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Larsen LD, Dockstader K, Olbrich CL, Cartwright IM, Spencer LA. Modulation of surface CD11c expression tracks plasticity in murine intestinal tissue eosinophils. J Leukoc Biol 2022; 111:943-952. [PMID: 35141942 PMCID: PMC9829035 DOI: 10.1002/jlb.3hi0821-432rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Intestinal eosinophils are implicated in the inflammatory pathology of eosinophilic gastrointestinal diseases and inflammatory bowel diseases. Eosinophils also contribute to intestinal immunologic and tissue homeostasis and host defense. Recent studies in allergic airway disease suggest functional subphenotypes of eosinophils may underly their pathogenic versus protective roles. However, subphenotypes of intestinal eosinophils have not been defined and are complicated by their constitutive expression of the putative eosinophil inflammatory marker CD11c. Here, we propose a framework for subphenotype characterization of intestinal eosinophils based on relative intensity of surface CD11c expression. Using this flow cytometry framework in parallel with histology and BrdU tracing, we characterize intestinal eosinophil subphenotypes and monitor their plasticity at baseline and within the context of acute allergic and chronic systemic inflammation. Data reveal a conserved continuum of CD11c expression amongst intestinal eosinophils in health and acute disease states that overall tracked with other markers of activation. Oral allergen challenge induced recruitment of eosinophils into small intestinal lamina propria surrounding crypts, followed by in situ induction of CD11c expression in parallel with eosinophil redistribution into intestinal villi. Allergen challenge also elicited eosinophil transepithelial migration and the appearance of CD11clo CD11bhi eosinophils in the intestinal lumen. Chronic inflammation driven by overexpression of TNFα led to a qualitative shift in the relative abundance of CD11c-defined eosinophil subphenotypes favoring CD11chi -expressing eosinophils. These findings provide new insights into heterogeneity of intestinal tissue eosinophils and offer a framework for measuring and tracking eosinophil subphenotype versatility in situ in health and disease.
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Affiliation(s)
- Leigha D. Larsen
- Gastrointestinal Eosinophilic Diseases Program, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA,Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Karen Dockstader
- Gastrointestinal Eosinophilic Diseases Program, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA,Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Courtney L. Olbrich
- Gastrointestinal Eosinophilic Diseases Program, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA,Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA,GI and Liver Innate Immune Program (GALIIP), and Mucosal Inflammation Program (MIP), University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Ian M. Cartwright
- GI and Liver Innate Immune Program (GALIIP), and Mucosal Inflammation Program (MIP), University of Colorado School of Medicine, Aurora, Colorado, USA,Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA,Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, USA
| | - Lisa A. Spencer
- Gastrointestinal Eosinophilic Diseases Program, Digestive Health Institute, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA,Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA,GI and Liver Innate Immune Program (GALIIP), and Mucosal Inflammation Program (MIP), University of Colorado School of Medicine, Aurora, Colorado, USA
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Abstract
Approximately one-sixth of the worlds' population is infected with helminths and this class of parasite takes a major toll on domestic livestock. The majority of species of parasitic helminth that infect mammals live in the gut (the only niche for tapeworms) where they contact the hosts' epithelial cells. Here, the helminth-intestinal epithelial interface is reviewed in terms of the impact on, and regulation of epithelial barrier function, both intrinsic (epithelial permeability) and extrinsic (mucin, bacterial peptides, commensal bacteria) elements of the barrier. The data available on direct effects of helminths on epithelial permeability are scant, fragmentary and pales in comparison with knowledge of mobilization of immune reactions and effector cells in response to helminth parasites and how these impact intestinal barrier function. The interaction of helminth-host and helminth-host-bacteria is an important determinant of gut form and function and precisely defining these interactions will radically alter our understanding of normal gut physiology and pathophysiological reactions, revealing new approaches to infection with parasitic helminths, bacterial pathogens and idiopathic auto-inflammatory disease.
