovered and characterized for the first time. The clinical sensitivity of the IgM immunoblotting method for diagnosing primary syphilis amounted to 85.53%, IgG immunoblotting 92.11%, which means that the method can be used to diagnose early forms of syphilis.
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KHAIRULLIN RF, ROTANOV SV, FRIGO NV, BELOUSOVA AV. Bioinformatic analysis of T. pallidum specific antigens. VESTNIK DERMATOLOGII I VENEROLOGII 2012. [DOI: 10.25208/vdv731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Using bioinformatics methods (PSI-BLAST, PSORTb, Cello, BOMP, TMBETADISC-PSSM, TMHMM, LipoP, UiB Lipo, SignalP servers), the authors analyzed sequences of fifteen T. pallidum proteins, which may be potential antigens for the diagnostics of the syphilitic infection. They revealed that Tp0259, Tp0453, Tp0608, Tp0326, Tp0249, Tp0136 and Tp0684 proteins may be promising for further studies.
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Whole genome sequence of Treponema pallidum ssp. pallidum, strain Mexico A, suggests recombination between yaws and syphilis strains. PLoS Negl Trop Dis 2012; 6:e1832. [PMID: 23029591 PMCID: PMC3447947 DOI: 10.1371/journal.pntd.0001832] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 08/11/2012] [Indexed: 01/08/2023] Open
Abstract
Background Treponema pallidum ssp. pallidum (TPA), the causative agent of syphilis, and Treponema pallidum ssp. pertenue (TPE), the causative agent of yaws, are closely related spirochetes causing diseases with distinct clinical manifestations. The TPA Mexico A strain was isolated in 1953 from male, with primary syphilis, living in Mexico. Attempts to cultivate TPA Mexico A strain under in vitro conditions have revealed lower growth potential compared to other tested TPA strains. Methodology/Principal Findings The complete genome sequence of the TPA Mexico A strain was determined using the Illumina sequencing technique. The genome sequence assembly was verified using the whole genome fingerprinting technique and the final sequence was annotated. The genome size of the Mexico A strain was determined to be 1,140,038 bp with 1,035 predicted ORFs. The Mexico A genome sequence was compared to the whole genome sequences of three TPA (Nichols, SS14 and Chicago) and three TPE (CDC-2, Samoa D and Gauthier) strains. No large rearrangements in the Mexico A genome were found and the identified nucleotide changes occurred most frequently in genes encoding putative virulence factors. Nevertheless, the genome of the Mexico A strain, revealed two genes (TPAMA_0326 (tp92) and TPAMA_0488 (mcp2-1)) which combine TPA- and TPE- specific nucleotide sequences. Both genes were found to be under positive selection within TPA strains and also between TPA and TPE strains. Conclusions/Significance The observed mosaic character of the TPAMA_0326 and TPAMA_0488 loci is likely a result of inter-strain recombination between TPA and TPE strains during simultaneous infection of a single host suggesting horizontal gene transfer between treponemal subspecies. Treponema pallidum is a Gram-negative spirochete that causes diseases with distinct clinical manifestations and uses different transmission strategies. While syphilis (caused by subspecies pallidum) is a worldwide venereal and congenital disease, yaws (caused by subspecies pertenue) is a tropical disease transmitted by direct skin contact. Currently the genetic basis and evolution of these diseases remain unknown. In this study, we describe a high quality whole genome sequence of T. pallidum ssp. pallidum strain Mexico A, determined using the ?next generation? sequencing technique (Illumina). Although the genome of this strain contains no large rearrangements in comparison with other treponemal genomes, we found two genes which combined sequences from both subspecies pallidum and pertenue. The observed mosaic character of these two genes is likely a result of inter-strain recombination between pallidum and pertenue during simultaneous infection of a single host.
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ROTANOV SV, HAYRULIN RF, FRIGO NV. Studies of T.pallidum proteome for the purpose of improving laboratory assessments for the syphilis diagnostics. VESTNIK DERMATOLOGII I VENEROLOGII 2012. [DOI: 10.25208/vdv691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The review covers problems related to the ways of development of modern methods of laboratory assessment used for syphilis diagnostics on the basis of the use of specific antigens of the pathogenic agent. Results of studies of some immune proteome proteins of T.pallidum have been provided. The data on the possibility of their use for the development of new laboratory methods based on the detection of antibodies to Т. pallidum target proteins in blood serum samples of patients with different clinical forms of syphilis.
