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De Meyst A, Alexiou Z, Lernout T, Morré SA, Vanrompay D. Challenges in Chlamydial Serology: Insights from a Belgian and a Dutch Population Cohort. Microorganisms 2024; 12:658. [PMID: 38674603 PMCID: PMC11052210 DOI: 10.3390/microorganisms12040658] [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: 01/29/2024] [Revised: 03/21/2024] [Accepted: 03/23/2024] [Indexed: 04/28/2024] Open
Abstract
Serology routinely serves as a diagnostic tool to confirm Chlamydia infections in humans. Particularly in delayed settings, such as post-outbreak scenarios where the acute phase of infection has subsided, serology is invaluable. Multiple studies, nonetheless, indicate deficiencies in specificity and sensitivity of current chlamydial antibody detection assays. Incorporation of multiple antigens per target is known to improve the accuracy of chlamydial serological assays. We, therefore, used the recomLine test (Mikrogen diagnostics) on serological samples of two cohorts, as it is the only commercially available test allowing detection of antibodies against three human pathogenic Chlamydia species (C. trachomatis, C. pneumoniae and C. psittaci) using multiple antigens per target. The first cohort (n = 156; samples collected between 2008 and 2022 during a C. trachomatis screening initiative) comprised women from the Netherlands (NL) with past exposure to C. trachomatis, while the second cohort (n = 44; samples collected in 2018 in a health examination survey) consisted of Belgian citizens (BE) with occupational or recreational exposure to chickens, representing a risk population for C. psittaci. The test indicated a statistically equivalent C. pneumoniae seroprevalence in both cohorts (39.10% in NL and 34.09% in BE; p = 0.337). As expected C. trachomatis seroprevalence was significantly higher (p < 0.001) in the Dutch cohort (48.72%), as compared to the Belgian cohort (4.55%). Lastly, C. psittaci seroprevalence did not significantly differ between the two groups (2.27% in BE and 1.92% in NL; p = 0.633), even though a higher prevalence was expected for the Belgian cohort. This prompts us to question whether the Belgian cohort truly constituted a C. psittaci risk population or whether the recomLine test is susceptible to cross-reaction of species-specific antibodies, thereby increasing C. psittaci prevalence in the Dutch cohort. We advocate for the development of affordable, highly sensitive antibody detection assays that can effectively distinguish between chlamydial species, addressing the increasing demand for enhanced serological testing methodologies.
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Affiliation(s)
- Anne De Meyst
- Laboratory of Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium;
| | - Zoïe Alexiou
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands;
- Institute for Public Health Genomics (IPHG), GROW Research Institute for Oncology and Reproduction, Maastricht University, 6211 LK Maastricht, The Netherlands;
| | - Tinne Lernout
- Epidemiology of Infectious Diseases, Epidemiology and Public Health, Sciensano, 1050 Brussels, Belgium;
| | - Servaas A. Morré
- Institute for Public Health Genomics (IPHG), GROW Research Institute for Oncology and Reproduction, Maastricht University, 6211 LK Maastricht, The Netherlands;
- Dutch Chlamydia trachomatis Reference Laboratory, Deptartment Medical Microbiology, Faculty of Health, Medicine & Life Sciences, Maastricht University, 6229 ER Maastricht, The Netherlands
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad 211007, Uttar Pradesh, India
| | - Daisy Vanrompay
- Laboratory of Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium;
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Sachse K, Hölzer M, Vorimore F, Barf LM, Sachse C, Laroucau K, Marz M, Lamkiewicz K. Genomic analysis of 61 Chlamydia psittaci strains reveals extensive divergence associated with host preference. BMC Genomics 2023; 24:288. [PMID: 37248517 DOI: 10.1186/s12864-023-09370-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 05/09/2023] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Chlamydia (C.) psittaci, the causative agent of avian chlamydiosis and human psittacosis, is a genetically heterogeneous species. Its broad host range includes parrots and many other birds, but occasionally also humans (via zoonotic transmission), ruminants, horses, swine and rodents. To assess whether there are genetic markers associated with host tropism we comparatively analyzed whole-genome sequences of 61 C. psittaci strains, 47 of which carrying a 7.6-kbp plasmid. RESULTS Following clean-up, reassembly and polishing of poorly assembled genomes from public databases, phylogenetic analyses using C. psittaci whole-genome sequence alignment revealed four major clades within this species. Clade 1 represents the most recent lineage comprising 40/61 strains and contains 9/10 of the psittacine strains, including type strain 6BC, and 10/13 of human isolates. Strains from different non-psittacine hosts clustered in Clades 2- 4. We found that clade membership correlates with typing schemes based on SNP types, ompA genotypes, multilocus sequence types as well as plasticity zone (PZ) structure and host preference. Genome analysis also revealed that i) sequence variation in the major outer membrane porin MOMP can result in 3D structural changes of immunogenic domains, ii) past host change of Clade 3 and 4 strains could be associated with loss of MAC/perforin in the PZ, rather than the large cytotoxin, iii) the distinct phylogeny of atypical strains (Clades 3 and 4) is also reflected in their repertoire of inclusion proteins (Inc family) and polymorphic membrane proteins (Pmps). CONCLUSIONS Our study identified a number of genomic features that can be correlated with the phylogeny and host preference of C. psittaci strains. Our data show that intra-species genomic divergence is associated with past host change and includes deletions in the plasticity zone, structural variations in immunogenic domains and distinct repertoires of virulence factors.
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Affiliation(s)
- Konrad Sachse
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743, Jena, Germany.
| | - Martin Hölzer
- Methodology and Research Infrastructure, Bioinformatics, Robert Koch Institute, 13353, Berlin, Germany
| | - Fabien Vorimore
- Laboratory for Animal Health, Identypath, ANSES Maisons-Alfort, Paris-Est University, 94706, Paris, France
| | - Lisa-Marie Barf
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Carsten Sachse
- Ernst-Ruska Centre 3 / Structural Biology, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
- Institute for Biological Information Processing 6 / Structural Cellular Biology, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
- Department of Biology, Heinrich Heine University, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Karine Laroucau
- Laboratory for Animal Health, Bacterial Zoonosis Unit, ANSES Maisons-Alfort, Paris-Est University, 94706, Paris, France
| | - Manja Marz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Kevin Lamkiewicz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743, Jena, Germany
- JRG Analytical MicroBioinformatics, Friedrich Schiller University Jena, 07743, Jena, Germany
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van der Wal FJ, Achterberg RP, van der Goot JA, Dinkla A, Bossers-de Vries R, van Solt-Smits C, Bossers A, Heijne M. Proof of concept for multiplex detection of antibodies against Chlamydia species in chicken serum using a bead-based suspension array with peptides as antigens. Vet Res 2023; 54:31. [PMID: 37016427 PMCID: PMC10074890 DOI: 10.1186/s13567-023-01159-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 03/02/2023] [Indexed: 04/06/2023] Open
Abstract
The available differentiating tests for Chlamydia are based on detection of genetic material and only give information about the actual infection status, but reveal nothing of past infections. As the use of serological methods increases the window of detection, the goal of this study was to investigate if it is possible to develop a differentiating serological test for antibodies against Chlamydia species in chicken sera. Focus was on C. psittaci, C. gallinacea, and two closely related species, i.e. C. abortus and C. avium. To enable differentiating serology, a bead-based Luminex suspension array was constructed, using peptides as antigens, derived from known immunoreactive Chlamydia proteins. For the majority of these peptides, species-specific seroreactivity in mammalian sera has been reported in literature. The suspension array correctly identified antibodies against various Chlamydia species in sera from experimentally infected mice, and was also able to differentiate between antibodies against C. psittaci and C. gallinacea in sera from experimentally infected chickens. In field sera, signals were difficult to interpret as insufficient sera from experimentally infected chickens were available for evaluating the seroreactivity of all peptides. Nevertheless, results of the suspension array with field sera are supported by published data on the occurrence of C. gallinacea in Dutch layers, thereby demonstrating the proof of concept of multiplex serology for Chlamydial species in poultry.