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Affiliation(s)
- Derek M McKay
- a Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology , Snyder Institute of Chronic Disease, Cumming School of Medicine, University of Calgary , Calgary , Alberta , Canada
| | - Adam Shute
- a Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology , Snyder Institute of Chronic Disease, Cumming School of Medicine, University of Calgary , Calgary , Alberta , Canada
| | - Fernando Lopes
- a Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology , Snyder Institute of Chronic Disease, Cumming School of Medicine, University of Calgary , Calgary , Alberta , Canada
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3
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Larose MC, Archambault AS, Provost V, Laviolette M, Flamand N. Regulation of Eosinophil and Group 2 Innate Lymphoid Cell Trafficking in Asthma. Front Med (Lausanne) 2017; 4:136. [PMID: 28848734 PMCID: PMC5554517 DOI: 10.3389/fmed.2017.00136] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/27/2017] [Indexed: 12/17/2022] Open
Abstract
Asthma is an inflammatory disease usually characterized by increased Type 2 cytokines and by an infiltration of eosinophils to the airways. While the production of Type 2 cytokines has been associated with TH2 lymphocytes, increasing evidence indicates that group 2 innate lymphoid cells (ILC2) play an important role in the production of the Type 2 cytokines interleukin (IL)-5 and IL-13, which likely amplifies the recruitment of eosinophils from the blood to the airways. In that regard, recent asthma treatments have been focusing on blocking Type 2 cytokines, notably IL-4, IL-5, and IL-13. These treatments mainly result in decreased blood or sputum eosinophil counts as well as decreased asthma symptoms. This supports that therapies blocking eosinophil recruitment and activation are valuable tools in the management of asthma and its severity. Herein, we review the mechanisms involved in eosinophil and ILC2 recruitment to the airways, with an emphasis on eotaxins, other chemokines as well as their receptors. We also discuss the involvement of other chemoattractants, notably the bioactive lipids 5-oxo-eicosatetraenoic acid, prostaglandin D2, and 2-arachidonoyl-glycerol. Given that eosinophil biology differs between human and mice, we also highlight and discuss their responsiveness toward the different eosinophil chemoattractants.
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Affiliation(s)
- Marie-Chantal Larose
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, QC, Canada
| | - Anne-Sophie Archambault
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, QC, Canada
| | - Véronique Provost
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, QC, Canada
| | - Michel Laviolette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, QC, Canada
| | - Nicolas Flamand
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Faculté de Médecine, Département de Médecine, Université Laval, Québec City, QC, Canada
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4
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Wang GD, Wang XY, Hu HZ, Fang XC, Liu S, Gao N, Xia Y. Platelet-activating factor in the enteric nervous system of the guinea pig small intestine. Am J Physiol Gastrointest Liver Physiol 2006; 291:G928-37. [PMID: 17030900 DOI: 10.1152/ajpgi.00153.2006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Platelet-activating factor (PAF) is a proinflammatory mediator that may influence neuronal activity in the enteric nervous system (ENS). Electrophysiology, immunofluorescence, Western blot analysis, and RT-PCR were used to study the action of PAF and the expression of PAF receptor (PAFR) in the ENS. PAFR immunoreactivity (IR) was expressed by 6.9% of the neurons in the myenteric plexus and 14.5% of the neurons in the submucosal plexus in all segments of the guinea pig intestinal tract as determined by double staining with anti-human neuronal protein antibody. PAFR IR was found in 6.1% of the neurons with IR for calbindin, 35.8% of the neurons with IR for neuropeptide Y (NPY), 30.6% of the neurons with IR for choline acetyltransferase (ChAT), and 1.96% of the neurons with IR for vasoactive intestinal peptide (VIP) in the submucosal plexus. PAFR IR was also found in 1.5% of the neurons with IR for calbindin, 51.1% of the neurons with IR for NPY, and 32.9% of the neurons with IR for ChAT in the myenteric plexus. In the submucosal plexus, exposure to PAF (200-600 nM) evoked depolarizing responses (8.2 +/- 3.8 mV) in 12.4% of the neurons with S-type electrophysiological behavior and uniaxonal morphology and in 12.5% of the neurons with AH-type electrophysiological behavior and Dogiel II morphology, whereas in the myenteric preparations, depolarizing responses were elicited by a similar concentration of PAF in 9.5% of the neurons with S-type electrophysiological behavior and uniaxonal morphology and in 12.0% of the neurons with AH-type electrophysiological behavior and Dogiel II morphology. The results suggest that subgroups of secreto- and musculomotor neurons in the submucosal and myenteric plexuses express PAFR. Coexpression of PAFR IR with ChAT IR in the myenteric plexus and ChAT IR and VIP IR in the submucosal plexus suggests that PAF, after release in the inflamed bowel, might act to elevate the excitability of submucosal secretomotor and myenteric musculomotor neurons. Enhanced excitability of motor neurons might lead to a state of neurogenic secretory diarrhea.
