1
|
Thompson-Souza GA, Vasconcelos CRI, Neves JS. Eosinophils: Focus on DNA extracellular traps. Life Sci 2022; 311:121191. [DOI: 10.1016/j.lfs.2022.121191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022]
|
2
|
Neves VH, Palazzi C, Bonjour K, Ueki S, Weller PF, Melo RCN. In Vivo ETosis of Human Eosinophils: The Ultrastructural Signature Captured by TEM in Eosinophilic Diseases. Front Immunol 2022; 13:938691. [PMID: 35874692 PMCID: PMC9301467 DOI: 10.3389/fimmu.2022.938691] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/15/2022] [Indexed: 12/23/2022] Open
Abstract
Eosinophilic diseases, also termed eosinophil-associated diseases (EADs), are characterized by eosinophil-rich inflammatory infiltrates and extensive eosinophil degranulation with clinically relevant organ pathology. Recent evidence shows that eosinophil cytolytic degranulation, that is, the release of intact, membrane-delimited granules that arises from the eosinophil cytolysis, occurs mainly through ETosis, meaning death with a cytolytic profile and extrusion of nucleus-originated DNA extracellular traps (ETs). The ultrastructural features of eosinophil ETosis (EETosis) have been studied mostly in vitro after stimulation, but are still poorly understood in vivo. Here, we investigated in detail, by transmission electron microscopy (TEM), the ultrastructure of EETosis in selected human EADs affecting several tissues and organ systems. Biopsies of patients diagnosed with eosinophilic chronic rhinosinusitis/ECRS (frontal sinus), ulcerative colitis/UC (intestine), and hypereosinophilic syndrome/HES (skin) were processed for conventional TEM. First, we found that a large proportion of tissue-infiltrated eosinophils in all diseases (~45-65% of all eosinophils) were undergoing cytolysis with release of free extracellular granules (FEGs). Second, we compared the morphology of tissue inflammatory eosinophils with that shown by in vitro ETosis-stimulated eosinophils. By applying single-cell imaging analysis, we sought typical early and late EETosis events: chromatin decondensation; nuclear delobulation and rounding; expanded nuclear area; nuclear envelope alterations and disruption; and extracellular decondensed chromatin spread as ETs. We detected that 53% (ECRS), 37% (UC), and 82% (HES) of all tissue cytolytic eosinophils had ultrastructural features of ETosis in different degrees. Eosinophils in early ETosis significantly increased their nuclear area compared to non-cytolytic eosinophils due to excessive chromatin decondensation and expansion observed before nuclear envelope disruption. ETosis led not only to the deposition of intact granules, but also to the release of eosinophil sombrero vesicles (EoSVs) and Charcot-Leyden crystals (CLCs). Free intact EoSVs and CLCs were associated with FEGs and extracellular DNA nets. Interestingly, not all cytolytic eosinophils in the same microenvironment exhibited ultrastructure of ETosis, thus indicating that different populations of eosinophils might be selectively activated into this pathway. Altogether, our findings captured an ultrastructural signature of EETosis in vivo in prototypic EADs highlighting the importance of this event as a form of eosinophil degranulation and release of inflammatory markers (EoSVs and CLCs).
Collapse
Affiliation(s)
- Vitor H. Neves
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Cinthia Palazzi
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
- Laboratory of Molecular and Morphological Pathology, Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Graduate School of Medicine, Akita University, Akita, Japan
| | - Peter F. Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Rossana C. N. Melo
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
- *Correspondence: Rossana C. N. Melo,
| |
Collapse
|
3
|
Nazarinia D, Behzadifard M, Gholampour J, Karimi R, Gholampour M. Eotaxin-1 (CCL11) in neuroinflammatory disorders and possible role in COVID-19 neurologic complications. Acta Neurol Belg 2022; 122:865-869. [PMID: 35690992 PMCID: PMC9188656 DOI: 10.1007/s13760-022-01984-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 05/18/2022] [Indexed: 12/20/2022]
Abstract
The related neurologic complications of SARS-CoV-2 infection in COVID-19 patients and survivors comprise symptoms including depression, anxiety, muscle pain, dizziness, headaches, fatigue, and anosmia/hyposmia that may continue for months. Recent studies have been demonstrated that chemokines have brain-specific attraction and effects such as chemotaxis, cell adhesion, modulation of neuroendocrine functions, and neuroinflammation. CCL11 is a member of the eotaxin family that is chemotactic agents for eosinophils and participate in innate immunity. Eotaxins may exert physiological and pathological functions in the central nerve system, and CCL11 may induce neuronal cytotoxicity effects by inducing the production of reactive oxygen species (ROS) in microglia cells. Plasma levels of CCL11 elevated in neuroinflammation and neurodegenerative disorders. COVID-19 patients display elevations in CCL11 levels. As CCL11 plays roles in physiosomatic and neuroinflammation, analyzing the level of this chemokine in COVID-19 patients during hospitalization and to predicting post-COVID-19-related neurologic complications may be worthwhile. Moreover, using chemokine modulators may be helpful in lessening the neurologic complications in such patients.
Collapse
Affiliation(s)
- Donya Nazarinia
- Department of Physiology, School of Paramedical Sciences, Dezful University of Medical Sciences, Dezful, Iran
| | - Mahin Behzadifard
- Department of Physiology, School of Paramedical Sciences, Dezful University of Medical Sciences, Dezful, Iran.
| | - Javad Gholampour
- Department of Nursing, Faculty of Nursing and Midwifery, Mashhad Branch of Islamic Azad University, Mashhad, Iran
| | - Roqaye Karimi
- Department of Hematology and Cell Therapy, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammadali Gholampour
- Department of Medicine, Lung Biology Center, Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| |
Collapse
|
4
|
Lee DH, Jang JH, Sim S, Choi Y, Park HS. Epithelial Autoantigen-Specific IgG Antibody Enhances Eosinophil Extracellular Trap Formation in Severe Asthma. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2022; 14:479-493. [PMID: 36174991 PMCID: PMC9523418 DOI: 10.4168/aair.2022.14.5.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/27/2022] [Accepted: 07/05/2022] [Indexed: 11/20/2022]
Affiliation(s)
- Dong-Hyun Lee
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
- Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Korea
| | - Jae-Hyuk Jang
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
| | - Soyoon Sim
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
- Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Korea
| | - Youngwoo Choi
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
| | - Hae-Sim Park
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
- Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Korea
| |
Collapse
|
5
|
Miyabe Y, Kobayashi Y, Fukuchi M, Saga A, Moritoki Y, Saga T, Akuthota P, Ueki S. Eosinophil-mediated inflammation in the absence of eosinophilia. Asia Pac Allergy 2021; 11:e30. [PMID: 34386406 PMCID: PMC8331253 DOI: 10.5415/apallergy.2021.11.e30] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 07/10/2021] [Indexed: 12/14/2022] Open
Abstract
The increase of eosinophil levels is a hallmark of type-2 inflammation. Blood eosinophil counts act as a convenient biomarker for asthma phenotyping and the selection of biologics, and they are even used as a prognostic factor for severe coronavirus disease 2019. However, the circulating eosinophil count does not always reflect tissue eosinophilia and vice versa. The mismatch of blood and tissue eosinophilia can be seen in various clinical settings. For example, blood eosinophil levels in patients with acute eosinophilic pneumonia are often within normal range despite the marked symptoms and increased number of eosinophils in bronchoalveolar lavage fluid. Histological studies using immunostaining for eosinophil granule proteins have revealed the extracellular deposition of granule proteins coincident with pathological conditions, even in the absence of a significant eosinophil infiltrate. The marked deposition of eosinophil granule proteins in tissue is often associated with cytolytic degranulation. Recent studies have indicated that extracellular trap cell death (ETosis) is a major mechanism of cytolysis. Cytolytic ETosis is a total cell degranulation in which cytoplasmic and nuclear contents, including DNA and histones that act as alarmins, are also released. In the present review, eosinophil-mediated inflammation in such mismatch conditions is discussed.
Collapse
Affiliation(s)
- Yui Miyabe
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Yoshiki Kobayashi
- Airway Disease Section, Department of Otorhinolaryngology, Kansai Medical University, Hirakata, Japan.,Allergy Center, Kansai Medical University, Hirakata, Japan
| | - Mineyo Fukuchi
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Akiko Saga
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Yuki Moritoki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Tomoo Saga
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Praveen Akuthota
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| |
Collapse
|
6
|
Fettrelet T, Gigon L, Karaulov A, Yousefi S, Simon HU. The Enigma of Eosinophil Degranulation. Int J Mol Sci 2021; 22:ijms22137091. [PMID: 34209362 PMCID: PMC8268949 DOI: 10.3390/ijms22137091] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 12/18/2022] Open
Abstract
Eosinophils are specialized white blood cells, which are involved in the pathology of diverse allergic and nonallergic inflammatory diseases. Eosinophils are traditionally known as cytotoxic effector cells but have been suggested to additionally play a role in immunomodulation and maintenance of homeostasis. The exact role of these granule-containing leukocytes in health and diseases is still a matter of debate. Degranulation is one of the key effector functions of eosinophils in response to diverse stimuli. The different degranulation patterns occurring in eosinophils (piecemeal degranulation, exocytosis and cytolysis) have been extensively studied in the last few years. However, the exact mechanism of the diverse degranulation types remains unknown and is still under investigation. In this review, we focus on recent findings and highlight the diversity of stimulation and methods used to evaluate eosinophil degranulation.
Collapse
Affiliation(s)
- Timothée Fettrelet
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
- Department of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland
| | - Lea Gigon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
| | - Alexander Karaulov
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
| | - Shida Yousefi
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
| | - Hans-Uwe Simon
- Institute of Pharmacology, University of Bern, Inselspital, INO-F, CH-3010 Bern, Switzerland; (T.F.); (L.G.); (S.Y.)