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Affiliation(s)
- Fimme J van der Wal
- Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB, Lelystad, Netherlands.
| | - René P Achterberg
- Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB, Lelystad, Netherlands
| | | | - Annemieke Dinkla
- Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB, Lelystad, Netherlands
| | | | | | - Alex Bossers
- Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB, Lelystad, Netherlands
| | - Marloes Heijne
- Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB, Lelystad, Netherlands
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Abstract
The diversity of the antigen-specific humoral immune response reflects the interaction of the immune system with pathogens and autoantigens. Peptide microarray analysis opens up new perspectives for the use of antibodies as diagnostic biomarkers and provides unique access to a more differentiated view on humoral responses to disease. This review focuses on the latest applications of peptide microarrays for the serologic medical diagnosis of autoimmunity, infectious diseases (including COVID-19), and cancer.
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Affiliation(s)
- Carsten Grötzinger
- Department of Hepatology and Gastroenterology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
- Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
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Vengesai A, Naicker T, Midzi H, Kasambala M, Mduluza-Jokonya TL, Rusakaniko S, Mutapi F, Mduluza T. Multiplex peptide microarray profiling of antibody reactivity against neglected tropical diseases derived B-cell epitopes for serodiagnosis in Zimbabwe. PLoS One 2022; 17:e0271916. [PMID: 35867689 PMCID: PMC9307155 DOI: 10.1371/journal.pone.0271916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
Introduction Peptides (B-cell epitopes) have broad applications in disease diagnosis and surveillance of pathogen exposure. In this framework, we present a pilot study to design and produce a peptide microarray for the integrated surveillance of neglected tropical diseases. The peptide microarray was evaluated against peptides derived from Ascaris lumbricoides, Necator americanus, Schistosoma haematobium, Schistosoma mansoni, Trichuris trichiura, Bacillus anthracis, Mycobacterium leprae, Wuchereria bancrofti, Rabies lyssavirus, Chlamydia trachomatis and Trypanosoma brucei. Methods S. haematobium was diagnosed using the urine filtration technique. S. mansoni, A. lumbricoides, N. americanus and T. trichiura were diagnosed using the Kato Katz and formal ether concentration techniques. Immunogenic peptides were retrieved from the Tackling Infection to Benefit Africa infectious diseases epitope microarray. Further peptides were predicted using ABCpred. IgG and IgM reactivity against the derived peptides were evaluated using peptide microarray multiplex immunoassays. Positive response was defined as fluorescence intensity ≥ 500 fluorescence units. Immunodominant peptides were identified using color-coded heat maps and bar graphs reflecting the obtained fluorescence signal intensities. Receiver Operating Characteristic analysis and Mann-Whitney-U test were performed to determine the diagnostic validity of the peptides. Results Species-specific responses with at least one peptide derived from each NTD pathogen were observed. The reactive peptides included; for S. haematobium, XP_035588858.1-206-220 and XP_035588858.1-206-220 immunodominant for IgG and IgM respectively, for S. mansoni, P20287.1-58-72 immunodominant for both antibodies and for T. trichiura, CDW52482.1-326-340 immunodominant for IgG and CDW57769.1-2017-2031 and CDW57769.1-1518-1532 immunodominant for IgM. According to ROC analysis most of the peptides selected were inaccurate; with AUC < 0.5. Some peptides had AUC values ranging from 0.5 to 0.5875 for both IgM and IgG suggesting no discrimination. Conclusion Multiplex peptide microarrays are a valuable tool for integrated NTDs surveillance and for screening parasites exposure in endemic areas. Species sero-reactivity observed in the study maybe indicative of exposure to the different NTDs parasites. However, although peptides with the least cross reactivity were selected there is need to validate the sero-reactivity with recombinant antigens and immune-blotting techniques such as western blotting.
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Affiliation(s)
- Arthur Vengesai
- Department of Biochemistry, Faculty of Medicine, Midlands State University, Gweru, Zimbabwe
- * E-mail:
| | - Thajasvarie Naicker
- Department of Optics and Imaging, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Herald Midzi
- Department of Optics and Imaging, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- Department of Biotechnology and Biochemistry, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe
| | - Maritha Kasambala
- Department of Biological Sciences and Ecology, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe
| | - Tariro L. Mduluza-Jokonya
- Department of Optics and Imaging, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Simbarashe Rusakaniko
- Family Medicine, Global and Public Health Unit, Faculty of Medicine and Health Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Francisca Mutapi
- Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - Takafira Mduluza
- Department of Biotechnology and Biochemistry, Faculty of Science, University of Zimbabwe, Harare, Zimbabwe
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Vengesai A, Kasambala M, Mutandadzi H, Mduluza-Jokonya TL, Mduluza T, Naicker T. Scoping review of the applications of peptide microarrays on the fight against human infections. PLoS One 2022; 17:e0248666. [PMID: 35077448 PMCID: PMC8789108 DOI: 10.1371/journal.pone.0248666] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 01/11/2022] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION This scoping review explores the use of peptide microarrays in the fight against infectious diseases. The research domains explored included the use of peptide microarrays in the mapping of linear B-cell and T cell epitopes, antimicrobial peptide discovery, immunosignature characterisation and disease immunodiagnostics. This review also provides a short overview of peptide microarray synthesis. METHODS Electronic databases were systematically searched to identify relevant studies. The review was conducted using the Joanna Briggs Institute methodology for scoping reviews and data charting was performed using a predefined form. The results were reported by narrative synthesis in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. RESULTS Ninety-five articles from 103 studies were included in the final data charting process. The majority (92. 0%) of the articles were published during 2010-2020 and were mostly from Europe (44.2%) and North America (34.7%). The findings were from the investigation of viral (45.6%), bacterial (32. 0%), parasitic (23.3%) and fungal (2. 0%) infections. Out of the serological studies, IgG was the most reported antibody type followed by IgM. The largest portion of the studies (77.7%) were related to mapping B-cell linear epitopes, 5.8% were on diagnostics, 5.8% reported on immunosignature characterisation and 8.7% reported on viral and bacterial cell binding assays. Two studies reported on T-cell epitope profiling. CONCLUSION The most important application of peptide microarrays was found to be B-cell epitope mapping or antibody profiling to identify diagnostic and vaccine targets. Immunosignatures identified by random peptide microarrays were found to be applied in the diagnosis of infections and interrogation of vaccine responses. The analysis of the interactions of random peptide microarrays with bacterial and viral cells using binding assays enabled the identification of antimicrobial peptides. Peptide microarray arrays were also used for T-cell linear epitope mapping which may provide more information for the design of peptide-based vaccines and for the development of diagnostic reagents.