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Affiliation(s)
- Guo-Du Wang
- Department of Anesthesiology, The Ohio State University, Columbus, OH 43210, USA
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Wu J, Nilsson Å, Jönsson B, Stenstad H, Agace W, Cheng Y, Duan RD. Intestinal alkaline sphingomyelinase hydrolyses and inactivates platelet-activating factor by a phospholipase C activity. Biochem J 2006; 394:299-308. [PMID: 16255717 PMCID: PMC1386028 DOI: 10.1042/bj20051121] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alkaline sphingomyelinase (alk-SMase) is a new member of the NPP (nucleotide pyrophosphatase/phosphodiesterase) family that hydrolyses SM (sphingomyelin) to generate ceramide in the intestinal tract. The enzyme may protect the intestinal mucosa from inflammation and tumorigenesis. PAF (platelet-activating factor) is a pro-inflammatory phospholipid involved in pathogenesis of inflammatory bowel diseases. We examined whether alk-SMase can hydrolyse and inactivate PAF. [3H]Octadecyl-labelled PAF was incubated with purified rat intestinal alk-SMase or recombinant human alk-SMase expressed in COS-7 cells. The hydrolytic products were assayed with TLC and MS. We found that alkSMase cleaved the phosphocholine head group from PAF and generated 1-O-alkyl-2-acetyl-sn-glycerol. Differing from the activity against SM, the activity against PAF was optimal at pH 7.5, inhibited by EDTA and stimulated by 0.1-0.25 mM Zn2+. The activity was abolished by site mutation of the predicted metal-binding sites that are conserved in all NPP members. Similar to the activity against SM, the activity against PAF was dependent on bile salt, particularly taurocholate and taurochenodeoxycholate. The V(max) for PAF hydrolysis was 374 mumol x h(-1) x (mg of protein)(-1). The hydrolysis of PAF and SM could be inhibited by the presence of SM and PAF respectively, the inhibition of PAF hydrolysis by SM being stronger. The PAF-induced MAPK (mitogen-activated protein kinase) activation and IL-8 (interleukin 8) release in HT-29 cells, and chemotaxis in leucocytes were abolished by alk-SMase treatment. In conclusion, alk-SMase hydrolyses and inactivates PAF by a phospholipase C activity. The finding reveals a novel function, by which alk-SMase may counteract the development of intestinal inflammation and colon cancer.
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Affiliation(s)
- Jun Wu
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Åke Nilsson
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Bo A. G. Jönsson
- †Department of Occupational and Environment Medicine, Institute of Laboratory Medicine, University Hospital, S-221 85 Lund, Sweden
| | - Hanna Stenstad
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - William Agace
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - Yajun Cheng
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Rui-Dong Duan
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
- To whom correspondence should be addressed (email )
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6
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Furuta GT, Nieuwenhuis EES, Karhausen J, Gleich G, Blumberg RS, Lee JJ, Ackerman SJ. Eosinophils alter colonic epithelial barrier function: role for major basic protein. Am J Physiol Gastrointest Liver Physiol 2005; 289:G890-7. [PMID: 16227527 DOI: 10.1152/ajpgi.00015.2005] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mucosal eosinophils increase in a number of gastrointestinal diseases that are often associated with altered epithelial barrier function, including food allergic enteropathies and inflammatory bowel diseases. Although eosinophils are known to secrete biologically active mediators including granule proteins, their role in gastrointestinal diseases is uncertain. The aim of this study was to determine the impact of eosinophils on intestinal barrier function. Epithelial barrier function was determined in a coculture of eosinophils and T84 epithelial cells and in a murine model of T helper (Th) type 2-mediated colitis. Coculture conditions resulted in decreased transepithelial resistance (TER) and increased transepithelial flux. Cell-free coculture supernatants contained a > or =5-kDa soluble factor that also diminished TER; these supernatants contained the eosinophil-granule proteins major basic protein (MBP) and eosinophil-derived neurotoxin (EDN). T84 barrier function decreased significantly when basolateral surfaces were exposed to native human MBP but not EDN. Additional studies identified downregulation of the tight junctional molecule occludin as at least one mechanism for MBP action. MBP-null mice were protected from inflammation associated with oxazolone colitis compared with wild-type mice. In conclusion, MBP decreases epithelial barrier function and in this manner contributes to the pathogenesis of inflammatory bowel diseases.