- Department of Clinical Immunology and Allergology, Sechenov University, 119991 Moscow, Russia;
- Laboratory of Molecular Immunology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420012 Kazan, Russia
- Institute of Biochemistry, Medical School Brandenburg, D-16816 Neuruppin, Germany
- Correspondence: ; Tel.: +41-31-632-3281
| |
Collapse
|
7
|
Persaud AT, Bennett SA, Thaya L, Burnie J, Guzzo C. Human monocytes store and secrete preformed CCL5, independent of de novo protein synthesis. J Leukoc Biol 2021; 111:573-583. [PMID: 34114669 DOI: 10.1002/jlb.3a0820-522rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Monocytes are a subset of circulating peripheral blood mononuclear cells with diverse roles in immunity, including sentinel roles in cytokine secretion. Conventionally, cytokines require an inductive stimulus for their expression and secretion, resulting in a time lag from the time of stimulation to when the proteins are packaged and secreted. Because cytokines are the main communicators in the immune system, their temporal expression is a key factor in coordinating responses to efficiently resolve infection. Herein, we identify that circulating human monocytes contain preformed cytokines that are stored intracellularly, in both resting and activated states. Having preformed cytokines bypasses the time lag associated with de novo synthesis, allowing monocytes to secrete immune mediators immediately upon activation or sensing of microbe-associated molecular patterns. We demonstrate here that, out of several cytokines evaluated, human monocytes contain a previously undescribed reservoir of the preformed chemokine CCL5. Furthermore, we showed that CCL5 could be secreted from monocytes treated with the protein synthesis inhibitor (cycloheximide) and Golgi blocker (brefeldin A). We examined the possibility for uptake of extracellular CCL5 from platelet aggregates and observed no significant levels of platelet binding to our enriched monocyte preparations, indicating that the source of preformed CCL5 was not from platelets. Preformed CCL5 was observed to be distributed throughout the cytoplasm and partially colocalized with CD63+ and Rab11A+ membranes, implicating endosomal compartments in the intracellular storage and trafficking of CCL5.
Collapse
Affiliation(s)
- Arvin Tejnarine Persaud
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Stephen Andrew Bennett
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Laxshaginee Thaya
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
8
|
Folci M, Ramponi G, Arcari I, Zumbo A, Brunetta E. Eosinophils as Major Player in Type 2 Inflammation: Autoimmunity and Beyond. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1347:197-219. [PMID: 34031864 DOI: 10.1007/5584_2021_640] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Eosinophils are a subset of differentiated granulocytes which circulate in peripheral blood and home in several body tissues. Along with their traditional relevance in helminth immunity and allergy, eosinophils have been progressively attributed important roles in a number of homeostatic and pathologic situations. This review aims at summarizing available evidence about eosinophils functions in homeostasis, infections, allergic and autoimmune disorders, and solid and hematological cancers.Their structural and biological features have been described, along with their physiological behavior. This includes their chemokines, cytokines, granular contents, and extracellular traps. Besides, pathogenic- and eosinophilic-mediated disorders have also been addressed, with the aim of highlighting their role in Th2-driven inflammation. In allergy, eosinophils are implicated in the pathogenesis of atopic dermatitis, allergic rhinitis, and asthma. They are also fundamentally involved in autoimmune disorders such as eosinophilic esophagitis, eosinophilic gastroenteritis, acute and chronic eosinophilic pneumonia, and eosinophilic granulomatosis with polyangiitis. In infections, eosinophils are involved in protection not only from parasites but also from fungi, viruses, and bacteria. In solid cancers, local eosinophilic infiltration is variably associated with an improved or worsened prognosis, depending on the histotype. In hematologic neoplasms, eosinophilia can be the consequence of a dysregulated cytokine production or the result of mutations affecting the myeloid lineage.Recent experimental evidence was thoroughly reviewed, with findings which elicit a complex role for eosinophils, in a tight balance between host defense and tissue damage. Eventually, emerging evidence about eosinophils in COVID-19 infection was also discussed.
Collapse
Affiliation(s)
- Marco Folci
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy. .,Department of Biomedical Sciences, Humanitas University, Milan, Italy.
| | - Giacomo Ramponi
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Ivan Arcari
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Aurora Zumbo
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Enrico Brunetta
- Humanitas Clinical and Research Center - IRCCS, Milan, Italy.,Department of Biomedical Sciences, Humanitas University, Milan, Italy
| |
Collapse
|
9
|
Daines JM, Schellhardt L, Wood MD. The Role of the IL-4 Signaling Pathway in Traumatic Nerve Injuries. Neurorehabil Neural Repair 2021; 35:431-443. [PMID: 33754913 DOI: 10.1177/15459683211001026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Following traumatic peripheral nerve injury, adequate restoration of function remains an elusive clinical goal. Recent research highlights the complex role that the immune system plays in both nerve injury and regeneration. Pro-regenerative processes in wounded soft tissues appear to be significantly mediated by cytokines of the type 2 immune response, notably interleukin (IL)-4. While IL-4 signaling has been firmly established as a critical element in general tissue regeneration during wound healing, it has also emerged as a critical process in nerve injury and regeneration. In this context of peripheral nerve injury, endogenous IL-4 signaling has recently been confirmed to influence more than leukocytes, but including also neurons, axons, and Schwann cells. Given the role IL-4 plays in nerve injury and regeneration, exogenous IL-4 and/or compounds targeting this signaling pathway have shown encouraging preliminary results to treat nerve injury or other neuropathy in rodent models. In particular, the exogenous stimulation of the IL-4 signaling pathway appears to promote postinjury neuron survival, axonal regeneration, remyelination, and thereby improved functional recovery. These preclinical data strongly suggest that targeting IL-4 signaling pathways is a promising translational therapy to augment treatment approaches of traumatic nerve injury. However, a better understanding of the type 2 immune response and associated signaling networks functioning within the nerve injury microenvironment is still needed to fully develop this promising therapeutic avenue.
Collapse
|
10
|
Gebremeskel S, Schanin J, Coyle KM, Butuci M, Luu T, Brock EC, Xu A, Wong A, Leung J, Korver W, Morin RD, Schleimer RP, Bochner BS, Youngblood BA. Mast Cell and Eosinophil Activation Are Associated With COVID-19 and TLR-Mediated Viral Inflammation: Implications for an Anti-Siglec-8 Antibody. Front Immunol 2021; 12:650331. [PMID: 33777047 PMCID: PMC7988091 DOI: 10.3389/fimmu.2021.650331] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/18/2021] [Indexed: 12/11/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection represents a global health crisis. Immune cell activation via pattern recognition receptors has been implicated as a driver of the hyperinflammatory response seen in COVID-19. However, our understanding of the specific immune responses to SARS-CoV-2 remains limited. Mast cells (MCs) and eosinophils are innate immune cells that play pathogenic roles in many inflammatory responses. Here we report MC-derived proteases and eosinophil-associated mediators are elevated in COVID-19 patient sera and lung tissues. Stimulation of viral-sensing toll-like receptors in vitro and administration of synthetic viral RNA in vivo induced features of hyperinflammation, including cytokine elevation, immune cell airway infiltration, and MC-protease production—effects suppressed by an anti-Siglec-8 monoclonal antibody which selectively inhibits MCs and depletes eosinophils. Similarly, anti-Siglec-8 treatment reduced disease severity and airway inflammation in a respiratory viral infection model. These results suggest that MC and eosinophil activation are associated with COVID-19 inflammation and anti-Siglec-8 antibodies are a potential therapeutic approach for attenuating excessive inflammation during viral infections.
Collapse
Affiliation(s)
| | | | - Krysta M Coyle
- Department of Molecular Biology and Biochemistry, Research Centre, Simon Fraser University, Vancouver, BC, Canada
| | | | - Thuy Luu
- Allakos Inc., Redwood City, CA, United States
| | | | - Alan Xu
- Allakos Inc., Redwood City, CA, United States
| | - Alan Wong
- Allakos Inc., Redwood City, CA, United States
| | - John Leung
- Allakos Inc., Redwood City, CA, United States
| | | | - Ryan D Morin
- Department of Molecular Biology and Biochemistry, Research Centre, Simon Fraser University, Vancouver, BC, Canada
| | - Robert P Schleimer
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Bruce S Bochner
- Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | | |
Collapse
|
11
|
Rojas-Hernandez CM. Hypereosinophilia: An Unusual Bystander in Cancer. JOURNAL OF IMMUNOTHERAPY AND PRECISION ONCOLOGY 2021; 4:26-27. [PMID: 35664824 PMCID: PMC9161664 DOI: 10.36401/jipo-20-x8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 10/23/2020] [Indexed: 06/15/2023]
Affiliation(s)
- Cristhiam M. Rojas-Hernandez
- Section of Benign Hematology, Department on Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| |
Collapse
|
12
|
Exosomes: A Key Piece in Asthmatic Inflammation. Int J Mol Sci 2021; 22:ijms22020963. [PMID: 33478047 PMCID: PMC7835850 DOI: 10.3390/ijms22020963] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
Asthma is a chronic disease of the airways that has an important inflammatory component. Multiple cells are implicated in asthma pathogenesis (lymphocytes, eosinophils, mast cells, basophils, neutrophils), releasing a wide variety of cytokines. These cells can exert their inflammatory functions throughout extracellular vesicles (EVs), which are small vesicles released by donor cells into the extracellular microenvironment that can be taken up by recipient cells. Depending on their size, EVs can be classified as microvesicles, exosomes, or apoptotic bodies. EVs are heterogeneous spherical structures secreted by almost all cell types. One of their main functions is to act as transporters of a wide range of molecules, such as proteins, lipids, and microRNAs (miRNAs), which are single-stranded RNAs of approximately 22 nucleotides in length. Therefore, exosomes could influence several physiological and pathological processes, including those involved in asthma. They can be detected in multiple cell types and biofluids, providing a wealth of information about the processes that take account in a pathological scenario. This review thus summarizes the most recent insights concerning the role of exosomes from different sources (several cell populations and biofluids) in one of the most prevalent respiratory diseases, asthma.