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Affiliation(s)
- Arthur Vengesai
- Optics & Imaging, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
- Department of Biochemistry, Faculty of Medicine, Midlands State University, Gweru, Zimbabwe
| | - Maritha Kasambala
- Department of Biology, Faculty of Science and Agriculture, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
| | - Hamlet Mutandadzi
- Faculty of Medicine and Health Sciences, Parirenyatwa Hospital, University of Zimbabwe, Harare, Zimbabwe
| | - Tariro L. Mduluza-Jokonya
- Optics & Imaging, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
| | - Takafira Mduluza
- Department of Biochemistry, Faculty of Medicine, Midlands State University, Gweru, Zimbabwe
| | - Thajasvarie Naicker
- Optics & Imaging, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
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Heijne M, van der Goot J, Buys H, Dinkla A, Roest HJ, van Keulen L, Koets A. Experimental Chlamydia gallinacea infection in chickens does not protect against a subsequent experimental Chlamydia psittaci infection. Vet Res 2021; 52:141. [PMID: 34801064 PMCID: PMC8605536 DOI: 10.1186/s13567-021-01011-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/21/2021] [Indexed: 11/23/2022] Open
Abstract
Chlamydia psittaci was considered the predominant chlamydial species in poultry until Chlamydia gallinacea was discovered in 2009. C. psittaci is a zoonotic obligate intracellular bacterium reported in more than 465 bird species including poultry. In poultry, infections can result in asymptomatic disease, but also in more severe systemic illness. The zoonotic potential of C. gallinacea has yet to be proven. Infections in poultry appear to be asymptomatic and in recent prevalence studies C. gallinacea was the main chlamydial species found in chickens. The high prevalence of C. gallinacea resulted in the question if an infection with C. gallinacea might protect against an infection with C. psittaci. To investigate possible cross protection, chickens were inoculated with C. gallinacea NL_G47 and subsequently inoculated with either a different strain of C. gallinacea (NL_F725) or C. psittaci. Chickens that had not been pre-inoculated with C. gallinacea NL_G47 were used as a C. gallinacea or C. psittaci infection control. In the groups that were inoculated with C. psittaci, no difference in pharyngeal or cloacal shedding, or in tissue dissemination was observed between the control group and the pre-inoculated group. In the groups inoculated with C. gallinacea NL_F725, shedding in cloacal swabs and tissues dissemination was lower in the group pre-inoculated with C. gallinacea NL_G47. These results indicate previous exposure to C. gallinacea does not protect against an infection with C. psittaci, but might protect against a new infection of C. gallinacea.
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Affiliation(s)
- Marloes Heijne
- Department of Bacteriology, Host-Pathogen Interaction and Diagnostics Development, Wageningen Bioveterinary Research, Lelystad, The Netherlands.
| | - Jeanet van der Goot
- Department of Diagnostics and Crisis Organisation, Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Herma Buys
- Department of Diagnostics and Crisis Organisation, Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Annemieke Dinkla
- Department of Bacteriology, Host-Pathogen Interaction and Diagnostics Development, Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Hendrik Jan Roest
- Department of Bacteriology, Host-Pathogen Interaction and Diagnostics Development, Wageningen Bioveterinary Research, Lelystad, The Netherlands.,Current Affiliation: Directorate Animal Supply Chain and Animal Welfare, Ministry of Agriculture, Nature and Food Quality, The Hague, The Netherlands
| | - Lucien van Keulen
- Department of Bacteriology, Host-Pathogen Interaction and Diagnostics Development, Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Ad Koets
- Department of Bacteriology, Host-Pathogen Interaction and Diagnostics Development, Wageningen Bioveterinary Research, Lelystad, The Netherlands.,Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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Rahman KS, Kaltenboeck B. Multipeptide Assays for Sensitive and Differential Detection of Anti-Chlamydia Trachomatis Antibodies. J Infect Dis 2021; 224:S86-S95. [PMID: 34396415 DOI: 10.1093/infdis/jiab016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Detection of anti-Chlamydia trachomatis (Ctr) antibodies is compromised by cross-reactivity and poor sensitivity of classic Ctr-antigens. We discovered 48 strongly reactive peptide antigens of Ctr-specific B-cell epitopes from 21 immunodominant proteins. In this study, we review the utility of peptide assays for diagnosis of Ctr infections. By combining many of these Ctr-specific B-cell epitopes from several proteins in separate or mixed multipeptide assays, they achieved vastly superior assay sensitivity and specificity over standard enzyme-linked immunosorbent assays. Such multipeptide assays eliminate cross-reactivities (false positives) and correct for stochastic gaps in antibody responses (false negatives). More importantly, we developed and validated a novel microarray platform in which hundreds of peptides from many proteins are spotted in a single reaction well. This offers the possibility of high-throughput screening of many candidate peptides for routine serological fingerprinting of Ctr infections. Discovery of optimal sets of antibody responses that associate with clinical pelvic inflammatory disease (PID) may identify diagnostically useful PID biomarker antigens.
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Affiliation(s)
- Kh Shamsur Rahman
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
| | - Bernhard Kaltenboeck
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
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Epitope mapping from Mycobacterium leprae proteins: Convergent data from in silico and in vitro approaches for serodiagnosis of leprosy. Mol Immunol 2021; 138:48-57. [PMID: 34343723 DOI: 10.1016/j.molimm.2021.07.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/13/2021] [Accepted: 07/26/2021] [Indexed: 02/05/2023]
Abstract
Knowledge of immunodominant B-cell epitopes is essential to design powerful diagnostic strategies aiming for antibody detection. Outstanding progress in computational prediction has achieved a significant contribution to the biomedical fields, including immunodiagnosis. In silico analysis may have an even more important role when information concerning antigens from etiologic agents of neglected diseases, such as leprosy, is scarce. The aim of this study was to provide mapping of B-cell epitopes from two Mycobacterium leprae-derived antigens (Ag85B and ML2055), confirm their antigenicity, and to assess the ability of in silico immunoinformatics tools to accurately predict them. Linear B-cell epitopes predicted by ABCpred and SVMTrip servers were compared to antigenic regions of synthetic overlapping peptides that exhibited reactivity to antibodies from patients with leprosy. Our in vitro results identified several immunodominant regions that had also been indicated by in silico prediction, providing agreement between experimental and simulated data. After chemical synthesis, we used enzyme-linked immunosorbent assays to determine the effectiveness of the first identified sequence (GTNVPAEFLENFVHG) which had 72 % sensitivity and 78 % specificity (AUC = 0.79) while the second one (PVSSEAQPGDPNAPS) had 72 % sensitivity and 93.8 % specificity (AUC = 0.85). Using dot blotting, an easy-to-read visual test, both peptides could distinguish sera from patients with leprosy from those with tuberculosis and from sera of healthy volunteers. Our findings suggest that these synthetic peptides, with some refinement, may be useful as serological diagnostic antigens for leprosy. In addition, it was displayed that immunoinformatics provides reliable information for mapping potential B-cell epitopes for development of peptide-based diagnostic assays for neglected diseases.