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Houston S, Hof R, Honeyman L, Hassler J, Cameron CE. Activation and proteolytic activity of the Treponema pallidum metalloprotease, pallilysin. PLoS Pathog 2012; 8:e1002822. [PMID: 22910436 PMCID: PMC3406077 DOI: 10.1371/journal.ppat.1002822] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 06/12/2012] [Indexed: 11/19/2022] Open
Abstract
Treponema pallidum is a highly invasive pathogen that undergoes rapid dissemination to establish widespread infection. Previous investigations identified the T. pallidum adhesin, pallilysin, as an HEXXH-containing metalloprotease that undergoes autocatalytic cleavage and degrades laminin and fibrinogen. In the current study we characterized pallilysin's active site, activation requirements, cellular location, and fibrin clot degradation capacity through both in vitro assays and heterologous treponemal expression and degradation studies. Site-directed mutagenesis showed the pallilysin HEXXH motif comprises at least part of the active site, as introduction of three independent mutations (AEXXH [H198A], HAXXH [E199A], and HEXXA [H202A]) abolished pallilysin-mediated fibrinogenolysis but did not adversely affect host component binding. Attainment of full pallilysin proteolytic activity was dependent upon autocatalytic cleavage of an N-terminal pro-domain, a process which could not occur in the HEXXH mutants. Pallilysin was shown to possess a thrombin cleavage site within its N-terminal pro-domain, and in vitro studies confirmed cleavage of pallilysin with thrombin generates a truncated pallilysin fragment that has enhanced proteolytic activity, suggesting pallilysin can also exploit the host coagulation process to facilitate protease activation. Opsonophagocytosis assays performed with viable T. pallidum demonstrated pallilysin is a target of opsonic antibodies, consistent with a host component-interacting, surface-exposed cellular location. Wild-type pallilysin, but not the HEXXA mutant, degraded fibrin clots, and similarly heterologous expression of pallilysin in the non-invasive spirochete Treponema phagedenis facilitated fibrin clot degradation. Collectively these results identify pallilysin as a surface-exposed metalloprotease within T. pallidum that possesses an HEXXH active site motif and requires autocatalytic or host-mediated cleavage of a pro-domain to attain full host component-directed proteolytic activity. Furthermore, our finding that expression of pallilysin confers upon T. phagedenis the capacity to degrade fibrin clots suggests this capability may contribute to the dissemination potential of T. pallidum. Syphilis, caused by the spirochete Treponema pallidum, is a chronic sexually transmitted disease which infects 12 million people annually. Treponema pallidum is highly invasive and undergoes widespread dissemination via the circulatory system. Similar to other invasive pathogens, T. pallidum has been shown to express a host-component-degrading protease, pallilysin, that binds and degrades human fibrinogen and laminin, suggesting a role for pallilysin in bacterial dissemination. Here we identify pallilysin active site residues using mutagenesis and show that, unlike wild-type, mutants fail to degrade fibrinogen. We show that pallilysin is converted into a highly proteolytically active form via truncation of a pro-domain through either autocatalytic cleavage or host-derived, thrombin-mediated cleavage. We also demonstrate that recombinant pallilysin enables clot dissolution and that pallilysin expressed on the surface of the non-invasive spirochete Treponema phagedenis confers the ability to degrade fibrin clots. Further, we show that pallilysin is present on the surface of T. pallidum and thus resides in a cellular location that facilitates direct contact with host components. Our study provides insight into the mechanism of interaction between pallilysin and two important coagulation system proteins, fibrinogen and thrombin, and suggests a novel mechanism that T. pallidum may utilize for dissemination during infection.
