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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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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [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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3
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Walker E, van Niekerk S, Hanning K, Kelton W, Hicks J. Mechanisms of host manipulation by Neisseria gonorrhoeae. Front Microbiol 2023; 14:1119834. [PMID: 36819065 PMCID: PMC9935845 DOI: 10.3389/fmicb.2023.1119834] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Neisseria gonorrhoeae (also known as gonococcus) has been causing gonorrhoea in humans since ancient Egyptian times. Today, global gonorrhoea infections are rising at an alarming rate, in concert with an increasing number of antimicrobial-resistant strains. The gonococcus has concurrently evolved several intricate mechanisms that promote pathogenesis by evading both host immunity and defeating common therapeutic interventions. Central to these adaptations is the ability of the gonococcus to manipulate various host microenvironments upon infection. For example, the gonococcus can survive within neutrophils through direct regulation of both the oxidative burst response and maturation of the phagosome; a concerning trait given the important role neutrophils have in defending against invading pathogens. Hence, a detailed understanding of how N. gonorrhoeae exploits the human host to establish and maintain infection is crucial for combating this pathogen. This review summarizes the mechanisms behind host manipulation, with a central focus on the exploitation of host epithelial cell signaling to promote colonization and invasion of the epithelial lining, the modulation of the host immune response to evade both innate and adaptive defenses, and the manipulation of host cell death pathways to both assist colonization and combat antimicrobial activities of innate immune cells. Collectively, these pathways act in concert to enable N. gonorrhoeae to colonize and invade a wide array of host tissues, both establishing and disseminating gonococcal infection.
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Affiliation(s)
- Emma Walker
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - Stacy van Niekerk
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - Kyrin Hanning
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand
| | - William Kelton
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand,Te Aka Mātuatua School of Science, University of Waikato, Hamilton, New Zealand
| | - Joanna Hicks
- Te Huataki Waiora, School of Health, University of Waikato, Hamilton, New Zealand,*Correspondence: Joanna Hicks,
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Bagri P, Anipindi VC, Kaushic C. The Role of IL-17 During Infections in the Female Reproductive Tract. Front Immunol 2022; 13:861444. [PMID: 35493460 PMCID: PMC9046847 DOI: 10.3389/fimmu.2022.861444] [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: 01/24/2022] [Accepted: 03/22/2022] [Indexed: 11/15/2022] Open
Abstract
Interleukin-17 (IL-17A) is a cytokine involved in a complex array of both protective and detrimental processes. Although early biological studies focused on the pro-inflammatory function of IL-17 in the context of autoimmune and inflammatory disorders, it has become increasingly evident that the roles of IL-17 are far more nuanced. Recent work has demonstrated that the functions of IL-17 are highly context- and tissue-dependent, and there is a fine balance between the pathogenic and protective functions of IL-17. This is especially evident in mucosal tissues such as the female reproductive tract, where IL-17 has been shown to play an important role in the immune response generated during fungal, bacterial and viral infections associated with protection, but also with inflammation. In this review, we discuss the evolving landscape of IL-17 biology within the context of the vaginal mucosa, focusing on key findings that highlight the importance of this cytokine in genital mucosal immunity.
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Affiliation(s)
- Puja Bagri
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Varun C. Anipindi
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Charu Kaushic
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- *Correspondence: Charu Kaushic,
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Abstract
Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea. Recently, there has been a surge in gonorrhoea cases that has been exacerbated by the rapid rise in gonococcal multidrug resistance to all useful antimicrobials resulting in this organism becoming a significant public health burden. Therefore, there is a clear and present need to understand the organism's biology through its physiology and pathogenesis to help develop new intervention strategies. The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation. Other adhesion strategies include the porin, PorB, and the phase variable outer membrane protein Opa. The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms. N. gonorrhoeae is a fastidious organism that is able to grow on a limited number of primary carbon sources such as glucose and lactate. The utilization of lactate by the gonococcus has been implicated in a number of pathogenicity mechanisms. The bacterium lives mainly in microaerobic environments and can grow both aerobically and anaerobically with the aid of nitrite. The gonococcus does not produce siderophores for scavenging iron but can utilize some produced by other bacteria, and it is able to successful chelate iron from host haem, transferrin and lactoferrin. The gonococcus is an incredibly versatile human pathogen; in the following chapter, we detail the intricate mechanisms used by the bacterium to invade and survive within the host.
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Affiliation(s)
- Luke R Green
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Joby Cole
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Ernesto Feliz Diaz Parga
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Jonathan G Shaw
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom.
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Duan Q, Carmody C, Donovan B, Guy RJ, Hui BB, Kaldor JM, Lahra MM, Law MG, Lewis DA, Maley M, McGregor S, McNulty A, Selvey C, Templeton DJ, Whiley DM, Regan DG, Wood JG. Modelling response strategies for controlling gonorrhoea outbreaks in men who have sex with men in Australia. PLoS Comput Biol 2021; 17:e1009385. [PMID: 34735428 PMCID: PMC8594806 DOI: 10.1371/journal.pcbi.1009385] [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: 02/07/2021] [Revised: 11/16/2021] [Accepted: 08/26/2021] [Indexed: 11/19/2022] Open
Abstract
The ability to treat gonorrhoea with current first-line drugs is threatened by the global spread of extensively drug resistant (XDR) Neisseria gonorrhoeae (NG) strains. In Australia, urban transmission is high among men who have sex with men (MSM) and importation of an XDR NG strain in this population could result in an epidemic that would be difficult and costly to control. An individual-based, anatomical site-specific mathematical model of NG transmission among Australian MSM was developed and used to evaluate the potential for elimination of an imported NG strain under a range of case-based and population-based test-and-treat strategies. When initiated upon detection of the imported strain, these strategies enhance the probability of elimination and reduce the outbreak size compared with current practice (current testing levels and no contact tracing). The most effective strategies combine testing targeted at regular and casual partners with increased rates of population testing. However, even with the most effective strategies, outbreaks can persist for up to 2 years post-detection. Our simulations suggest that local elimination of imported NG strains can be achieved with high probability using combined case-based and population-based test-and-treat strategies. These strategies may be an effective means of preserving current treatments in the event of wider XDR NG emergence. In most high-income settings, gonorrhoea is endemic among men who have sex with men (MSM). While gonorrhoea remains readily treatable with antibiotics, there are major concerns about the threat of antimicrobial resistance arising from recent reports of treatment failure with first-line therapy and limited remaining treatment options. Here we investigated the potential for test-and-treat response strategies to eliminate such strains before their prevalence reaches a level requiring a shift to new first line therapies. Rather than directly consider resistance, we explore the mitigating effect of various test-and-treat measures on outbreaks of a generic imported strain which remains treatable. This is done within the framework of a realistic mathematical model of gonorrhoea spread in an MSM community that captures cases, anatomical sites of infection and sexual contacts at an individual level, calibrated to relevant Australian epidemiological data. The results indicate that strategies such as partner testing and treatment in combination with elevated asymptomatic community testing are highly effective in mitigating outbreaks but can take up to 2 years to achieve elimination. As there are currently no clear alternative drugs of proven efficacy and safety to replace ceftriaxone in first-line therapy, these promising results suggest potential for use of these outbreak response strategies to preserve current treatment recommendations.
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Affiliation(s)
- Qibin Duan
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- The Kirby Institute, UNSW Sydney, Sydney, Australia
| | - Chris Carmody
- Liverpool Sexual Health Clinic, South Western Sydney Local Health District, Sydney, Australia
- Western Sydney University, Sydney, Australia
| | - Basil Donovan
- The Kirby Institute, UNSW Sydney, Sydney, Australia
- Sydney Sexual Health Centre, South Eastern Sydney Local Health District, Sydney, Australia
| | | | - Ben B. Hui
- The Kirby Institute, UNSW Sydney, Sydney, Australia
| | | | - Monica M. Lahra
- Microbiology Department, New South Wales Health Pathology, The Prince of Wales Hospital, Sydney, Australia
- School of Medical Sciences, UNSW Sydney, Sydney, Australia
| | | | - David A. Lewis
- Western Sydney Sexual Health Centre, Western Sydney Local Health District, Sydney, Australia
- Westmead Clinical School, Faculty of Health and Medicine & Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, Australia
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Michael Maley
- Department of Microbiology and Infectious Diseases, Liverpool Hospital, Sydney, Australia
- South Western Clinical School, UNSW Sydney, Sydney, Australia
| | | | - Anna McNulty
- Sydney Sexual Health Centre, South Eastern Sydney Local Health District, Sydney, Australia
- School of Population Health, UNSW Sydney, Sydney, Australia
| | - Christine Selvey
- Communicable Diseases Branch, Health Protection NSW, Sydney, Australia
| | - David J. Templeton
- The Kirby Institute, UNSW Sydney, Sydney, Australia
- Department of Sexual Health Medicine, Sydney Local Health District and Discipline of Medicine, Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - David M. Whiley
- Centre for Clinical Research, University of Queensland, Brisbane, Australia
| | | | - James G. Wood
- School of Population Health, UNSW Sydney, Sydney, Australia
- * E-mail:
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Russell MW. Immune Responses to Neisseria gonorrhoeae: Challenges and Opportunities With Respect to Pelvic Inflammatory Disease. J Infect Dis 2021; 224:S96-S102. [PMID: 34396399 DOI: 10.1093/infdis/jiaa766] [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: 11/14/2022] Open
Abstract
Pelvic inflammatory disease and infertility frequently develop after female genital tract infection with Neisseria gonorrhoeae, but determining their etiology from among various possibilities presents difficulties. Exploitation of serology to identify the causative agent is complicated by numerous factors, and no immunological test currently exists to determine unequivocally whether an individual currently is, or has been, infected with N. gonorrhoeae. The extensive antigenic variability of N. gonorrhoeae and its expression of antigens shared with other Neisseria species commonly carried in humans render problematic an assay that is specific for all gonococcal strains. However, novel conserved gonococcal antigens identified for potential vaccines may find additional application in diagnostic assays. N. gonorrhoeae also interferes with the adaptive immune response, and antibody responses to uncomplicated infection are usually weak. Elucidating the mechanisms whereby N. gonorrhoeae manipulates the human immune system may lead to improved understanding of the pathogenesis of pelvic inflammatory disease and infertility.