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Collatz M, Mock F, Barth E, Hölzer M, Sachse K, Marz M. EpiDope: a deep neural network for linear B-cell epitope prediction. Bioinformatics 2021; 37:448-455. [PMID: 32915967 DOI: 10.1093/bioinformatics/btaa773] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/06/2020] [Accepted: 09/01/2020] [Indexed: 02/01/2023] Open
Abstract
MOTIVATION By binding to specific structures on antigenic proteins, the so-called epitopes, B-cell antibodies can neutralize pathogens. The identification of B-cell epitopes is of great value for the development of specific serodiagnostic assays and the optimization of medical therapy. However, identifying diagnostically or therapeutically relevant epitopes is a challenging task that usually involves extensive laboratory work. In this study, we show that the time, cost and labor-intensive process of epitope detection in the lab can be significantly reduced using in silico prediction. RESULTS Here, we present EpiDope, a python tool which uses a deep neural network to detect linear B-cell epitope regions on individual protein sequences. With an area under the curve between 0.67 ± 0.07 in the receiver operating characteristic curve, EpiDope exceeds all other currently used linear B-cell epitope prediction tools. Our software is shown to reliably predict linear B-cell epitopes of a given protein sequence, thus contributing to a significant reduction of laboratory experiments and costs required for the conventional approach. AVAILABILITYAND IMPLEMENTATION EpiDope is available on GitHub (http://github.com/mcollatz/EpiDope). SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Maximilian Collatz
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science
| | - Florian Mock
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science
| | - Emanuel Barth
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science.,Bioinformatics Core Facility Jena, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Martin Hölzer
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science.,RNA Bioinformatics/High Throughput Analysis, European Virus Bioinformatics Center (EVBC), Jena 07743, Germany
| | - Konrad Sachse
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science
| | - Manja Marz
- RNA Bioinformatics /High Throughput Analysis, Faculty of Mathematics and Computer Science.,Bioinformatics Core Facility Jena, Friedrich Schiller University Jena, Jena 07743, Germany.,RNA Bioinformatics/High Throughput Analysis, European Virus Bioinformatics Center (EVBC), Jena 07743, Germany.,RNA Bioinformatics/High Throughput Analysis, FLI Leibniz Institute for Age Research, Jena 07745, Germany
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11
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Wang A, Jiang M, Liu H, Liu Y, Zhou J, Chen Y, Ding P, Wang Y, Pang W, Qi Y, Zhang G. Development and characterization of monoclonal antibodies against the N-terminal domain of African swine fever virus structural protein, p54. Int J Biol Macromol 2021; 180:203-211. [PMID: 33737177 DOI: 10.1016/j.ijbiomac.2021.03.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/11/2021] [Accepted: 03/11/2021] [Indexed: 12/28/2022]
Abstract
African swine fever virus (ASFV), a re-emerging DNA virus, causes a highly contagious disease for domestic pigs. It is running rife worldwide and threatening the global swine industry. Protein p54 is an attractive candidate for ASFV diagnostic and vaccine design. In this work, we designed a peptide to mimic the N-terminal domain (NTD) of ASFV p54 and pretested it with sera from ASFV-infected pigs. The peptide could be well recognized by the sera, implying that the NTD of p54 contained some potential linear B cell epitopes. Then, the conjugates of the peptide with bovine serum albumin were used as the immunogen to generate monoclonal antibodies (mAbs). A total of six mAbs specific to the NTD of ASFV p54 protein were developed. Five of them well reacted with ASFV HLJ/18 strain and recognized a same linear B cell epitope 5FFQPV9. Furthermore, epitope 5FFQPV9 could be well recognized by ASFV-positive sera from natural infected pigs, suggesting that it was a natural linear B-cell epitope. Conservation analysis indicated that epitope 5FFQPV9 were highly conserved among ASFV epidemic isolates belonging to genotype I and II. Alanine-scanning mutagenesis further revealed that the residues (6F to 9V) of epitope 5FFQPV9 were the core binding sites for antibody recognition. This is the first research to characterize specific mAbs against NTD of p54 protein. These findings may help further understand the function of p54 protein and the improvement of ASFV diagnosis.
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Affiliation(s)
- Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Min Jiang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Hongliang Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yankai Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jingming Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yumei Chen
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Peiyang Ding
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yanwei Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Weisheng Pang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yanhua Qi
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Gaiping Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China.
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12
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Wang Q, Sun Z, Li J, Qin T, Ma H, Chen S, Peng D, Liu X. Identification of a universal antigen epitope of influenza A virus using peptide microarray. BMC Vet Res 2021; 17:22. [PMID: 33413356 PMCID: PMC7792037 DOI: 10.1186/s12917-020-02725-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/15/2020] [Indexed: 02/08/2023] Open
Abstract
Background Hemagglutinin is a major surface protein in influenza A virus (IAV), and HA2 is relative conserved among different IAVs. It will be meaningful to identify broad-spectrum epitopes based on the HA2 protein. Results Overlapping peptides of the HA2 protein of the H5N1 IAV A/Mallard/Huadong/S/2005 were synthesized and loaded on modified silica gel film to form a microarray, and antisera against different subtypes of IAVs were used to screen universal epitopes. The selected epitope was further confirmed by western blotting using anti-peptide immune serum and viruses rescued with amino acid substitution. The results showed that 485-FYHKCDNECME-495 of the H5 14th peptide in HA2 had broad-spectrum binding activity with antisera against H1, H3, H4, H5, H6, H7, H8, H9, and H10 subtype IAV. Substitution of amino acids (K or D) in rescued viruses resulted in decreased serum binding, indicating that they were critical residues for serum binding activity. In Immune Epitope Database, some epitopes containing 14–4 peptide were confirmed as MHC-II-restricted CD4 T cell epitope and had effects on releasing IL-2 or IFN. Conclusion The identified epitope should be a novel universal target for detection and vaccine design and its ability to generate immune protection needs further exploration. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-020-02725-5.
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Affiliation(s)
- Qiuxia Wang
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, 225009, Jiangsu, People's Republic of China
| | - Zhihao Sun
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, 225009, Jiangsu, People's Republic of China
| | - Jingzhi Li
- Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215000, People's Republic of China
| | - Tao Qin
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, 225009, Jiangsu, People's Republic of China
| | - Hongwei Ma
- Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215000, People's Republic of China
| | - Sujuan Chen
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China. .,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China. .,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, 225009, Jiangsu, People's Republic of China. .,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, 225009, People's Republic of China.
| | - Daxin Peng
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China. .,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China. .,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, 225009, Jiangsu, People's Republic of China. .,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, 225009, People's Republic of China.
| | - Xiufan Liu
- College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu, 225009, People's Republic of China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009, Jiangsu, People's Republic of China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, 225009, People's Republic of China
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13
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Hölzer M, Barf LM, Lamkiewicz K, Vorimore F, Lataretu M, Favaroni A, Schnee C, Laroucau K, Marz M, Sachse K. Comparative Genome Analysis of 33 Chlamydia Strains Reveals Characteristic Features of Chlamydia Psittaci and Closely Related Species. Pathogens 2020; 9:E899. [PMID: 33126635 PMCID: PMC7694038 DOI: 10.3390/pathogens9110899] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022] Open
Abstract
To identify genome-based features characteristic of the avian and human pathogen Chlamydia(C.) psittaci and related chlamydiae, we analyzed whole-genome sequences of 33 strains belonging to 12 species. Using a novel genome analysis tool termed Roary ILP Bacterial Annotation Pipeline (RIBAP), this panel of strains was shown to share a large core genome comprising 784 genes and representing approximately 80% of individual genomes. Analyzing the most variable genomic sites, we identified a set of features of C. psittaci that in its entirety is characteristic of this species: (i) a relatively short plasticity zone of less than 30,000 nt without a tryptophan operon (also in C. abortus, C. avium, C. gallinacea, C. pneumoniae), (ii) a characteristic set of of Inc proteins comprising IncA, B, C, V, X, Y (with homologs in C. abortus, C. caviae and C. felis as closest relatives), (iii) a 502-aa SinC protein, the largest among Chlamydia spp., and (iv) an elevated number of Pmp proteins of subtype G (14 in C. psittaci, 14 in Cand. C. ibidis). In combination with future functional studies, the common and distinctive criteria revealed in this study provide important clues for understanding the complexity of host-specific behavior of individual Chlamydia spp.
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Affiliation(s)
- Martin Hölzer
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
| | - Lisa-Marie Barf
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
| | - Kevin Lamkiewicz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
| | - Fabien Vorimore
- Animal Health Laboratory, Bacterial Zoonoses Unit, University Paris-Est, Anses, 94706 Maisons-Alfort, France; (F.V.); (K.L.)
| | - Marie Lataretu
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
| | - Alison Favaroni
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), 07743 Jena, Germany; (A.F.); (C.S.)
| | - Christiane Schnee
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), 07743 Jena, Germany; (A.F.); (C.S.)
| | - Karine Laroucau
- Animal Health Laboratory, Bacterial Zoonoses Unit, University Paris-Est, Anses, 94706 Maisons-Alfort, France; (F.V.); (K.L.)
| | - Manja Marz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
| | - Konrad Sachse
- RNA Bioinformatics and High-Throughput Analysis, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany; (M.H.); (L.-M.B.); (K.L.); (M.L.); (M.M.)
