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Fraser-Pitt D, Mercer DK, Francis ML, Toledo-Aparicio D, Smith DW, O'Neil DA. Cysteamine-mediated blockade of the glycine cleavage system modulates epithelial cell inflammatory and innate immune responses to viral infection. Biochem Biophys Res Commun 2023; 677:168-181. [PMID: 37597441 DOI: 10.1016/j.bbrc.2023.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/21/2023]
Abstract
Transient blockade of glycine decarboxylase (GLDC) can restrict de novo pyrimidine synthesis, which is a well-described strategy for enhancing the host interferon response to viral infection and a target pathway for some licenced anti-inflammatory therapies. The aminothiol, cysteamine, is produced endogenously during the metabolism of coenzyme A, and is currently being investigated in a clinical trial as an intervention in community acquired pneumonia resulting from viral (influenza and SARS-CoV-2) and bacterial respiratory infection. Cysteamine is known to inhibit both bacterial and the eukaryotic host glycine cleavage systems via competitive inhibition of GLDC at concentrations, lower than those required for direct antimicrobial or antiviral activity. Here, we demonstrate for the first time that therapeutically achievable concentrations of cysteamine can inhibit glycine utilisation by epithelial cells and improve cell-mediated responses to infection with respiratory viruses, including human coronavirus 229E and Influenza A. Cysteamine reduces interleukin-6 (IL-6) and increases the interferon-λ (IFN-λ) response to viral challenge and in response to liposomal polyinosinic:polycytidylic acid (poly I:C) simulant of RNA viral infection.
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Affiliation(s)
- Douglas Fraser-Pitt
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom.
| | - Derry K Mercer
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom; Bioaster, LYON (headquarters) 40, Avenue Tony Garnier, 69007, Lyon, France
| | - Marie-Louise Francis
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom
| | - David Toledo-Aparicio
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom
| | - Daniel W Smith
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom
| | - Deborah A O'Neil
- NovaBiotics Ltd, Silverburn Crescent, Bridge of Don, Aberdeen, AB23 8EW, United Kingdom
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Fraser-Pitt DJ, Dolan SK, Toledo-Aparicio D, Hunt JG, Smith DW, Lacy-Roberts N, Nupe Hewage PS, Stoyanova TN, Manson E, McClean K, Inglis NF, Mercer DK, O'Neil DA. Cysteamine Inhibits Glycine Utilisation and Disrupts Virulence in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2021; 11:718213. [PMID: 34631600 PMCID: PMC8494450 DOI: 10.3389/fcimb.2021.718213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/11/2021] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas aeruginosa is a major opportunistic human pathogen which employs a myriad of virulence factors. In people with cystic fibrosis (CF) P. aeruginosa frequently colonises the lungs and becomes a chronic infection that evolves to become less virulent over time, but often adapts to favour persistence in the host with alginate-producing mucoid, slow-growing, and antibiotic resistant phenotypes emerging. Cysteamine is an endogenous aminothiol which has been shown to prevent biofilm formation, reduce phenazine production, and potentiate antibiotic activity against P. aeruginosa, and has been investigated in clinical trials as an adjunct therapy for pulmonary exacerbations of CF. Here we demonstrate (for the first time in a prokaryote) that cysteamine prevents glycine utilisation by P. aeruginosa in common with previously reported activity blocking the glycine cleavage system in human cells. Despite the clear inhibition of glycine metabolism, cysteamine also inhibits hydrogen cyanide (HCN) production by P. aeruginosa, suggesting a direct interference in the regulation of virulence factor synthesis. Cysteamine impaired chemotaxis, lowered pyocyanin, pyoverdine and exopolysaccharide production, and reduced the toxicity of P. aeruginosa secreted factors in a Galleria mellonella infection model. Thus, cysteamine has additional potent anti-virulence properties targeting P. aeruginosa, further supporting its therapeutic potential in CF and other infections.