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Affiliation(s)
- Michael W Russell
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
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Haese EC, Thai VC, Kahler CM. Vaccine Candidates for the Control and Prevention of the Sexually Transmitted Disease Gonorrhea. Vaccines (Basel) 2021; 9:vaccines9070804. [PMID: 34358218 PMCID: PMC8310131 DOI: 10.3390/vaccines9070804] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/14/2021] [Accepted: 07/17/2021] [Indexed: 11/25/2022] Open
Abstract
The World Health Organization (WHO) has placed N. gonorrhoeae on the global priority list of antimicrobial resistant pathogens and is urgently seeking the development of new intervention strategies. N. gonorrhoeae causes 86.9 million cases globally per annum. The effects of gonococcal disease are seen predominantly in women and children and especially in the Australian Indigenous community. While economic modelling suggests that this infection alone may directly cost the USA health care system USD 11.0–20.6 billion, indirect costs associated with adverse disease and pregnancy outcomes, disease prevention, and productivity loss, mean that the overall effect of the disease is far greater still. In this review, we summate the current progress towards the development of a gonorrhea vaccine and describe the clinical trials being undertaken in Australia to assess the efficacy of the current formulation of Bexsero® in controlling disease.
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Distinct Patterns of Host Adherence by Neisseria gonorrhoeae Isolated from Experimental Gonorrhea. ACTA ACUST UNITED AC 2021; 2021:7865405. [PMID: 34093925 PMCID: PMC8140856 DOI: 10.1155/2021/7865405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 03/30/2021] [Accepted: 04/03/2021] [Indexed: 12/29/2022]
Abstract
Neisseria gonorrhoeae (N. gonorrhoeae, gonococci, or GC), the etiologic agent of gonorrhea, is a human-obligate bacterial pathogen. The GC surface contains pili that mediate the adherence to host cells. Studies have shown that GC pili, coded by pilin genes, undergo remarkable changes during human experimental gonorrhea, possibly generated by DNA phase variation during infection. The question that arises is whether the changes in pilins can alter the adherence capacity of N. gonorrhoeae to host cells. In this study, six variants initially isolated from male volunteers infected with one single clone of GC were examined for their adherence patterns with human Chang conjunctiva cells. In this study, we showed that the variants showed distinct adherence patterns to this cell line under light microscopy and scanning electron microscopy. Moreover, two reisolates showed higher adherence capacities than that of the input strain. The results provide an additional example as to how the pilus variation may play a role in the pathogenesis of N. gonorrhoeae.
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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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Ayinde O, Ross JDC. Time to resolution of genital symptoms for uncomplicated gonorrhoea: a prospective cohort study. Sex Transm Infect 2020; 97:368-374. [PMID: 32829308 DOI: 10.1136/sextrans-2020-054626] [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: 05/29/2020] [Revised: 07/10/2020] [Accepted: 07/26/2020] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES To determine the time to resolution of symptoms (TTR) following treatment of uncomplicated gonorrhoea and to identify factors associated with TTR in a cohort of sexual health clinic attendees. METHODS Participants were recruited from 14 clinics across England into the 'Gentamicin for the Treatment of Gonorrhoea (GToG)' trial between October 2014 and November 2016. We analysed demographic, behavioural and clinical data in a subset of the GToG study cohort presenting with genital discharge and/or dysuria, who subsequently experienced microbiological clearance of Neisseria gonorrhoeae 2 weeks after treatment. Testing for gonorrhoea was performed using a nucleic acid amplification test. The results were expressed as median TTR (IQR) and HRs with 95% CIs for resolution of symptoms. RESULTS 216 participants (89% male) with a mean age of 32 years reported genital discharge (204/216 (94%)) or dysuria (173/216 (80%)) at their baseline visit. Symptom resolution occurred in 202/216 (94%) at the 2-week follow-up appointment. The median TTR was 2 days (IQR 1-3 days). 50/216 (23%) patients presented with gonorrhoea-chlamydia coinfection at their baseline attendance and in this group symptom resolution was slower (3 days for gonorrhoea-chlamydia coinfection compared with 2 days for gonorrhoea only, HR 0.68 (95% CI 0.48 to 0.95)). TTR was also longer in women (4 days for females compared with 2 days for males, HR 0.47 (95% CI 0.29 to 0.77)). CONCLUSIONS The time to resolution of genital symptoms following effective treatment of gonorrhoea is variable, but 90% of patients report symptom resolution within 1 week. Concurrent chlamydia infection and being female were associated with prolonged TTR.
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Affiliation(s)
- Oluseyi Ayinde
- Department of Sexual Health and HIV, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Jonathan D C Ross
- Department of Sexual Health and HIV, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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Mensforth S, Ayinde OC, Ross J. Spontaneous clearance of genital and extragenital Neisseria gonorrhoeae: data from GToG. Sex Transm Infect 2020; 96:556-561. [PMID: 32732336 DOI: 10.1136/sextrans-2020-054500] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/11/2020] [Accepted: 06/16/2020] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Neisseria gonorrhoeae (NG) infection can resolve without antibiotic treatment, however the literature describing the frequency of clearance at individual sites, how rapidly it occurs and potential predictive factors is limited. In this analysis of a subpopulation identified from a large multicentre UK cohort, we describe the overall rate of spontaneous clearance of infection and explore factors associated with this. METHODS Data from the Gentamicin compared with Ceftriaxone for the Treatment of Gonorrhoea randomised controlled trial consisting of 720 patients with NG were analysed. A subgroup of individuals had both a pretrial test sample and a trial enrolment sample taken. Those who had cleared NG between initial presentation and subsequent entry into the trial without antibiotic treatment were deemed to have spontaneously cleared. Sociodemographic characteristics, sexual history and sites of infection for those who spontaneously cleared infection were compared with that of those who did not. We also estimated the time interval to clearance. RESULTS Overall, the proportion who had spontaneous clearance was 20.5% (83/405). Clearance of infection occurred over a median of 10 days (IQR 7-15 days). The cohort who spontaneously cleared were similar to those who did not in terms of age, gender, sexual orientation, HIV status and previous NG infection. Chlamydia coinfection was more frequent in the 'no spontaneous clearance group' (11.1% (9/83) cf 22.0% (69/322)) (p=0.029). Dysuria was reported more often in the 'no spontaneous clearance group' (4.8% (4/83) cf 13.0% (42/322)) (p=0.035). CONCLUSION We present data from a large cohort of NG-infected individuals, of whom a significant proportion had spontaneous clearance of infection. This is consistent with previous smaller studies. If this is indicative of cure, point-of-care testing prior to treatment has the potential to reduce unnecessary exposure to antimicrobials. Further work to assess the importance of bacterial load, genotype and host immune response on spontaneous clearance of infection is required. TRIAL REGISTRATION NUMBER ISRCTN51783227.
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Affiliation(s)
- Sarah Mensforth
- Department of Sexual Health and HIV, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Oluseyi Cyril Ayinde
- Department of Sexual Health and HIV, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Jonathan Ross
- Department of Sexual Health and HIV, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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Yadav R, Noinaj N, Ostan N, Moraes T, Stoudenmire J, Maurakis S, Cornelissen CN. Structural Basis for Evasion of Nutritional Immunity by the Pathogenic Neisseriae. Front Microbiol 2020; 10:2981. [PMID: 31998268 PMCID: PMC6965322 DOI: 10.3389/fmicb.2019.02981] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/10/2019] [Indexed: 12/17/2022] Open
Abstract
The pathogenic Neisseria species are human-adapted pathogens that cause quite distinct diseases. Neisseria gonorrhoeae causes the common sexually transmitted infection gonorrhea, while Neisseria meningitidis causes a potentially lethal form of bacterial meningitis. During infection, both pathogens deploy a number of virulence factors in order to thrive in the host. The focus of this review is on the outer membrane transport systems that enable the Neisseriae to utilize host-specific nutrients, including metal-binding proteins such as transferrin and calprotectin. Because acquisition of these critical metals is essential for growth and survival, understanding the structures of receptor-ligand complexes may be an important step in developing preventative or therapeutic strategies focused on thwarting these pathogens. Much can also be learned by comparing structures with antigenic diversity among the transporter sequences, as conserved functional domains in these essential transporters could represent the pathogens' "Achilles heel." Toward this goal, we present known or modeled structures for the transport systems produced by the pathogenic Neisseria species, overlapped with sequence diversity derived by comparing hundreds of neisserial protein sequences. Given the concerning increase in N. gonorrhoeae incidence and antibiotic resistance, these outer membrane transport systems appear to be excellent targets for new therapies and preventative vaccines.
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Affiliation(s)
- Ravi Yadav
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, United States
| | - Nicholas Noinaj
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, United States
| | - Nicholas Ostan
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Trevor Moraes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Julie Stoudenmire
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, United States
| | - Stavros Maurakis
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, United States
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14
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Clow F, O’Hanlon CJ, Christodoulides M, Radcliff FJ. Feasibility of Using a Luminescence-Based Method to Determine Serum Bactericidal Activity against Neisseria gonorrhoeae. Vaccines (Basel) 2019; 7:vaccines7040191. [PMID: 31766474 PMCID: PMC6963289 DOI: 10.3390/vaccines7040191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/12/2019] [Accepted: 11/19/2019] [Indexed: 01/15/2023] Open
Abstract
Development of a vaccine to limit the impact of antibiotic resistant Neisseria gonorrhoeae is now a global priority. Serum bactericidal antibody (SBA) is a possible indicator of protective immunity to N. gonorrhoeae, but conventional assays measure colony forming units (CFU), which is time-consuming. A luminescent assay that quantifies ATP as a surrogate measure of bacterial viability was tested on N. gonorrhoeae strains FA1090, MS11 and P9-17 and compared to CFU-based readouts. There was a linear relationship between CFU and ATP levels for all three strains (r > 0.9). Normal human serum (NHS) is a common source of complement for SBA assays, but needs to be screened for non-specific bactericidal activity. NHS from 10 individuals were used for serum sensitivity assays-sensitivity values were significantly reduced with the ATP method for FA1090 (5/10, p < 0.05) and MS11 (10/10, p < 0.05), whereas P9-17 data were comparable for all donors. Our results suggest that measuring ATP underestimates serum sensitivity of N. gonorrhoeae and that the CFU method is a better approach. However, mouse anti-P9-17 outer membrane vesicles (OMV) SBA titres to P9-17 were comparable with both methods (r = 0.97), suggesting this assay can be used to rapidly screen sera for bactericidal antibodies to gonococci.