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Affiliation(s)
- Simon Houston
- 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
| | - Lisa Honeyman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Julia Hassler
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail:
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Smajs D, Norris SJ, Weinstock GM. Genetic diversity in Treponema pallidum: implications for pathogenesis, evolution and molecular diagnostics of syphilis and yaws. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2012; 12:191-202. [PMID: 22198325 PMCID: PMC3786143 DOI: 10.1016/j.meegid.2011.12.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 12/05/2011] [Accepted: 12/07/2011] [Indexed: 02/08/2023]
Abstract
Pathogenic uncultivable treponemes, similar to syphilis-causing Treponema pallidum subspecies pallidum, include T. pallidum ssp. pertenue, T. pallidum ssp. endemicum and Treponema carateum, which cause yaws, bejel and pinta, respectively. Genetic analyses of these pathogens revealed striking similarity among these bacteria and also a high degree of similarity to the rabbit pathogen, Treponema paraluiscuniculi, a treponeme not infectious to humans. Genome comparisons between pallidum and non-pallidum treponemes revealed genes with potential involvement in human infectivity, whereas comparisons between pallidum and pertenue treponemes identified genes possibly involved in the high invasivity of syphilis treponemes. Genetic variability within syphilis strains is considered as the basis of syphilis molecular epidemiology with potential to detect more virulent strains, whereas genetic variability within a single strain is related to its ability to elude the immune system of the host. Genome analyses also shed light on treponemal evolution and on chromosomal targets for molecular diagnostics of treponemal infections.
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Affiliation(s)
- David Smajs
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 5, Building A6, 625 00 Brno, Czech Republic.
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ROTANOV SV, FRIGO NV, MANUKIAN TYE, PODGURSKY GM. Assessment of the clinical significance of the chemiluminescence immuncassay in the diagnostics of the syphilitic infection. VESTNIK DERMATOLOGII I VENEROLOGII 2012. [DOI: 10.25208/vdv649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The authors present the results of an assessment of the clinical efficacy of the use of the chemiluminescence immunоassay (CLIA) for determination of anti- T. pallidum antibodies in the diagnostics of the syphilitic infection with the use of IMMULITE® 2000 Syphilis Screen, a reagent kit developed on the basis of Tp17 recombinant antigen. The use of 306 samples of blood serum collected from patients suffering from different clinical forms of the syphilitic infection, 61 samples collected from active blood donors and 20 samples collected from persons with biologically false-positive immunochemical (serological) reactions for syphilis demonstrated a high clinical sensitivity (99.68%), specificity (96.30%) and reproducibility (100%) of the chemiluminescence immunоassay results. The high clinical efficacy of the study results combined with the speed of its performance and full automation of the laboratory study process are sufficient to recommend including the chemiluminescence immunоassay in regulated methods for primary examination (screening) of the population for the syphilitic infection along with treponemal tests such as immunoenzyme assay (IEA) and passive hemagglutination reaction.
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Ho EL, Lukehart SA. Syphilis: using modern approaches to understand an old disease. J Clin Invest 2011; 121:4584-92. [PMID: 22133883 DOI: 10.1172/jci57173] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Syphilis is a fascinating and perplexing infection, with protean clinical manifestations and both diagnostic and management ambiguities. Treponema pallidum subsp. pallidum, the agent of syphilis, is challenging to study in part because it cannot be cultured or genetically manipulated. Here, we review recent progress in the application of modern molecular techniques to understanding the biological basis of this multistage disease and to the development of new tools for diagnosis, for predicting efficacy of treatment with alternative antibiotics, and for studying the transmission of infection through population networks.