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Affiliation(s)
- Glenn T Furuta
- Combined Program in Pediatric Gastroenterology and Nutrition, Harvard Medical School, Boston, MA 02115, USA.
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7
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Ngo P, Furuta G, Burks W. The pathobiology of eosinophilic gastroenteritis of childhood: is it really the eosinophil, allergic mediated, or something else? Curr Gastroenterol Rep 2004; 6:436-40. [PMID: 15527672 DOI: 10.1007/s11894-004-0064-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Over the past decade clinicians have witnessed a dramatic rise in the prevalence of eosinophilic gastrointestinal diseases. Diverse symptoms, a broad range of endoscopic findings, and varying histopathologic features pose several questions: Do eosinophils represent an allergic response? What mechanisms drive eosinophils to specific mucosal targets? How do eosinophils affect the gastrointestinal tissues? Recent clinical and basic studies are investigating the pathogenesis of eosinophilic gastrointestinal diseases. This review highlights the literature concerning the mechanisms that govern these diseases, with a specific focus on diseases of gastrointestinal columnar epithelia (eosinophilic gastroenteritis and eosinophilic colitis). The roles of specific chemokines, such as eotaxin, and the data supporting the involvement of eosinophil granule proteins in disease states, are discussed.
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Affiliation(s)
- Peter Ngo
- Division of Pediatric Gastroenterology, Children's Hospital of Boston, 300 Longwood Avenue, Hunnewell, Ground Floor, Boston, MA 02115, USA
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8
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Michail S, Abernathy F. A new model for studying eosinophil migration across cultured intestinal epithelial monolayers. J Pediatr Gastroenterol Nutr 2004; 39:56-63. [PMID: 15187782 DOI: 10.1097/00005176-200407000-00012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Eosinophils play an important role in some gastrointestinal inflammatory conditions. Stimulated eosinophils migrate across the vascular endothelial wall and into the intestinal epithelium where by-products such as proteases may contribute to intestinal epithelial damage. Little is known about the epithelial migration of the eosinophils in the gut. The lack of data is attributable in part to the scarcity of human eosinophils for studies. HL-60-differentiated eosinophils present a means to perform studies on eosinophil function and chemotaxis. HL-60 clone 15 can be induced to differentiate into cells closely resembling human eosinophils. The authors describe a novel model for studying eosinophil migration across the intestinal epithelium. METHODS Fluorescent-labeled HL-60 eosinophils were incubated for 150 minutes on the basolateral surface of confluent and inverted T-84 monolayers separated by fluoroblock insert membranes. Chemotactic gradients of n-formyl methionyl leucyl phenylalanine (fMLP), eotaxin, and platelet aggregating factor (PAF) were used in variable concentrations. Changes in transepithelial electrical resistance (TEER) were compared with baseline values. RESULTS Differentiated HL-60 eosinophils undergo migration in response to fMLP, PAF, and eotaxin. Migration is associated with a drop in TEER. CONCLUSION In this model, HL-60-differentiated eosinophils migrate in response to stimulants chemotactic for human eosinophils. The transepithelial migration of eosinophils is associated with epithelial barrier dysfunction, which may contribute to the development of disease.
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Affiliation(s)
- Sonia Michail
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Wright State University School of Medicine, and The Children's Medical Center in Dayton, Ohio, USA.
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9
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Abstract
Eosinophils release lipid mediators, including leukotriene C4, platelet-activating factor, and liposins, and contain four distinct granule cationic proteins, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin, which may cause dysfunction and destruction of other cells. Eosinophils are primarily thought of as terminal effectors of allergic responses and of parasite elimination. Eosinophils are characteristically present within the airway lumina of asthmatics, and these airway eosinophils have been induced in vivo to express major histocompatibility complex II (MHC-II) complexes and costimulatory molecules, which are required for T lymphocytes to be functionally activated. In in vitro experiments, eosinophils can process antigen and express the costimulatory molecules, and after cytokine-elicited induction of MHC-II, expression can function as antigen-presenting cells in stimulating T lymphocyte responses. Airway luminal eosinophils can migrate into draining paratracheal lymph nodes, localized to T cell-rich paracortical areas, and stimulate antigen-specific T cell proliferation in vivo within paratracheal lymph nodes, which was CD80- and CD86-dependent and limited to CD4+ T cells. Furthermore, eosinophils within the lumina of airways promote expansion of T helper cell type 2 (Th2) by presenting antigen, suggesting that eosinophils actively modulate immune responses by amplifying Th2 cell responses.