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Affiliation(s)
- Fiona Clow
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (F.C.); (C.J.O.)
| | - Conor J O’Hanlon
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (F.C.); (C.J.O.)
| | - Myron Christodoulides
- Faculty of Medicine, Academic Unit of Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, University of Southampton, Southampton SO166YD, UK;
| | - Fiona J Radcliff
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (F.C.); (C.J.O.)
- Correspondence: ; Tel.: +64-9923-6272
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15
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Russell MW, Jerse AE, Gray-Owen SD. Progress Toward a Gonococcal Vaccine: The Way Forward. Front Immunol 2019; 10:2417. [PMID: 31681305 PMCID: PMC6803597 DOI: 10.3389/fimmu.2019.02417] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/27/2019] [Indexed: 12/26/2022] Open
Abstract
The concept of immunizing against gonorrhea has received renewed interest because of the recent emergence of strains of Neisseria gonorrhoeae that are resistant to most currently available antibiotics, an occurrence that threatens to render gonorrhea untreatable. However, despite efforts over many decades, no vaccine has yet been successfully developed for human use, leading to pessimism over whether this goal was actually attainable. Several factors have contributed to this situation, including extensive variation of the expression and specificity of many of the gonococcal surface antigens, and the ability of N. gonorrhoeae to resist destruction by complement and other innate immune defense mechanisms. The natural host restriction of N. gonorrhoeae for humans, coupled with the absence of any definable state of immunity arising from an episode of gonorrhea, have also complicated efforts to study gonococcal pathogenesis and the host's immune responses. However, recent findings have elucidated how the gonococcus exploits and manipulates the host's immune system for its own benefit, utilizing human-specific receptors for attachment to and invasion of tissues, and subverting adaptive immune responses that might otherwise be capable of eliminating it. While no single experimental model is capable of providing all the answers, experiments utilizing human cells and tissues in vitro, various in vivo animal models, including genetically modified strains of mice, and both experimental and observational human clinical studies, have combined to yield important new insight into the immuno-pathogenesis of gonococcal infection. In turn, these have now led to novel approaches for the development of a gonococcal vaccine. Ongoing investigations utilizing all available tools are now poised to make the development of an effective human vaccine against gonorrhea an achievable goal within a foreseeable time-frame.
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Affiliation(s)
- Michael W. Russell
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, NY, United States
| | - Ann E. Jerse
- Department of Microbiology and Immunology, F. Edward Herbert School of Medicine, Uniformed Services University, Bethesda, MD, United States
| | - Scott D. Gray-Owen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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16
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Lovett A, Duncan JA. Human Immune Responses and the Natural History of Neisseria gonorrhoeae Infection. Front Immunol 2019; 9:3187. [PMID: 30838004 PMCID: PMC6389650 DOI: 10.3389/fimmu.2018.03187] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 12/31/2018] [Indexed: 11/13/2022] Open
Abstract
The intimate relationship between humans and Neisseria gonorrhoeae infections span centuries, which is evidenced in case reports from studies dating back to the late 1700s and historical references that predate medical literature. N. gonorrhoeae is an exclusive human pathogen that infects the genital tract of both men and women as well as other mucosal surfaces including the oropharynx and rectum. In symptomatic infections, N. gonorrhoeae induces a robust inflammatory response at the site of infection. However, infections can also present asymptomatically complicating efforts to reduce transmission. N. gonorrhoeae infections have been effectively treated with antibiotics since their use was introduced in humans. Despite the existence of effective antibiotic treatments, N. gonorrhoeae remains one of the most common sexually transmitted pathogens and antibiotic resistant strains have arisen that limit treatment options. Development of a vaccine to prevent infection is considered a critical element of controlling this pathogen. The efforts to generate an effective gonococcal vaccine is limited by our poor understanding of the natural immunologic responses to infection. It is largely accepted that natural protective immunity to N. gonorrhoeae infections in humans does not occur or is very rare. Previous studies of the natural history of infection as well as some of the humoral and cellular immune responses to infection offer a window into the issues surrounding N. gonorrhoeae vaccine development. In this review, we summarize the current body of knowledge pertaining to human immune responses to gonococcal infections and the role of these responses in mediating protection from N. gonorrhoeae.
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Affiliation(s)
- Angela Lovett
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Joseph A Duncan
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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17
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Vincent LR, Jerse AE. Biological feasibility and importance of a gonorrhea vaccine for global public health. Vaccine 2018; 37:7419-7426. [PMID: 29680200 PMCID: PMC6892272 DOI: 10.1016/j.vaccine.2018.02.081] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/05/2018] [Accepted: 02/19/2018] [Indexed: 02/06/2023]
Abstract
78 million new infections annually; greatest impact on women and neonates in LMIC. Current control measures are inadequate and challenged by antibiotic resistance. Conserved candidate vaccine antigens and adjuvant strategies are being developed. There is a need for human studies to investigate correlates of immunity. A meningococcal outer membrane vesicle vaccine may protect against gonorrhea.
There is a growing public health interest in controlling sexually transmitted infections (STIs) through vaccination due to increasing recognition of the global disease burden of STIs and the role of STIs in women’s reproductive health, adverse pregnancy outcomes, and the health and well-being of neonates. Neisseria gonorrhoeae has historically challenged vaccine development through the expression of phase and antigenically variable surface molecules and its capacity to cause repeated infections without inducing protective immunity. An estimated 78 million new N. gonorrhoeae infections occur annually and the greatest disease burden is carried by low- and middle-income countries (LMIC). Current control measures are clearly inadequate and threatened by the rapid emergence of antibiotic resistance. The gonococcus now holds the status of “super-bug” as there is currently no single reliable monotherapy for empirical treatment of gonorrhea. The problem of antibiotic resistance has elevated treatment costs and necessitated the establishment of large surveillance programs to track the spread of resistant strains. Here we review the need for a gonorrhea vaccine with respect to global disease burden and related socioeconomic and treatment costs, with an emphasis on the impact of gonorrhea on women and newborns. We also highlight the challenge of estimating the impact of a gonorrhea vaccine due to the need for more data on the burden of gonococcal pelvic inflammatory disease and related sequelae and of gonorrhea-associated adverse pregnancy outcomes and the problem of empirical diagnosis and treatment of STIs in LMIC. There is also a lack of clinical and basic science research in the area of gonococcal/chlamydia coinfection, which occurs in a high percentage of individuals with gonorrhea and should be considered when testing the efficacy of gonorrhea vaccines. Finally, we review recent research that suggests a gonorrhea vaccine is feasible and discuss challenges and research gaps in gonorrhea vaccine development.
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Affiliation(s)
- Leah R Vincent
- National Institute of Allergy and Infectious Diseases, 5601 Fishers Lane, Rockville, MD 20852, United States.
| | - Ann E Jerse
- Department of Microbiology and Immunology F. Edward Herbert School of Medicine, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20854, United States.
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18
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Abstract
The host-adapted human pathogen Neisseria gonorrhoeae is the causative agent of gonorrhoea. Consistent with its proposed evolution from an ancestral commensal bacterium, N. gonorrhoeae has retained features that are common in commensals, but it has also developed unique features that are crucial to its pathogenesis. The continued worldwide incidence of gonorrhoeal infection, coupled with the rising resistance to antimicrobials and the difficulties in controlling the disease in developing countries, highlights the need to better understand the molecular basis of N. gonorrhoeae infection. This knowledge will facilitate disease prevention, surveillance and control, improve diagnostics and may help to facilitate the development of effective vaccines or new therapeutics. In this Review, we discuss sex-related symptomatic gonorrhoeal disease and provide an overview of the bacterial factors that are important for the different stages of pathogenesis, including transmission, colonization and immune evasion, and we discuss the problem of antibiotic resistance.
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Affiliation(s)
- Sarah Jane Quillin
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - H Steven Seifert
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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19
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Cornelissen CN. Subversion of nutritional immunity by the pathogenic Neisseriae. Pathog Dis 2018; 76:4553517. [PMID: 29045638 PMCID: PMC6251569 DOI: 10.1093/femspd/ftx112] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022] Open
Abstract
The pathogenic Neisseria species, including Neisseria meningitidis and Neisseria gonorrhoeae, are obligate human pathogens that cause significant morbidity and mortality. The success of these pathogens, with regard to causing disease in humans, is inextricably linked to their ability to acquire necessary nutrients in the hostile environment of the host. Humans deploy a significant arsenal of weaponry to defend against bacterial pathogens, not least of which are the metal-sequestering proteins that entrap and withhold transition metals, including iron, zinc and manganese, from invaders. This review will discuss the general strategies that bacteria employ to overcome these metal-sequestering attempts by the host, and then will focus on the relatively uncommon 'metal piracy' approaches utilized by the pathogenic Neisseria for this purpose. Because acquiring metals from the environment is critical to microbial survival, interfering with this process could impede growth and therefore disease initiation or progression. This review will also discuss how interfering with metal uptake by the pathogenic Neisseriae could be deployed in the development of novel or improved preventative or therapeutic measures against these important pathogens.