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Affiliation(s)
- Emily L Ho
- Department of Neurology, University of Washington School of Medicine, Seattle, Washington, USA
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Woodbury DJ, Rees CA, Thompson A, Meiners P, Adams A. An assay to quantitate reducible cysteines from nanograms of GST-fusion proteins. Anal Biochem 2011; 417:165-73. [DOI: 10.1016/j.ab.2011.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 06/07/2011] [Accepted: 06/15/2011] [Indexed: 10/18/2022]
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Desrosiers DC, Anand A, Luthra A, Dunham-Ems SM, LeDoyt M, Cummings MAD, Eshghi A, Cameron CE, Cruz AR, Salazar JC, Caimano MJ, Radolf JD. TP0326, a Treponema pallidum β-barrel assembly machinery A (BamA) orthologue and rare outer membrane protein. Mol Microbiol 2011; 80:1496-515. [PMID: 21488980 PMCID: PMC3115443 DOI: 10.1111/j.1365-2958.2011.07662.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Definitive identification of Treponema pallidum rare outer membrane proteins (OMPs) has long eluded researchers. TP0326, the sole protein in T. pallidum with sequence homology to a Gram-negative OMP, belongs to the BamA family of proteins essential for OM biogenesis. Structural modelling predicted that five polypeptide transport-associated (POTRA) domains comprise the N-terminus of TP0326, while the C-terminus forms an 18-stranded amphipathic β-barrel. Circular dichroism, heat modifiability by SDS-PAGE, Triton X-114 phase partitioning and liposome incorporation supported these topological predictions and confirmed that the β-barrel is responsible for the native protein's amphiphilicity. Expression analyses revealed that native TP0326 is expressed at low abundance, while a protease-surface accessibility assay confirmed surface exposure. Size-exclusion chromatography and blue native polyacrylamide gel electrophoresis revealed a modular Bam complex in T. pallidum larger than that of Escherichia coli. Non-orthologous ancillary factors and self-association of TP0326 via its β-barrel may both contribute to the Bam complex. T. pallidum-infected rabbits mount a vigorous antibody response to both POTRA and β-barrel portions of TP0326, whereas humans with secondary syphilis respond predominantly to POTRA. The syphilis spirochaete appears to have devised a stratagem for harnessing the Bam pathway while satisfying its need to limit surface antigenicity.
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Affiliation(s)
- Daniel C. Desrosiers
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Arvind Anand
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Amit Luthra
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Star M Dunham-Ems
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Morgan LeDoyt
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Michael A. D. Cummings
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Azad Eshghi
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Adriana R. Cruz
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
| | - Juan C. Salazar
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
- Department of Pediatrics, Connecticut Children's Medical Center, Division of Pediatric Infectious Diseases, Hartford, CT 06106
| | - Melissa J. Caimano
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
| | - Justin D. Radolf
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, CT 06030
- Department of Pediatrics, Connecticut Children's Medical Center, Division of Pediatric Infectious Diseases, Hartford, CT 06106
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Bifunctional role of the Treponema pallidum extracellular matrix binding adhesin Tp0751. Infect Immun 2010; 79:1386-98. [PMID: 21149586 DOI: 10.1128/iai.01083-10] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Treponema pallidum, the causative agent of syphilis, is a highly invasive pathogenic spirochete capable of attaching to host cells, invading the tissue barrier, and undergoing rapid widespread dissemination via the circulatory system. The T. pallidum adhesin Tp0751 was previously shown to bind laminin, the most abundant component of the basement membrane, suggesting a role for this adhesin in host tissue colonization and bacterial dissemination. We hypothesized that similar to that of other invasive pathogens, the interaction of T. pallidum with host coagulation proteins, such as fibrinogen, may also be crucial for dissemination via the circulatory system. To test this prediction, we used enzyme-linked immunosorbent assay (ELISA) methodology to demonstrate specific binding of soluble recombinant Tp0751 to human fibrinogen. Click-chemistry-based palmitoylation profiling of heterologously expressed Tp0751 confirmed the presence of a lipid attachment site within this adhesin. Analysis of the Tp0751 primary sequence revealed the presence of a C-terminal putative HEXXH metalloprotease motif, and in vitro degradation assays confirmed that recombinant Tp0751 purified from both insect and Escherichia coli expression systems degrades human fibrinogen and laminin. The proteolytic activity of Tp0751 was abolished by the presence of the metalloprotease inhibitor 1,10-phenanthroline. Further, inductively coupled plasma-mass spectrometry showed that Tp0751 binds zinc and calcium. Collectively, these results indicate that Tp0751 is a zinc-dependent, membrane-associated protease that exhibits metalloprotease-like characteristics. However, site-directed mutagenesis of the HEXXH motif to HQXXH did not abolish the proteolytic activity of Tp0751, indicating that further mutagenesis studies are required to elucidate the critical active site residues associated with this protein. This study represents the first published description of a T. pallidum protease capable of degrading host components and thus provides novel insight into the mechanism of T. pallidum dissemination.