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Affiliation(s)
- Huan-Zhong Shi
- First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, P. R. China.
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Liu L, Hakansson L, Ridefelt P, Garcia RC, Venge P. Priming of eosinophil migration across lung epithelial cell monolayers and upregulation of CD11b/CD18 are elicited by extracellular Ca2+. Am J Respir Cell Mol Biol 2003; 28:713-21. [PMID: 12760968 DOI: 10.1165/rcmb.4771] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In patients with asthma, eosinophils are primed and massively infiltrate lung tissues and migrate across epithelia into airways. Using blocking monoclonal antibodies, we found that eosinophil transmigration across a lung epithelial cell monolayer depended on the functions of alphaMbeta2 integrin CD11b/CD18. To study the role of Ca2+ in eosinophil priming and transepithelial migration, we treated eosinophils with eotaxin or thapsigargin (TG), reagents that increase cytoplasmic free Ca2+ concentrations by receptor- or nonreceptor-mediated mechanisms, respectively. Pretreatment of eosinophils with TG enhanced CD11b/CD18-dependent transmigration across lung epithelium. Within minutes, TG time- and dose-dependently upregulated the expression of CD11b/CD18 but did not upregulate the expression of alphaL (CD11a) or beta1 (CD29) integrin. The upregulation of CD11b/CD18 expression by eotaxin or TG was prevented when Ca2+ entry was blocked. The priming of eosinophil transmigration by TG was also abrogated by the blockade of Ca2+ entry. Our results indicate that induction of Ca2+ entry by the depletion of Ca2+ from intracellular stores upregulates CD11b/CD18 expression on eosinophils and primes eosinophil transmigration across lung epithelium. Both responses are therefore elicited by extracellular Ca2+. We suggest that, as an important priming signal for human eosinophil functional responses, store-operated Ca2+ entry may be one of the underlying mechanisms of eosinophilic inflammation in asthma.
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Affiliation(s)
- Lixin Liu
- Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
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11
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Jeziorska M, Haboubi N, Schofield P, Woolley DE. Distribution and activation of eosinophils in inflammatory bowel disease using an improved immunohistochemical technique. J Pathol 2001; 194:484-92. [PMID: 11523058 DOI: 10.1002/path.904] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Eosinophils are a recognized feature of inflammatory bowel disease (IBD), but their tissue distribution and functional importance in Crohn's disease (CD) and ulcerative colitis (UC) remain obscure. This study describes an improved immunohistochemical protocol to identify eosinophils in full thickness bowel wall specimens of IBD (n=40) and their in situ relationships with the chemoattractants eotaxin and RANTES. Eosinophils were identified using immunohistochemistry with a combination of monoclonal antibodies (EG1+EG2+MBP), an ultrasensitive technique superior to other methodologies, and their tissue distributions were related to those for eotaxin, RANTES, mast cells and neutrophils. Increased numbers of eosinophils (up to 400 cells/mm(2)) were observed in active, fulminant inflammation in both CD and UC, this being related to the severity of inflammation and not the diagnosis of the two disorders. The chemoattractants eotaxin (CCL11) and RANTES (CCL5) were upregulated in IBD tissues showing eosinophilia. Neutrophils and mast cells were commonly associated with eosinophil accumulations. Eosinophil numbers and their in situ activation are increased in active rather than chronic IBD. The observations strongly suggest a pivotal role for the eosinophil and its potent mediators in many pathophysiological symptoms of CD and UC, where it represents the major proportion of all granulocytic cells in active inflammatory bowel disease.