Collapse
|
13
|
Abstract
PURPOSE OF REVIEW Lineage commitment is governed by instructive and stochastic signals, which drive both active induction of the lineage program and repression of alternative fates. Eosinophil lineage commitment is driven by the ordered interaction of transcription factors, supported by cytokine signals. This review summarizes key findings in the study of eosinophil lineage commitment and examines new data investigating the factors that regulate this process. RECENT FINDINGS Recent and past studies highlight how intrinsic and extrinsic signals modulate transcription factor network and lineage decisions. Early action of the transcription factors C/EBPα and GATA binding protein-1 along with C/EBPε supports lineage commitment and eosinophil differentiation. This process is regulated and enforced by the pseudokinase Trib1, a regulator of C/EBPα levels. The cytokines interleukin (IL)-5 and IL-33 also support early eosinophil development. However, current studies suggest that these cytokines are not specifically required for lineage commitment. SUMMARY Together, recent evidence suggests a model where early transcription factor activity drives expression of key eosinophil genes and cytokine receptors to prime lineage commitment. Understanding the factors and signals that control eosinophil lineage commitment may guide therapeutic development for eosinophil-mediated diseases and provide examples for fate choices in other lineages.
Collapse
|
14
|
Morphological and phenotypical diversity of eosinophils in the rat ileum. Cell Tissue Res 2020; 381:439-450. [PMID: 32424506 DOI: 10.1007/s00441-020-03209-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 03/26/2020] [Indexed: 12/17/2022]
Abstract
Eosinophils are abundantly present in intestinal mucosa. However, the morphological characteristics of their cellular population are still largely unknown. In this study, we examine their characteristics in the rat ileal mucosa using histological and ultrastructural methods. The results indicated that ileal eosinophils could be distinguished into two main groups based on their nuclear shapes and distribution: eosinophils with spheric or reniform nuclei mainly localized in the villous region and eosinophils with annular or bacilliform nuclei as the major population around crypts. Immunohistochemical analysis revealed that all eosinophils in the lamina propria (LP) were immunopositive for CD11b, whereas eosinophils in LP of the intestinal villus but not those in LP around the crypt, were immunopositive for CD11c. Three-dimensional ultrastructural analysis using serial block-face scanning electron microscopy showed that the eosinophils with spheric or reniform nuclei were abundant in the upper portions of the intestinal villus, whereas those with annular nuclei were abundant in the lower portions of the intestinal villus and around crypts. The eosinophils with spheric or reniform nuclei possessed broader cellular bodies with greater abundance of surface projections compared with those with annular nuclei. Eosinophils in the upper portions of intestinal villus frequently extended their cellular bodies into the intraepithelial space. The number of total and eosinophil-specific granules was positively correlated with the minor axis of the nuclear holes in the annular nuclei. These data suggest that ileal eosinophils exhibit not homogenous but rather diverse characteristics, possible due to the mixture of eosinophils at different maturation and/or activation stages.
Collapse
|
15
|
Carmo LAS, Bonjour K, Spencer LA, Weller PF, Melo RCN. Single-Cell Analyses of Human Eosinophils at High Resolution to Understand Compartmentalization and Vesicular Trafficking of Interferon-Gamma. Front Immunol 2018; 9:1542. [PMID: 30038615 PMCID: PMC6046373 DOI: 10.3389/fimmu.2018.01542] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/21/2018] [Indexed: 12/16/2022] Open
Abstract
Human eosinophils release numerous cytokines that are pre-synthesized and stored within their cytoplasmic-specific (secretory) granules. For example, high levels of interferon-gamma (IFN-γ) are constitutively expressed in these cells, but the intracellular compartments involved in the transport and release of this cytokine remain to be established. In this work, we used a single-cell approach to investigate the subcellular localization of IFN-γ in human eosinophils stimulated or not with tumor necrosis factor alpha (TNF-α) or CC-chemokine ligand 11 CCL11 (eotaxin-1), inflammatory mediators that induce eosinophil activation and secretion. A pre-embedding immunonanogold transmission electron microscopy (TEM) technique that combines optimal epitope preservation and access to membrane microdomains was applied to detect precise localization of IFN-γ in combination with computational quantitative analyses. In parallel, degranulation processes and formation of eosinophil sombrero vesicles (EoSVs), large transport carriers involved in the transport of granule-derived cytokines, were investigated. Quantitative TEM revealed that both CCL11 and TNF-α-activated eosinophils significantly increased the total number of EoSVs compared to the unstimulated group, indicating that this vesicular system is actively formed in response to cell activation. Ultrastructural immunolabeling identified a robust pool of IFN-γ on secretory granules in both unstimulated and stimulated cells. Moreover, EoSVs carrying IFN-γ were seen around or/and in contact with secretory granules and also distributed in the cytoplasm. Labeling was clearly associated with EoSV membranes. The total number of IFN-γ-positive EoSVs was significantly higher in stimulated compared to unstimulated cells, and these labeled vesicles had a differential distribution in the cytoplasm of activated cells, being significantly higher in the cell periphery compared with the inner cell, thus revealing intracellular IFN-γ mobilization for release. IFN-γ extracellular labeling was found at the cell surface, including on extracellular vesicles. Our results provide direct evidence that human eosinophils compartmentalize IFN-γ within secretory granules and identify, for the first time, a vesicular trafficking of IFN-γ associated with large transport carriers. This is important to understand how IFN-γ is trafficked and secreted during inflammatory responses.
Collapse
Affiliation(s)
- Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil.,Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| |
Collapse
|
16
|
Melo RCN, Weller PF. Contemporary understanding of the secretory granules in human eosinophils. J Leukoc Biol 2018; 104:85-93. [PMID: 29749658 DOI: 10.1002/jlb.3mr1217-476r] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 12/12/2022] Open
Abstract
Eosinophil secretory (specific) granules have a unique morphology and are both a morphologic hallmark of eosinophils and fundamental to eosinophil-mediated responses. Eosinophil mediators with multiple functional activities are presynthesized and stored within these granules, poised for very rapid, stimulus-induced secretion. The structural organization and changes of eosinophil specific granules are revealing in demonstrating the complex and diverse secretory activities of this cell. Here, we review our current knowledge on the architecture, composition, and function of eosinophil specific granules as highly elaborated organelles able to produce vesiculotubular carriers and to interplay with the intracellular vesicular trafficking. We reconsider prior identifications of eosinophil cytoplasmic granules, including "primary," "secondary," "microgranules," and "small granules"; and consonant with advances, we provide a contemporary recognition that human eosinophils contain a single population of specific granules and their developmental precursors and derived secretory vesicles.
Collapse
Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, Brazil.,Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, Brazil
| |
Collapse
|
17
|
Abstract
Eosinophils are a prominent cell type in particular host responses such as the response to helminth infection and allergic disease. Their effector functions have been attributed to their capacity to release cationic proteins stored in cytoplasmic granules by degranulation. However, eosinophils are now being recognized for more varied functions in previously underappreciated diverse tissue sites, based on the ability of eosinophils to release cytokines (often preformed) that mediate a broad range of activities into the local environment. In this Review, we consider evolving insights into the tissue distribution of eosinophils and their functional immunobiology, which enable eosinophils to secrete in a selective manner cytokines and other mediators that have diverse, 'non-effector' functions in health and disease.
Collapse
Affiliation(s)
- Peter F Weller
- Division of Allergy and Inflammation, Harvard Medical School, Beth Israel Deaconess Medical Center, CLS 943, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
| | - Lisa A Spencer
- Division of Allergy and Inflammation, Harvard Medical School, Beth Israel Deaconess Medical Center, CLS 943, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
| |
Collapse
|
18
|
Thompson-Souza GA, Gropillo I, Neves JS. Cysteinyl Leukotrienes in Eosinophil Biology: Functional Roles and Therapeutic Perspectives in Eosinophilic Disorders. Front Med (Lausanne) 2017; 4:106. [PMID: 28770202 PMCID: PMC5515036 DOI: 10.3389/fmed.2017.00106] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/29/2017] [Indexed: 12/16/2022] Open
Abstract
Cysteinyl leukotrienes (cysLTs), LTC4, and its extracellular metabolites, LTD4 and LTE4, have varied and multiple roles in mediating eosinophilic disorders including host defense against parasitic helminthes and allergic inflammation, especially in the lung and in asthma. CysLTs are known to act through at least 2 receptors termed cysLT1 receptor (CysLT1R) and cysLT2 receptor (CysLT2R). Eosinophils contain a dominant population of cytoplasmic crystalloid granules that store various preformed proteins. Human eosinophils are sources of cysLTs and are known to express the two known cysLTs receptors (CysLTRs). CysLTs can have varied functions on eosinophils, ranging from intracrine regulators of secretion of granule-derived proteins to paracrine/autocrine roles in eosinophil chemotaxis, differentiation, and survival. Lately, it has been recognized the expression of CysLTRs in the membranes of eosinophil granules. Moreover, cysLTs have been shown to evoke secretion from isolated cell-free eosinophil granules operating through their receptors expressed on granule membranes. In this work, we review the functional roles of cysLTs in eosinophil biology. We review cysLTs biosynthesis, their receptors, and argue the intracrine and paracrine/autocrine responses induced by cysLTs in eosinophils and in isolated free extracellular eosinophil granules. We also examine and speculate on the therapeutic relevance of targeting CysLTRs in the treatment of eosinophilic disorders.
Collapse
Affiliation(s)
| | - Isabella Gropillo
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Josiane S Neves
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
19
|
McBrien CN, Menzies-Gow A. The Biology of Eosinophils and Their Role in Asthma. Front Med (Lausanne) 2017; 4:93. [PMID: 28713812 PMCID: PMC5491677 DOI: 10.3389/fmed.2017.00093] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/13/2017] [Indexed: 12/22/2022] Open
Abstract
This review will describe the structure and function of the eosinophil. The roles of several relevant cell surface molecules and receptors will be discussed. We will also explore the systemic and local processes triggering eosinophil differentiation, maturation, and migration to the lungs in asthma, as well as the cytokine-mediated pathways that result in eosinophil activation and degranulation, i.e., the release of multiple pro-inflammatory substances from eosinophil-specific granules, including cationic proteins, cytokines, chemokines growth factors, and enzymes. We will discuss the current understanding of the roles that eosinophils play in key asthma processes such as airway hyperresponsiveness, mucus hypersecretion, and airway remodeling, in addition to the evidence relating to eosinophil–pathogen interactions within the lungs.
