1
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Børud B, Koomey M. Sweet complexity: O-linked protein glycosylation in pathogenic Neisseria. Front Cell Infect Microbiol 2024; 14:1407863. [PMID: 38808060 PMCID: PMC11130364 DOI: 10.3389/fcimb.2024.1407863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 04/29/2024] [Indexed: 05/30/2024] Open
Abstract
The genus Neisseria, which colonizes mucosal surfaces, includes both commensal and pathogenic species that are exclusive to humans. The two pathogenic Neisseria species are closely related but cause quite different diseases, meningococcal sepsis and meningitis (Neisseria meningitidis) and sexually transmitted gonorrhea (Neisseria gonorrhoeae). Although obvious differences in bacterial niches and mechanisms for transmission exists, pathogenic Neisseria have high levels of conservation at the levels of nucleotide sequences, gene content and synteny. Species of Neisseria express broad-spectrum O-linked protein glycosylation where the glycoproteins are largely transmembrane proteins or lipoproteins localized on the cell surface or in the periplasm. There are diverse functions among the identified glycoproteins, for example type IV biogenesis proteins, proteins involved in antimicrobial resistance, as well as surface proteins that have been suggested as vaccine candidates. The most abundant glycoprotein, PilE, is the major subunit of pili which are an important colonization factor. The glycans attached can vary extensively due to phase variation of protein glycosylation (pgl) genes and polymorphic pgl gene content. The exact roles of glycosylation in Neisseria remains to be determined, but increasing evidence suggests that glycan variability can be a strategy to evade the human immune system. In addition, pathogenic and commensal Neisseria appear to have significant glycosylation differences. Here, the current knowledge and implications of protein glycosylation genes, glycan diversity, glycoproteins and immunogenicity in pathogenic Neisseria are summarized and discussed.
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Affiliation(s)
- Bente Børud
- Department of Bacteriology, Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Michael Koomey
- Department of Biosciences, Section for Genetics and Evolutionary Biology, University of Oslo, Oslo, Norway
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2
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Williams E, Seib KL, Fairley CK, Pollock GL, Hocking JS, McCarthy JS, Williamson DA. Neisseria gonorrhoeae vaccines: a contemporary overview. Clin Microbiol Rev 2024; 37:e0009423. [PMID: 38226640 PMCID: PMC10938898 DOI: 10.1128/cmr.00094-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024] Open
Abstract
Neisseria gonorrhoeae infection is an important public health issue, with an annual global incidence of 87 million. N. gonorrhoeae infection causes significant morbidity and can have serious long-term impacts on reproductive and neonatal health and may rarely cause life-threatening disease. Global rates of N. gonorrhoeae infection have increased over the past 20 years. Importantly, rates of antimicrobial resistance to key antimicrobials also continue to increase, with the United States Centers for Disease Control and Prevention identifying drug-resistant N. gonorrhoeae as an urgent threat to public health. This review summarizes the current evidence for N. gonorrhoeae vaccines, including historical clinical trials, key N. gonorrhoeae vaccine preclinical studies, and studies of the impact of Neisseria meningitidis vaccines on N. gonorrhoeae infection. A comprehensive survey of potential vaccine antigens, including those identified through traditional vaccine immunogenicity approaches, as well as those identified using more contemporary reverse vaccinology approaches, are also described. Finally, the potential epidemiological impacts of a N. gonorrhoeae vaccine and research priorities for further vaccine development are described.