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Affiliation(s)
- M Jeziorska
- University Department of Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK
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12
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Shi HZ, Humbles A, Gerard C, Jin Z, Weller PF. Lymph node trafficking and antigen presentation by endobronchial eosinophils. J Clin Invest 2000; 105:945-53. [PMID: 10749574 PMCID: PMC377484 DOI: 10.1172/jci8945] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Because eosinophils recruited into the airways in allergic diseases are exposed to inhaled allergens, we evaluated whether eosinophils within the endobronchial lumen can function in vivo as antigen-presenting cells for inhaled antigens. We recovered eosinophils from the airways after aerosol antigen challenge in sensitized mice or from the peritoneal cavities of IL-5 transgenic mice and fluorescently labeled these cells ex vivo. These labeled cells, instilled intratracheally into normal mice, migrated into draining paratracheal lymph nodes and localized to T cell-rich paracortical areas. The homing of airway eosinophils to lymph nodes was not governed by eotaxin, because CCR3(-/-) and CCR3(+/+) eosinophils migrated identically. Airway eosinophils, recovered after inhalational antigen challenge in sensitized mice, expressed MHC class II and costimulatory CD80 and CD86 proteins and functioned in vitro as CD80- and CD86-dependent, antigen-specific, antigen-presenting cells. Moreover, when instilled into the airways of antigen-sensitized recipient mice, airway eosinophils recovered after inhalational antigen challenge stimulated antigen-specific CD4(+) T cell proliferation within paratracheal lymph nodes. Thus, eosinophils within the lumina of airways can process inhaled antigens, traffic to regional lymph nodes, and function in vivo as antigen-presenting cells to stimulate responses of CD4(+) T cells.
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Affiliation(s)
- H Z Shi
- Department of Medicine, Harvard Thorndike Laboratories, Charles A. Dana Research Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Ishii S, Shimizu T. Platelet-activating factor (PAF) receptor and genetically engineered PAF receptor mutant mice. Prog Lipid Res 2000; 39:41-82. [PMID: 10729607 DOI: 10.1016/s0163-7827(99)00016-8] [Citation(s) in RCA: 279] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a biologically active phospholipid mediator. Although PAF was initially recognized for its potential to induce platelet aggregation and secretion, intense investigations have elucidated potent biological actions of PAF in a broad range of cell types and tissues, many of which also produce the molecule. PAF acts by binding to a unique G-protein-coupled seven transmembrane receptor. PAF receptor is linked to intracellular signal transduction pathways, including turnover of phosphatidylinositol, elevation in intracellular calcium concentration, and activation of kinases, resulting in versatile bioactions. On the basis of numerous pharmacological reports, PAF is thought to have many pathophysiological and physiological functions. Recently advanced molecular technics enable us not only to clone PAF receptor cDNAs and genes, but also generate PAF receptor mutant animals, i.e., PAF receptor-overexpressing mouse and PAF receptor-deficient mouse. These mutant mice gave us a novel and specific approach for identifying the pathophysiological and physiological functions of PAF. This review also describes the phenotypes of these mutant mice and discusses them by referring to previously reported pharmacological and genetical data.
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Affiliation(s)
- S Ishii
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
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14
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Wang H, Tan X, Chang H, Huang W, Gonzalez-Crussi F, Hsueh W. Platelet-activating factor receptor mRNA is localized in eosinophils and epithelial cells in rat small intestine: regulation by dexamethasone and gut flora. Immunology 1999; 97:447-54. [PMID: 10447766 PMCID: PMC2326856 DOI: 10.1046/j.1365-2567.1999.00784.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet-activating factor (PAF) is a potent mediator involved in bowel injury. We investigated PAF receptor transcription and its mRNA localization in the small intestine of normal (conventionally fed) and germ-free rats, by competitive polymerase chain reaction (PCR) and in situ hybridization. A dose of PAF (1.5 microg/kg, i.v.) insufficient to cause gross bowel injury was injected into rats. Some rats were pretreated with dexamethasone (1 mg/kg). We found: (1) PAF receptor (PAF-R) mRNA localized predominantly in lamina propria eosinophils and in epithelial cells; (2) PAF increased PAF-receptor signals in the epithelial cells; (3) Dexamethasone depleted eosinophils in the intestine and markedly decreased PAF-receptor transcripts; the response to PAF was also weaker than control rats; (4) Germ-free rats had less PAF-R mRNA than normal rats, and showed a weaker response to PAF than conventionally fed rats. Thus, we conclude: (1) PAF receptor mRNA is constitutively expressed in the epithelium and in lamina propria eosinophils in the intestine. (2) PAF-R transcription is up-regulated by PAF and gut flora, mostly in the epithelium. (3) PAF-R transcription is down-regulated by glucocorticoids, mainly as a result of eosinophil depletion. These results suggest a functional role for PAF receptors both in host defence and the inflammatory response in the small intestine.