Collapse
Affiliation(s)
| | - Andrew Menzies-Gow
- Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
20
|
Diny NL, Rose NR, Čiháková D. Eosinophils in Autoimmune Diseases. Front Immunol 2017; 8:484. [PMID: 28496445 PMCID: PMC5406413 DOI: 10.3389/fimmu.2017.00484] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/07/2017] [Indexed: 12/15/2022] Open
Abstract
Eosinophils are multifunctional granulocytes that contribute to initiation and modulation of inflammation. Their role in asthma and parasitic infections has long been recognized. Growing evidence now reveals a role for eosinophils in autoimmune diseases. In this review, we summarize the function of eosinophils in inflammatory bowel diseases, neuromyelitis optica, bullous pemphigoid, autoimmune myocarditis, primary biliary cirrhosis, eosinophilic granulomatosis with polyangiitis, and other autoimmune diseases. Clinical studies, eosinophil-targeted therapies, and experimental models have contributed to our understanding of the regulation and function of eosinophils in these diseases. By examining the role of eosinophils in autoimmune diseases of different organs, we can identify common pathogenic mechanisms. These include degranulation of cytotoxic granule proteins, induction of antibody-dependent cell-mediated cytotoxicity, release of proteases degrading extracellular matrix, immune modulation through cytokines, antigen presentation, and prothrombotic functions. The association of eosinophilic diseases with autoimmune diseases is also examined, showing a possible increase in autoimmune diseases in patients with eosinophilic esophagitis, hypereosinophilic syndrome, and non-allergic asthma. Finally, we summarize key future research needs.
Collapse
Affiliation(s)
- Nicola L Diny
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Noel R Rose
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniela Čiháková
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
21
|
Akuthota P, Carmo LAS, Bonjour K, Murphy RO, Silva TP, Gamalier JP, Capron KL, Tigges J, Toxavidis V, Camacho V, Ghiran I, Ueki S, Weller PF, Melo RCN. Extracellular Microvesicle Production by Human Eosinophils Activated by "Inflammatory" Stimuli. Front Cell Dev Biol 2016; 4:117. [PMID: 27833910 PMCID: PMC5081571 DOI: 10.3389/fcell.2016.00117] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 10/07/2016] [Indexed: 01/08/2023] Open
Abstract
A key function of human eosinophils is to secrete cytokines, chemokines and cationic proteins, trafficking, and releasing these mediators for roles in inflammation and other immune responses. Eosinophil activation leads to secretion of pre-synthesized granule-stored mediators through different mechanisms, but the ability of eosinophils to secrete extracellular vesicles (EVs), very small vesicles with preserved membrane topology, is still poorly understood. In the present work, we sought to identify and characterize EVs released from human eosinophils during different conditions: after a culturing period or after isolation and stimulation with inflammatory stimuli, which are known to induce eosinophil activation and secretion: CCL11 (eotaxin-1) and tumor necrosis factor alpha (TNF-α). EV production was investigated by nanoscale flow cytometry, conventional transmission electron microscopy (TEM) and pre-embedding immunonanogold EM. The tetraspanins CD63 and CD9 were used as EV biomarkers for both flow cytometry and ultrastructural immunolabeling. Nanoscale flow cytometry showed that human eosinophils produce EVs in culture and that a population of EVs expressed detectable CD9, while CD63 was not consistently detected. When eosinophils were stimulated immediately after isolation and analyzed by TEM, EVs were clearly identified as microvesicles (MVs) outwardly budding off the plasma membrane. Both CCL11 and TNF-α induced significant increases of MVs compared to unstimulated cells. TNF-α induced amplified release of MVs more than CCL11. Eosinophil MV diameters varied from 20 to 1000 nm. Immunonanogold EM revealed clear immunolabeling for CD63 and CD9 on eosinophil MVs, although not all MVs were labeled. Altogether, we identified, for the first time, that human eosinophils secrete MVs and that this production increases in response to inflammatory stimuli. This is important to understand the complex secretory activities of eosinophils underlying immune responses. The contribution of the eosinophil-derived MVs to the regulation of immune responses awaits further investigation.
Collapse
Affiliation(s)
- Praveen Akuthota
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical SchoolBoston, MA, USA; Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California San DiegoLa Jolla, CA, USA
| | - Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Ryann O Murphy
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Thiago P Silva
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Juliana P Gamalier
- Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de Fora Juiz de Fora, Brazil
| | - Kelsey L Capron
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - John Tigges
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Vasilis Toxavidis
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Virginia Camacho
- Flow Cytometry Core, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Ionita Ghiran
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine Akita, Japan
| | - Peter F Weller
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA
| | - Rossana C N Melo
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical SchoolBoston, MA, USA; Laboratory of Cellular Biology, Department of Biology, Institute of Biological Sciences (ICB), Federal University of Juiz de ForaJuiz de Fora, Brazil
| |
Collapse
|
22
|
Melo RCN, Weller PF. Vesicular trafficking of immune mediators in human eosinophils revealed by immunoelectron microscopy. Exp Cell Res 2016; 347:385-90. [PMID: 27562864 DOI: 10.1016/j.yexcr.2016.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 08/19/2016] [Accepted: 08/20/2016] [Indexed: 01/21/2023]
Abstract
Electron microscopy (EM)-based techniques are mostly responsible for our current view of cell morphology at the subcellular level and continue to play an essential role in biological research. In cells from the immune system, such as eosinophils, EM has helped to understand how cells package and release mediators involved in immune responses. Ultrastructural investigations of human eosinophils enabled visualization of secretory processes in detail and identification of a robust, vesicular trafficking essential for the secretion of immune mediators via a non-classical secretory pathway associated with secretory (specific) granules. This vesicular system is mainly organized as large tubular-vesicular carriers (Eosinophil Sombrero Vesicles - EoSVs) actively formed in response to cell activation and provides a sophisticated structural mechanism for delivery of granule-stored mediators. In this review, we highlight the application of EM techniques to recognize pools of immune mediators at vesicular compartments and to understand the complex secretory pathway within human eosinophils involved in inflammatory and allergic responses.
Collapse
Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA.
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA
| |
Collapse
|
23
|
Carmo LAS, Bonjour K, Ueki S, Neves JS, Liu L, Spencer LA, Dvorak AM, Weller PF, Melo RCN. CD63 is tightly associated with intracellular, secretory events chaperoning piecemeal degranulation and compound exocytosis in human eosinophils. J Leukoc Biol 2016; 100:391-401. [PMID: 26965633 PMCID: PMC6608091 DOI: 10.1189/jlb.3a1015-480r] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/18/2016] [Accepted: 02/02/2016] [Indexed: 12/26/2022] Open
Abstract
Eosinophil activation leads to secretion of presynthesized, granule-stored mediators that determine the course of allergic, inflammatory, and immunoregulatory responses. CD63, a member of the transmembrane-4 glycoprotein superfamily (tetraspanins) and present on the limiting membranes of eosinophil-specific (secretory) granules, is considered a potential surface marker for eosinophil degranulation. However, the intracellular secretory trafficking of CD63 in eosinophils and other leukocytes is not understood. Here, we provide a comprehensive investigation of CD63 trafficking at high resolution within human eosinophils stimulated with inflammatory stimuli, CCL11 and tumor necrosis factor α, which induce distinctly differing secretory processes in eosinophils: piecemeal degranulation and compound exocytosis, respectively. By using different transmission electron microscopy approaches, including an immunonanogold technique, for enhanced detection of CD63 at subcellular compartments, we identified a major intracellular pool of CD63 that is directly linked to eosinophil degranulation events. Transmission electron microscopy quantitative analyses demonstrated that, in response to stimulation, CD63 is concentrated within granules undergoing secretion by piecemeal degranulation or compound exocytosis and that CD63 tracks with the movements of vesicles and granules in the cytoplasm. Although CD63 was observed at the cell surface after stimulation, immunonanogold electron microscopy revealed that a strong CD63 pool remains in the cytoplasm. It is remarkable that CCL11 and tumor necrosis factor α triggered increased formation of CD63(+) large vesiculotubular carriers (eosinophil sombrero vesicles), which fused with granules in the process of secretion, likely acting in the intracellular translocation of CD63. Altogether, we identified active, intracellular CD63 trafficking connected to eosinophil granule-derived secretory pathways. This is important for understanding the complex secretory activities of eosinophils underlying immune responses.
Collapse
Affiliation(s)
- Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil
| | - Shigeharu Ueki
- Department of General Internal Medicine and Clinical Laboratory Medicine, Akita University Graduate School of Medicine, Akita, Japan
| | - Josiane S Neves
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Linying Liu
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Ann M Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Juiz de Fora, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
| |
Collapse
|
24
|
May RD, Fung M. Strategies targeting the IL-4/IL-13 axes in disease. Cytokine 2016; 75:89-116. [PMID: 26255210 DOI: 10.1016/j.cyto.2015.05.018] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 05/15/2015] [Indexed: 02/07/2023]
Abstract
IL-4 and IL-13 are pleiotropic Th2 cytokines produced by a wide variety of different cell types and responsible for a broad range of biology and functions. Physiologically, Th2 cytokines are known to mediate host defense against parasites but they can also trigger disease if their activities are dysregulated. In this review we discuss the rationale for targeting the IL-4/IL-13 axes in asthma, atopic dermatitis, allergic rhinitis, COPD, cancer, inflammatory bowel disease, autoimmune disease and fibrotic disease as well as evaluating the associated clinical data derived from blocking IL-4, IL-13 or IL-4 and IL-13 together.