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14
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Mao S, Liang Y, Chen P, Zhang Y, Yin X, Zhang M. In-depth proteomics approach reveals novel biomarkers of cardiac remodelling after myocardial infarction: An exploratory analysis. J Cell Mol Med 2020; 24:10042-10051. [PMID: 32701210 PMCID: PMC7520298 DOI: 10.1111/jcmm.15611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/09/2020] [Accepted: 06/15/2020] [Indexed: 01/05/2023] Open
Abstract
Cardiac remodelling following myocardial infarction (MI) is a maladaptive change associated with progressive heart failure and compromises long‐term clinical outcome. A substantial proportion of patients afflicted by MI still develop adverse outcomes associated with cardiac remodelling. Therefore, it is crucial to identify biomarkers for the early prediction of cardiac remodelling. An in‐depth proteomics approach, including both semi‐quantitative and quantitative antibody arrays, was used to identify circulating biomarkers that may be associated with detrimental cardiac remodelling. Furthermore, statistical correlation analysis was performed between the candidate biomarkers and clinical cardiac remodelling data to demonstrate their clinical utility. A systematic proteomics approach revealed that sclerostin (SOST), growth differentiation factor‐15 (GDF‐15), urokinase‐type plasminogen activator (uPA), and midkine (MK) were increased, while monocyte chemotactic protein‐3 (MCP‐3) was uniquely decreased in MI patients who developed cardiac remodelling, compared to MI patients who did not develop cardiac remodelling and healthy humen. Moreover, correlation analyses between serum proteomes and cardiac remodelling echocardiographic parameters demonstrated a moderate positive association between left ventricular end‐diastolic volume index (LVEDVi) and the three serum proteins, uPA, MK and GDF‐15 (P < .05, respectively), and a moderate negative correlation between LV ejection fraction (LVEF) and these serum proteins (P < .05, respectively). Importantly, uPA and MK were firstly identified to be associated with the development of cardiac remodelling. The present study contributes to a better understanding of the various cytokines expressed during adverse cardiac remodelling. The identified biomarkers may facilitate early identification of patients at high risk of ischaemic heart failure pending further confirmation through larger clinical trials.
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Affiliation(s)
- Shuai Mao
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Yubin Liang
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Peipei Chen
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Yuzhuo Zhang
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xin Yin
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Minzhou Zhang
- Key Discipline of Integrated Chinese and Western Medicine, Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
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15
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Loreck K, Mitrenga S, Heinze R, Ehricht R, Engemann C, Lueken C, Ploetz M, Greiner M, Meemken D. Use of meat juice and blood serum with a miniaturised protein microarray assay to develop a multi-parameter IgG screening test with high sample throughput potential for slaughtering pigs. BMC Vet Res 2020; 16:106. [PMID: 32252773 PMCID: PMC7137480 DOI: 10.1186/s12917-020-02308-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 03/10/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Serological screening of pig herds at the abattoir is considered a potential tool to improve meat inspection procedures and herd health management. Therefore, we previously reported the feasibility of a miniaturised protein microarray as a new serological IgG screening test for zoonotic agents and production diseases in pigs. The present study investigates whether the protein microarray-based assay is applicable for high sample throughput using either blood serum or meat juice. MATERIAL AND METHODS Microarrays with 12 different antigens were produced by Abbott (formerly Alere Technologies GmbH) Jena, Germany in a previously offered 'ArrayTube' platform and in an 'ArrayStrip' platform for large-scale use. A test protocol for the use of meat juice on both microarray platforms was developed. Agreement between serum and meat juice was analysed with 88 paired samples from three German abattoirs. Serum was diluted 1:50 and meat juice 1:2. ELISA results for all tested antigens from a preceding study were used as reference test to perform Receiver Operating Characteristic analysis for both test specimens on both microarray platforms. RESULTS High area under curve values (AUC > 0.7) were calculated for the analysis of T. gondii (0.87), Y. enterocolitica (0.97), Mycoplasma hyopneumoniae (0.84) and Actinobacillus pleuropneumoniae (0.71) with serum as the test specimen and for T. gondii (0.99), Y. enterocolitica (0.94), PRRSV (0.88), A. pleuropneumoniae (0.78) and Salmonella spp. (0.72) with meat juice as the test specimen on the ArrayStrip platform. Cohens kappa values of 0.92 for T. gondii and 0.82 for Y. enterocolitica were obtained for the comparison between serum and meat juice. When applying the new method in two further laboratories, kappa values between 0.63 and 0.94 were achieved between the laboratories for these two pathogens. CONCLUSION Further development of a miniaturised pig-specific IgG protein microarray assay showed that meat juice can be used on microarray platforms. Two out of twelve tested antigens (T. gondii, Y. enterocolitica) showed high test accuracy on the ArrayTube and the ArrayStrip platform with both sample materials.
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Affiliation(s)
- Katharina Loreck
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173, Hannover, Germany.
| | - Sylvia Mitrenga
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173, Hannover, Germany
| | - Regina Heinze
- Abbott (Alere Technologies GmbH), Löbstedter Straße 103-105, D-07749, Jena, Germany
| | - Ralf Ehricht
- Department for Optical Molecular Diagnostics and Systems Technology, Leibniz-Institute of Photonic Technology (IPHT), Albert-Einstein-Straße 9, D-07745, Jena, Germany
- InfectoGnostics Research Campus, Centre for Applied Research, Philosophenweg 7, D-07743, Jena, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, D-07737, Jena, Germany
| | - Claudia Engemann
- Indical Bioscience GmbH, Deutscher Platz 5b, D-04103, Leipzig, Germany
| | - Caroline Lueken
- LUFA Nord-West, Institut für Tiergesundheit, Ammerländer Heerstraße 123, D-26129, Oldenburg, Germany
| | - Madeleine Ploetz
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173, Hannover, Germany
| | - Matthias Greiner
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173, Hannover, Germany
- Department of Exposure, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, D-10589, Berlin, Germany
| | - Diana Meemken
- Institute of Food Safety and Food Hygiene, Section Meat Hygiene, Freie Universität Berlin, Königsweg 67, D-14163, Berlin, Germany
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16
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Abstract
Chlamydiae are obligate intracellular bacterial pathogens of humans. Infections in animals are also widespread with some species, such as Chlamydia psittaci, long recognised as a serious threat to human health. Critical to the public health response of any zoonotic disease outbreaks is reliable and up-to-date information on the epidemiology of the target pathogen. Aided by advances in the use of quantitative PCR, molecular typing and culture-independent genomic studies, significant recent work has highlighted an expanded diversity and host range of chlamydial pathogens in animals. New and unexpected cases of chlamydial zoonoses have now been recently documented in Australia and elsewhere, emphasising the importance of multi-disciplinary ‘One Health' collaboration and the use of standardised methods to detect and characterise chlamydial pathogens in humans and animals.
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17
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Hagemann JB, Simnacher U, Marschall MT, Maile J, Soutschek E, Wellinghausen N, Essig A. Analysis of humoral immune responses to recombinant Chlamydia pneumoniae antigens. Int J Infect Dis 2019; 91:232-239. [PMID: 31841725 DOI: 10.1016/j.ijid.2019.12.007] [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: 09/20/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES Chlamydia pneumoniae is a difficult to diagnose respiratory pathogen. This study was performed to systematically characterize humoral immune responses to selected C. pneumoniae antigens in order to provide novel serodiagnostic perspectives for clinical and epidemiological issues. METHODS Based on a literature search, gene library screening, and serological proteome analysis, 15 immunogenic surface-associated, virulence-associated, and hypothetical C. pneumoniae antigens were selected, recombinantly expressed, and lined on a nitrocellulose strip. Specific IgM and IgG reactivity was measured in a total of 172 PCR- and micro-immunofluorescence testing (MIF)-characterized serum samples from patients with respiratory infections. A theoretical model was conceived to approximate a putative course of C. pneumoniae antigen expression and assess the potential of early and late antigens. RESULTS While surface antigens performed poorly, the virulence-associated TARP was a reliable antigen for IgM detection, with a sensitivity of 80.0% and a diagnostic specificity of 90.2%. The hypothetical protein YwbM proved powerful for IgG detection with MIF-correlative sensitivities of up to 94.4% and a diagnostic specificity of 95.1%. CONCLUSIONS This study provides new insights into antibody profiles to immunogenic proteins in C. pneumoniae infection. The study findings offer antigen candidates for more reliable and standardized serological investigations of C. pneumoniae infections, including studies on seroprevalence and epidemiology.