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Affiliation(s)
- H Wang
- Department of Pathology, Children's Memorial Hospital, Northwestern University Medical School, Chicago, IL 60614, USA
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15
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Liu L, Zuurbier AEM, Mul FPJ, Verhoeven AJ, Lutter R, Knol EF, Roos D. Triple Role of Platelet-Activating Factor in Eosinophil Migration Across Monolayers of Lung Epithelial Cells: Eosinophil Chemoattractant and Priming Agent and Epithelial Cell Activator. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.6.3064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Infiltration of eosinophils into the lung lumen is a hallmark of allergic asthmatic inflammation. To reach the lung lumen, eosinophils must migrate across the vascular endothelium, through the interstitial matrix, and across the lung epithelium. The regulation of this process is obscure. In this study, we investigated the migration of human eosinophils across confluent monolayers of either human lung H292 epithelial cells or primary human bronchial epithelial cells. Established eosinophil chemoattractants (IL-8, RANTES, platelet-activating factor (PAF), leukotriene B4, and complement fragment 5a (C5a)) or activation of the epithelial cells with IL-1β induced little eosinophil transmigration (<7% in 2 h). In contrast, addition of PAF in combination with C5a induced extensive (>20%) transepithelial migration of unprimed and IL-5-primed eosinophils. Eosinophil migration assessed in a Boyden chamber assay, i.e., without an epithelial monolayer, was only slightly increased upon addition of PAF and C5a. Preincubation of eosinophils with the PAF receptor antagonist WEB 2086 only inhibited migration of unprimed eosinophils toward PAF and C5a, whereas preincubation of epithelial cells with WEB 2086 abolished migration of both IL-5-primed and unprimed eosinophils. This latter result indicated the presence of PAF receptors on epithelial cells. Indeed, addition of PAF to epithelial cells induced an increase in cytosolic free Ca2+, which was blocked by the PAF receptor antagonists WEB 2086 and TCV-309. Our results show that PAF induces permissive changes in epithelial cells, and that PAF acts as a chemoattractant and priming agent for the eosinophils.
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Affiliation(s)
- Lixin Liu
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
| | - Astrid E. M. Zuurbier
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
| | - Frederik P. J. Mul
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
| | - Arthur J. Verhoeven
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
| | - René Lutter
- †Department of Pulmonology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Edward F. Knol
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
| | - Dirk Roos
- *Central Laboratory of The Netherlands Red Cross Blood Transfusion Service and Laboratory of Experimental and Clinical Immunology, and
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16
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Carlson SA, Chatterjee TK, Murphy KP, Fisher RA. Mutation of a putative amphipathic alpha-helix in the third intracellular domain of the platelet-activating factor receptor disrupts receptor/G protein coupling and signaling. Mol Pharmacol 1998; 53:451-8. [PMID: 9495811 DOI: 10.1124/mol.53.3.451] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Platelet-activating factor (PAF) is a potent phospholipid mediator that interacts with G protein-coupled PAF receptors to elicit diverse physiological and pathophysiological actions. We recently demonstrated that the third intracellular domain of the rat PAF receptor (rPAFR) is a critical determinant in its coupling to phosphoinositide phospholipase C-activating G proteins. Here, we report identification of a putative amphipathic helix in the third intracellular domain of the rPAFR and the effects of mutational disruption of its amphipathic character on G protein coupling of and signaling by the rPAFR. Modeling of the third intracellular domain and adjacent transmembrane regions of the rPAFR identified a single amphipathic helix located in the amino-terminal region of the third intracellular domain of the receptor. Baby hamster kidney cells were transiently transfected with cDNAs encoding the rPAFR or rPAFR mutants in which nonconserved substitutions were made separately in the hydrophobic or polar face of this amphipathic helix. The number and affinity of binding sites for specific PAF receptor antagonist WEB2086 were identical in membranes prepared from rPAFR and amphipathic helix mutant PAFR transfectants. However, only membranes derived from rPAFR transfectants possessed high affinity PAF binding sites that were sensitive to the G protein-uncoupling effects of guanosine-5'-O-(3-thio)triphosphate. These results show that substitutions into either face of the amphipathic helical domain abolished the ability of the rPAFR to undergo coupling to G proteins to form a high affinity agonist/receptor/G protein ternary complex. To examine the effects of these mutations on rPAFR signaling, PAF-stimulated inositol phosphate accumulation was determined in cells transfected with cDNAs encoding the wild-type or amphipathic helix mutant PAFRs. Although PAF stimulated 10-fold increases in inositol phosphate accumulation in rPAFR transfectants, it had no effects on inositol phosphate accumulation in amphipathic helix mutant PAFR transfectants. These results suggest that an amphipathic helix located in the amino-terminal region of the third intracellular domain of the rPAFR is required for its coupling to and activation of G proteins. This study provides the first insight into the structure of the receptor interface for G protein coupling of a PAFR and suggests a conserved role of amphipathic helices in G protein coupling of receptors ranging from those for biogenic amines to the phospholipid mediator PAF.