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Affiliation(s)
- Cynthia Nau Cornelissen
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Box 980678, Richmond, VA 23298-0678, USA
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20
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Liu Y, Hammer LA, Liu W, Hobbs MM, Zielke RA, Sikora AE, Jerse AE, Egilmez NK, Russell MW. Experimental vaccine induces Th1-driven immune responses and resistance to Neisseria gonorrhoeae infection in a murine model. Mucosal Immunol 2017; 10:1594-1608. [PMID: 28272393 PMCID: PMC5591041 DOI: 10.1038/mi.2017.11] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/23/2017] [Indexed: 02/04/2023]
Abstract
Female mice were immunized intravaginally with gonococcal outer membrane vesicles (OMVs) plus microencapsulated interleukin-12 (IL-12), and challenged using an established model of genital infection with Neisseria gonorrhoeae. Whereas sham-immunized and control animals cleared the infection in 10-13 days, those immunized with OMV plus IL-12 cleared infection with homologous gonococcal strains in 6-9 days. Significant protection was also seen after challenge with antigenically distinct strains of N. gonorrhoeae, and protective anamnestic immunity persisted for at least 6 months after immunization. Serum and vaginal immunoglobulin G (IgG) and IgA antibodies were generated against antigens expressed by homologous and heterologous strains. Iliac lymph node CD4+ T cells secreted interferon-γ (IFNγ), but not IL-4, in response to immunization, and produced IL-17 in response to challenge regardless of immunization. Antigens recognized by immunized mouse serum included several shared between gonococcal strains, including two identified by immunoproteomics approaches as elongation factor-Tu (EF-Tu) and PotF3. Experiments with immunodeficient mice showed that protective immunity depended upon IFNγ and B cells, presumably to generate antibodies. The results demonstrated that immunity to gonococcal infection can be induced by immunization with a nonliving gonococcal antigen, and suggest that efforts to develop a human vaccine should focus on strategies to generate type 1 T helper cell (Th1)-driven immune responses in the genital tract.
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Affiliation(s)
- Yingru Liu
- TherapyX, Inc., Buffalo, NY, USA,Department of Microbiology and Immunology, University at Buffalo, Buffalo, NY, USA
| | | | - Wensheng Liu
- Department of Pediatrics, Digestive Diseases and Nutrition Center, University at Buffalo, Buffalo, NY, USA
| | - Marcia M. Hobbs
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR, USA
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR, USA
| | - Ann E. Jerse
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Nejat K. Egilmez
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, USA
| | - Michael W. Russell
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, NY, USA
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21
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Knilans KJ, Hackett KT, Anderson JE, Weng C, Dillard JP, Duncan JA. Neisseria gonorrhoeae Lytic Transglycosylases LtgA and LtgD Reduce Host Innate Immune Signaling through TLR2 and NOD2. ACS Infect Dis 2017; 3:624-633. [PMID: 28585815 DOI: 10.1021/acsinfecdis.6b00088] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Neisseria gonorrhoeae releases anhydro peptidoglycan monomers during growth through the action of two lytic transglycosylases encoded in the N. gonorrhoeae genome, LtgA and LtgD. Because peptidoglycan and peptidoglycan components activate innate immune signaling, we hypothesized that the activity of LtgA and LtgD would influence the host responses to gonococcal infection. N. gonorrhoeae lacking LtgA and LtgD caused increased host production of inflammatory cytokines IL-1β and TNF-α. Culture supernatants from ΔltgA/ΔltgD N. gonorrhoeae contain more shed outer membrane-associated proteins and multimeric peptidoglycan fragments rather than monomers. These culture supernatants were more potent activators of host TLR2 and NOD2 signaling when compared to supernatants from the isogenic parental N. gonorrhoeae strain. Purified peptidoglycan monomers containing anhydro muramic acid produced by LtgA were poor stimulators of NOD2, whereas peptidoglycan monomers containing reducing muramic acid produced by host lysozyme were potent stimulators of NOD2. These data indicate that LtgA and LtgD reduce recognition of N. gonorrhoeae by TLR2 and NOD2.
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Affiliation(s)
- Kayla J. Knilans
- Department
of Pharmacology, University of North Carolina—Chapel Hill School of Medicine, 4009 Genetic
Medicine Building, 120 Mason Farm Road, Chapel Hill, North Carolina 27599-7365, United States
| | - Kathleen T. Hackett
- Department
of Medical Microbiology and Immunology, University of Wisconsin—Madison School of Medicine and Public Health, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - James E. Anderson
- Division
of Infectious Diseases, Department of Medicine, University of North Carolina—Chapel Hill School of Medicine, Bioinformatics Building, 130 Mason
Farm Road, Chapel Hill, North
Carolina 27599-7030, United States
| | - Chengyu Weng
- Department
of Pharmacology, University of North Carolina—Chapel Hill School of Medicine, 4009 Genetic
Medicine Building, 120 Mason Farm Road, Chapel Hill, North Carolina 27599-7365, United States
| | - Joseph P. Dillard
- Department
of Medical Microbiology and Immunology, University of Wisconsin—Madison School of Medicine and Public Health, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Joseph A. Duncan
- Division
of Infectious Diseases, Department of Medicine, University of North Carolina—Chapel Hill School of Medicine, Bioinformatics Building, 130 Mason
Farm Road, Chapel Hill, North
Carolina 27599-7030, United States
- Lineberger
Comprehensive Cancer Center, University of North Carolina—Chapel Hill School of Medicine, 450 West Drive, Chapel Hill, North Carolina 27599-7295, United States
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22
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Shewell LK, Jen FEC, Jennings MP. Refinement of immunizing antigens to produce functional blocking antibodies against the AniA nitrite reductase of Neisseria gonorrhoeae. PLoS One 2017; 12:e0182555. [PMID: 28771632 PMCID: PMC5542605 DOI: 10.1371/journal.pone.0182555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/20/2017] [Indexed: 01/16/2023] Open
Abstract
The emergence of multi-drug resistant Neisseria gonorrhoeae has generated an urgent need for novel therapies or a vaccine to prevent gonococcal disease. In this study we investigate the potential of targeting the surface exposed nitrite reductase, AniA, to block activity by producing functional blocking antibodies. AniA activity is essential for anaerobic growth and biofilm formation of N. gonorrhoeae and functional blocking antibodies may prevent colonisation and disease. Seven peptides covering regions adjacent to the active site were designed based on the AniA structure. Six of the seven peptide conjugates generated immune responses. Peptide 7, GALGQLKVEGAEN, was able to elicit antibodies capable of blocking AniA activity. Antiserum raised against the peptide 7 conjugate detected AniA in 20 N. gonorrhoeae clinical isolates. Recombinant AniA protein antigens were also assessed in this study and generated high-titre, functional blocking antibody responses. Peptide 7 conjugates or truncated recombinant AniA antigens have potential for inclusion in a vaccine against N. gonorrhoeae.
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Affiliation(s)
- Lucy K. Shewell
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Freda E.-C Jen
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
- * E-mail:
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23
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Edwards JL, Jennings MP, Apicella MA, Seib KL. Is gonococcal disease preventable? The importance of understanding immunity and pathogenesis in vaccine development. Crit Rev Microbiol 2016; 42:928-41. [PMID: 26805040 PMCID: PMC4958600 DOI: 10.3109/1040841x.2015.1105782] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/01/2015] [Accepted: 10/06/2015] [Indexed: 12/31/2022]
Abstract
Gonorrhea is a major, global public health problem for which there is no vaccine. The continuing emergence of antibiotic-resistant strains raises concerns that untreatable Neisseria gonorrhoeae may become widespread in the near future. Consequently, there is an urgent need for increased efforts towards the development of new anti-gonococcal therapeutics and vaccines, as well as suitable models for potential pre-clinical vaccine trials. Several current issues regarding gonorrhea are discussed herein, including the global burden of disease, the emergence of antibiotic-resistance, the status of vaccine development and, in particular, a focus on the model systems available to evaluate drug and vaccine candidates. Finally, alternative approaches to evaluate vaccine candidates are presented. Such approaches may provide valuable insights into the protective mechanisms, and correlates of protection, required to prevent gonococcal transmission, local infection and disease sequelae.
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Affiliation(s)
- Jennifer L. Edwards
- Department of Pediatrics, The Research Institute at Nationwide Children's Hospital and The Ohio State UniversityColumbus,
OH,
USA
| | | | | | - Kate L. Seib
- Institute for Glycomics, Griffith University,
Gold Coast,
Australia
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24
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ATP Induces IL-1 β Secretion in Neisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis. Mediators Inflamm 2016; 2016:1258504. [PMID: 27803513 PMCID: PMC5075643 DOI: 10.1155/2016/1258504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 08/12/2016] [Accepted: 09/06/2016] [Indexed: 12/24/2022] Open
Abstract
Neisseria gonorrhoeae (Ngo) has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1β secretion of infected human monocyte-derived macrophages (MDM). Here, we investigate the role of adenosine triphosphate (ATP) in production and release of IL-1β in Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1β levels about ten times compared with unexposed Ngo-infected MDM (P < 0.01). However, we did not observe any changes in inflammasome transcriptional activation of speck-like protein containing a caspase recruitment domain (CARD) (ASC, P > 0.05) and caspase-1 (CASP1, P > 0.05). In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P > 0.01). Notably ATP treatment defined an increase of positive staining for IL-1β with a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1β secretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.