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Affiliation(s)
| | - Stephen K Dolan
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | | | | | | | - Piumi Sara Nupe Hewage
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Teodora N Stoyanova
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Erin Manson
- College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kevin McClean
- Proteomics Facility Services, Moredun Research Institute, Penicuik, United Kingdom
| | - Neil F Inglis
- Proteomics Facility Services, Moredun Research Institute, Penicuik, United Kingdom
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O'Neil DA. Innovation in infectious disease therapies from immunology. Drug Discov Today 2021; 26:2090-2094. [PMID: 33798650 DOI: 10.1016/j.drudis.2021.03.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/09/2021] [Accepted: 03/24/2021] [Indexed: 11/25/2022]
Abstract
Antimicrobial therapies developed from immunology, specifically the primary function of the immune system in host defence against microbial pathogens, could offer some of the step-change strategies in drug design and development urgently required to generate much needed, truly novel interventions in infectious disease. The immune system is an as yet underexploited resource of novel molecules and the blueprints for new approaches to combating infection with non-antibiotic, directly antimicrobial strategies.
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Devereux G, Wrolstad D, Bourke SJ, Daines CL, Doe S, Dougherty R, Franco R, Innes A, Kopp BT, Lascano J, Layish D, MacGregor G, Murray L, Peckham D, Lucidi V, Lovie E, Robertson J, Fraser-Pitt DJ, O'Neil DA. Oral cysteamine as an adjunct treatment in cystic fibrosis pulmonary exacerbations: An exploratory randomized clinical trial. PLoS One 2020; 15:e0242945. [PMID: 33370348 PMCID: PMC7769283 DOI: 10.1371/journal.pone.0242945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Emerging data suggests a possible role for cysteamine as an adjunct treatment for pulmonary exacerbations of cystic fibrosis (CF) that continue to be a major clinical challenge. There are no studies investigating the use of cysteamine in pulmonary exacerbations of CF. This exploratory randomized clinical trial was conducted to answer the question: In future pivotal trials of cysteamine as an adjunct treatment in pulmonary exacerbations of CF, which candidate cysteamine dosing regimens should be tested and which are the most appropriate, clinically meaningful outcome measures to employ as endpoints? METHODS AND FINDINGS Multicentre double-blind randomized clinical trial. Adults experiencing a pulmonary exacerbation of CF being treated with standard care that included aminoglycoside therapy were randomized equally to a concomitant 14-day course of placebo, or one of 5 dosing regimens of cysteamine. Outcomes were recorded on days 0, 7, 14 and 21 and included sputum bacterial load and the patient reported outcome measures (PROMs): Chronic Respiratory Infection Symptom Score (CRISS), the Cystic Fibrosis Questionnaire-Revised (CFQ-R); FEV1, blood leukocyte count, and inflammatory markers. Eighty nine participants in fifteen US and EU centres were randomized, 78 completed the 14-day treatment period. Cysteamine had no significant effect on sputum bacterial load, however technical difficulties limited interpretation. The most consistent findings were for cysteamine 450mg twice daily that had effects additional to that observed with placebo, with improved symptoms, CRISS additional 9.85 points (95% CI 0.02, 19.7) p = 0.05, reduced blood leukocyte count by 2.46x109 /l (95% CI 0.11, 4.80), p = 0.041 and reduced CRP by geometric mean 2.57 nmol/l (95% CI 0.15, 0.99), p = 0.049. CONCLUSION In this exploratory study cysteamine appeared to be safe and well-tolerated. Future pivotal trials investigating the utility of cysteamine in pulmonary exacerbations of CF need to include the cysteamine 450mg doses and CRISS and blood leukocyte count as outcome measures. CLINICAL TRIAL REGISTRATION NCT03000348; www.clinicaltrials.gov.