Collapse
|
25
|
Expression and subcellular localization of the Qa-SNARE syntaxin17 in human eosinophils. Exp Cell Res 2015; 337:129-135. [PMID: 26254897 DOI: 10.1016/j.yexcr.2015.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 06/29/2015] [Accepted: 07/06/2015] [Indexed: 01/21/2023]
Abstract
BACKGROUND SNARE members mediate membrane fusion during intracellular trafficking underlying innate and adaptive immune responses by different cells. However, little is known about the expression and function of these proteins in human eosinophils, cells involved in allergic, inflammatory and immunoregulatory responses. Here, we investigate the expression and distribution of the Qa-SNARE syntaxin17 (STX17) within human eosinophils isolated from the peripheral blood. METHODS Flow cytometry and a pre-embedding immunonanogold electron microscopy (EM) technique that combines optimal epitope preservation and secondary Fab-fragments of antibodies linked to 1.4 nm gold particles for optimal access to microdomains, were used to investigate STX17. RESULTS STX17 was detected within unstimulated eosinophils. Immunogold EM revealed STX17 on secretory granules and on granule-derived vesiculotubular transport carriers (Eosinophil Sombrero Vesicles-EoSVs). Quantitative EM analyses showed that 77.7% of the granules were positive for STX17 with a mean±SEM of 3.9±0.2 gold particles/granule. Labeling was present on both granule outer membranes and matrices while EoSVs showed clear membrane-associated labeling. STX17 was also present in secretory granules in eosinophils stimulated with the cytokine tumor necrosis factor alpha (TNF-α) or the CC-chemokine ligand 11 CCL11 (eotaxin-1), stimuli that induce eosinophil degranulation. The number of secretory granules labeled for STX17 was significantly higher in CCL11 compared with the unstimulated group. The level of cell labeling did not change when unstimulated cells were compared with TNF-α-stimulated eosinophils. CONCLUSIONS The present study clearly shows by immunanonogold EM that STX17 is localized in eosinophil secretory granules and transport vesicles and might be involved in the transport of granule-derived cargos.
Collapse
|
26
|
Multifaceted roles of cysteinyl leukotrienes in eliciting eosinophil granule protein secretion. BIOMED RESEARCH INTERNATIONAL 2015; 2015:848762. [PMID: 25866815 PMCID: PMC4383494 DOI: 10.1155/2015/848762] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 10/09/2014] [Indexed: 12/19/2022]
Abstract
Cysteinyl leukotrienes (cysLTs) are cell membrane-impermeant lipid mediators that play major roles in the pathogenesis of eosinophilic inflammation and are recognized to act via at least 2 receptors, namely, cysLT1 receptor (cysLT1R) and cysLT2 receptor (cysLT2R). Eosinophils, which are granulocytes classically associated with host defense against parasitic helminthes and allergic conditions, are distinguished from leukocytes by their dominant population of cytoplasmic crystalloid (also termed secretory, specific, or secondary) granules that contain robust stores of diverse preformed proteins. Human eosinophils are the main source of cysLTs and are recognized to express both cysLTs receptors (cysLTRs) on their surface, at the plasma membrane. More recently, we identified the expression of cysLTRs in eosinophil granule membranes and demonstrated that cysLTs, acting via their granule membrane-expressed receptors, elicit secretion from cell-free human eosinophil granules. Herein, we review the multifaceted roles of cysLTs in eliciting eosinophil granule protein secretion. We discuss the intracrine and autocrine/paracrine secretory responses evoked by cysLTs in eosinophils and in cell-free extracellular eosinophil crystalloid granules. We also discuss the importance of this finding in eosinophil immunobiology and speculate on its potential role(s) in eosinophilic diseases.
Collapse
|
27
|
Spencer LA, Bonjour K, Melo RCN, Weller PF. Eosinophil secretion of granule-derived cytokines. Front Immunol 2014; 5:496. [PMID: 25386174 PMCID: PMC4209865 DOI: 10.3389/fimmu.2014.00496] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 09/23/2014] [Indexed: 12/30/2022] Open
Abstract
Eosinophils are tissue-dwelling leukocytes, present in the thymus, and gastrointestinal and genitourinary tracts of healthy individuals at baseline, and recruited, often in large numbers, to allergic inflammatory foci and sites of active tissue repair. The biological significance of eosinophils is vast and varied. In health, eosinophils support uterine and mammary gland development, and maintain bone marrow plasma cells and adipose tissue alternatively activated macrophages, while in response to tissue insult eosinophils function as inflammatory effector cells, and, in the wake of an inflammatory response, promote tissue regeneration, and wound healing. One common mechanism driving many of the diverse eosinophil functions is the regulated and differential secretion of a vast array of eosinophil-derived cytokines. Eosinophils are distinguished from most other leukocytes in that many, if not all, of the over three dozen eosinophil-derived cytokines are pre-synthesized and stored within intracellular granules, poised for very rapid, stimulus-induced secretion. Eosinophils engaged in cytokine secretion in situ utilize distinct pathways of cytokine release that include classical exocytosis, whereby granules themselves fuse with the plasma membrane and release their entire contents extracellularly; piecemeal degranulation, whereby granule-derived cytokines are selectively mobilized into vesicles that emerge from granules, traverse the cytoplasm and fuse with the plasma membrane to release discrete packets of cytokines; and eosinophil cytolysis, whereby intact granules are extruded from eosinophils, and deposited within tissues. In this latter scenario, extracellular granules can themselves function as stimulus-responsive secretory-competent organelles within the tissue. Here, we review the distinctive processes of differential secretion of eosinophil granule-derived cytokines.
Collapse
Affiliation(s)
- Lisa A Spencer
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA
| | - Kennedy Bonjour
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF) , Juiz de Fora , Brazil
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF) , Juiz de Fora , Brazil
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA , USA
| |
Collapse
|
28
|
Min A, Lee YA, Kim KA, El-Benna J, Shin MH. NOX2-derived ROS-mediated surface translocation of BLT1 is essential for exocytosis in human eosinophils induced by LTB4. Int Arch Allergy Immunol 2014; 165:40-51. [PMID: 25323785 DOI: 10.1159/000366277] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 08/01/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Leukotriene B4 (LTB4) is a proinflammatory lipid mediator that elicits eosinophil exocytosis, leading to allergic inflammation. However, the detailed intracellular signaling mechanisms of eosinophil exocytosis induced by LTB4 are poorly understood. Herein, we report that NADPH oxidase (NOX)2-derived reactive oxygen species (ROS)-mediated BLT1 migration to the cell surface is required for exocytosis in human eosinophils induced by LTB4. METHODS Peripheral blood eosinophils were purified and stimulated for up to 60 min with LTB4. The signaling role of NOX2-derived ROS in BLT1-dependent exocytosis in LTB4-stimulated eosinophils was investigated. RESULTS Stimulating eosinophils with LTB4 induced intracellular ROS production and surface upregulation of the exocytosis marker protein CD63 via BLT1-mediated signaling. LTB4 induced p47(phox) phosphorylation and 91(phox) expression required for NOX2 activation in a BLT1-dependent manner. Pretreatment with NOX2 inhibitors, but not mitochondria inhibitor, prevented LTB4-induced ROS generation and exocytosis. At 30 min after stimulation with LTB4, BLT1 expression at the cell surface was upregulated. LTB4-triggered surface upregulation of BLT1 was also blocked by inhibition of ROS generation with NOX2 inhibitors. Moreover, stimulation for 30 min with LTB4 resulted in the interaction of BLT1 with NOX2 by immunoprecipitation. LTB4-induced ROS generation, surface upregulation of BLT1 and exocytosis was also inhibited by pretreatment with a lipid raft disruptor, protein kinase C inhibitor, or Src kinase inhibitor. CONCLUSION These results suggest that NOX2-derived ROS-mediated BLT1 trafficking to the cell surface plays a key role in the exocytosis of human eosinophils induced by LTB4.
Collapse
Affiliation(s)
- Arim Min
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | | | | | | |
Collapse
|
29
|
Melo RCN, Morgan E, Monahan-Earley R, Dvorak AM, Weller PF. Pre-embedding immunogold labeling to optimize protein localization at subcellular compartments and membrane microdomains of leukocytes. Nat Protoc 2014; 9:2382-94. [PMID: 25211515 DOI: 10.1038/nprot.2014.163] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Precise immunolocalization of proteins within a cell is central to understanding cell processes and functions such as intracellular trafficking and secretion of molecules during immune responses. Here we describe a protocol for ultrastructural detection of proteins in leukocytes. The method uses a pre-embedding approach (immunolabeling before standard processing for transmission electron microscopy (TEM)). This protocol combines several strategies for ultrastructure and antigen preservation, robust blocking of nonspecific binding sites, as well as superior antibody penetration for detecting molecules at subcellular compartments and membrane microdomains. A further advantage of this technique is that electron microscopy (EM) processing is quick. This method has been used to study leukocyte biology, and it has helped demonstrate how activated leukocytes deliver specific cargos. It may also potentially be applied to a variety of different cell types. Excluding the initial time required for sample preparation (15 h) and the final resin polymerization step (16 h), the protocol (immunolabeling and EM procedures) can be completed in 8 h.
