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Law S, Hardisty G, Dransfield I, Gray R. P221 Neutrophil extracellular traps are elevated in cystic fibrosis sputum and associated with neutrophilic inflammation and lung function decline. J Cyst Fibros 2019. [DOI: 10.1016/s1569-1993(19)30514-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Dransfield I, Zagórska A, Lew ED, Michail K, Lemke G. Mer receptor tyrosine kinase mediates both tethering and phagocytosis of apoptotic cells. Cell Death Dis 2015; 6:e1646. [PMID: 25695599 PMCID: PMC4669813 DOI: 10.1038/cddis.2015.18] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/11/2014] [Accepted: 01/06/2015] [Indexed: 01/12/2023]
Abstract
Billions of inflammatory leukocytes die and are phagocytically cleared each day. This regular renewal facilitates the normal termination of inflammatory responses, suppressing pro-inflammatory mediators and inducing their anti-inflammatory counterparts. Here we investigate the role of the receptor tyrosine kinase (RTK) Mer and its ligands Protein S and Gas6 in the initial recognition and capture of apoptotic cells (ACs) by macrophages. We demonstrate extremely rapid binding kinetics of both ligands to phosphatidylserine (PtdSer)-displaying ACs, and show that ACs can be co-opsonized with multiple PtdSer opsonins. We further show that macrophage phagocytosis of ACs opsonized with Mer ligands can occur independently of a requirement for αV integrins. Finally, we demonstrate a novel role for Mer in the tethering of ACs to the macrophage surface, and show that Mer-mediated tethering and subsequent AC engulfment can be distinguished by their requirement for Mer kinase activity. Our results identify Mer as a receptor uniquely capable of both tethering ACs to the macrophage surface and driving their subsequent internalization.
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Affiliation(s)
- I Dransfield
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - A Zagórska
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA, USA
| | - E D Lew
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA, USA
| | - K Michail
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - G Lemke
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA, USA
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Treweeke AT, Winterburn TJ, Mackenzie I, Barrett F, Barr C, Rushworth GF, Dransfield I, MacRury SM, Megson IL. N-Acetylcysteine inhibits platelet-monocyte conjugation in patients with type 2 diabetes with depleted intraplatelet glutathione: a randomised controlled trial. Diabetologia 2012; 55:2920-8. [PMID: 22935960 PMCID: PMC3464379 DOI: 10.1007/s00125-012-2685-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/09/2012] [Indexed: 02/05/2023]
Abstract
AIMS/HYPOTHESIS The aim of this study was to determine whether oral dosing with N-acetylcysteine (NAC) increases intraplatelet levels of the antioxidant, glutathione (GSH), and reduces platelet-monocyte conjugation in blood from patients with type 2 diabetes. METHODS In this placebo-controlled randomised crossover study, the effect of oral NAC dosing on platelet-monocyte conjugation and intraplatelet GSH was investigated in patients with type 2 diabetes (eligibility criteria: men or post-menopausal women with well-controlled diabetes (HbA(1c) < 10%), not on aspirin or statins). Patients (n = 14; age range 43-79 years, HbA(1c) = 6.9 ± 0.9% [52.3 ± 10.3 mmol/mol]) visited the Highland Clinical Research Facility, Inverness, UK on day 0 and day 7 for each arm of the study. Blood was sampled before and 2 h after oral administration of placebo or NAC (1,200 mg) on day 0 and day 7. Patients received placebo or NAC capsules for once-daily dosing on the intervening days. The order of administration of NAC and placebo was allocated by a central office and all patients and research staff involved in the study were blinded to the allocation until after the study was complete and the data fully analysed. The primary outcome for the study was platelet-monocyte conjugation. RESULTS Oral NAC reduced platelet-monocyte conjugation (from 53.1 ± 4.5% to 42.5 ± 3.9%) at 2 h after administration and the effect was maintained after 7 days of dosing. Intraplatelet GSH was raised in individuals with depleted GSH and there was a negative correlation between baseline intraplatelet GSH and platelet-monocyte conjugation. There were no adverse events. CONCLUSIONS/INTERPRETATION The NAC-induced normalisation of intraplatelet GSH, coupled with a reduction in platelet-monocyte conjugation, suggests that NAC might help to reduce atherothrombotic risk in type 2 diabetes. FUNDING Chief Scientist Office (CZB/4/622), Scottish Funding Council, Highlands & Islands Enterprise and European Regional Development Fund. TRIAL REGISTRATION isrctn.org ISRCTN89304265.