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Affiliation(s)
- Graham Devereux
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Danielle Wrolstad
- Precision for Medicine, Oncology and Rare Disease, Carlsbad, CA, United States of America
| | | | - Cori L. Daines
- Banner University of Arizona Medical Center, Tucson, Arizona, United States of America
| | - Simon Doe
- Royal Victoria Infirmary, Newcastle, United Kingdom
| | - Ryan Dougherty
- San Francisco Critical Care Medical Group California Pacific Medical Center, San Francisco, United States of America
| | - Rose Franco
- The Medical College of Wisconsin/Froedtert Hospital, Milwaukee, Wisconsin, United States of America
| | | | - Benjamin T. Kopp
- Nationwide Children's Hospital, Columbus, OH, United States of America
| | - Jorge Lascano
- University of Florida, Gainesville, Florida, United States of America
| | - Daniel Layish
- Central Florida Pulmonary Group, Orlando, Florida, United States of America
| | | | | | | | - Vincenzina Lucidi
- Ospedale Padiatrico Bambino Gesu Centro Fibrosi Cistica, Rome, Italy
| | - Emma Lovie
- NovaBiotics Ltd, Aberdeen, United Kingdom
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Mercer DK, Robertson JC, Miller L, Stewart CS, O'Neil DA. NP213 (Novexatin®): A unique therapy candidate for onychomycosis with a differentiated safety and efficacy profile. Med Mycol 2020; 58:1064-1072. [PMID: 32232410 PMCID: PMC7657096 DOI: 10.1093/mmy/myaa015] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/18/2020] [Accepted: 02/28/2020] [Indexed: 12/17/2022] Open
Abstract
NP213 (Novexatin®) is a novel antifungal peptide specifically designed for the topical treatment of onychomycosis. NP213 was designed using host defense peptides (HDP), essential components of the innate immune response to infection, as a template. NP213 is a water-soluble cyclic fungicidal peptide that effectively penetrates human nail. NP213 demonstrated a promising preclinical and clinical safety profile, with no evidence of systemic exposure following topical application to the skin and nails. NP213 was efficacious in two phase IIa human trials with 43.3% of patients having no fungi detectable by culture of fragments from NP213-treated nails after 180 days in the first study and likewise 56.5% of patients were culture negative for dermatophytes after 360 days in the second phase IIa study. In both trials, NP213 was applied daily for only 28 days in marked contrast to other topical onychomycosis treatments that require application for up to 52 weeks. Patient reported outcomes from the phase IIa studies were positive with participants recording an improved appearance of their nails after only 14 days of application. All fungi identified in these studies were Trichophyton spp. NP213 (Novexatin®) is a promising, highly differentiated peptide-based candidate for the topical treatment of onychomycosis, addressing the infectious cause and cosmetic issues of this very common condition.
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Affiliation(s)
- Derry K Mercer
- NovaBiotics Ltd, Bridge of Don, Aberdeen, United Kingdom
| | | | - Lorna Miller
- NovaBiotics Ltd, Bridge of Don, Aberdeen, United Kingdom
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Mercer DK, O'Neil DA. Innate Inspiration: Antifungal Peptides and Other Immunotherapeutics From the Host Immune Response. Front Immunol 2020; 11:2177. [PMID: 33072081 PMCID: PMC7533533 DOI: 10.3389/fimmu.2020.02177] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022] Open
Abstract
The purpose of this review is to describe antifungal therapeutic candidates in preclinical and clinical development derived from, or directly influenced by, the immune system, with a specific focus on antimicrobial peptides (AMP). Although the focus of this review is AMP with direct antimicrobial effects on fungi, we will also discuss compounds with direct antifungal activity, including monoclonal antibodies (mAb), as well as immunomodulatory molecules that can enhance the immune response to fungal infection, including immunomodulatory AMP, vaccines, checkpoint inhibitors, interferon and colony stimulating factors as well as immune cell therapies. The focus of this manuscript will be a non-exhaustive review of antifungal compounds in preclinical and clinical development that are based on the principles of immunology and the authors acknowledge the incredible amount of in vitro and in vivo work that has been conducted to develop such therapeutic candidates.
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Mercer DK, Torres MDT, Duay SS, Lovie E, Simpson L, von Köckritz-Blickwede M, de la Fuente-Nunez C, O'Neil DA, Angeles-Boza AM. Antimicrobial Susceptibility Testing of Antimicrobial Peptides to Better Predict Efficacy. Front Cell Infect Microbiol 2020; 10:326. [PMID: 32733816 PMCID: PMC7358464 DOI: 10.3389/fcimb.2020.00326] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022] Open
Abstract
During the development of antimicrobial peptides (AMP) as potential therapeutics, antimicrobial susceptibility testing (AST) stands as an essential part of the process in identification and optimisation of candidate AMP. Standard methods for AST, developed almost 60 years ago for testing conventional antibiotics, are not necessarily fit for purpose when it comes to determining the susceptibility of microorganisms to AMP. Without careful consideration of the parameters comprising AST there is a risk of failing to identify novel antimicrobials at a time when antimicrobial resistance (AMR) is leading the planet toward a post-antibiotic era. More physiologically/clinically relevant AST will allow better determination of the preclinical activity of drug candidates and allow the identification of lead compounds. An important consideration is the efficacy of AMP in biological matrices replicating sites of infection, e.g., blood/plasma/serum, lung bronchiolar lavage fluid/sputum, urine, biofilms, etc., as this will likely be more predictive of clinical efficacy. Additionally, specific AST for different target microorganisms may help to better predict efficacy of AMP in specific infections. In this manuscript, we describe what we believe are the key considerations for AST of AMP and hope that this information can better guide the preclinical development of AMP toward becoming a new generation of urgently needed antimicrobials.