Collapse
Affiliation(s)
- Rossana C N Melo
- 1] Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil. [2] Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ellen Morgan
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Rita Monahan-Earley
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ann M Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter F Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
30
|
Dias FF, Amaral KB, Carmo LAS, Shamri R, Dvorak AM, Weller PF, Melo RCN. Human Eosinophil Leukocytes Express Protein Disulfide Isomerase in Secretory Granules and Vesicles: Ultrastructural Studies. J Histochem Cytochem 2014; 62:450-459. [PMID: 24670795 DOI: 10.1369/0022155414531437] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Protein disulfide isomerase (PDI) has fundamental roles in the oxidative folding of proteins in the endoplasmic reticulum (ER) of eukaryotic cells. The study of this molecule has been attracting considerable attention due to its association with other cell functions and human diseases. In leukocytes, such as neutrophils, PDI is involved with cell adhesion, signaling and inflammation. However, the expression of PDI in other leukocytes, such as eosinophils, important cells in inflammatory, allergic and immunomodulatory responses, remains to be defined. Here we used different approaches to investigate PDI expression within human eosinophils. Western blotting and flow cytometry demonstrated high PDI expression in both unstimulated and CCL11/eotaxin-1-stimulated eosinophils, with similar levels in both conditions. By using an immunogold electron microscopy technique that combines better epitope preservation and secondary Fab-fragments of antibodies linked to 1.4-nm gold particles for optimal access to microdomains, we identified different intracellular sites for PDI. In addition to predictable strong PDI labeling at the nuclear envelope, other unanticipated sites, such as secretory granules, lipid bodies and vesicles, including large transport vesicles (eosinophil sombrero vesicles), were also labeled. Thus, we provide the first identification of PDI in human eosinophils, suggesting that this molecule may have additional/specific functions in these leukocytes.
Collapse
Affiliation(s)
- Felipe F Dias
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Kátia B Amaral
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Lívia A S Carmo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Revital Shamri
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Ann M Dvorak
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Peter F Weller
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| | - Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil (FFD,KBA,LASC,RCNM)Department of Pathology (AMD)Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts (RS,PFW,RCNM)
| |
Collapse
|
31
|
Silva TP, Noyma NP, Duque TLA, Gamalier JP, Vidal LO, Lobão LM, Chiarini-Garcia H, Roland F, Melo RCN. Visualizing aquatic bacteria by light and transmission electron microscopy. Antonie van Leeuwenhoek 2013; 105:1-14. [PMID: 24132727 DOI: 10.1007/s10482-013-0047-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 10/01/2013] [Indexed: 10/26/2022]
Abstract
The understanding of the functional role of aquatic bacteria in microbial food webs is largely dependent on methods applied to the direct visualization and enumeration of these organisms. While the ultrastructure of aquatic bacteria is still poorly known, routine observation of aquatic bacteria by light microscopy requires staining with fluorochromes, followed by filtration and direct counting on filter surfaces. Here, we used a new strategy to visualize and enumerate aquatic bacteria by light microscopy. By spinning water samples from varied tropical ecosystems in a cytocentrifuge, we found that bacteria firmly adhere to regular slides, can be stained by fluorochoromes with no background formation and fast enumerated. Significant correlations were found between the cytocentrifugation and filter-based methods. Moreover, preparations through cytocentrifugation were more adequate for bacterial viability evaluation than filter-based preparations. Transmission electron microscopic analyses revealed a morphological diversity of bacteria with different internal and external structures, such as large variation in the cell envelope and capsule thickness, and presence or not of thylakoid membranes. Our results demonstrate that aquatic bacteria represent an ultrastructurally diverse population and open avenues for easy handling/quantification and better visualization of bacteria by light microscopy without the need of filter membranes.
Collapse
Affiliation(s)
- Thiago P Silva
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, 36036-900, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Bouffi C, Rochman M, Zust CB, Stucke EM, Kartashov A, Fulkerson PC, Barski A, Rothenberg ME. IL-33 markedly activates murine eosinophils by an NF-κB-dependent mechanism differentially dependent upon an IL-4-driven autoinflammatory loop. THE JOURNAL OF IMMUNOLOGY 2013; 191:4317-25. [PMID: 24043894 DOI: 10.4049/jimmunol.1301465] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Eosinophils are major effector cells in type 2 inflammatory responses and become activated in response to IL-4 and IL-33, yet the molecular mechanisms and cooperative interaction between these cytokines remain unclear. Our objective was to investigate the molecular mechanism and cooperation of IL-4 and IL-33 in eosinophil activation. Eosinophils derived from bone marrow or isolated from Il5-transgenic mice were activated in the presence of IL-4 or IL-33 for 1 or 4 h, and the transcriptome was analyzed by RNA sequencing. The candidate genes were validated by quantitative PCR and ELISA. We demonstrated that murine-cultured eosinophils respond to IL-4 and IL-33 by phosphorylation of STAT-6 and NF-κB, respectively. RNA sequence analysis of murine-cultured eosinophils indicated that IL-33 induced 519 genes, whereas IL-4 induced only 28 genes, including 19 IL-33-regulated genes. Interestingly, IL-33 induced eosinophil activation via two distinct mechanisms, IL-4 independent and IL-4 secretion/autostimulation dependent. Anti-IL-4 or anti-IL-4Rα Ab-treated cultured and mature eosinophils, as well as Il4- or Stat6-deficient cultured eosinophils, had attenuated protein secretion of a subset of IL-33-induced genes, including Retnla and Ccl17. Additionally, IL-33 induced the rapid release of preformed IL-4 protein from eosinophils by a NF-κB-dependent mechanism. However, the induction of most IL-33-regulated transcripts (e.g., Il6 and Il13) was IL-4 independent and blocked by NF-κB inhibition. In conclusion, we have identified a novel activation pathway in murine eosinophils that is induced by IL-33 and differentially dependent upon an IL-4 auto-amplification loop.
Collapse
Affiliation(s)
- Carine Bouffi
- Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | | | | | | | | | | | | | | |
Collapse
|
33
|
An extragranular compartment of blood eosinophils contains eosinophil protein X/eosinophil-derived neurotoxin (EPX/EDN). Inflammation 2013; 36:320-9. [PMID: 23053729 DOI: 10.1007/s10753-012-9549-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Serum and plasma profiles of eosinophil protein X (EPX/EDN) and those of other eosinophil proteins differ in various conditions, suggesting a different mobilisation from storage granules. This work studied the subcellular localisation of EPX/EDN in non-primed and in vivo primed blood eosinophils from healthy and allergic subjects, during and out of the pollen season. Primed eosinophils contain easily mobilisable secretory proteins. By fractionation on sucrose density gradients, EPX/EDN localised in the specific granules as well as in a cytoplasmic extra-granular compartment of low equilibrium density that partially overlapped with vesicular structures, cytosolic proteins and plasma membranes. This compartment was clearly separate from the low density peak of ECP that increases during the pollen season. There were no significant differences in the amounts of EPX/EDN present in the low density peak of healthy and allergic subjects. Immuno-gold labelling electron microscopy showed EPX/EDN in specific granules, cytoplasm and associated to plasma membranes. In conclusion, substantial amounts of EPX/EDN localise in an extra-granular, low equilibrium density compartment of human eosinophils.
Collapse
|
34
|
Stow JL, Murray RZ. Intracellular trafficking and secretion of inflammatory cytokines. Cytokine Growth Factor Rev 2013; 24:227-39. [PMID: 23647915 DOI: 10.1016/j.cytogfr.2013.04.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The secretion of cytokines by immune cells plays a significant role in determining the course of an inflammatory response. The levels and timing of each cytokine released are critical for mounting an effective but confined response, whereas excessive or dysregulated inflammation contributes to many diseases. Cytokines are both culprits and targets for effective treatments in some diseases. The multiple points and mechanisms that have evolved for cellular control of cytokine secretion highlight the potency of these mediators and the fine tuning required to manage inflammation. Cytokine production in cells is regulated by cell signaling, and at mRNA and protein synthesis levels. Thereafter, the intracellular transport pathways and molecular trafficking machinery have intricate and essential roles in dictating the release and activity of cytokines. The trafficking machinery and secretory (exocytic) pathways are complex and highly regulated in many cells, involving specialized membranes, molecules and organelles that enable these cells to deliver cytokines to often-distinct areas of the cell surface, in a timely manner. This review provides an overview of secretory pathways - both conventional and unconventional - and key families of trafficking machinery. The prevailing knowledge about the trafficking and secretion of a number of individual cytokines is also summarized. In conclusion, we present emerging concepts about the functional plasticity of secretory pathways and their modulation for controlling cytokines and inflammation.
Collapse
Affiliation(s)
- Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
| | | |
Collapse
|
35
|
Melo RCN, Paganoti GF, Dvorak AM, Weller PF. The internal architecture of leukocyte lipid body organelles captured by three-dimensional electron microscopy tomography. PLoS One 2013; 8:e59578. [PMID: 23555714 PMCID: PMC3608657 DOI: 10.1371/journal.pone.0059578] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/15/2013] [Indexed: 01/04/2023] Open
Abstract
Lipid bodies (LBs), also known as lipid droplets, are complex organelles of all eukaryotic cells linked to a variety of biological functions as well as to the development of human diseases. In cells from the immune system, such as eosinophils, neutrophils and macrophages, LBs are rapidly formed in the cytoplasm in response to inflammatory and infectious diseases and are sites of synthesis of eicosanoid lipid mediators. However, little is known about the structural organization of these organelles. It is unclear whether leukocyte LBs contain a hydrophobic core of neutral lipids as found in lipid droplets from adipocytes and how diverse proteins, including enzymes involved in eicosanoid formation, incorporate into LBs. Here, leukocyte LB ultrastructure was studied in detail by conventional transmission electron microscopy (TEM), immunogold EM and electron tomography. By careful analysis of the two-dimensional ultrastructure of LBs from human blood eosinophils under different conditions, we identified membranous structures within LBs in both resting and activated cells. Cyclooxygenase, a membrane inserted protein that catalyzes the first step in prostaglandin synthesis, was localized throughout the internum of LBs. We used fully automated dual-axis electron tomography to study the three-dimensional architecture of LBs in high resolution. By tracking 4 nm-thick serial digital sections we found that leukocyte LBs enclose an intricate system of membranes within their “cores”. After computational reconstruction, we showed that these membranes are organized as a network of tubules which resemble the endoplasmic reticulum (ER). Our findings explain how membrane-bound proteins interact and are spatially arranged within LB “cores” and support a model for LB formation by incorporating cytoplasmic membranes of the ER, instead of the conventional view that LBs emerge from the ER leaflets. This is important to understand the functional capabilities of leukocyte LBs in health and during diverse diseases in which these organelles are functionally involved.
