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Smith KJ, Gwyer Findlay E. Expression of antimicrobial host defence peptides in the central nervous system during health and disease. DISCOVERY IMMUNOLOGY 2022; 1:kyac003. [PMID: 38566904 PMCID: PMC10917193 DOI: 10.1093/discim/kyac003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/13/2022] [Accepted: 07/21/2022] [Indexed: 04/04/2024]
Abstract
Antimicrobial host defence peptides (HDP) are critical for the first line of defence against bacterial, viral, and fungal pathogens. Over the past decade we have become more aware that, in addition to their antimicrobial roles, they also possess the potent immunomodulatory capacity. This includes chemoattracting immune cells, activating dendritic cells and macrophages, and altering T-cell differentiation. Most examinations of their immunomodulatory roles have focused on tissues in which they are very abundant, such as the intestine and the inflamed skin. However, HDP have now been detected in the brain and the spinal cord during a number of conditions. We propose that their presence in the central nervous system (CNS) during homeostasis, infection, and neurodegenerative disease has the potential to contribute to immunosurveillance, alter host responses and skew developing immunity. Here, we review the evidence for HDP expression and function in the CNS in health and disease. We describe how a wide range of HDP are expressed in the CNS of humans, rodents, birds, and fish, suggesting a conserved role in protecting the brain from pathogens, with evidence of production by resident CNS cells. We highlight differences in methodology used and how this may have resulted in the immunomodulatory roles of HDP being overlooked. Finally, we discuss what HDP expression may mean for CNS immune responses.
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Affiliation(s)
- Katie J Smith
- Centre for Inflammation Research, University of Edinburgh, 47 Little France Crescent, EH16 4TJ, Edinburgh, UK
| | - Emily Gwyer Findlay
- Centre for Inflammation Research, University of Edinburgh, 47 Little France Crescent, EH16 4TJ, Edinburgh, UK
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Cieślik M, Bagińska N, Górski A, Jończyk-Matysiak E. Human β-Defensin 2 and Its Postulated Role in Modulation of the Immune Response. Cells 2021; 10:cells10112991. [PMID: 34831214 PMCID: PMC8616480 DOI: 10.3390/cells10112991] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 12/17/2022] Open
Abstract
Studies described so far suggest that human β-defensin 2 is an important protein of innate immune response which provides protection for the human organism against invading pathogens of bacterial, viral, fungal, as well as parasitical origin. Its pivotal role in enhancing immunity was proved in infants. It may also be considered a marker of inflammation. Its therapeutic administration has been suggested for maintenance of the balance of systemic homeostasis based on the appropriate composition of the microbiota. It has been suggested that it may be an important therapeutic tool for modulating the response of the immune system in many inflammatory diseases, offering new treatment modalities. For this reason, its properties and role in the human body discussed in this review should be studied in more detail.
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Affiliation(s)
- Martyna Cieślik
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
| | - Natalia Bagińska
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
| | - Andrzej Górski
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
- Phage Therapy Unit, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland
- Infant Jesus Hospital, The Medical University of Warsaw, 02-006 Warsaw, Poland
- Correspondence:
| | - Ewa Jończyk-Matysiak
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
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Rocha-Ferreira E, Hristova M. Antimicrobial peptides and complement in neonatal hypoxia-ischemia induced brain damage. Front Immunol 2015; 6:56. [PMID: 25729383 PMCID: PMC4325932 DOI: 10.3389/fimmu.2015.00056] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/29/2015] [Indexed: 12/22/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is a clinical condition in the neonate, resulting from oxygen deprivation around the time of birth. HIE affects 1-5/1000 live births worldwide and is associated with the development of neurological deficits, including cerebral palsy, epilepsy, and cognitive disabilities. Even though the brain is considered as an immune-privileged site, it has innate and adaptive immune response and can produce complement (C) components and antimicrobial peptides (AMPs). Dysregulation of cerebral expression of AMPs and C can exacerbate or ameliorate the inflammatory response within the brain. Brain ischemia triggers a prolonged inflammatory response affecting the progression of injury and secondary energy failure and involves both innate and adaptive immune systems, including immune-competent and non-competent cells. Following injury to the central nervous system (CNS), including neonatal hypoxia-ischemia (HI), resident microglia, and astroglia are the main cells providing immune defense to the brain in a stimulus-dependent manner. They can express and secrete pro-inflammatory cytokines and therefore trigger prolonged inflammation, resulting in neurodegeneration. Microglial cells express and release a wide range of inflammation-associated molecules including several components of the complement system. Complement activation following neonatal HI injury has been reported to contribute to neurodegeneration. Astrocytes can significantly affect the immune response of the CNS under pathological conditions through production and release of pro-inflammatory cytokines and immunomodulatory AMPs. Astrocytes express β-defensins, which can chemoattract and promote maturation of dendritic cells (DC), and can also limit inflammation by controlling the viability of these same DC. This review will focus on the balance of complement components and AMPs within the CNS following neonatal HI injury and the effect of that balance on the subsequent brain damage.