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Affiliation(s)
| | - Marcelo D. T. Torres
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, Penn Institute for Computational Science, and Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Searle S. Duay
- Department of Chemistry, Institute of Materials Science, University of Connecticut, Storrs, CT, United States
| | - Emma Lovie
- NovaBiotics Ltd, Aberdeen, United Kingdom
| | | | | | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, Penn Institute for Computational Science, and Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | | | - Alfredo M. Angeles-Boza
- Department of Chemistry, Institute of Materials Science, University of Connecticut, Storrs, CT, United States
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van Esch C, Hopkins MM, O'Neil DA, Bilimoria D. How perceived riskiness influences the selection of women and men as senior leaders. Hum Resour Manage 2018. [DOI: 10.1002/hrm.21902] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The purpose of this perspective article is to present the argument that authentic leadership is a gendered representation of leadership. We first provide a brief history of leadership theories and definitions of authentic leadership. We then critique authentic leadership and offer arguments to support the premise that authentic leadership is not gender-neutral and is especially challenging for women.
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Affiliation(s)
| | - Deborah A O'Neil
- Management, Bowling Green State University, Bowling Green, OH USA
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Abstract
In this Perspective article we propose that in order to pave the way for women’s career advancement into the senior ranks of organizations, attention must be directed at the systemic norms and structures that drive the gendered nature of the workplace. A focus on individual level issues, i.e., women lacking confidence and women opting out, detracts from the work that must be done at the organizational level in order to dismantle the system of pervasive, structural disadvantage facing women seeking to advance to senior leadership positions.
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Affiliation(s)
- Deborah A O'Neil
- Department of Management, College of Business Administration, Bowling Green State University , Bowling Green, OH, USA
| | - Margaret M Hopkins
- Department of Management, College of Business and Innovation, University of Toledo , Toledo, OH, USA
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Abstract
Purpose
– The purpose of this paper is to determine the particular competencies demonstrated by effective physician leaders. Changing organizational and environmental dynamics present unique challenges to leaders in the field of healthcare. An accelerated emphasis on increasing the quality of health care delivery, containing costs, and restructuring the delivery of health care itself are redefining the very nature of healthcare and the roles of physicians as leaders. Given this context, the authors propose to identify the essential competencies for twenty-first century physician leadership.
Design/methodology/approach
– In all, 53 critical incident interviews from 28 physicians identified as emerging leaders at the Cleveland Clinic, a top-rated US academic healthcare institution, were examined in two ways: an existing leadership competency model was applied to each critical incident and inductively derived themes were identified through thematic analysis of the incidents.
Findings
– The predominant distinguishing leadership competencies demonstrated by the physician leaders included: Empathy, Initiative, Emotional Self-Awareness and Organizational Awareness. Communicating deliberately, getting buy-in from colleagues, focussing on the mission of the organization and showing respect for others were also discovered through thematic analysis to be essential practices of these effective physician leaders. Over 90 percent of the critical incident stories dealt with colleague-to-colleague interactions.
Research limitations/implications
– The research was conducted in one academic healthcare organization, thus limiting the generalizability of the results. Additional research testing these results in a variety of healthcare institutions is warranted.
Originality/value
– This study identified specific competencies that distinguish effective physician leaders. These leaders actively sought to work with colleagues to obtain their input and consensus in order to enact organizational change and improve health care delivery in their institution. Importantly, their intentions were neither self-focussed nor self-promoting but strongly mission driven. The identification of physician leader competencies will assist incumbent and emerging physician leaders in their ability to be effective leaders, as well as inform the design of training and development programs for physicians.