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25
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Hill SA, Masters TL, Wachter J. Gonorrhea - an evolving disease of the new millennium. MICROBIAL CELL (GRAZ, AUSTRIA) 2016; 3:371-389. [PMID: 28357376 PMCID: PMC5354566 DOI: 10.15698/mic2016.09.524] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 01/30/2016] [Indexed: 12/21/2022]
Abstract
Etiology, transmission and protection: Neisseria gonorrhoeae (the gonococcus) is the etiological agent for the strictly human sexually transmitted disease gonorrhea. Infections lead to limited immunity, therefore individuals can become repeatedly infected. Pathology/symptomatology: Gonorrhea is generally a non-complicated mucosal infection with a pustular discharge. More severe sequellae include salpingitis and pelvic inflammatory disease which may lead to sterility and/or ectopic pregnancy. Occasionally, the organism can disseminate as a bloodstream infection. Epidemiology, incidence and prevalence: Gonorrhea is a global disease infecting approximately 60 million people annually. In the United States there are approximately 300, 000 cases each year, with an incidence of approximately 100 cases per 100,000 population. Treatment and curability: Gonorrhea is susceptible to an array of antibiotics. Antibiotic resistance is becoming a major problem and there are fears that the gonococcus will become the next "superbug" as the antibiotic arsenal diminishes. Currently, third generation extended-spectrum cephalosporins are being prescribed. Molecular mechanisms of infection: Gonococci elaborate numerous strategies to thwart the immune system. The organism engages in extensive phase (on/off switching) and antigenic variation of several surface antigens. The organism expresses IgA protease which cleaves mucosal antibody. The organism can become serum resistant due to its ability to sialylate lipooligosaccharide in conjunction with its ability to subvert complement activation. The gonococcus can survive within neutrophils as well as in several other lymphocytic cells. The organism manipulates the immune response such that no immune memory is generated which leads to a lack of protective immunity.
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Affiliation(s)
- Stuart A. Hill
- Department of Epidemiology, Gillings School of Global Public Health,
University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7435
| | - Thao L. Masters
- Department of Epidemiology, Gillings School of Global Public Health,
University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7435
| | - Jenny Wachter
- Department of Epidemiology, Gillings School of Global Public Health,
University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7435
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Kandler JL, Acevedo RV, Dickinson MK, Cash DR, Shafer WM, Cornelissen CN. The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions. Mol Microbiol 2016; 102:137-51. [PMID: 27353397 DOI: 10.1111/mmi.13450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 01/01/2023]
Abstract
Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.
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Affiliation(s)
- Justin L Kandler
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia
| | - Rosuany Vélez Acevedo
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Mary Kathryne Dickinson
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Devin R Cash
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Medical Center, Laboratories of Microbial Pathogenesis, Decatur, Georgia
| | - Cynthia Nau Cornelissen
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia.
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The reproductive cycle is a pathogenic determinant during gonococcal pelvic inflammatory disease in mice. Mucosal Immunol 2016; 9:1051-64. [PMID: 26693700 PMCID: PMC4915993 DOI: 10.1038/mi.2015.122] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 10/08/2015] [Indexed: 02/04/2023]
Abstract
Women with asymptomatic Neisseria gonorrhoeae infection are at risk of developing pelvic inflammatory disease (PID) if the bacteria ascend from the endocervix into the uterus and oviducts. Factors that affect disease severity, ranging from mild discomfort to severe inflammation, pain, and infertility, remain elusive. Herein we perform direct transcervical inoculation of N. gonorrhoeae into the uterus of mice to establish an infection that leads to PID. Profoundly different disease outcomes were apparent at different stages of the reproductive cycle. Mice that were infected during the diestrus stage of the reproductive cycle displayed extensive gonococcal penetration into the submucosa, severe inflammation, and clinical signs reflecting discomfort. Meanwhile, infection during the intervening estrus stage showed only modest effects. Furthermore, a gonococcal-specific humoral response was only elicited following the penetrative upper genital tract (UGT) infection during diestrus but not estrus. Strikingly, the potential for antibodies to contribute to protection during re-infection also depends upon the reproductive stage, as antigonococcal antibodies within the genital tract were markedly higher when mice were in diestrus. Combined, this work establishes a robust new model reflecting gonococcal PID in humans and reveals how the reproductive cycle determines the pathogenic outcome of gonococcal infections of the UGT.
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Jones C, Sadarangani M, Lewis S, Payne I, Saleem M, Derrick JP, Pollard AJ. Characterisation of the Immunomodulatory Effects of Meningococcal Opa Proteins on Human Peripheral Blood Mononuclear Cells and CD4+ T Cells. PLoS One 2016; 11:e0154153. [PMID: 27111850 PMCID: PMC4844130 DOI: 10.1371/journal.pone.0154153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 04/09/2016] [Indexed: 01/15/2023] Open
Abstract
Opa proteins are major surface-expressed proteins located in the Neisseria meningitidis outer membrane, and are potential meningococcal vaccine candidates. Although Opa proteins elicit high levels of bactericidal antibodies following immunisation in mice, progress towards human clinical trials has been delayed due to previous findings that Opa inhibits T cell proliferation in some in vitro assays. However, results from previous studies are conflicting, with different Opa preparations and culture conditions being used. We investigated the effects of various Opa+ and Opa- antigens from N. meningitidis strain H44/76 in a range of in vitro conditions using peripheral blood mononuclear cells (PBMCs) and purified CD4+ T cells, measuring T cell proliferation by CFSE dilution using flow cytometry. Wild type recombinant and liposomal Opa proteins inhibited CD4+ T cell proliferation after stimulation with IL-2, anti-CD3 and anti-CD28, and these effects were reduced by mutation of the CEACAM1-binding region of Opa. These effects were not observed in culture with ex vivo PBMCs. Opa+ and Opa- OMVs did not consistently exert a stimulatory or inhibitory effect across different culture conditions. These data do not support a hypothesis that Opa proteins would be inhibitory to T cells if given as a vaccine component, and T cell immune responses to OMV vaccines are unlikely to be significantly affected by the presence of Opa proteins.
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MESH Headings
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Bacterial/pharmacology
- Antigens, CD/genetics
- Antigens, CD/immunology
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/immunology
- Bacterial Outer Membrane Proteins/pharmacology
- Binding Sites
- CD28 Antigens/antagonists & inhibitors
- CD28 Antigens/genetics
- CD28 Antigens/immunology
- CD3 Complex/genetics
- CD3 Complex/immunology
- CD4-Positive T-Lymphocytes/drug effects
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/microbiology
- Cell Adhesion Molecules/genetics
- Cell Adhesion Molecules/immunology
- Cell Proliferation/drug effects
- Cell Separation
- Gene Expression
- Humans
- Immunomodulation/drug effects
- Interleukin-2/pharmacology
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/microbiology
- Lymphocyte Activation/drug effects
- Meningitis, Meningococcal/immunology
- Meningitis, Meningococcal/microbiology
- Meningitis, Meningococcal/prevention & control
- Meningococcal Vaccines/biosynthesis
- Neisseria meningitidis/genetics
- Neisseria meningitidis/immunology
- Primary Cell Culture
- Protein Binding
- Protein Isoforms/genetics
- Protein Isoforms/immunology
- Protein Isoforms/pharmacology
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Recombinant Proteins/pharmacology
- Vaccination
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Affiliation(s)
- Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and NIHR Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Manish Sadarangani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and NIHR Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Susan Lewis
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and NIHR Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Isabelle Payne
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and NIHR Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Muhammad Saleem
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Jeremy P. Derrick
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and NIHR Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
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Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile. PLoS One 2015; 10:e0130713. [PMID: 26125939 PMCID: PMC4488386 DOI: 10.1371/journal.pone.0130713] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/22/2015] [Indexed: 01/15/2023] Open
Abstract
Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ) and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ) or alternative-M2 (M2-MФ) activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM) upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1), widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies.
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Diffusion of antibiotics through the PilQ secretin in Neisseria gonorrhoeae occurs through the immature, sodium dodecyl sulfate-labile form. J Bacteriol 2015; 197:1308-21. [PMID: 25605303 DOI: 10.1128/jb.02628-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED In strains of Neisseria gonorrhoeae harboring the mtr and penB determinants that decrease permeation of antibiotics into the periplasm, mutation or deletion of the PilQ secretin of type IV pili increases resistance to penicillin by ∼3-fold, indicating a role for PilQ in antibiotic permeation. In this study, we examined spontaneously arising mutants with decreased susceptibility to penicillin. One class of mutants had a phenotype indistinguishable from that of a previously characterized pilQ2 mutation that interfered with the formation of SDS-resistant PilQ multimers. A second class of mutants contained frameshift mutations in genes upstream of pilQ in the pilMNOPQ operon that increased resistance to levels similar to those of the pilQ2 mutation. In-frame deletions of these genes were constructed, but only the frameshift mutations increased antibiotic resistance, suggesting that the mutations had polar effects on PilQ. Consistent with this result, titration of wild-type PilQ levels revealed a direct correlation between resistance and expression levels of PilQ. To determine which form of PilQ, the monomer or the multimer, was responsible for antibiotic permeation, we manipulated and quantified these forms in different mutants. Deletion of PilW, which is responsible for the maturation of PilQ into SDS-resistant multimers, had no effect on resistance. Moreover, Western blot analysis revealed that while SDS-resistant multimer levels were decreased by 26% in frameshift mutants, the levels of PilQ monomers were decreased by 48%. These data suggest that immature, SDS-labile complexes, not mature, SDS-resistant PilQ complexes, serve as the route of entry of antibiotics into the periplasm. IMPORTANCE The capacity of antibiotics to reach their target is crucial for their activity. In Neisseria gonorrhoeae, the PilQ secretin of type IV pili plays an important role in antibiotic influx when diffusion of antibiotics through porins is limited (e.g., in most resistant strains). On Western blots, PilQ exists both as a mature higher-order multimer and an immature, SDS-labile monomer. In this study, we examined spontaneously arising mutations in PilQ and in the genes upstream of PilQ in the pilMNOPQ operon that increase resistance to penicillin. We provide evidence that PilQ monomers associate by mass action to form immature multimers and that these complexes likely mediate the diffusion of antibiotics across the outer membrane.