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Affiliation(s)
- Eloise Williams
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Reference Laboratory at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Christopher K. Fairley
- Melbourne Sexual Health Centre, Alfred Health, Melbourne, Victoria, Australia
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Georgina L. Pollock
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Jane S. Hocking
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - James S. McCarthy
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Service, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Deborah A. Williamson
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Reference Laboratory at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
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Roe SK, Felter B, Zheng B, Ram S, Wetzler LM, Garges E, Zhu T, Genco CA, Massari P. In Vitro Pre-Clinical Evaluation of a Gonococcal Trivalent Candidate Vaccine Identified by Transcriptomics. Vaccines (Basel) 2023; 11:1846. [PMID: 38140249 PMCID: PMC10747275 DOI: 10.3390/vaccines11121846] [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: 11/06/2023] [Revised: 12/03/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Gonorrhea, a sexually transmitted disease caused by Neisseria gonorrhoeae, poses a significant global public health threat. Infection in women can be asymptomatic and may result in severe reproductive complications. Escalating antibiotic resistance underscores the need for an effective vaccine. Approaches being explored include subunit vaccines and outer membrane vesicles (OMVs), but an ideal candidate remains elusive. Meningococcal OMV-based vaccines have been associated with reduced rates of gonorrhea in retrospective epidemiologic studies, and with accelerated gonococcal clearance in mouse vaginal colonization models. Cross-protection is attributed to shared antigens and possibly cross-reactive, bactericidal antibodies. Using a Candidate Antigen Selection Strategy (CASS) based on the gonococcal transcriptome during human mucosal infection, we identified new potential vaccine targets that, when used to immunize mice, induced the production of antibodies with bactericidal activity against N. gonorrhoeae strains. The current study determined antigen recognition by human sera from N. gonorrhoeae-infected subjects, evaluated their potential as a multi-antigen (combination) vaccine in mice and examined the impact of different adjuvants (Alum or Alum+MPLA) on functional antibody responses to N. gonorrhoeae. Our results indicated that a stronger Th1 immune response component induced by Alum+MPLA led to antibodies with improved bactericidal activity. In conclusion, a combination of CASS-derived antigens may be promising for developing effective gonococcal vaccines.
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Affiliation(s)
- Shea K. Roe
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; (S.K.R.); (C.A.G.)
| | - Brian Felter
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; (S.K.R.); (C.A.G.)
| | - Bo Zheng
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA (S.R.)
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA (S.R.)
| | - Lee M. Wetzler
- Section of Infectious Diseases, Boston University School of Medicine, Boston, MA 02118, USA;
| | - Eric Garges
- Department of Preventive Medicine and Biostatistics, F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, MD 20814, USA;
| | - Tianmou Zhu
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; (S.K.R.); (C.A.G.)
| | - Caroline A. Genco
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; (S.K.R.); (C.A.G.)
| | - Paola Massari
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA; (S.K.R.); (C.A.G.)
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Gray MC, Thomas KS, Lamb ER, Werner LM, Connolly KL, Jerse AE, Criss AK. Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine. Infect Immun 2023; 91:e0030923. [PMID: 37991382 PMCID: PMC10715150 DOI: 10.1128/iai.00309-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/27/2023] [Indexed: 11/23/2023] Open
Abstract
The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as four-component meningococcal B vaccine (4CMenB) are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here, we present the development and optimization of assays to evaluate antibody functionality after immunization of mice: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils [polymorphonuclear leukocytes (PMNs)]. These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical studies and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae.
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Affiliation(s)
- Mary C. Gray
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Keena S. Thomas
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Evan R. Lamb
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Lacie M. Werner
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Kristie L. Connolly
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
| | - Ann E. Jerse
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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Omeershffudin UNM, Kumar S. Emerging threat of antimicrobial resistance in Neisseria gonorrhoeae: pathogenesis, treatment challenges, and potential for vaccine development. Arch Microbiol 2023; 205:330. [PMID: 37688619 DOI: 10.1007/s00203-023-03663-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 09/11/2023]
Abstract
The continuous rise of antimicrobial resistance (AMR) is a serious concern as it endangers the effectiveness of healthcare interventions that rely on antibiotics in the long run. The increasing resistance of Neisseria gonorrhoeae, the bacteria responsible for causing gonorrhea, to commonly used antimicrobial drugs, is a major concern. This has now become a critical global health crisis. In the coming years, there is a risk of a hidden epidemic caused by the emergence of gonococcal AMR. This will worsen the global situation. Infections caused by N. gonorrhoeae were once considered easily treatable. However, over time, they have become increasingly resistant to commonly used therapeutic medications, such as penicillin, ciprofloxacin, and azithromycin. As a result, this pathogen is developing into a true "superbug," which means that ceftriaxone is now the only available option for initial empirical treatment. Effective management strategies are urgently needed to prevent severe consequences, such as infertility and pelvic inflammatory disease, which can result from delayed intervention. This review provides a thorough analysis of the escalating problem of N. gonorrhoeae, including its pathogenesis, current treatment options, the emergence of drug-resistant mechanisms, and the potential for vaccine development. We aim to provide valuable insights for healthcare practitioners, policymakers, and researchers in their efforts to combat N. gonorrhoeae antibiotic resistance by elucidating the multifaceted aspects of this global challenge.