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Affiliation(s)
- Eridan Rocha-Ferreira
- Perinatal Brain Repair Group, Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London , London , UK
| | - Mariya Hristova
- Perinatal Brain Repair Group, Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London , London , UK
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Kountouras J, Deretzi G, Gavalas E, Zavos C, Polyzos SA, Kazakos E, Giartza-Taxidou E, Vardaka E, Kountouras C, Katsinelos P, Boziki M, Giouleme O. A proposed role of human defensins in Helicobacter pylori-related neurodegenerative disorders. Med Hypotheses 2014; 82:368-73. [PMID: 24472867 DOI: 10.1016/j.mehy.2013.12.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 12/13/2013] [Accepted: 12/27/2013] [Indexed: 12/18/2022]
Abstract
Cationic host defence peptides (CHDPs), also known as antimicrobial peptides (AMPs), are essential components of the innate immunity with antimicrobial and pleiotropic immunomodulatory properties. In mammals the two major families of CHDPs are defensins and cathelicidins that comprise an arsenal of innate regulators of principal importance in the host tissues. Research in the last decade has demonstrated that defensins are crucial effectors of both innate and adaptive immunity. Defensins can modulate immune responses, either by stimulation or suppression, thereby controlling inflammatory processes and infections. Currently only few data, mostly hypothetical, focus on the role of defensins in central nervous system (CNS) physiopathology and neurodegeneration. Defensins may function as an initial line of defense within the CNS either as an antimicrobial, immunomodulator, or both. A dysregulation of brain expression of specific defensins might either exacerbate or ameliorate the inflammatory response within the CNS depending upon which extracellular conditions predominate. It is proposed that reduction or abnormal elevation of AMP expression by cerebral microglia, astrocytes or choroid plexus epithelium might contribute to loss of AMP-induced regulation of immune responses, thereby promoting neuronal cell injury and death observed in Alzheimer's disease and possibly in other neurodegenerative disorders. Nevertheless, whether certain AMPs play a crucial role in the onset or promotion of the neuroinflammatory process and neurodegeneration is currently unknown, thereby emphasizing the necessity of further investigation into the regulatory mechanisms that control innate and adaptive immunity within the brain. Recent data indicate that Helicobacter pylori (H. pylori) induces defensins' release associated with chronic inflammatory tissue damage. However, it remains unclear whether and how H. pylori evades the attack by defensins. Moreover, recent evidence indicates that H. pylori infection might contribute to the pathogenesis of neurodegenerative diseases, by releasing several inflammatory mediators that could induce blood-brain barrier breakdown, thereby being involved in the pathogenesis of neurodegeneration. However, currently there are no data regarding the potential impact of human defensins on H. pylori-related neurodegenerative disorders. We herein propose that human defensins might contribute to the pathophysiology of H. pylori-related neurodegenerative disorders by modulating variably innate and adaptive immune system responses. Better understanding of the mechanisms regarding human defensins' possible involvement in H. pylori-induced neurodegeneration might help develop novel therapeutic strategies against H. pylori-related neurodegenerative disorders.