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Hopkins MM, O'Neil DA, FitzSimons K, Bailin PL, Stoller JK. Leadership and organization development in health-care: lessons from the Cleveland Clinic. Adv Health Care Manag 2011; 10:151-65. [PMID: 21887943 DOI: 10.1108/s1474-8231(2011)0000010015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Leaders in health-care today are faced with a wide array of complex issues. This chapter describes an innovative physician leadership development program at the Cleveland Clinic intended to enhance the leadership capacities of individuals and the organization. Propositions regarding the program's impact on organizational innovation, organizational commitment, social capital, and the human element of physician practice are offered for future examination.
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Hopkins MM, O'Neil DA, Passarelli A, Bilimoria D. Women's leadership development strategic practices for women and organizations. ACTA ACUST UNITED AC 2008. [DOI: 10.1037/a0014093] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Evidence for the central role that intestinal beta-defensins play in maintaining gut health continues to accumulate within the literature. Two epithelially-derived enteric beta-defensins, hBD1 and hBD2, have been identified thus far and the following chapter reviews our current understanding of how the expression and secretion of these endogenous antimicrobial, chemotactic and adjuvant peptides is regulated within the context of the most microbe-rich of mucosal environments, the gastrointestinal tract. The agonists and microbial moieties identified as being responsible for the direct receptor-mediated induction of enteric epithelial beta-defensins, the signaling and nuclear events that are triggered as a consequence and which drive defensin gene transcription, the potential antimicrobial and immunomodulatory consequences of beta-defensin release within the luminal and mucosal aspects of the alimentary tract thereafter and the validity of animal models for the study of these key immune effector molecules in vivo are discussed. These significant and recent discoveries have provided much in the way of momentum for the pace with which this exciting and dynamic area of mucosal immunology research continues to move forward.
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Affiliation(s)
- Deborah A O'Neil
- Gut Immunology Group, The Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB51 0UX, UK.
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O'Neil DA, Cole SP, Martin-Porter E, Housley MP, Liu L, Ganz T, Kagnoff MF. Regulation of human beta-defensins by gastric epithelial cells in response to infection with Helicobacter pylori or stimulation with interleukin-1. Infect Immun 2000; 68:5412-5. [PMID: 10948173 PMCID: PMC101807 DOI: 10.1128/iai.68.9.5412-5415.2000] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Gastric epithelial cells in vitro and in vivo are shown to constitutively express the peptide antibiotic human beta-defensin type 1 (hBD-1). In contrast, hBD-2 expression is regulated in gastric epithelial cells and increases in response to infection with Helicobacter pylori or stimulation with the proinflammatory cytokine interleukin-1. These data suggest that hBD-2 is a component of the regulated host gastric epithelial cell response to H. pylori infection and proinflammatory mediators.
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Affiliation(s)
- D A O'Neil
- Laboratory of Mucosal Immunology, Department of Medicine, University of California, San Diego, La Jolla, California 92093-0623, USA
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O'Neil DA, Porter EM, Elewaut D, Anderson GM, Eckmann L, Ganz T, Kagnoff MF. Expression and regulation of the human beta-defensins hBD-1 and hBD-2 in intestinal epithelium. J Immunol 1999; 163:6718-24. [PMID: 10586069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The intestinal epithelium forms a physical barrier to limit access of enteric microbes to the host and contributes to innate host defense by producing effector molecules against luminal microbes. To further define the role of the intestinal epithelium in antimicrobial host defense, we analyzed the expression, regulation, and production of two antimicrobial peptides, human defensins hBD-1 and hBD-2, by human intestinal epithelial cells in vitro and in vivo. The human colon epithelial cell lines HT-29 and Caco-2 constitutively express hBD-1 mRNA and protein but not hBD-2. However, hBD-2 expression is rapidly induced by IL-1alpha stimulation or infection of those cells with enteroinvasive bacteria. Moreover, hBD-2 functions as a NF-kappaB target gene in the intestinal epithelium as blocking NF-kappaB activation inhibits the up-regulated expression of hBD-2 in response to IL-1alpha stimulation or bacterial infection. Caco-2 cells produce two hBD-1 isoforms and a hBD-2 peptide larger in size than previously described hBD-2 isoforms. Paralleling the in vitro findings, human fetal intestinal xenografts constitutively express hBD-1, but not hBD-2, and hBD-2 expression, but not hBD-1, is up-regulated in xenografts infected intraluminally with Salmonella. hBD-1 is expressed by the epithelium of normal human colon and small intestine, with a similar pattern of expression in inflamed colon. In contrast, there is little hBD-2 expression by the epithelium of normal colon, but abundant hBD-2 expression by the epithelium of inflamed colon. hBD-1 and hBD-2 may be integral components of epithelial innate immunity in the intestine, with each occupying a distinct functional niche in intestinal mucosal defense.