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Affiliation(s)
- Umairah Natasya Mohd Omeershffudin
- Post Graduate Centre, Management and Science University, University Drive, Off Persiaran Olahraga, Section 13, 40100, Selangor, Malaysia
| | - Suresh Kumar
- Faculty of Health and Life Sciences, Management and Science University, Seksyen 13, 40100, Shah Alam, Selangor, Malaysia.
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Belcher T, Rollier CS, Dold C, Ross JDC, MacLennan CA. Immune responses to Neisseria gonorrhoeae and implications for vaccine development. Front Immunol 2023; 14:1248613. [PMID: 37662926 PMCID: PMC10470030 DOI: 10.3389/fimmu.2023.1248613] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 07/26/2023] [Indexed: 09/05/2023] Open
Abstract
Neisseria gonorrheoae is the causative agent of gonorrhea, a sexually transmitted infection responsible for a major burden of disease with a high global prevalence. Protective immunity to infection is often not observed in humans, possible due to high variability of key antigens, induction of blocking antibodies, or a large number of infections being relatively superficial and not inducing a strong immune response. N. gonorrhoeae is a strictly human pathogen, however, studies using mouse models provide useful insights into the immune response to gonorrhea. In mice, N. gonorrhoea appears to avoid a protective Th1 response by inducing a less protective Th17 response. In mouse models, candidate vaccines which provoke a Th1 response can accelerate the clearance of gonococcus from the mouse female genital tract. Human studies indicate that natural infection often induces a limited immune response, with modest antibody responses, which may correlate with the clinical severity of gonococcal disease. Studies of cytokine responses to gonococcal infection in humans provide conflicting evidence as to whether infection induces an IL-17 response. However, there is evidence for limited induction of protective immunity from a study of female sex workers in Kenya. A controlled human infection model (CHIM) has been used to examine the immune response to gonococcal infection in male volunteers, but has not to date demonstrated protection against re-infection. Correlates of protection for gonorrhea are lacking, which has hampered the progress towards developing a successful vaccine. However, the finding that the Neisseria meningitidis serogroup B vaccines, elicit cross-protection against gonorrhea has invigorated the gonococcal vaccine field. More studies of infection in humans, either natural infection or CHIM studies, are needed to understand better gonococcal protective immunity.
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Affiliation(s)
- Thomas Belcher
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Christina Dold
- The Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Jonathan D. C. Ross
- Sexual Health and HIV, University Hospitals Birmingham NHS Trust, Birmingham, United Kingdom
| | - Calman A. MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Gray MC, Thomas KS, Lamb ER, Werner LM, Connolly KL, Jerse AE, Criss AK. Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551882. [PMID: 37577557 PMCID: PMC10418180 DOI: 10.1101/2023.08.03.551882] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as 4CMenB are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here we present assays to evaluate antibody functionality after immunization: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils (polymorphonuclear leukocytes). These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical study and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae .