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Affiliation(s)
- Jürgen Benjamin Hagemann
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany.
| | - Ulrike Simnacher
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Miriam Theresia Marschall
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Julia Maile
- Mikrogen Diagnostik, Floriansbogen 2, D-82061 Neuried, Germany
| | - Erwin Soutschek
- Mikrogen Diagnostik, Floriansbogen 2, D-82061 Neuried, Germany
| | | | - Andreas Essig
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
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18
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Shastry DG, Karande P. Microarrays for the screening and identification of carbohydrate-binding peptides. Analyst 2019; 144:7378-7389. [PMID: 31670365 DOI: 10.1039/c9an01465a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of carbohydrate-binding ligands is crucial for expanding knowledge on the glycocode and for achieving systematic carbohydrate targeting. Amongst such ligands, carbohydrate-binding peptides (CBPs) are attractive for use in bioanalytical and biomedical systems due to their biochemical and physicochemical properties; moreover, given the biological significance of lectin-carbohydrate interactions, these ligands offer an opportunity to study peptide sequence and binding characteristics to inform on natural target/ligand interactions. Here, a high-throughput microarray screening technique is described for the identification and study of CBPs, with a focus on polysialic acid (PSA), a polysaccharide found on neural stem cells. The chemical and biological uniqueness of PSA suggests that an ability to exclusively target this glycan may promote a number of diagnostic and therapeutic applications. PSA-binding peptides from phage display screening and from epitope mapping of an scFv for oligosialic acid were screened in an optimized microarray format with three ligand density conditions. Hypothesis-driven mutations were additionally applied to select peptides to modulate peptide affinity and selectivity to PSA. Peptide compositional and positional analyses revealed the significance of various residues for PSA binding and suggested the importance of basic residue positioning for PSA recognition. Furthermore, selectivity studies performed directly on microarrays with chondroitin sulfate A (CS-A) demonstrated the value of screening for both affinity and selectivity in the development of CBPs. Thus, the integrated approach described, with attention to design strategy, screening, and peptide characterization, successfully identified novel PSA-binding ligands and offers a platform for the identification and study of additional polysaccharide-binding peptides.
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Affiliation(s)
- Divya G Shastry
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
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19
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Abstract
PURPOSE OF REVIEW Recent studies regarding the frequency of Chlamydia-induced reactive arthritis (ReA) are reviewed, with a focus on the question of whether the entity is in fact disappearing or whether it is simply being underdiagnosed/underreported. Epidemiological reports indicate diversity in the frequency of Chlamydia-associated ReA in various parts of the world, with evidence of declining incidence in some regions. RECENT FINDINGS The hypothesis that early effective treatment with antibiotics prevents the manifestation of Chlamydia-associated ReA requires further investigation. For clinicians, it is important to remember that ReA secondary to Lymphogranuloma venereum (LGV) serovars L1-L3 of C. trachomatis is probably underestimated due to a limited awareness of this condition, the re-emergence in Western countries of LGV overall, and the present increasingly rare classical inguinal presentation.
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20
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Rahman KS, Kaltenboeck B. Multi-peptide ELISAs overcome cross-reactivity and inadequate sensitivity of conventional Chlamydia pneumoniae serology. Sci Rep 2019; 9:15078. [PMID: 31636331 PMCID: PMC6803651 DOI: 10.1038/s41598-019-51501-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/27/2019] [Indexed: 12/12/2022] Open
Abstract
Cross-reactivity of classical chlamydial antigens compromises Chlamydia (C.) pneumoniae serology. By testing with 185 human antisera, we expanded 18 previously discovered C. pneumoniae-specific B-cell epitopes to 48 peptide antigens from 12 C. pneumoniae immunodominant proteins. For specific detection of antibodies against C. pneumoniae, we developed novel ELISAs with strongly reactive individual peptide antigens and mixtures of these peptides. By comparison to a composite reference standard (CRS) for anti-C. pneumoniae antibody status of human sera, the top-performing CpnMixF12 peptide assay showed 91% sensitivity at 95% specificity, significantly higher than 4 commercial anti-C. pneumoniae IgG ELISAs (36-12% sensitivity at 95% specificity). Human C. pneumoniae (Cpn) and C. trachomatis (Ctr) seroreactivity was 54% biased towards co-positivity in commercial Cpn and Ctr ELISAs, but unbiased in Cpn and Ctr peptide antibody assays, suggesting severe cross-reactivity of commercial ELISAs. Using hyperimmune mouse sera against each of 11 Chlamydia spp., we confirm that commercial Cpn and Ctr ELISA antigens are cross-reactive among all Chlamydia spp., but Cpn and Ctr peptide antigens react only with antisera against the cognate chlamydial species. With simultaneously high specificity and sensitivity, and convenient use for non-specialized laboratories, these ELISAs have the potential to improve serodiagnosis of C. pneumoniae infection.
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Affiliation(s)
- Kh Shamsur Rahman
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.
| | - Bernhard Kaltenboeck
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
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21
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Darville T, Albritton HL, Zhong W, Dong L, O'Connell CM, Poston TB, Quayle AJ, Goonetilleke N, Wiesenfeld HC, Hillier SL, Zheng X. Anti-chlamydia IgG and IgA are insufficient to prevent endometrial chlamydia infection in women, and increased anti-chlamydia IgG is associated with enhanced risk for incident infection. Am J Reprod Immunol 2019; 81:e13103. [PMID: 30784128 DOI: 10.1111/aji.13103] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 12/23/2022] Open
Abstract
PROBLEM Chlamydia infections in women can ascend to the upper genital tract, and repeated infections are common, placing women at risk for sequelae. The protective role of anti-chlamydia antibodies to surface exposed antigens in ascending and incident infection is unclear. METHOD OF STUDY A whole-bacterial ELISA was used to quantify chlamydia-specific IgG and IgA in serum and cervical secretions of 151 high-risk women followed longitudinally. Correlations were determined between antibody and cervical burden, and causal mediation analysis investigated the effect of antibody on ascension. We examined the relationship of antibody to incident infection using the marginal Cox model. RESULTS Serum and cervical anti-chlamydia IgG and cervical IgA levels correlated inversely with cervical burden. While lower burden was associated with reduced ascension, causal mediation analysis revealed that the indirect effects of antibody mediated through reductions in bacterial burden were insufficient to prevent ascension. Analysis of women uninfected at enrollment revealed that serum and cervical anti-chlamydia IgG were associated with increased risk of incident infection; hazard ratio increased 3.6-fold (95% CI, 1.3-10.3), and 22.6-fold (95% CI, 3.1-165.2) with each unit of serum and cervical IgG, respectively. CONCLUSION Although anti-chlamydia IgG and IgA correlated with reduced cervical chlamydia burden, they failed to prevent ascension and increased levels of anti-chlamydia IgG were associated with increased risk for incident infection.