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Russell MW, Whittum-Hudson J, Fidel PL, Hook EW, Mestecky J. Immunity to Sexually Transmitted Infections. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.00112-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Contrasting within- and between-host immune selection shapes Neisseria Opa repertoires. Sci Rep 2014; 4:6554. [PMID: 25296566 PMCID: PMC4894414 DOI: 10.1038/srep06554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 09/08/2014] [Indexed: 11/30/2022] Open
Abstract
Pathogen evolution is influenced strongly by the host immune response. Previous studies of the effects of herd immunity on the population structure of directly transmitted, short-lived pathogens have primarily focused on the impact of competition for hosts. In contrast, for long-lived infections like HIV, theoretical work has focused on the mechanisms promoting antigenic variation within the host. In reality, successful transmission requires that pathogens balance both within- and between-host immune selection. The Opa adhesins in the bacterial Neisseria genus provide a unique system to study the evolution of the same antigens across two major pathogens: while N. meningitidis is an airborne, respiratory pathogen colonising the nasopharynx relatively transiently, N. gonorrhoeae can cause sexually transmitted, long-lived infections. We use a simple mathematical model and genomic data to show that trade-offs between immune selection pressures within- and between-hosts can explain the contrasting Opa repertoires observed in meningococci and gonococci.
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Neisseria gonorrhoeae induces a tolerogenic phenotype in macrophages to modulate host immunity. Mediators Inflamm 2013; 2013:127017. [PMID: 24204097 PMCID: PMC3800590 DOI: 10.1155/2013/127017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/09/2013] [Accepted: 07/31/2013] [Indexed: 12/05/2022] Open
Abstract
Neisseria gonorrhoeae is the etiological agent of gonorrhoea, which is a sexually transmitted disease widespread throughout the world. N. gonorrhoeae does not improve immune response in patients with reinfection, suggesting that gonococcus displays several mechanisms to evade immune response and survive in the host. N. gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and dendritic cells. In this study, we determined whether N. gonorrhoeae directly conditions the phenotype of RAW 264.7 murine macrophage cell line and its response. We established that gonococcus was effectively phagocytosed by the RAW 264.7 cells and upregulates production of immunoregulatory cytokines (IL-10 and TGF-β1) but not the production of proinflammatory cytokine TNF-α, indicating that gonococcus induces a shift towards anti-inflammatory cytokine production. Moreover, N. gonorrhoeae did not induce significant upregulation of costimulatory CD86 and MHC class II molecules. We also showed that N. gonorrhoeae infected macrophage cell line fails to elicit proliferative CD4+ response. This implies that macrophage that can phagocytose gonococcus do not display proper antigen-presenting functions. These results indicate that N. gonorrhoeae induces a tolerogenic phenotype in antigen-presenting cells, which seems to be one of the mechanisms to induce evasion of immune response.
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Jerse AE, Bash MC, Russell MW. Vaccines against gonorrhea: current status and future challenges. Vaccine 2013; 32:1579-87. [PMID: 24016806 DOI: 10.1016/j.vaccine.2013.08.067] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/10/2013] [Accepted: 08/17/2013] [Indexed: 01/11/2023]
Abstract
Gonorrhea occurs at high incidence throughout the world and significantly impacts reproductive health and the spread of human immunodeficiency virus. Current control measures are inadequate and seriously threatened by the rapid emergence of antibiotic resistance. Progress on gonorrhea vaccines has been slow; however, recent advances justify significant effort in this area. Conserved vaccine antigens have been identified that elicit bactericidal antibodies and, or play key roles in pathogenesis that could be targeted by a vaccine-induced response. A murine genital tract infection model is available for systematic testing of antigens, immunization routes and adjuvants, and transgenic mice exist to relieve some host restrictions. Furthermore, mechanisms by which Neisseria gonorrhoeae avoids inducing a protective adaptive response are being elucidated using human cells and the mouse model. Induction of a Th1 response in mice clears infection and induces a memory response, which suggests Th1-inducing adjuvants may be key in vaccine-induced protection. Continued research in this area should include human testing and clinical studies to confirm or negate findings from experimental systems and to define protective host factors.
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Affiliation(s)
- Ann E Jerse
- Department of Microbiology and Immunology, F. Edward Hebért School of Medicine, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA.
| | - Margaret C Bash
- Division of Bacterial, Parasitic and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, 1400 Rockville Pike, Bethesda, MD 20814, USA.
| | - Michael W Russell
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-3000, USA.
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Liu Y, Islam EA, Jarvis GA, Gray-Owen SD, Russell MW. Neisseria gonorrhoeae selectively suppresses the development of Th1 and Th2 cells, and enhances Th17 cell responses, through TGF-β-dependent mechanisms. Mucosal Immunol 2012; 5:320-31. [PMID: 22354319 PMCID: PMC3328619 DOI: 10.1038/mi.2012.12] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Infection with Neisseria gonorrhoeae does not induce specific immunity or immune memory. Our previous studies in a murine model of vaginal gonococcal infection showed that innate immunity governed by Th17 cells was a critical aspect of the immune response elicited by this pathogen. Herein we show that N. gonorrhoeae selectively inhibited Th1 and Th2 cells and enhanced Th17 cell development through the induction of TGF-β. Whereas Th17 responses depended on gonococcal lipooligosaccharide acting through TLR4, the inhibitory effect of N. gonorrhoeae on Th1/Th2 responses involved gonococcal Opa proteins. In vitro Th17 responses to N. gonorrhoeae could be diverted to Th1/Th2 by blockade of TGF-β, but not by blockade of IL-17. The results reveal that N. gonorrhoeae suppresses Th1/Th2-mediated adaptive immune response through mechanisms dependent on TGF-β, and that this effect can be manipulated to promote the development of adaptive immunity.
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Affiliation(s)
- Yingru Liu
- Department of Microbiology and Immunology, and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY 14214, USA
| | - Epshita A. Islam
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Gary A. Jarvis
- Center for Immunochemistry, Veterans Affairs Medical Center, San Francisco, CA, 94121; and Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Scott D. Gray-Owen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Michael W. Russell
- Department of Microbiology and Immunology, and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY 14214, USA
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So NSY, Ostrowski MA, Gray-Owen SD. Vigorous response of human innate functioning IgM memory B cells upon infection by Neisseria gonorrhoeae. THE JOURNAL OF IMMUNOLOGY 2012; 188:4008-22. [PMID: 22427638 DOI: 10.4049/jimmunol.1100718] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Neisseria gonorrhoeae, the cause of the sexually transmitted infection gonorrhea, elicits low levels of specific Ig that decline rapidly after the bacteria are cleared. Reinfection with the same serovar can occur, and prior gonococcal infection does not alter the Ig response upon subsequent exposure, suggesting that protective immunity is not induced. The mucosal Ig response apparent during gonorrhea does not correlate with that observed systemically, leading to a suggestion that it is locally generated. In considering whether N. gonorrhoeae directly influences B cells, we observed that gonococcal infection prolonged viability of primary human B cells in vitro and elicited robust activation and vigorous proliferative responses in the absence of T cells. Furthermore, we observed the specific expansion of IgD(+)CD27(+) B cells in response to gonococcal infection. These cells are innate in function, conferring protection against diverse microbes by producing low-affinity, broadly reactive IgM without inducing classical immunologic memory. Although gonococcal infection of B cells produced small amounts of gonococcal-specific IgM, IgM specific for irrelevant Ags were also produced, suggesting a broad, polyspecific Ig response. The gonococci were effectively bound and engulfed by B cells. TLR9-inhibitory CpGs blocked B cell responses, indicating that intracellular bacterial degradation allows for innate immune detection within the phagolysosome. To our knowledge, this is the first report of a bacterial pathogen having specific affinity for the human IgM memory B cells, driving their potent activation and polyclonal Ig response. This unfocused T-independent response explains the localized Ig response that occurs, despite an absence of immunologic memory elicited during gonorrhea.
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Affiliation(s)
- Nancy S Y So
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Fur-mediated activation of gene transcription in the human pathogen Neisseria gonorrhoeae. J Bacteriol 2012; 194:1730-42. [PMID: 22287521 DOI: 10.1128/jb.06176-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
It is well established that the ferric uptake regulatory protein (Fur) functions as a transcriptional repressor in diverse microorganisms. Recent studies demonstrated that Fur also functions as a transcriptional activator. In this study we defined Fur-mediated activation of gene transcription in the sexually transmitted disease pathogen Neisseria gonorrhoeae. Analysis of 37 genes which were previously determined to be iron induced and which contained putative Fur boxes revealed that only 30 of these genes exhibited reduced transcription in a gonococcal fur mutant strain. Fur-mediated activation was established by examining binding of Fur to the putative promoter regions of 16 Fur-activated genes with variable binding affinities observed. Only ∼50% of the newly identified Fur-regulated genes bound Fur in vitro, suggesting that additional regulatory circuits exist which may function through a Fur-mediated indirect mechanism. The gonococcal Fur-activated genes displayed variable transcription patterns in a fur mutant strain, which correlated with the position of the Fur box in each (promoter) region. These results suggest that Fur-mediated direct transcriptional activation is fulfilled by multiple mechanisms involving either competing with a repressor or recruiting RNA polymerase. Collectively, our studies have established that gonococcal Fur functions as an activator of gene transcription through both direct and indirect mechanisms.
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Zhu W, Chen CJ, Thomas CE, Anderson JE, Jerse AE, Sparling PF. Vaccines for gonorrhea: can we rise to the challenge? Front Microbiol 2011; 2:124. [PMID: 21687431 PMCID: PMC3109613 DOI: 10.3389/fmicb.2011.00124] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 05/19/2011] [Indexed: 12/14/2022] Open
Abstract
Immune responses to the gonococcus after natural infection ordinarily result in little immunity to reinfection, due to antigenic variation of the gonococcus, and redirection or suppression of immune responses. Brinton and colleagues demonstrated that parenteral immunization of male human volunteers with a purified pilus vaccine gave partial protection against infection by the homologous strain. However, the vaccine failed in a clinical trial. Recent vaccine development efforts have focused on the female mouse model of genital gonococcal infection. Here we discuss the state of the field, including our unpublished data regarding efficacy in the mouse model of either viral replicon particle (VRP) vaccines, or outer membrane vesicle (OMV) vaccines. The OMV vaccines failed, despite excellent serum and mucosal antibody responses. Protection after a regimen consisting of a PorB-VRP prime plus recombinant PorB boost was correlated with apparent Th1, but not with antibody, responses. Protection probably was due to powerful adjuvant effects of the VRP vector. New tools including novel transgenic mice expressing human genes required for gonococcal infection should enable future research. Surrogates for immunity are needed. Increasing antimicrobial resistance trends among gonococci makes development of a vaccine more urgent.