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8
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Lin EY, Adamson PC, Klausner JD. Epidemiology, Treatments, and Vaccine Development for Antimicrobial-Resistant Neisseria gonorrhoeae: Current Strategies and Future Directions. Drugs 2021; 81:1153-1169. [PMID: 34097283 PMCID: PMC8182353 DOI: 10.1007/s40265-021-01530-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2021] [Indexed: 12/12/2022]
Abstract
Neisseria gonorrhoeae is the second most common bacterial sexually transmitted infection in the world after Chlamydia trachomatis. The pathogen has developed resistance to every antibiotic currently approved for treatment, and multidrug-resistant strains have been identified globally. The current treatment recommended by the World Health Organization is ceftriaxone and azithromycin dual therapy. However, resistance to azithromycin and ceftriaxone are increasing and treatment failures have been reported. As a result, there is a critical need to develop novel strategies for mitigating the spread of antimicrobial-resistant N. gonorrhoeae through improved diagnosis and treatment of resistant infections. Strategies that are currently being pursued include developing molecular assays to predict resistance, utilizing higher doses of ceftriaxone, repurposing older antibiotics, and developing newer agents. In addition, efforts to discover a vaccine for N. gonorrhoeae have been reignited in recent years with the cross-protectivity provided by the N. meningitidis vaccine, with several new strategies and targets. Despite the significant progress that has been made, there is still much work ahead to combat antimicrobial-resistant N. gonorrhoeae globally.
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Affiliation(s)
- Eric Y Lin
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Paul C Adamson
- Division of Infectious Diseases, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave. CHS 52-215, Los Angeles, CA, 90095, USA
| | - Jeffrey D Klausner
- Department of Preventive Medicine, Keck School of Medicine of USC, Los Angeles, CA, USA.
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Jefferson A, Smith A, Fasinu PS, Thompson DK. Sexually Transmitted Neisseria gonorrhoeae Infections-Update on Drug Treatment and Vaccine Development. MEDICINES 2021; 8:medicines8020011. [PMID: 33562607 PMCID: PMC7914478 DOI: 10.3390/medicines8020011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/17/2021] [Accepted: 02/03/2021] [Indexed: 12/15/2022]
Abstract
Background: Sexually transmitted gonorrhea, caused by the Gram-negative diplococcus Neisseria gonorrhoeae, continues to be a serious global health challenge despite efforts to eradicate it. Multidrug resistance among clinical N. gonorrhoeae isolates has limited treatment options, and attempts to develop vaccines have not been successful. Methods: A search of published literature was conducted, and information extracted to provide an update on the status of therapeutics and vaccine development for gonorrheal infection. Results: Recommended pharmacological treatment for gonorrhea has changed multiple times due to increasing acquisition of resistance to existing antibiotics by N. gonorrhoeae. Only broad-spectrum cephalosporin-based combination therapies are currently recommended for treatment of uncomplicated urogenital and anorectal gonococcal infections. With the reported emergence of ceftriaxone resistance, successful strategies addressing the global burden of gonorrhea must include vaccination. Century-old efforts at developing an effective vaccine against gonorrhea, leading to only four clinical trials, have not yielded any successful vaccine. Conclusions: While it is important to continue to explore new drugs for the treatment of gonorrhea, the historical trend of resistance acquisition suggests that any long-term strategy should include vaccine development. Advanced technologies in proteomics and in silico approaches to vaccine target identification may provide templates for future success.
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Affiliation(s)
- Amber Jefferson
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Amanda Smith
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Pius S. Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
| | - Dorothea K. Thompson
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
- Correspondence: ; Tel.: +1-910-893-7463
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Hammond JA, Gordon EA, Socarras KM, Chang Mell J, Ehrlich GD. Beyond the pan-genome: current perspectives on the functional and practical outcomes of the distributed genome hypothesis. Biochem Soc Trans 2020; 48:2437-2455. [PMID: 33245329 PMCID: PMC7752077 DOI: 10.1042/bst20190713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 01/08/2023]
Abstract
The principle of monoclonality with regard to bacterial infections was considered immutable prior to 30 years ago. This view, espoused by Koch for acute infections, has proven inadequate regarding chronic infections as persistence requires multiple forms of heterogeneity among the bacterial population. This understanding of bacterial plurality emerged from a synthesis of what-were-then novel technologies in molecular biology and imaging science. These technologies demonstrated that bacteria have complex life cycles, polymicrobial ecologies, and evolve in situ via the horizontal exchange of genic characters. Thus, there is an ongoing generation of diversity during infection that results in far more highly complex microbial communities than previously envisioned. This perspective is based on the fundamental tenet that the bacteria within an infecting population display genotypic diversity, including gene possession differences, which result from horizontal gene transfer mechanisms including transformation, conjugation, and transduction. This understanding is embodied in the concepts of the supragenome/pan-genome and the distributed genome hypothesis (DGH). These paradigms have fostered multiple researches in diverse areas of bacterial ecology including host-bacterial interactions covering the gamut of symbiotic relationships including mutualism, commensalism, and parasitism. With regard to the human host, within each of these symbiotic relationships all bacterial species possess attributes that contribute to colonization and persistence; those species/strains that are pathogenic also encode traits for invasion and metastases. Herein we provide an update on our understanding of bacterial plurality and discuss potential applications in diagnostics, therapeutics, and vaccinology based on perspectives provided by the DGH with regard to the evolution of pathogenicity.