Collapse
Affiliation(s)
- Rossana C. N. Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Guillherme F. Paganoti
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
| | - Ann M. Dvorak
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter F. Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
36
|
Melo RCN, Liu L, Xenakis JJ, Spencer LA. Eosinophil-derived cytokines in health and disease: unraveling novel mechanisms of selective secretion. Allergy 2013; 68:274-84. [PMID: 23347072 DOI: 10.1111/all.12103] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2012] [Indexed: 12/13/2022]
Abstract
Over the past two decades, our understanding of eosinophils has evolved from that of categorically destructive effector cells to include active participation in immune modulation, tissue repair processes, and normal organ development, in both health and disease. At the core of their newly appreciated functions is the capacity of eosinophils to synthesize, store within intracellular granules, and very rapidly secrete a highly diverse repertoire of cytokines. Mechanisms governing the selective secretion of preformed cytokines from eosinophils are attractive therapeutic targets and may well be more broadly applicable to other immune cells. Here, we discuss recent advances in deciphering pathways of cytokine secretion, both from intact eosinophils and from tissue-deposited cell-free eosinophil granules, extruded from eosinophils undergoing a lytic cell death.
Collapse
Affiliation(s)
| | - L. Liu
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
| | - J. J. Xenakis
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
| | - L. A. Spencer
- Division of Allergy and Inflammation; Department of Medicine; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston; MA; USA
| |
Collapse
|
37
|
Eosinophil extracellular DNA trap cell death mediates lytic release of free secretion-competent eosinophil granules in humans. Blood 2013; 121:2074-83. [PMID: 23303825 DOI: 10.1182/blood-2012-05-432088] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Eosinophils release their granule proteins extracellularly through exocytosis, piecemeal degranulation, or cytolytic degranulation. Findings in diverse human eosinophilic diseases of intact extracellular eosinophil granules, either free or clustered, indicate that eosinophil cytolysis occurs in vivo, but the mechanisms and consequences of lytic eosinophil degranulation are poorly understood. We demonstrate that activated human eosinophils can undergo extracellular DNA trap cell death (ETosis) that cytolytically releases free eosinophil granules. Eosinophil ETosis (EETosis), in response to immobilized immunoglobulins (IgG, IgA), cytokines with platelet activating factor, calcium ionophore, or phorbol myristate acetate, develops within 120 minutes in a reduced NADP (NADPH) oxidase-dependent manner. Initially, nuclear lobular formation is lost and some granules are released by budding off from the cell as plasma membrane-enveloped clusters. Following nuclear chromatolysis, plasma membrane lysis liberates DNA that forms weblike extracellular DNA nets and releases free intact granules. EETosis-released eosinophil granules, still retaining eosinophil cationic granule proteins, can be activated to secrete when stimulated with CC chemokine ligand 11 (eotaxin-1). Our results indicate that an active NADPH oxidase-dependent mechanism of cytolytic, nonapoptotic eosinophil death initiates nuclear chromatolysis that eventuates in the release of intact secretion-competent granules and the formation of extracellular DNA nets.
Collapse
|
38
|
Rosenberg HF, Dyer KD, Foster PS. Eosinophils: changing perspectives in health and disease. Nat Rev Immunol 2012. [PMID: 23154224 DOI: 10.1038/nri334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Eosinophils have been traditionally perceived as terminally differentiated cytotoxic effector cells. Recent studies have profoundly altered this simplistic view of eosinophils and their function. New insights into the molecular pathways that control the development, trafficking and degranulation of eosinophils have improved our understanding of the immunomodulatory functions of these cells and their roles in promoting homeostasis. Likewise, recent developments have generated a more sophisticated view of how eosinophils contribute to the pathogenesis of different diseases, including asthma and primary hypereosinophilic syndromes, and have also provided us with a more complete appreciation of the activities of these cells during parasitic infection.
Collapse
Affiliation(s)
- Helene F Rosenberg
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | |
Collapse
|
39
|
Abstract
Eosinophils have been traditionally perceived as terminally differentiated cytotoxic effector cells. Recent studies have profoundly altered this simplistic view of eosinophils and their function. New insights into the molecular pathways that control the development, trafficking and degranulation of eosinophils have improved our understanding of the immunomodulatory functions of these cells and their roles in promoting homeostasis. Likewise, recent developments have generated a more sophisticated view of how eosinophils contribute to the pathogenesis of different diseases, including asthma and primary hypereosinophilic syndromes, and have also provided us with a more complete appreciation of the activities of these cells during parasitic infection.
Collapse
|
40
|
Lee JJ, Jacobsen EA, Ochkur SI, McGarry MP, Condjella RM, Doyle AD, Luo H, Zellner KR, Protheroe CA, Willetts L, Lesuer WE, Colbert DC, Helmers RA, Lacy P, Moqbel R, Lee NA. Human versus mouse eosinophils: "that which we call an eosinophil, by any other name would stain as red". J Allergy Clin Immunol 2012; 130:572-84. [PMID: 22935586 DOI: 10.1016/j.jaci.2012.07.025] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 12/20/2022]
Abstract
The respective life histories of human subjects and mice are well defined and describe a unique story of evolutionary conservation extending from sequence identity within the genome to the underpinnings of biochemical, cellular, and physiologic pathways. As a consequence, the hematopoietic lineages of both species are invariantly maintained, each with identifiable eosinophils. This canonical presence nonetheless does not preclude disparities between human and mouse eosinophils, their effector functions, or both. Indeed, many books and reviews dogmatically highlight differences, providing a rationale to discount the use of mouse models of human eosinophilic diseases. We suggest that this perspective is parochial and ignores the wealth of available studies and the consensus of the literature that overwhelming similarities (and not differences) exist between human and mouse eosinophils. The goal of this review is to summarize this literature and in some cases provide experimental details comparing and contrasting eosinophils and eosinophil effector functions in human subjects versus mice. In particular, our review will provide a summation and an easy-to-use reference guide to important studies demonstrating that although differences exist, more often than not, their consequences are unknown and do not necessarily reflect inherent disparities in eosinophil function but instead species-specific variations. The conclusion from this overview is that despite nominal differences, the vast similarities between human and mouse eosinophils provide important insights as to their roles in health and disease and, in turn, demonstrate the unique utility of mouse-based studies with an expectation of valid extrapolation to the understanding and treatment of patients.
Collapse
Affiliation(s)
- James J Lee
- Division of Pulmonary Medicine, Department of Biochemistry and Molecular Biology, Mayo Clinic Arizona, Scottsdale, AZ, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Muniz VS, Weller PF, Neves JS. Eosinophil crystalloid granules: structure, function, and beyond. J Leukoc Biol 2012; 92:281-8. [PMID: 22672875 DOI: 10.1189/jlb.0212067] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Eosinophils are granulocytes associated with host defense against parasitic helminths with allergic conditions and more recently, with immunoregulatory responses. Eosinophils are distinguished from leukocytes by their dominant population of cytoplasmic crystalloid (also termed secretory, specific, or secondary) granules that contain robust stores of diverse, preformed cationic proteins. Here, we provide an update on our knowledge about the unique and complex structure of human eosinophil crystalloid granules. We discuss their significance as rich sites of a variety of receptors and review our own recent research findings and those of others that highlight discoveries concerning the function of intracellular receptors and their potential implications in cell signaling. Special focus is provided on how eosinophils might use these intracellular receptors as mechanisms to secrete, selectively and rapidly, cytokines or chemokines and enable cell-free extracellular eosinophil granules to function as independent secretory structures. Potential roles of cell-free eosinophil granules as immune players in the absence of intact eosinophils will also be discussed.
Collapse
Affiliation(s)
- Valdirene S Muniz
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | | | | |
Collapse
|
42
|
Shamri R, Melo RCN, Young KM, Bivas-Benita M, Xenakis JJ, Spencer LA, Weller PF. CCL11 elicits secretion of RNases from mouse eosinophils and their cell-free granules. FASEB J 2012; 26:2084-93. [PMID: 22294786 DOI: 10.1096/fj.11-200246] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rapid secretion of eosinophil-associated RNases (EARs), such as the human eosinophilic cationic protein (ECP), from intracellular granules is central to the role of eosinophils in allergic diseases and host immunity. Our knowledge regarding allergic inflammation has advanced based on mouse experimental models. However, unlike human eosinophils, capacities of mouse eosinophils to secrete granule proteins have been controversial. To study mechanisms of mouse eosinophil secretion and EAR release, we combined an RNase assay of mouse EARs with ultrastructural studies. In vitro, mouse eosinophils stimulated with the chemokine eotaxin-1 (CCL11) secreted enzymatically active EARs (EC(50) 5 nM) by piecemeal degranulation. In vivo, in a mouse model of allergic airway inflammation, increased airway eosinophil infiltration (24-fold) correlated with secretion of active RNases (3-fold). Moreover, we found that eosinophilic inflammation in mice can involve eosinophil cytolysis and release of cell-free granules. Cell-free mouse eosinophil granules expressed functional CCR3 receptors and secreted their granule proteins, including EAR and eosinophil peroxidase in response to CCL11. Collectively, these data demonstrate chemokine-dependent secretion of EARs from both intact mouse eosinophils and their cell-free granules, findings pertinent to understanding the pathogenesis of eosinophil-associated diseases, in which EARs are key factors.
Collapse
Affiliation(s)
- Revital Shamri
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Cytokine release from innate immune cells: association with diverse membrane trafficking pathways. Blood 2011; 118:9-18. [PMID: 21562044 DOI: 10.1182/blood-2010-08-265892] [Citation(s) in RCA: 252] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cytokines released from innate immune cells play key roles in the regulation of the immune response. These intercellular messengers are the source of soluble regulatory signals that initiate and constrain inflammatory responses to pathogens and injury. Although numerous studies describe detailed signaling pathways induced by cytokines and their specific receptors, there is little information on the mechanisms that control the release of cytokines from different cell types. Indeed, the pathways, molecules, and mechanisms of cytokine release remain a "black box" in immunology. Here, we review research findings and new approaches that have begun to generate information on cytokine trafficking and release by innate immune cells in response to inflammatory or infectious stimuli. Surprisingly complex machinery, multiple organelles, and specialized membrane domains exist in these cells to ensure the selective, temporal, and often polarized release of cytokines in innate immunity.