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Affiliation(s)
- Weiyan Zhu
- Department of Medicine, University of North Carolina Chapel Hill, NC, USA
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Diversion of the immune response to Neisseria gonorrhoeae from Th17 to Th1/Th2 by treatment with anti-transforming growth factor β antibody generates immunological memory and protective immunity. mBio 2011; 2:e00095-11. [PMID: 21610119 PMCID: PMC3101786 DOI: 10.1128/mbio.00095-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The immune response to Neisseria gonorrhoeae is poorly understood, but its extensive antigenic variability and resistance to complement are thought to allow it to evade destruction by the host’s immune defenses. We propose that N. gonorrhoeae also avoids inducing protective immune responses in the first place. We previously found that N. gonorrhoeae induces interleukin-17 (IL-17)-dependent innate responses in mice and suppresses Th1/Th2-dependent adaptive responses in murine cells in vitro through the induction of transforming growth factor β (TGF-β). In this study using a murine model of vaginal gonococcal infection, mice treated with anti-TGF-β antibody during primary infection showed accelerated clearance of N. gonorrhoeae, with incipient development of Th1 and Th2 responses and diminished Th17 responses in genital tract tissue. Upon secondary reinfection, mice that had been treated with anti-TGF-β during primary infection showed anamnestic recall of both Th1 and Th2 responses, with the development of antigonococcal antibodies in sera and secretions, and enhanced resistance to reinfection. In mouse knockout strains defective in Th1 or Th2 responses, accelerated clearance of primary infection due to anti-TGF-β treatment was dependent on Th1 activity but not Th2 activity, whereas resistance to secondary infection resulting from anti-TGF-β treatment during primary infection was due to both Th1- and Th2-dependent memory responses. We propose that N. gonorrhoeae proactively elicits Th17-driven innate responses that it can resist and concomitantly suppresses Th1/Th2-driven specific adaptive immunity that would protect the host. Blockade of TGF-β reverses this pattern of host immune responsiveness and facilitates the emergence of protective antigonococcal immunity. Pathogen-host interactions during infectious disease are conventionally thought of as two-way reactions, that of the host against the pathogen and vice versa, with the outcome dependent on which one ultimately prevails. We propose that Neisseria gonorrhoeae, a pathogen that has become extremely well adapted to its exclusive human host, proactively directs the manner in which the host responds in ways that are beneficial to its own survival but detrimental to the host. Gonorrhea is a widely prevalent sexually transmitted infection, and naturally occurring gonococcal strains are becoming resistant to most available antibiotics, yet no effective vaccine has been developed. These new insights into the immune response to N. gonorrhoeae should lead to novel therapeutic strategies and facilitate new approaches to vaccine development.
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Liu Y, Feinen B, Russell MW. New concepts in immunity to Neisseria gonorrhoeae: innate responses and suppression of adaptive immunity favor the pathogen, not the host. Front Microbiol 2011; 2:52. [PMID: 21833308 PMCID: PMC3153028 DOI: 10.3389/fmicb.2011.00052] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/08/2011] [Indexed: 12/31/2022] Open
Abstract
It is well-known that gonorrhea can be acquired repeatedly with no apparent development of protective immunity arising from previous episodes of infection. Symptomatic infection is characterized by a purulent exudate, but the host response mechanisms are poorly understood. While the remarkable antigenic variability displayed by Neisseria gonorrhoeae and its capacity to inhibit complement activation allow it to evade destruction by the host's immune defenses, we propose that it also has the capacity to avoid inducing specific immune responses. In a mouse model of vaginal gonococcal infection, N. gonorrhoeae elicits Th17-driven inflammatory–immune responses, which recruit innate defense mechanisms including an influx of neutrophils. Concomitantly, N. gonorrhoeae suppresses Th1- and Th2-dependent adaptive immunity, including specific antibody responses, through a mechanism involving TGF-β and regulatory T cells. Blockade of TGF-β alleviates the suppression of specific anti-gonococcal responses and allows Th1 and Th2 responses to emerge with the generation of immune memory and protective immunity. Genital tract tissues are naturally rich in TGF-β, which fosters an immunosuppressive environment that is important in reproduction. In exploiting this niche, N. gonorrhoeae exemplifies a well-adapted pathogen that proactively elicits from its host innate responses that it can survive and concomitantly suppresses adaptive immunity. Comprehension of these mechanisms of gonococcal pathogenesis should allow the development of novel approaches to therapy and facilitate the development of an effective vaccine.
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Affiliation(s)
- Yingru Liu
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo Buffalo, NY, USA
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Sadarangani M, Pollard AJ, Gray-Owen SD. Opa proteins and CEACAMs: pathways of immune engagement for pathogenic Neisseria. FEMS Microbiol Rev 2011; 35:498-514. [PMID: 21204865 DOI: 10.1111/j.1574-6976.2010.00260.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are globally important pathogens, which in part owe their success to their ability to successfully evade human immune responses over long periods. The phase-variable opacity-associated (Opa) adhesin proteins are a major surface component of these organisms, and are responsible for bacterial adherence and entry into host cells and interactions with the immune system. Most immune interactions are mediated via binding to members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family. These Opa variants are able to bind to different receptors of the CEACAM family on epithelial cells, neutrophils, and T and B lymphocytes, influencing the innate and adaptive immune responses. Increased epithelial cell adhesion creates the potential for prolonged infection, invasion and dissemination. Furthermore, Opa proteins may inhibit T-lymphocyte activation and proliferation, B-cell antibody production, and innate inflammatory responses by infected epithelia, in addition to conferring increased resistance to antibody-dependent, complement-mediated killing. While vaccines containing Opa proteins could induce adhesion-blocking and bactericidal antibodies, the consequence of CEACAM binding by a candidate Opa-containing vaccine requires further investigation. This review summarizes current knowledge of the immunological consequences of the interaction between meningococcal and gonococcal Opa proteins and human CEACAMs, considering the implications for pathogenesis and vaccine development.
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Affiliation(s)
- Manish Sadarangani
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, UK.
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The relationship between the symptoms of female gonococcal infections and serum progesterone level and the genotypes of Neisseria gonorrhoeae multi-antigen sequence type (NG-MAST) in Wuhan, China. Eur J Clin Microbiol Infect Dis 2010; 30:113-6. [PMID: 20820835 PMCID: PMC2998644 DOI: 10.1007/s10096-010-1040-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 08/04/2010] [Indexed: 11/03/2022]
Abstract
The objective of this investigation was to study the relationship between the symptoms of female gonococcal infections and serum progesterone level and the genotypes of Neisseria gonorrhoeae multi-antigen sequence type (NG-MAST) in Wuhan, China. Eighty-one strains of N. gonorrhoeae were harvested from the vaginal discharge of 975 adult females in Wuhan and were genotyped by using NG-MAST. Serum progesterone (P) and estradiol (E(2)) levels were measured by radio immunoassay (RIA) in 39 gonorrhea-infected patients with slight symptoms (asymptomatic group) and 42 patients with conspicuous symptoms (symptomatic group). The average levels of serum progesterone in the asymptomatic group were significantly higher than in the symptomatic group (p < 0.05), while no significant difference was found in serum estradiol between the two groups. Of 81 wild-type isolates, 50 NG-MAST sequence types were associated with female infections in Wuhan, and N. gonorrhoeae ST2951, ST735, and ST436 were principally found in asymptomatic patients. ST809 and ST369, however, were mainly detected in asymptomatic female subjects. Gonococcal genetic island (GGI)-positive and GGI-negative strains were found in both the asymptomatic group and the symptomatic group. In females with gonococcal infection, high serum progesterone level is associated with the absence of symptoms, but no association was revealed between genotypes and the presence of symptoms. The GGI bears no relation to the absence of symptoms in the patients.
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Russell MW, Mestecky J. Tolerance and protection against infection in the genital tract. Immunol Invest 2010; 39:500-25. [PMID: 20450289 DOI: 10.3109/08820131003674834] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The genital tract is a unique immunological environment that must support the reproductive function and resist infection. Particularly in the female tract, immunoregulatory and immunosuppressive activities that permit the growth of the fetus create an environment that can readily be exploited by microbes that have become well-adapted to this location. Cellular and molecular mediators of immune responses differ from those found at other mucosal surfaces. Mechanisms of immune response induction and delivery, as well as immune effector functions at the genital mucosae need to be considered in the development of vaccines against infections of the genital tract.
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Affiliation(s)
- Michael W Russell
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, New York 14214, USA.
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Feinen B, Jerse AE, Gaffen SL, Russell MW. Critical role of Th17 responses in a murine model of Neisseria gonorrhoeae genital infection. Mucosal Immunol 2010; 3:312-21. [PMID: 20107432 PMCID: PMC2857675 DOI: 10.1038/mi.2009.139] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Host immune responses, including the characteristic influx of neutrophils, against Neisseria gonorrhoeae are poorly understood; adaptive immunity is minimal and non-protective. We hypothesize that N. gonorrhoeae selectively elicits Th17-dependent responses, which trigger innate defense mechanisms, including neutrophils and antimicrobial proteins, that it can resist. We found that N. gonorrhoeae induced the production of interleukin-17 (IL-17) in mouse T-cells and Th17-inducing cytokines in mouse and human APCs in vitro. IL-17 was induced in the iliac lymph nodes in vivo in a female mouse model of genital tract gonococcal infection. Antibody blockade of IL-17 or deletion of the major IL-17 receptor (IL-17R) in IL-17RA(KO) mice led to prolonged infection and diminished neutrophil influx. Genital tract tissue from IL-17RA(KO) mice showed reduced production of neutrophil-attractant chemokines in response to culture with N. gonorrhoeae. These results imply a crucial role for IL-17 and Th17 cells in the immune response to N. gonorrhoeae.