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Affiliation(s)
- Jocelyn A. Hammond
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, U.S.A
| | - Emma A. Gordon
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, U.S.A
| | - Kayla M. Socarras
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Center for Surgical Infections and Biofilms, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, U.S.A
| | - Joshua Chang Mell
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Meta-omics Shared Resource Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, U.S.A
| | - Garth D. Ehrlich
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Center for Surgical Infections and Biofilms, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, U.S.A
- Meta-omics Shared Resource Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, U.S.A
- Department of Otolaryngology – Head and Neck Surgery, Drexel University College of Medicine, Philadelphia, PA, U.S.A
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Omics and Bioinformatics Approaches to Identify Novel Antigens for Vaccine Investigation and Development. Vaccines (Basel) 2020; 8:vaccines8040653. [PMID: 33153200 PMCID: PMC7711724 DOI: 10.3390/vaccines8040653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 11/02/2020] [Indexed: 12/23/2022] Open
Abstract
Despite the outstanding technological advances achieved in the last few decades, infectious diseases remain a major societal challenge. From the variolation carried out in ancient China during the 15th century to the more advanced RNA and DNA vaccines presently available, vaccines have been proven as highly effective therapeutic tools to combat various infectious diseases. Vaccine research and development is now empowered with recent advances in Omics sciences and the developments of powerful bioinformatics tools. This Special Issue has gathered a total of nine original papers, including seven research papers and two reviews, illustrating the use of Omics data and bioinformatics in the research, design and development of vaccines against pathogens and cancer. The integration of knowledge from Omics and Bioinformatics will certainly boost vaccine research and development, leading to novel therapeutic tools against new and old pathogens and cancer in the near future.
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Semchenko EA, Day CJ, Seib KL. The Neisseria gonorrhoeae Vaccine Candidate NHBA Elicits Antibodies That Are Bactericidal, Opsonophagocytic and That Reduce Gonococcal Adherence to Epithelial Cells. Vaccines (Basel) 2020; 8:E219. [PMID: 32414194 PMCID: PMC7349534 DOI: 10.3390/vaccines8020219] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 11/17/2022] Open
Abstract
Due to the continuing emergence of multidrug resistant strains of Neisseria gonorrhoeae there is an urgent need for the development of a gonococcal vaccine. We evaluated the gonococcal Neisseria heparin binding antigen (NHBA) as a potential vaccine candidate, in terms of its sequence conservation and expression in a range of N. gonorrhoeae strains, as well as its immunogenicity and the functional activity of antibodies raised to either the full length NHBA or a C-terminal fragment of NHBA (NHBA-c). The gene encoding NHBA is highly conserved and expressed in all N. gonorrhoeae strains investigated. Recombinant NHBA is immunogenic, and mice immunized with either NHBA or NHBA-c adjuvanted with either Freund's or aluminium hydroxide (alum) generated a humoral immune response, with predominantly IgG1 antibodies. Antibodies generated by both NHBA and NHBA-c antigens promoted complement activation and mediated bacterial killing via both serum bactericidal activity and opsonophagocytic activity, with slightly higher titers seen for the NHBA-c antigen. Anti-NHBA was also able to block the functional activity of NHBA by reducing binding to heparin and adherence to cervical and urethral epithelial cells. These data suggest that the gonococcal NHBA is a promising vaccine antigen to include in a vaccine to control N. gonorrhoeae.
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Affiliation(s)
| | | | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast 4215, Australia; (E.A.S.); (C.J.D.)
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