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Affiliation(s)
- D A O'Neil
- Laboratory of Mucosal Immunology, Department of Medicine, University of California at San Diego, La Jolla 92093, USA
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Schneyer AL, O'Neil DA, Crowley WF. Activin-binding proteins in human serum and follicular fluid. J Clin Endocrinol Metab 1992; 74:1320-4. [PMID: 1592877 DOI: 10.1210/jcem.74.6.1592877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Binding proteins that transport and/or modify the biological action of peptide hormones and growth factors have been identified for an increasing number of endocrinologically important substances. Since these binding proteins can mask epitopes critical for recognition in immunoassays and can neutralize the bioactivity of their targets, elucidation of hormonal physiology can be intricately tied to analysis of binding protein structure and function. Therefore, we investigated whether circulating activin- and inhibin-binding proteins exist in human serum by incubating purified recombinant human 125I-activin with serum samples. After gel permeation chromatography, radioactive activin was identified in three peaks, a high molecular wt (mol wt) binding protein peak (230 kDa), a lower mol wt binding protein peak (60 kDa), and free activin (22.5 kDa). Bound activin was displaced from the lower mol wt binding protein with either activin or inhibin, but was not displaced from the high mol wt peak with a 10-fold greater concentration of activin. Since an activin-binding protein, follistatin, has been identified in ovarian and pituitary extracts, these same analytical techniques were applied to analysis of human follicular fluid as well. A large, 60 kDa binding protein peak eluting in a position similar to the lower mol wt peak in serum was observed, consistent with this protein being follistatin. These results demonstrate the presence of at least two activin-binding proteins, distinguishable by size, in human serum that may interfere with attempts to assay activin levels in circulation without prior extraction, and may also be involved in regulating the biological actions of activin.
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Affiliation(s)
- A L Schneyer
- Department of Medicine, Massachusetts General Hospital, Boston 02114
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Goldring SR, Schiller AL, Roelke M, Rourke CM, O'Neil DA, Harris WH. The synovial-like membrane at the bone-cement interface in loose total hip replacements and its proposed role in bone lysis. J Bone Joint Surg Am 1983; 65:575-84. [PMID: 6304106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
UNLABELLED The membrane present at the bone-cement interface was retrieved from twenty patients with a loose, non-septic failed total hip replacement at a site clearly remote from the pseudocapsule that reformed postoperatively. The orientation of the membrane was carefully marked to identify the surface in contact with cement. The membrane was studied histologically, histochemically, by cell culture, by organ culture, and by assessment of its ability to synthesize prostaglandin E2 and collagenase. This membrane, rather than being a nondescript so-called fibrous membrane, has the histological and histochemical characteristics of a synovial-like lining. The synovial-like cells are adjacent to the cement layer. Deep to them macrophages predominate. Inflammatory cells are absent. Cell cultures of this membrane contain stellate cells similar to those found in cell cultures of normal and rheumatoid synovial tissue. This membrane has the capacity to produce large amounts of prostaglandin E2 and collagenase. CLINICAL RELEVANCE This transformation of tissue at the bone-cement interface in patients with a non-septic, loose total hip component to a synovial-like tissue with the capacity to generate prostaglandin E2 and collagenase may explain the progressive lysis of bone that is seen in some patients with loose cemented total joint implants. Loosening of the component may be a stimulus to the synthetic activity of this tissue, which leads to further resorption of bone. Understanding and the possibility of pharmacological control of this membrane may contribute to improved duration of total joint implants.
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