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MESH Headings
- Animals
- Antibodies/immunology
- Antibodies/pharmacology
- Disease Models, Animal
- Female
- Gonorrhea/genetics
- Gonorrhea/immunology
- Gonorrhea/metabolism
- Gonorrhea/pathology
- Humans
- Immunity, Innate
- Interleukin-17/genetics
- Interleukin-17/immunology
- Interleukin-17/metabolism
- Lymph Nodes/immunology
- Lymph Nodes/metabolism
- Lymph Nodes/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Neisseria gonorrhoeae/immunology
- Neutrophil Infiltration/drug effects
- Neutrophil Infiltration/genetics
- Neutrophil Infiltration/immunology
- Neutrophils/immunology
- Neutrophils/metabolism
- Neutrophils/pathology
- Receptors, Interleukin-17/antagonists & inhibitors
- Receptors, Interleukin-17/genetics
- Receptors, Interleukin-17/immunology
- Receptors, Interleukin-17/metabolism
- T-Lymphocytes, Helper-Inducer/immunology
- T-Lymphocytes, Helper-Inducer/metabolism
- T-Lymphocytes, Helper-Inducer/pathology
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Affiliation(s)
- Brandon Feinen
- Department of Microbiology and Immunology, and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY
| | - Ann E. Jerse
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Sarah L. Gaffen
- Division of Rheumatology and Clinical Immunology, University of Pittsburgh, Pittsburgh, PA
| | - Michael W. Russell
- Department of Microbiology and Immunology, and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY
- Department of Oral Biology, University at Buffalo, Buffalo, NY
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Expression of homing receptors on IgA1 and IgA2 plasmablasts in blood reflects differential distribution of IgA1 and IgA2 in various body fluids. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:393-401. [PMID: 20089794 DOI: 10.1128/cvi.00475-09] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although secretory IgA is the most abundantly produced Ig isotype, the mechanisms underlying the differential distribution of IgA subclasses in various body fluids remain unclear. To explore these mechanisms, we examined the distribution of IgA subclasses, the influence of the nature and sites of encounters with antigens, and the correlation between IgA subclass distribution and homing potentials of circulating IgA plasmablasts. IgA1 predominated in serum, tears, nasal wash fluid, and saliva; the levels of IgA1 and IgA2 were comparable in vaginal wash fluid; and IgA2 predominated in intestinal lavage fluids. Seventy-one percent of circulating IgA plasmablasts secreted IgA1. The intestinal homing receptor (HR), alpha4beta7, was expressed more frequently on IgA2 than on IgA1 plasmablasts, with no differences in the expression of other HRs. IgA subclass distribution among circulating antigen-specific antibody-secreting cells (ASC) was dependent on the nature of the antigen: following vaccination with Salmonella enterica serovar Typhi, unconjugated pneumococcal polysaccharide, or Haemophilus influenzae polysaccharide-diphtheria toxoid conjugate, the proportions of specific IgA1 ASC were 74%, 47%, 56%, and 80%, respectively. HR expression depended on the route of administration: expression of HRs was different after oral than after parenteral vaccination, while no difference was seen between HR expression of antigen-specific IgA1 and IgA2 ASC induced via the same route. The key factors determining IgA subclass distribution in a given secretion are the nature of the antigens encountered at a particular site and the site-specific homing instructions given to lymphocytes at that site. These two factors are reflected as differences in the homing profiles of the total populations of circulating IgA1 and IgA2 plasmablasts.
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Horton RE, Kaefer N, Songok E, Guijon FB, Kettaf N, Boucher G, Sekaly RP, Ball TB, Plummer FA. A comparative analysis of gene expression patterns and cell phenotypes between cervical and peripheral blood mononuclear cells. PLoS One 2009; 4:e8293. [PMID: 20011545 PMCID: PMC2790076 DOI: 10.1371/journal.pone.0008293] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 11/18/2009] [Indexed: 12/25/2022] Open
Abstract
Studies of the immunological environment in the female genital tract (FGT) are critical for the development of vaccines or microbicides to halt the spread of sexually transmitted infections. Challenges arise due to the difficulties of sampling from this site, and the majority of studies have been conducted utilising peripheral blood mononuclear cells. Identifying functional differences between immune cells of the FGT and peripheral blood would aid in our understanding of mucosal immunology. We compared the gene expression profile of mononuclear cells at these two sites. Messenger RNA expression analysis was performed using gene expression arrays on matched cervical mononuclear cells and peripheral blood mononuclear cells. Further cellular phenotyping was done by 10 colour flow cytometry. Of the 22,185 genes expressed by these samples, 5345 genes were significantly differentially expressed between the cell populations. Most differences can be explained by significantly lower levels of T and B cells and higher levels of macrophages and dendritic cells in the FGT compared with peripheral blood. Several immunologically relevant pathways such as apoptosis and innate immune signalling, and a variety of cytokines and cytokine receptors were differentially expressed. This study highlights the importance of the unique immunological environment of the FGT and identifies important differences between systemic and mucosal immune compartments.
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Affiliation(s)
- Rachel E Horton
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
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Mouse strain-dependent differences in susceptibility to Neisseria gonorrhoeae infection and induction of innate immune responses. Infect Immun 2009; 78:433-40. [PMID: 19901062 DOI: 10.1128/iai.00711-09] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Acute gonorrhea in women is characterized by a mucopurulent exudate that contains polymorphonuclear leukocytes (PMNs) with intracellular gonococci. Asymptomatic infections are also common. Information on the innate response to Neisseria gonorrhoeae in women is limited to studies with cultured cells, isolated immune cells, and analyses of cervicovaginal fluids. 17beta-Estradiol-treated BALB/c mice can be experimentally infected with N. gonorrhoeae, and a vaginal PMN influx occurs in 50 to 80% of mice. Here, we compared the colonization loads and proinflammatory responses of BALB/c, C57BL/6 and C3H/HeN mice to N. gonorrhoeae. BALB/c and C57BL/6 mice were colonized at similar levels following inoculation with 10(6) CFU of N. gonorrhoeae. BALB/c, but not C57BL/6, mice exhibited a marked vaginal PMN influx. Tumor necrosis factor alpha, interleukin-6, macrophage inflammatory protein 2 (MIP-2), and keratinocyte-derived chemokine were elevated in vaginal secretions from infected BALB/c mice, but not in those from C57BL/6 mice. MIP-2 levels positively correlated with a vaginal PMN influx. In contrast to BALB/c and C57BL/6 mice, C3H/HeN mice were resistant to infection, and there was no evidence of an inflammatory response. We conclude that N. gonorrhoeae causes a productive infection in BALB/c mice that is characterized by the induction of proinflammatory cytokines and chemokines and the recruitment of PMNs. Infection of C57BL/6 mice, in contrast, is more similar to asymptomatic infection. C3H/HeN mice are inherently resistant to N. gonorrhoeae infection, and this resistance is not due to an overwhelming inflammatory response to infection. Host genetic factors can therefore impact susceptibility and the immune response to N. gonorrhoeae.
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Johnson LF, Alkema L, Dorrington RE. A Bayesian approach to uncertainty analysis of sexually transmitted infection models. Sex Transm Infect 2009; 86:169-74. [PMID: 19880971 DOI: 10.1136/sti.2009.037341] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES To propose a Bayesian approach to uncertainty analysis of sexually transmitted infection (STI) models, which can be used to quantify uncertainty in model assessments of policy options, estimate regional STI prevalence from sentinel surveillance data and make inferences about STI transmission and natural history parameters. METHODS Prior distributions are specified to represent uncertainty regarding STI parameters. A likelihood function is defined using a hierarchical approach that takes account of variation between study populations, variation in diagnostic accuracy as well as random binomial variation. The method is illustrated using a model of syphilis, gonorrhoea, chlamydial infection and trichomoniasis in South Africa. RESULTS Model estimates of STI prevalence are in good agreement with observations. Out-of-sample projections and cross-validations also show that the model is reasonably well calibrated. Model predictions of the impact of interventions are subject to significant uncertainty: the predicted reductions in the prevalence of syphilis by 2020, as a result of doubling the rate of health seeking, increasing the proportion of private practitioners using syndromic management protocols and screening all pregnant women for syphilis, are 43% (95% CI 3% to 77%), 9% (95% CI 1% to 19%) and 6% (95% CI 4% to 7%), respectively. CONCLUSIONS This study extends uncertainty analysis techniques for fitted HIV/AIDS models to models that are fitted to other STI prevalence data. There is significant uncertainty regarding the relative effectiveness of different STI control strategies. The proposed technique is reasonable for estimating uncertainty in past STI prevalence levels and for projections of future STI prevalence.
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Affiliation(s)
- Leigh F Johnson
- Centre for Actuarial Research, University of Cape Town, Rondebosch, Cape Town, South Africa.
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50
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Abstract
The pathogenic Neisseria sp. encode a family of phase-variable and antigenically distinct Opa proteins that allow bacterial attachment to virtually every cell type encountered during infection. Some Opa variants bind cell surface-expressed heparan sulfate proteoglycans, including members of the syndecan family of receptors, and extracellular matrix proteins such as fibronectin and vitronectin. Other variants bind members of the carcinoembryonic antigen family of cellular adhesion molecules. Depending on the Opa variant(s) expressed, these receptor interactions can allow neisserial entry and transcellular transcytosis across polarized epithelial cell monolayers, entry into endothelial cells, suppression of lymphocyte function and/or bacterial engulfment and killing by neutrophils. Recent advances in our understanding of how these Opa protein-mediated interactions influence the host cellular response are discussed in the context of their impact on various stages of neisserial infection.
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Affiliation(s)
- Scott D Gray-Owen
- Department of Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario, Canada.
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