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Surface immunolabeling and consensus computational framework to identify candidate rare outer membrane proteins of Treponema pallidum. Infect Immun 2010; 78:5178-94. [PMID: 20876295 DOI: 10.1128/iai.00834-10] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Treponema pallidum reacts poorly with the antibodies present in rabbit and human syphilitic sera, a property attributed to the paucity of proteins in its outer membrane. To better understand the basis for the syphilis spirochete's "stealth pathogenicity," we used a dual-label, 3-step amplified assay in which treponemes encapsulated in gel microdroplets were probed with syphilitic sera in parallel with anti-FlaA antibodies. A small (approximately 5 to 10%) but reproducible fraction of intact treponemes bound IgG and/or IgM antibodies. Three lines of evidence supported the notion that the surface antigens were likely β-barrel-forming outer membrane proteins (OMPs): (i) surface labeling with anti-lipoidal (VDRL) antibodies was not observed, (ii) immunoblot analysis confirmed prior results showing that T. pallidum glycolipids are not immunoreactive, and (iii) labeling of intact organisms was not appreciably affected by proteinase K (PK) treatment. With this method, we also demonstrate that TprK (TP0897), an extensively studied candidate OMP, and TP0136, a lipoprotein recently reported to be surface exposed, are both periplasmic. Consistent with the immunolabeling studies, TprK was also found to lack amphiphilicity, a characteristic property of β-barrel-forming proteins. Using a consensus computational framework that combined subcellular localization and β-barrel structural prediction tools, we generated ranked groups of candidate rare OMPs, the predicted T. pallidum outer membrane proteome (OMPeome), which we postulate includes the surface-exposed molecules detected by our enhanced gel microdroplet assay. In addition to underscoring the syphilis spirochete's remarkably poor surface antigenicity, our findings help to explain the complex and shifting balance between pathogen and host defenses that characterizes syphilitic infection.
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Burbelo PD, Ching KH, Bush ER, Han BL, Iadarola MJ. Antibody-profiling technologies for studying humoral responses to infectious agents. Expert Rev Vaccines 2010; 9:567-78. [PMID: 20518713 PMCID: PMC3417761 DOI: 10.1586/erv.10.50] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Analyses of humoral responses against different infectious agents are critical for infectious disease diagnostics, understanding pathogenic mechanisms, and the development and monitoring of vaccines. While ELISAs are often used to measure antibody responses to one or several targets, new antibody-profiling technologies, such as protein microarrays, can now evaluate antibody responses to hundreds, or even thousands, of recombinant antigens at one time. These large-scale studies have uncovered new antigenic targets, provided new insights into vaccine research and yielded an overview of immunoreactivity against almost the entire proteome of certain pathogens. However, solid-phase antigen arrays also have drawbacks that limit the type of information obtained, including suboptimal detection of conformational epitopes, high backgrounds due to impure antigens and a narrow dynamic range of detection. We have developed a solution-phase antibody-profiling technology, luciferase immunoprecipitation systems (LIPS), which harnesses light-emitting recombinant antigen fusion proteins to quantitatively measure patient antibody titers. Owing to the highly linear light output of the luciferase reporter, some antibodies can be detected without serum dilution in a dynamic range of detection often spanning seven orders of magnitude. When LIPS is applied iteratively with multiple target antigens, a high-definition antibody profile is obtained. Here, we discuss the application of these different antibody-profiling technologies and their associated limitations with particular emphasis on protein microarrays. We also describe LIPS in detail and discuss several clinically relevant uses of the technology. Together, these new technologies offer new tools for understanding humoral responses to known and emerging infectious agents.
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Affiliation(s)
- Peter D Burbelo
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Building 49, Room 1C20, 49 Convent Drive, Bethesda, MD 20892-4410, USA.
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Abstract
OBJECTIVE To assess the sensitivity, specificity, and feasibility of a new chemiluminescence immunoassay (CLIA) in the diagnosis of syphilis. METHODS At first, a retrospective study was conducted, using 135 documented cases of syphilis and 30 potentially interfering samples and 80 normal sera. A prospective study was also performed by testing 2, 071 unselected samples for routine screening for syphilis. CLIA was compared with a nontreponemal test (TRUST) and a treponemal test (TPPA). RESULTS There was an agreement of 100% between CLIA and TPPA in the respective study. The percentage of agreement among the 245 sera tested was 100.0%. Compared with TPPA, the specificity of CLIA was 99.9% (1817/1819), the sensitivity of CLIA was 100.0% (244/244) in the prospective study. CLIA showed 99.5% agreement with TPPA by testing 2, 071 unselected samples. And CLIA seemed to be more sensitive than TPPA in detecting the samples of primary syphilis. CONCLUSIONS CLIA is easy to perform and the indicator results are objective and unequivocal. It may be suitable for large-scale screening as a treponemal test substituted for TPPA.