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Affiliation(s)
- Jannis Kountouras
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece.
| | - Georgia Deretzi
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Emmanouel Gavalas
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Christos Zavos
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Stergios A Polyzos
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Evangelos Kazakos
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Evangelia Giartza-Taxidou
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Elisabeth Vardaka
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Constantinos Kountouras
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Panagiotis Katsinelos
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Marina Boziki
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
| | - Olga Giouleme
- Department of Medicine, Second Medical Clinic, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece
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Tiszlavicz Z, Somogyvári F, Szolnoki Z, Sztriha LK, Németh B, Vécsei L, Mándi Y. Genetic polymorphisms of human β-defensins in patients with ischemic stroke. Acta Neurol Scand 2012; 126:109-15. [PMID: 22050386 DOI: 10.1111/j.1600-0404.2011.01613.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVES AND METHODS Genetic predisposition of the inflammatory host response may affect the development of stroke. On the basis of the theory of infectious burden and risk of stroke, we considered it of interest to investigate the relevance of the single-nucleotide polymorphisms (SNPs) in the DEFB1 gene and the copy number variant (CNV) of the DEFB4 genes in ischemic stroke. RESULTS There were no significant differences in the genotype frequencies of the three SNPs of the DEFB1 gene between the patients with stroke (n = 312) and the healthy blood donors (n = 221). However, a higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with ischemic stroke as compared with the healthy controls (40% vs 24%, respectively). Additionally, low plasma concentrations of hBD-2 (187 ± 20 pg/ml) were characteristic of the patients with fewer than four copy numbers relative to those with more than four copy numbers (385 ± 35 pg/ml). CONCLUSIONS The low copy number of the DEFB4 gene, involving a weakened antimicrobial defense of the host, might be important in the pathogenesis of stroke.
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Affiliation(s)
- Z Tiszlavicz
- Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary
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Yount NY, Yeaman MR. Emerging themes and therapeutic prospects for anti-infective peptides. Annu Rev Pharmacol Toxicol 2012; 52:337-60. [PMID: 22235859 DOI: 10.1146/annurev-pharmtox-010611-134535] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pathogens resistant to most conventional anti-infectives are a harbinger of the need to discover and develop novel anti-infective agents and strategies. Endogenous host defense peptides (HDPs) have retained evolution-tested efficacy against pathogens that have become refractory to traditional antibiotics. Evidence indicates that HDPs target membrane integrity, bioenergetics, and other essential features of microbes that may be less mutable than conventional antibiotic targets. For these reasons, HDPs have received increasing attention as templates for development of potential anti-infective therapeutics. Unfortunately, advances toward this goal have proven disappointing, in part owing to limited understanding of relevant structure-activity and selective toxicity relationships in vivo, a limited number of reports and overall understanding of HDP pharmacology, and the difficulty of cost-effective production of such peptides on a commodity scale. However, recent molecular insights and technology innovations have led to novel HDP-based and mimetic anti-infective peptide candidates designed to overcome these limitations. Although initial setbacks have presented challenges to therapeutic development, emerging themes continue to highlight the potential of HDP-based anti-infectives as a platform for next-generation therapeutics that will help address the growing threat of multidrug-resistant infections.
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Affiliation(s)
- Nannette Y Yount
- Divisions of Infectious Diseases and Molecular Medicine, Los Angeles County Harbor-UCLA Medical Center, Torrance, California 90509, USA
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Williams WM, Castellani RJ, Weinberg A, Perry G, Smith MA. Do β-defensins and other antimicrobial peptides play a role in neuroimmune function and neurodegeneration? ScientificWorldJournal 2012; 2012:905785. [PMID: 22606066 PMCID: PMC3346844 DOI: 10.1100/2012/905785] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 10/26/2011] [Indexed: 12/25/2022] Open
Abstract
It is widely accepted that the brain responds to mechanical trauma and development of most neurodegenerative diseases with an inflammatory sequelae that was once thought exclusive to systemic immunity. Mostly cationic peptides, such as the β-defensins, originally assigned an antimicrobial function are now recognized as mediators of both innate and adaptive immunity. Herein supporting evidence is presented for the hypothesis that neuropathological changes associated with chronic disease conditions of the CNS involve abnormal expression and regulatory function of specific antimicrobial peptides. It is also proposed that these alterations exacerbate proinflammatory conditions within the brain that ultimately potentiate the neurodegenerative process.
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Affiliation(s)
- Wesley M Williams
- Department of Biological Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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