Collapse
|
44
|
Melo RCN, Dvorak AM, Weller PF. Contributions of electron microscopy to understand secretion of immune mediators by human eosinophils. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2010; 16:653-60. [PMID: 20875166 PMCID: PMC3420811 DOI: 10.1017/s1431927610093864] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Mechanisms governing secretion of proteins underlie the biologic activities and functions of human eosinophils, leukocytes of the innate immune system, involved in allergic, inflammatory, and immunoregulatory responses. In response to varied stimuli, eosinophils are recruited from the circulation into inflammatory foci, where they modulate immune responses through the release of granule-derived products. Transmission electron microscopy (TEM) is the only technique that can clearly identify and distinguish between different modes of cell secretion. In this review, we highlight the advances in understanding mechanisms of eosinophil secretion, based on TEM findings, that have been made over the past years and that have provided unprecedented insights into the functional capabilities of these cells.
Collapse
Affiliation(s)
- Rossana C N Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil.
| | | | | |
Collapse
|
45
|
Shamri R, Xenakis JJ, Spencer LA. Eosinophils in innate immunity: an evolving story. Cell Tissue Res 2010; 343:57-83. [PMID: 21042920 DOI: 10.1007/s00441-010-1049-6] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 09/01/2010] [Indexed: 12/27/2022]
Abstract
Eosinophils are innate immune leukocytes found in relatively low numbers within the blood. Terminal effector functions of eosinophils, deriving from their capacity to release their content of tissue-destructive cationic proteins, have historically been considered primary effector mechanisms against specific parasites, and are likewise implicated in tissue damage accompanying allergic responses such as asthma. However, the past decade has seen dramatic advancements in the field of eosinophil immunobiology, revealing eosinophils to also be key participants in many other facets of innate immunity, from bridging innate and adaptive immune responses to orchestrating tissue remodeling events. Here, we review the multifaceted functions of eosinophils in innate immunity that are currently known, and discuss new avenues in this evolving story.
Collapse
Affiliation(s)
- Revital Shamri
- Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | | | | |
Collapse
|
46
|
Crivellato E, Nico B, Gallo VP, Ribatti D. Cell secretion mediated by granule-associated vesicle transport: a glimpse at evolution. Anat Rec (Hoboken) 2010; 293:1115-24. [PMID: 20340095 DOI: 10.1002/ar.21146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Regulated secretion allows extrusion of cell products stored in specialized membrane-bound organelles called secretory granules or secretory vesicles. Regulated secretion provides basic functions in living organisms, and in a phylogenetic perspective, it is recognizable in the most primitive eukaryotic forms. This article is an attempt to trace the evolutionary history of a special type of secretory pattern, which has been referred to as vesicle-mediated degranulation or piecemeal degranulation (PMD). First described in the early 70s of the last century in inflammatory cells, such as the basophils, mast cells, and eosinophils, this regulated secretory route has subsequently been recognized in endocrine cells, in particular in the chromaffin cells of the adrenal medulla. This vesicle-mediated degranulation is held to mobilize small and specific aliquots of granule-associated material for selective paracrine or endocrine transport to the cell exterior. PMD has been identified in many vertebrate classes. By contrast, no data are available for invertebrates. We speculate that this pattern of cell secretion emerged early in phylogenesis, when the first metazoans appeared. In this review article, we will first revise the concept of vesicle-mediated degranulation in the light of the most recent experimental discoveries and theoretical implications. Then, the distribution of this secretory mode among vertebrates and its molecular basis will be highlighted. Finally, the potential occurrence of PMD in invertebrates, its biological significance from an evolutionary perspective and the future direction of investigations will be briefly sketched.
Collapse
Affiliation(s)
- Enrico Crivellato
- Department of Medical and Morphological Research, Section of Anatomy, University of Udine School of Medicine, Udine, Italy.
| | | | | | | |
Collapse
|
47
|
Melo RC, Weller PF. Piecemeal degranulation in human eosinophils: a distinct secretion mechanism underlying inflammatory responses. Histol Histopathol 2010; 25:1341-54. [PMID: 20712018 PMCID: PMC3427618 DOI: 10.14670/hh-25.1341] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Secretion is a fundamental cell process underlying different physiological and pathological events. In cells from the human immune system such as eosinophils, secretion of mediators generally occurs by means of piecemeal degranulation, an unconventional secretory pathway characterized by vesicular transport of small packets of materials from the cytoplasmic secretory granules to the cell surface. During piecemeal degranulation in eosinophils, a distinct transport vesicle system, which includes large, pleiomorphic vesiculo-tubular carriers is mobilized and enables regulated release of granule-stored proteins such as cytokines and major basic protein. Piecemeal degranulation underlies distinct functions of eosinophils as effector and immunoregulatory cells. This review focuses on the structural and functional advances that have been made over the last years concerning the intracellular trafficking and secretion of eosinophil proteins by piecemeal degranulation during inflammatory responses.
Collapse
Affiliation(s)
- Rossana C.N. Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Peter F. Weller
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
48
|
Virus-bacterium coupling driven by both turbidity and hydrodynamics in an Amazonian floodplain lake. Appl Environ Microbiol 2010; 76:7194-201. [PMID: 20833790 DOI: 10.1128/aem.01161-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The importance of viruses in aquatic ecosystem functioning has been widely described. However, few studies have examined tropical aquatic ecosystems. Here, we evaluated for the first time viruses and their relationship with other planktonic communities in an Amazonian freshwater ecosystem. Coupling between viruses and bacteria was studied, focusing both on hydrologic dynamics and anthropogenic forced turbidity in the system (Lake Batata). Samples were taken during four hydrologic seasons at both natural and impacted sites to count virus-like particles (VLP) and bacteria. In parallel, virus-infected bacteria were identified and quantified by transmission electron microscopy (TEM). Viral abundance ranged from 0.5 × 10⁷ ± 0.2 × 10⁷ VLP ml⁻¹ (high-water season, impacted site) to 1.7 × 10⁷ ± 0.4 × 10⁷ VLP ml⁻¹ (low-water season, natural site). These data were strongly correlated with the bacterial abundance (r² = 0.84; P < 0.05), which ranged from 1.0 × 10⁶ ± 0.5 × 10⁶ cells ml⁻¹ (high water, impacted site) to 3.4 × 10⁶ ± 0.7 × 10⁶ cells ml⁻¹ (low water, natural site). Moreover, the viral abundance was weakly correlated with chlorophyll a, suggesting that most viruses were bacteriophages. TEM quantitative analyses revealed that the frequency of visibly infected cells was 20%, with 10 ± 3 phages per cell section. In general, we found a low virus-bacterium ratio (<7). Both the close coupling between the viral and bacterial abundances and the low virus-bacterium ratio suggest that viral abundance tends to be driven by the reduction of hosts for viral infection. Our results demonstrate that viruses are controlled by biological substrates, whereas in addition to grazing, bacteria are regulated by physical processes caused by turbidity, which affect underwater light distribution and dissolved organic carbon availability.
Collapse
|
49
|
Abstract
Cytokine secretion is a widely studied process, although little is known regarding the specific mechanisms that regulate cytokine release. Recent findings have shed light on some of the precise molecular pathways that regulate the packaging of newly synthesized cytokines from immune cells. These findings begin to elucidate pathways and mechanisms that underpin cytokine release in all cells. In this article, we review the highlights of some of these novel discoveries.
Collapse
Affiliation(s)
- Amanda C. Stanley
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia; and
| | - Paige Lacy
- Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
50
|
Dyer KD, Percopo CM, Xie Z, Yang Z, Kim JD, Davoine F, Lacy P, Druey KM, Moqbel R, Rosenberg HF. Mouse and human eosinophils degranulate in response to platelet-activating factor (PAF) and lysoPAF via a PAF-receptor-independent mechanism: evidence for a novel receptor. THE JOURNAL OF IMMUNOLOGY 2010; 184:6327-34. [PMID: 20421642 DOI: 10.4049/jimmunol.0904043] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Platelet-activating factor (PAF [1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine]) is a phospholipid mediator released from activated macrophages, mast cells, and basophils that promotes pathophysiologic inflammation. Eosinophil responses to PAF are complex and incompletely elucidated. We show in this article that PAF and its 2-deacetylated metabolite (lysoPAF) promote degranulation (release of eosinophil peroxidase) via a mechanism that is independent of the characterized PAFR. Specifically, we demonstrate that receptor antagonists CV-3988 and WEB-2086 and pertussis toxin have no impact on PAF- or lysoPAF-mediated degranulation. Furthermore, cultured mouse eosinophils from PAFR(-/-) bone marrow progenitors degranulate in response to PAF and lysoPAF in a manner indistinguishable from their wild-type counterparts. In addition to PAF and lysoPAF, human eosinophils degranulate in response to lysophosphatidylcholine, but not phosphatidylcholine, lysophosphatidylethanolamine, or phosphatidylethanolamine, demonstrating selective responses to phospholipids with a choline head-group and minimal substitution at the sn-2 hydroxyl. Human eosinophils release preformed cytokines in response to PAF, but not lysoPAF, also via a PAFR-independent mechanism. Mouse eosinophils do not release cytokines in response to PAF or lysoPAF, but they are capable of doing so in response to IL-6. Overall, our work provides the first direct evidence for a role for PAF in activating and inducing degranulation of mouse eosinophils, a crucial feature for the interpretation of mouse models of PAF-mediated asthma and anaphylaxis. Likewise, we document and define PAF and lysoPAF-mediated activities that are not dependent on signaling via PAFR, suggesting the existence of other unexplored molecular signaling pathways mediating responses from PAF, lysoPAF, and closely related phospholipid mediators.
Collapse
Affiliation(s)
- Kimberly D Dyer
- Section of Eosinophil Biology, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1883, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|