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Abstract
Treponema pallidum subsp. pallidum is the causative agent of syphilis, a sexually transmitted disease characterized by widespread tissue dissemination and chronic infection. In this study, we analyzed the proteome of T. pallidum by the isoelectric focusing (IEF) and nonequilibrating pH gel electrophoresis (NEPHGE) forms of two-dimensional gel electrophoresis (2DGE), coupled with matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis. We determined the identity of 148 T. pallidum protein spots, representing 88 T. pallidum polypeptides; 63 of these polypeptides had not been identified previously at the protein level. To examine which of these proteins are important in the antibody response to syphilis, we performed immunoblot analysis using infected rabbit sera or human sera from patients at different stages of syphilis infection. Twenty-nine previously described antigens (predominantly lipoproteins) were detected, as were a number of previously unidentified antigens. The reactivity patterns obtained with sera from infected rabbits and humans were similar; these patterns included a subset of antigens reactive with all serum samples tested, including CfpA, MglB-2, TmpA, TmpB, flagellins, and the 47-kDa, 17-kDa, and 15-kDa lipoproteins. A unique group of antigens specifically reactive with infected human serum was also identified and included the previously described antigen TpF1 and the hypothetical proteins TP0584, TP0608, and TP0965. This combined proteomic and serologic analysis further delineates the antigens potentially useful as vaccine candidates or diagnostic markers and may provide insight into the host-pathogen interactions that occur during T. pallidum infection.
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47
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Sun AH, Mao YF, Hu Y, Sun Q, Yan J. Sensitive and specific ELISA coated by TpN15-TpN17-TpN47 fusion protein for detection of antibodies to Treponema pallidum. Clin Chem Lab Med 2009; 47:321-6. [PMID: 19676144 DOI: 10.1515/cclm.2009.071] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND We constructed an artificial fusion gene tpN15-17-47 and then used the prokaryotic expression fusion protein rTpN15-17-47 as the coated antigen to establish a new enzyme-linked immunosorbent assay (ELISA) for serological diagnosis of syphilis. METHODS tpN15, tpN17, and tpN47 genes were amplified separately by polymerase chain reaction (PCR) and then assembled into a fusion gene coding a trigeminy protein antigen by primer linking PCR. The target recombinant protein antigens rTpN15, rTpN17, rTpN-47, and rTpN15-17-47 were expressed and then purified antigens were immobilized on the surface of microplate wells for detecting Treponema pallidum-specific antibodies by ELISAs. RESULTS The relative positive rate of rTpN15-17-47-ELISA in 965 serum specimens of syphilis patients was 99.5%, which was higher than that of the T. pallidum hemagglutination assay (TPHA) (98.3%) (p<0.05) and much higher than that of the rTpN15-ELISA (83.1%), the rTpN17-ELISA (84.4%), the rTpN47-ELISA (82.1%), and the toluidine red unheated serum test (TRUST) (72.2%) (p<0.01). All the ELISAs and the TPHA in detecting serum specimens from 62 cases with systemic lupus erythematosus (SLE), 86 cases with rheumatic arthritis (RA), and 250 healthy cases were negative, but the TRUST was positive in five cases with SLE, seven cases with RA, and two healthy cases. CONCLUSIONS The rTpN15-17-47-ELISA is a sensitive and specific serological screening or a diagnostic method for syphilis in the clinical setting.
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Affiliation(s)
- Ai Hua Sun
- Faculty of Basic Medicine, Zhejiang Medical College, Zhejiang Hangzhou, PR China
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Common strategies for antigenic variation by bacterial, fungal and protozoan pathogens. Nat Rev Microbiol 2009; 7:493-503. [PMID: 19503065 DOI: 10.1038/nrmicro2145] [Citation(s) in RCA: 234] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The complex relationships between infectious organisms and their hosts often reflect the continuing struggle of the pathogen to proliferate and spread to new hosts, and the need of the infected individual to control and potentially eradicate the infecting population. This has led, in the case of mammals and the pathogens that infect them, to an 'arms race', in which the highly adapted mammalian immune system has evolved to control the proliferation of infectious organisms and the pathogens have developed correspondingly complex genetic systems to evade this immune response. We review how bacterial, protozoan and fungal pathogens from distant evolutionary lineages have evolved surprisingly similar mechanisms of antigenic variation to avoid eradication by the host immune system and can therefore maintain persistent infections and ensure their transmission to new hosts.