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Affiliation(s)
- Toni Darville
- Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina
| | - Hannah L Albritton
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Wujuan Zhong
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina
| | - Li Dong
- Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina
| | | | - Taylor B Poston
- Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina
| | - Alison J Quayle
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Nilu Goonetilleke
- Departments of Microbiology & Immunology and Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Harold C Wiesenfeld
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, The Magee-Womens Research Institute, Pittsburgh, Pennsylvania
| | - Sharon L Hillier
- Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine, The Magee-Womens Research Institute, Pittsburgh, Pennsylvania
| | - Xiaojing Zheng
- Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina
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22
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Bommana S, Jelocnik M, Borel N, Marsh I, Carver S, Polkinghorne A. The limitations of commercial serological assays for detection of chlamydial infections in Australian livestock. J Med Microbiol 2019; 68:627-632. [PMID: 30839254 DOI: 10.1099/jmm.0.000951] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Chlamydia pecorum and Chlamydia abortus are related ruminant pathogens endemic to different global regions. Potential co-infections combined with the lack of species-specific serological assays challenge accurate diagnosis. Serological screening revealed low C. abortus seropositivity with the peptide-based ELISA (1/84; 1.2%) in Australian sheep yet moderate seropositivity in a Swiss flock with history of C. abortus-associated abortions (17/63; 26.9%). By whole cell antigen complement fixation tests (CFT) and ELISA, chlamydial seropositivity was significantly higher in all groups, suggesting cross-reactivity between these two chlamydial species and non-specificity of the tests. However, only C. pecorum DNA could be detected by qPCR in Chlamydia seropositive Australian animals screened, suggesting chlamydial seropositivity was due to cross-reactivity with endemic C. pecorum infections. These results suggest ascribing Chlamydia seropositivity to chlamydial species in livestock using whole-cell antigen CFT or ELISA should be treated with caution; and that peptide-based ELISA and qPCR provide greater chlamydial species-specificity.
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Affiliation(s)
- Sankhya Bommana
- Animal Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Martina Jelocnik
- Animal Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Nicole Borel
- Institute of Veterinary Pathology, Department of Pathobiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Ian Marsh
- Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales, Australia
| | - Scott Carver
- Department of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Adam Polkinghorne
- Animal Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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23
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Brambilla D, Chiari M, Gori A, Cretich M. Towards precision medicine: the role and potential of protein and peptide microarrays. Analyst 2019; 144:5353-5367. [DOI: 10.1039/c9an01142k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Techniques to comprehensively analyze protein signatures are pivotal to unravel disease mechanisms, develop novel biomarkers and targeted therapies. In this frame, protein and peptide microarrays can play a major role in fuelling precision medicine.
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Affiliation(s)
- Dario Brambilla
- Consiglio Nazionale delle Ricerche
- Istituto di Chimica del Riconoscimento Molecolare (ICRM)
- Milano
- Italy
| | - Marcella Chiari
- Consiglio Nazionale delle Ricerche
- Istituto di Chimica del Riconoscimento Molecolare (ICRM)
- Milano
- Italy
| | - Alessandro Gori
- Consiglio Nazionale delle Ricerche
- Istituto di Chimica del Riconoscimento Molecolare (ICRM)
- Milano
- Italy
| | - Marina Cretich
- Consiglio Nazionale delle Ricerche
- Istituto di Chimica del Riconoscimento Molecolare (ICRM)
- Milano
- Italy
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24
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Mixed Chlamydia trachomatis Peptide Antigens Provide a Specific and Sensitive Single-Well Colorimetric Enzyme-Linked Immunosorbent Assay for Detection of Human Anti -C. trachomatis Antibodies. mSphere 2018; 3:3/6/e00484-18. [PMID: 30404936 PMCID: PMC6222056 DOI: 10.1128/msphere.00484-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
For detection of anti-C. trachomatis antibodies by serological assays, use of classical chlamydial antigens results in high cross-reactivity and poor sensitivity. Previously, we discovered 48 strongly reactive peptide antigens of C. trachomatis-specific B-cell epitopes from 21 immunodominant proteins, and individual testing and combined scoring of 5 to 11 peptide antigens provided highly sensitive and specific detection of anti-C. trachomatis antibodies in chemiluminescent ELISAs. To simplify this method, this study established a single-well labor-saving colorimetric ELISA using a mixture of 12 strongly reactive C. trachomatis peptide antigens (Ctr Mix1) for detection of anti-C. trachomatis antibodies. This Ctr Mix1 ELISA (94% sensitivity and 98% specificity) outperformed 4 commercial ELISAs (49% to 79% sensitivity and 98% specificity). This ELISA can be easily implemented and commercialized, with convenient setup for use in nonspecialized laboratories. Thus, this mixed peptide assay with superior specificity and sensitivity will improve serodiagnosis of C. trachomatis infections. Sensitive and specific detection of anti-Chlamydia trachomatis antibodies in standard enzyme-linked immunosorbent assays (ELISAs) is compromised by cross-reactivity and poor sensitivity of classical C. trachomatis antigens. Previously, we discovered 48 strongly reactive peptide antigens of C. trachomatis-specific B-cell epitopes from 21 immunodominant proteins. By comprehensive individual testing of 11 top-ranked peptide antigens, we found very high sensitivity and specificity for detection of anti-C. trachomatis antibodies in chemiluminescent ELISAs. The current study established a labor-saving colorimetric ELISA by using a mixture of 12 strongly reactive C. trachomatis peptide antigens (Ctr Mix1) in a single well/serum rather than assaying reactivity to each individual peptide. For performance evaluation, we used a simulated population of 212 anti-C. trachomatis antibody-positive and -negative sera from 125 women with NAAT-confirmed active C. trachomatis infection and from 87 healthy women at low risk for C. trachomatis infection. In comparison to a composite reference standard (CRS) for anti-C. trachomatis antibody status, the Ctr Mix1 IgG ELISA achieved 93.9% sensitivity, significantly superior to the 49% to 79% sensitivities of four commercial anti-C. trachomatis IgG ELISAs, and 98% specificity of all tested assays. Compared to the labor-intensive individual peptide testing, this mixed peptide ELISA retained high specificity with only marginal, ∼5% sensitivity loss. By ROC-AUC, likelihood ratio, and predictive value analyses, the Ctr Mix1 ELISA performed satisfactorily at 10% to 75% prevalence range of anti-C. trachomatis antibodies but significantly better than commercial ELISAs. Thus, the labor-saving mixed peptide colorimetric ELISA format provides simultaneously high specificity and sensitivity for detection of anti-C. trachomatis antibodies. IMPORTANCE For detection of anti-C. trachomatis antibodies by serological assays, use of classical chlamydial antigens results in high cross-reactivity and poor sensitivity. Previously, we discovered 48 strongly reactive peptide antigens of C. trachomatis-specific B-cell epitopes from 21 immunodominant proteins, and individual testing and combined scoring of 5 to 11 peptide antigens provided highly sensitive and specific detection of anti-C. trachomatis antibodies in chemiluminescent ELISAs. To simplify this method, this study established a single-well labor-saving colorimetric ELISA using a mixture of 12 strongly reactive C. trachomatis peptide antigens (Ctr Mix1) for detection of anti-C. trachomatis antibodies. This Ctr Mix1 ELISA (94% sensitivity and 98% specificity) outperformed 4 commercial ELISAs (49% to 79% sensitivity and 98% specificity). This ELISA can be easily implemented and commercialized, with convenient setup for use in nonspecialized laboratories. Thus, this mixed peptide assay with superior specificity and sensitivity will improve serodiagnosis of C. trachomatis infections.
