1
|
Shen K, Zhang M, Zhao R, Li Y, Li C, Hou X, Sun B, Liu B, Xiang M, Lin J. Eosinophil extracellular traps in asthma: implications for pathogenesis and therapy. Respir Res 2023; 24:231. [PMID: 37752512 PMCID: PMC10523707 DOI: 10.1186/s12931-023-02504-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/04/2023] [Indexed: 09/28/2023] Open
Abstract
Asthma is a common, chronic inflammatory disease of the airways that affects millions of people worldwide and is associated with significant healthcare costs. Eosinophils, a type of immune cell, play a critical role in the development and progression of asthma. Eosinophil extracellular traps (EETs) are reticular structures composed of DNA, histones, and granulins that eosinophils form and release into the extracellular space as part of the innate immune response. EETs have a protective effect by limiting the migration of pathogens and antimicrobial activity to a controlled range. However, chronic inflammation can lead to the overproduction of EETs, which can trigger and exacerbate allergic asthma. In this review, we examine the role of EETs in asthma.
Collapse
Affiliation(s)
- Kunlu Shen
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Mengyuan Zhang
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ruiheng Zhao
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Yun Li
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Chunxiao Li
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking University Health Science Center, Beijing, China
| | - Xin Hou
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking University Health Science Center, Beijing, China
| | - Bingqing Sun
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Bowen Liu
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Min Xiang
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Jiangtao Lin
- National Center for Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Institute of Respiratory Medicine, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, Chinese Academy of Medical Sciences, Friendship Hospital, No.2, East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
- Beijing University of Chinese Medicine, Beijing, China.
- Peking University Health Science Center, Beijing, China.
| |
Collapse
|
2
|
Colciaghi F, Costanza M. Unveiling Leukocyte Extracellular Traps in Inflammatory Responses of the Central Nervous System. Front Immunol 2022; 13:915392. [PMID: 35844591 PMCID: PMC9283689 DOI: 10.3389/fimmu.2022.915392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Over the past nearly two decades, increasing evidence has uncovered how immune cells can actively extrude genetic material to entrap invading pathogens or convey sterile inflammatory signals that contribute to shaping immune responses. Originally identified in neutrophils, the release of decondensed chromatin fibers decorated with antimicrobial proteins, called extracellular traps (ETs), has been recognized as a specific form of programmed inflammatory cell death, which is now known to occur in several other leukocytes. Subsequent reports have shown that self-DNA can be extruded from immune cells even in the absence of cell death phenomena. More recent data suggest that ETs formation could exacerbate neuroinflammation in several disorders of the central nervous system (CNS). This review article provides an overview of the varied types, sources, and potential functions of extracellular DNA released by immune cells. Key evidence suggesting the involvement of ETs in neurodegenerative, traumatic, autoimmune, and oncological disorders of the CNS will be discussed, outlining ongoing challenges and drawing potentially novel lines of investigation.
Collapse
Affiliation(s)
- Francesca Colciaghi
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Massimo Costanza
- Molecular Neuro-Oncology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- *Correspondence: Massimo Costanza,
| |
Collapse
|
3
|
Persson C. In vivo observations provide insight into roles of eosinophils and epithelial cells in asthma. Eur Respir J 2019; 54:13993003.00470-2019. [PMID: 31248957 DOI: 10.1183/13993003.00470-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/18/2019] [Indexed: 01/10/2023]
Abstract
Observations in vivo in patients, supported by guinea-pig in vivo data, take centre stage in this perspective. Its objective is to highlight dichotomies between asthma features observed in vivo and accepted views involving cell/molecular biology research paradigms. For example, increased bronchial epithelial permeability is now considered a major paradigm and trait of asthma, yet, absorption of inhaled tracers has not been increased in vivo in asthma. Such maintained barrier function in exudative asthma reflects in vivo asymmetry of the epithelial lining as barrier between outside and inside world of molecules and cells. In desquamatory asthma, maintained epithelial tightness may be explained by in vivo demonstrations of exceedingly patchy epithelial loss, prompt creation of plasma-derived provisional barriers, and high-speed epithelial regeneration. Acknowledged protein/peptide secretion by epithelial cells in vitro is contrasted here with a dominant, unidirectional movement in vivo of plasma-derived proteins/peptides (including antimicrobial peptides) to the surface of an intact epithelial lining. Furthermore, longstanding claims that epithelium-produced adenosine is a mediator of asthma are eroded by observations in vivo in asthmatics. Notions concerning activation/fate of mucosal tissue eosinophils illustrate additional distinctions between accepted views and in vivo patient observations. Finally, in vitro-based paradigms preaching defect epithelial regeneration and increased permeability in pathogenesis of asthma are contrasted with experimental in vivo observations of exaggerated epithelial regeneration, which is multipathogenic in its own right. In conclusion, unexpected and challenging in vivo observations in recent decades underpin novel insights into mucosal mechanisms in asthma.
Collapse
Affiliation(s)
- Carl Persson
- Laboratory Medicine University Hospital, Lund, Sweden
| |
Collapse
|
4
|
Mukherjee M, Lacy P, Ueki S. Eosinophil Extracellular Traps and Inflammatory Pathologies-Untangling the Web! Front Immunol 2018; 9:2763. [PMID: 30534130 PMCID: PMC6275237 DOI: 10.3389/fimmu.2018.02763] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022] Open
Abstract
Eosinophils are an enigmatic white blood cell, whose immune functions are still under intense investigation. Classically, the eosinophil was considered to fulfill a protective role against parasitic infections, primarily large multicellular helminths. Although eosinophils are predominantly associated with parasite infections, evidence of a role for eosinophils in mediating immunity against bacterial, viral, and fungal infections has been recently reported. Among the mechanisms by which eosinophils are proposed to exert their protective effects is the production of DNA-based extracellular traps (ETs). Remarkably, DNA serves a role that extends beyond its biochemical function in encoding RNA and protein sequences; it is also a highly effective substance for entrapment of bacteria and other extracellular pathogens, and serves as valuable scaffolding for antimicrobial mediators such as granule proteins from immune cells. Extracellular trap formation from eosinophils appears to fulfill an important immune response against extracellular pathogens, although overproduction of traps is evident in pathologies. Here, we discuss the discovery and characterization of eosinophil extracellular traps (EETs) in response to a variety of stimuli, and suggest a role for these structures in the pathogenesis of disease as well as the establishment of autoimmunity in chronic, unresolved inflammation.
Collapse
Affiliation(s)
- Manali Mukherjee
- Department of Medicine, McMaster University and St Joseph's Healthcare, Hamilton, ON, Canada
| | - Paige Lacy
- Department of Medicine, Alberta Respiratory Centre, University of Alberta, Edmonton, AB, Canada
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| |
Collapse
|