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Candidate antigens for Q fever serodiagnosis revealed by immunoscreening of a Coxiella burnetii protein microarray. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1771-9. [PMID: 18845831 DOI: 10.1128/cvi.00300-08] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Q fever is a widespread zoonosis caused by Coxiella burnetii. Diagnosis of Q fever is usually based on serological testing of patient serum. The diagnostic antigen of test kits is formalin-fixed phase I and phase II organisms of the Nine Mile reference strain. Deficiencies of this antigen include (i) potential for cross-reactivity with other pathogens; (ii) an inability to distinguish between C. burnetii strains; and (iii) a need to propagate and purify C. burnetii, a difficult and potentially hazardous process. Consequently, there is a need for sensitive and specific serodiagnostic tests utilizing defined antigens, such as recombinant C. burnetii protein(s). Here we describe the use of a C. burnetii protein microarray to comprehensively identify immunodominant antigens recognized by antibody in the context of human C. burnetii infection or vaccination. Transcriptionally active PCR products corresponding to 1,988 C. burnetii open reading frames (ORFs) were generated. Full-length proteins were successfully synthesized from 75% of the ORFs by using an Escherichia coli-based in vitro transcription and translation system (IVTT). Nitrocellulose microarrays were spotted with crude IVTT lysates and probed with sera from acute Q fever patients and individuals vaccinated with Q-Vax. Immune sera strongly reacted with approximately 50 C. burnetii proteins, including previously identified immunogens, an ankyrin repeat-domain containing protein, and multiple hypothetical proteins. Recombinant protein corresponding to selected array-reactive antigens was generated, and the immunoreactivity was confirmed by enzyme-linked immunosorbent assay. This sensitive and high-throughput method for identifying immunoreactive C. burnetii proteins will aid in the development of Q fever serodiagnostic tests based on recombinant antigen.
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Matejková P, Strouhal M, Smajs D, Norris SJ, Palzkill T, Petrosino JF, Sodergren E, Norton JE, Singh J, Richmond TA, Molla MN, Albert TJ, Weinstock GM. Complete genome sequence of Treponema pallidum ssp. pallidum strain SS14 determined with oligonucleotide arrays. BMC Microbiol 2008; 8:76. [PMID: 18482458 PMCID: PMC2408589 DOI: 10.1186/1471-2180-8-76] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Accepted: 05/15/2008] [Indexed: 11/26/2022] Open
Abstract
Background Syphilis spirochete Treponema pallidum ssp. pallidum remains the enigmatic pathogen, since no virulence factors have been identified and the pathogenesis of the disease is poorly understood. Increasing rates of new syphilis cases per year have been observed recently. Results The genome of the SS14 strain was sequenced to high accuracy by an oligonucleotide array strategy requiring hybridization to only three arrays (Comparative Genome Sequencing, CGS). Gaps in the resulting sequence were filled with targeted dideoxy-terminators (DDT) sequencing and the sequence was confirmed by whole genome fingerprinting (WGF). When compared to the Nichols strain, 327 single nucleotide substitutions (224 transitions, 103 transversions), 14 deletions, and 18 insertions were found. On the proteome level, the highest frequency of amino acid-altering substitution polymorphisms was in novel genes, while the lowest was in housekeeping genes, as expected by their evolutionary conservation. Evidence was also found for hypervariable regions and multiple regions showing intrastrain heterogeneity in the T. pallidum chromosome. Conclusion The observed genetic changes do not have influence on the ability of Treponema pallidum to cause syphilitic infection, since both SS14 and Nichols are virulent in rabbit. However, this is the first assessment of the degree of variation between the two syphilis pathogens and paves the way for phylogenetic studies of this fascinating organism.
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Affiliation(s)
- Petra Matejková
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Alkek N1619, Houston, TX 77030, USA.
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