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25
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Abstract
Current serological assays for species-specific detection of anti-Chlamydia species antibodies suffer from well-known shortcomings in specificity and ease of use. Due to the high prevalences of both anti-C. trachomatis and anti-C. pneumoniae antibodies in human populations, species-specific serology is unreliable. Therefore, novel specific and simple assays for chlamydial serology are urgently needed. Conventional antigens are problematic due to extensive cross-reactivity within Chlamydia spp. Using accurate B cell epitope prediction and a robust peptide ELISA methodology developed in our laboratory, we identified immunodominant C. trachomatis B cell epitopes by screening performed with sera from C. trachomatis-infected women. We discovered 38 novel human host-dependent antigens from 20 immunodominant C. trachomatis proteins, in addition to confirming 10 host-independent mouse serum peptide antigens that had been identified previously. This extended set of highly specific C. trachomatis peptide antigens can be used in simple ELISA or multiplexed microarray formats and will provide high specificity and sensitivity to human C. trachomatis serodiagnosis. Chlamydia species-specific serology is compromised by cross-reactivity of the gold standard microimmunofluorescence (MIF) or commercial enzyme-linked immunosorbent assays (ELISAs). This study was conducted to discover novel C. trachomatis-specific peptide antigens that were recognized only by the antibody response of the natural human host. We evaluated a library of 271 peptide antigens from immunodominant C. trachomatis proteins by reactivity with 125 C. trachomatis antibody-positive sera from women with PCR-confirmed C. trachomatis infection and 17 C. trachomatis antibody-negative sera from low-risk women never diagnosed with C. trachomatis infection. These C. trachomatis peptide antigens had been predicted in silico to contain B cell epitopes but had been nonreactive with mouse hyperimmune sera against C. trachomatis. We discovered 38 novel human host-dependent antigens from 20 immunodominant C. trachomatis proteins (PmpD, IncE, IncG, CT529, CT618, CT442, TarP, CT143, CT813, CT795, CT223, PmpC, CT875, CT579, LcrE, IncA, CT226, CT694, Hsp60, and pGP3). Using these human sera, we also confirmed 10 C. trachomatis B cell epitopes from 6 immunodominant C. trachomatis proteins (OmpA, PmpD, IncE, IncG, CT529, and CT618) as host species-independent epitopes that had been previously identified by their reactivity with mouse hyperimmune sera against C. trachomatis. ELISA reactivities against these peptides correlated strongly with the C. trachomatis microimmunofluorescence (MIF) text results (Pearson’s correlation coefficient [R] = 0.80; P < 10−6). These C. trachomatis peptide antigens do not cross-react with antibodies against other Chlamydia species and are therefore suitable for species-specific detection of antibodies against C. trachomatis. This study identified an extended set of peptide antigens for simple C. trachomatis-specific ELISA serology. IMPORTANCE Current serological assays for species-specific detection of anti-Chlamydia species antibodies suffer from well-known shortcomings in specificity and ease of use. Due to the high prevalences of both anti-C. trachomatis and anti-C. pneumoniae antibodies in human populations, species-specific serology is unreliable. Therefore, novel specific and simple assays for chlamydial serology are urgently needed. Conventional antigens are problematic due to extensive cross-reactivity within Chlamydia spp. Using accurate B cell epitope prediction and a robust peptide ELISA methodology developed in our laboratory, we identified immunodominant C. trachomatis B cell epitopes by screening performed with sera from C. trachomatis-infected women. We discovered 38 novel human host-dependent antigens from 20 immunodominant C. trachomatis proteins, in addition to confirming 10 host-independent mouse serum peptide antigens that had been identified previously. This extended set of highly specific C. trachomatis peptide antigens can be used in simple ELISA or multiplexed microarray formats and will provide high specificity and sensitivity to human C. trachomatis serodiagnosis.
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26
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Comprehensive Molecular Serology of Human Chlamydia trachomatis Infections by Peptide Enzyme-Linked Immunosorbent Assays. mSphere 2018; 3:3/4/e00253-18. [PMID: 30068559 PMCID: PMC6070734 DOI: 10.1128/msphere.00253-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
For detection of anti-Chlamydia trachomatis antibodies by serological assays, use of classical whole-organism chlamydial antigens results in high cross-reactivity. These antigens bind mainly antibodies against the major outer membrane protein (OmpA) and bind antibodies against other immunodominant non-OmpA proteins to a lesser extent, resulting in poor assay sensitivity. The specificity of C. trachomatis serology is also compromised by the high prevalence of cross-reactive anti-C. pneumoniae antibodies in human populations. We previously identified 48 highly specific C. trachomatis B cell epitope peptide antigens of 21 immunodominant proteins. This study validated peptide antigen-based novel ELISAs that provide highly specific and sensitive detection of anti-C. trachomatis antibodies. Compared to four commercial ELISAs that achieved only poor sensitivities (51.5% to 64.8%), the combined signals of 5 to 11 peptides provided high sensitivity (86.5% to 91.8%) at the same 98% specificity. Thus, by using multiple peptide antigens of immunodominant proteins, we created simple ELISAs with specificity and sensitivity superior to standard C. trachomatis serodiagnosis. Sensitive species-specific detection of anti-Chlamydia trachomatis antibodies is compromised by cross-reactivity of the C. trachomatis antigens used in standard microimmunofluorescence (MIF) testing and enzyme-linked immunosorbent assays (ELISAs). Previously, we discovered 48 strongly reactive C. trachomatis-specific B cell epitope peptides from 21 immunodominant proteins. Here we comprehensively evaluated the 11 top-ranked C. trachomatis-specific peptide antigens from 8 proteins for use in C. trachomatis serology. Sera from 125 women with nucleic acid amplification test (NAAT)-confirmed active C. trachomatis infection and from 49 healthy women with a low risk of C. trachomatis infection were used as anti-C. trachomatis antibody-positive and -negative sera. Results obtained for detection of IgG1, IgG3, and IgA1 antibodies against the 11 C. trachomatis peptide antigens were compared to results from 4 commercial anti-C. trachomatis IgG ELISAs. Using composite reference standards (CRS) of all assays for anti-C. trachomatis antibody status, commercial ELISAs detected antibodies in antibody-positive women with sensitivities of 51.5% to 64.8%. In contrast, a combination of the results of all 11 peptides detected IgG (IgG1 and IgG3) antibodies with 91.8% sensitivity, and a labor-saving combination of the 5 optimal peptides still detected antibodies in antibody-positive women with 86.5% sensitivity (all at 98% specificity). The superior performance of the combined peptide ELISAs was confirmed by area under the receiver operating characteristic curve (ROC-AUC), likelihood ratio, and predictive value analyses. The higher sensitivity of the peptide assays results from using multiple B cell epitopes of several C. trachomatis immunodominant proteins, including OmpA, compared to exclusively using the OmpA antigens used in commercial ELISAs. Thus, ELISAs with combined use of synthetic peptide antigens for C. trachomatis antibody detection have the advantage of simultaneous high sensitivity and high specificity. IMPORTANCE For detection of anti-Chlamydia trachomatis antibodies by serological assays, use of classical whole-organism chlamydial antigens results in high cross-reactivity. These antigens bind mainly antibodies against the major outer membrane protein (OmpA) and bind antibodies against other immunodominant non-OmpA proteins to a lesser extent, resulting in poor assay sensitivity. The specificity of C. trachomatis serology is also compromised by the high prevalence of cross-reactive anti-C. pneumoniae antibodies in human populations. We previously identified 48 highly specific C. trachomatis B cell epitope peptide antigens of 21 immunodominant proteins. This study validated peptide antigen-based novel ELISAs that provide highly specific and sensitive detection of anti-C. trachomatis antibodies. Compared to four commercial ELISAs that achieved only poor sensitivities (51.5% to 64.8%), the combined signals of 5 to 11 peptides provided high sensitivity (86.5% to 91.8%) at the same 98% specificity. Thus, by using multiple peptide antigens of immunodominant proteins, we created simple ELISAs with specificity and sensitivity superior to standard C. trachomatis serodiagnosis.
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