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Affiliation(s)
- S A Carlson
- Department of Pharmacology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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17
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Bennett SAL, Birnboim HC. Receptor-mediated and protein kinase-dependent growth enhancement of primary human fibroblasts by platelet activating factor. Mol Carcinog 1997. [DOI: 10.1002/(sici)1098-2744(199712)20:4<366::aid-mc6>3.0.co;2-h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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18
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McKay DM, Philpott DJ, Perdue MH. Review article: In vitro models in inflammatory bowel disease research--a critical review. Aliment Pharmacol Ther 1997; 11 Suppl 3:70-80. [PMID: 9467981 DOI: 10.1111/j.1365-2036.1997.tb00811.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Research efforts in inflammatory bowel disease (IBD) have been directed towards the epithelium as it has become clear that epithelial cells play a critical role in inflammatory response. Most research involving IBD employs in vitro techniques. In vitro epithelial cell studies have played and are continuing to play a major role in providing specific information relevant to IBD. Thus, such studies have provided irrefutable evidence that epithelial responses can be induced by microbes/microbial products and by immune activation. Culture experiments have provided insights into the effects of individual cytokines and other inflammatory mediators on epithelial pathophysiology, injury and repair, apoptosis, necrosis, and other processes that may be involved in IBD. Activated epithelial cells can participate in and even orchestrate immune responses, by stimulating T cells (and possibly others) and by producing cytokines that recruit specific inflammatory cells. Physiological regulation of epithelial tight junctions has been demonstrated by in vitro studies; the implication of this information for treating IBD is just beginning to be explored. It is becoming increasingly clear that epithelial processing and presentation of antigens is critical to the outcome of the immune response.
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Affiliation(s)
- D M McKay
- Intestinal Disease Research Programme, McMaster University, Hamilton, Ontario, Canada
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19
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Shindo K, Koide K, Fukumura M. PAF-induced eosinophil chemotaxis increases during an asthmatic attack and is inhibited by prednisolone in vivo and in vitro. Biochem Biophys Res Commun 1997; 237:146-51. [PMID: 9266847 DOI: 10.1006/bbrc.1997.7098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated platelet-activating factor (PAF)-induced migration in eosinophils obtained from asthmatic patients who were treated with or without intravenous prednisolone. The migration of asthmatic eosinophils in remission and during an attack was significantly greater than that in healthy volunteers. The migration of asthmatic eosinophils exposed to prednisolone in vivo and in vitro was significantly inhibited, compared to asthmatic eosinophils not exposed to prednisolone. These findings suggest that an intracellular factor causes asthmatic eosinophils to migrate, and that prednisolone inhibits PAF-induced eosinophil migration.
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Affiliation(s)
- K Shindo
- First Department of Internal Medicine, Yokohama City University School of Medicine, Japan
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20
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Abstract
Mainly located in the skin or mucosa of patients with allergic diseases, eosinophils contribute directly to tissue damage and chronic inflammation. The past year has seen significant advances in the study of the factors involved in the specific tissue recruitment of eosinophils, including chemoattractants and their receptors. New data have been obtained on the synthesis by eosinophils of various cytokines mostly released by immune complexes.
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Affiliation(s)
- P Desreumaux
- Clinique des Maladies de l'Appareil Digestif et de la Nutrition, Hôpital Huriez, University Hospital, Lille, France
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