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Affiliation(s)
- A T Treweeke
- Free Radical Research Facility, Department of Diabetes & Cardiovascular Science, University of the Highlands & Islands, Centre for Health Science, Inverness IV2 3JH, UK
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Wicks E, Maciocia P, Bournazos S, Hilling-Smith R, Dransfield I, Uren N. 412 EFFECTS OF INTENSIVE LIPID-LOWERING ON PLATELET ACTIVATION & MARKERS OF SYSTEMIC INFLAMMATION IN PATIENTS AT ELEVATED CARDIOVASCULAR RISK. ATHEROSCLEROSIS SUPP 2011. [DOI: 10.1016/s1567-5688(11)70413-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Receptors for immunoglobulins (Fc receptors) play a central role during an immune response, as they mediate the specific recognition of antigens of almost infinite diversity by leucocytes, thereby linking the humoral and cellular components of immunity. Indeed, engagement of Fc receptors by immunoglobulins initiates a range of immunoregulatory processes that might also play a role in disease pathogenesis. In the circulation, five main types of immunoglobulins (Ig) exist - namely IgG, IgA, IgE, IgM and IgD and receptors with the ability to recognize and bind to IgG (Fc gamma receptor family), IgE (Fc epsilon RI and CD23), IgA (CD89; Fc alpha/microR) and IgM (Fc alpha/microR) have been identified and characterized. However, it is astonishing that nearly all the known human Fc receptors display extensive genetic variation with clear implications for their function, thus representing a substantial genetic risk factor for the pathogenesis of a range of chronic inflammatory disorders.
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Affiliation(s)
- S Bournazos
- Medical Research Council (MRC) Centre for Inflammation Research, Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, UK
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Dransfield I, Rossi AG, Brown SB, Hart SP. Neutrophils: dead or effete? Cell surface phenotype and implications for phagocytic clearance. Cell Death Differ 2005; 12:1363-7. [PMID: 15962007 DOI: 10.1038/sj.cdd.4401695] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- I Dransfield
- MRC Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK.
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Vivers S, Heasman SJ, Hart SP, Dransfield I. Divalent cation-dependent and -independent augmentation of macrophage phagocytosis of apoptotic neutrophils by CD44 antibody. Clin Exp Immunol 2005; 138:447-52. [PMID: 15544621 PMCID: PMC1809234 DOI: 10.1111/j.1365-2249.2004.02638.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Phagocytosis of apoptotic neutrophils by macrophages is required for resolution of an inflammatory response. Removal of intact apoptotic neutrophils prevents the release of cytotoxic granules that would otherwise cause tissue damage and may lead to development of fibrosis. Importantly, macrophage phagocytosis of apoptotic neutrophils fails to induce release of proinflammatory mediators, consistent with a 'safe' pathway for disposal of potentially harmful inflammatory cells. One pathway for increasing phagocytosis of apoptotic cells to allow matching of tissue phagocyte capacity to apoptotic cell load in vitro is via antibody-mediated cross-linking of CD44, providing a mechanism for limiting tissue damage during resolution of inflammation. In this study, we have defined divalent cation-dependent and -independent actions of the CD44 antibody. For the divalent cation-independent CD44 antibody effect, we provide evidence that 'enabled' CD32 on the apoptotic neutrophil binds to intact CD44 antibody on the macrophage surface. One implication is that macrophages can phagocytose apoptotic neutrophils that are 'tethered' to the macrophage surface in a manner that is independent of defined apoptotic mechanisms. These data also provide an explanation for the greater efficacy of intact CD44 antibody when compared with F(ab')2 fragments.
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Affiliation(s)
- S Vivers
- Rayne Laboratory, MRC Centre for Inflammation Research, University of Edinburgh Medical School, Edinburgh, UK
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Rossi AG, Ward C, Dransfield I. Getting to grips with the granulocyte: manipulation of granulocyte behaviour and apoptosis by protein transduction methods. Biochem Soc Trans 2005; 32:452-5. [PMID: 15157158 DOI: 10.1042/bst0320452] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human granulocytes clearly play an important role in host defence against invading organisms, however they have also been implicated in the pathogenesis and progression of many chronic inflammatory diseases. In addition, these cells have been paramount in gaining a better understanding of many key-signalling pathways regulating fundamental biological processes. Since granulocytes are terminally differentiated and undergo relatively rapid constitutive apoptosis it has been difficult to manipulate intracellular events by transfection or transduction procedures. It has been shown in recent years that the HIV-TAT protein transduction system can be successfully used in granulocytes to manipulate key signalling mechanisms regulating functional responsiveness and survival. In this paper, we review recent literature highlighting important developments using this system in isolated human granulocytes and in inflammatory process in vivo where these cells play a prominent role.
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Affiliation(s)
- A G Rossi
- MRC Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK.
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11
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Abstract
Granulocyte apoptosis is a crucial part of the successful resolution of inflammation. In vitro results show that activation of NF-κB (nuclear factor κB) in granulocytes is a survival mechanism. NF-κB inhibitors increase the rate of constitutive apoptosis in neutrophils and eosinophils and cause these cells to respond to the pro-apoptotic effects of TNF-α (tumour necrosis factor-α). Results from both in vivo and in vitro experiments suggest that there are at least two important waves of NF-κB activation in inflammatory loci, which increase the expression of COX-2 (cyclooxygenase-2), itself an NF-κB controlled gene. The first wave causes the production of inflammatory mediators such as PGE2 (prostaglandin E2), allowing the establishment of inflammation. The second wave causes the synthesis of PGD2 and its metabolites that induce granulocyte apoptosis by inhibiting NF-κB activation. These metabolites may therefore be important physiological mediators controlling the resolution of inflammation. Although NF-κB is an important target for anti-inflammatory therapy, the timing of inhibition in vivo may be crucial, to ensure that production of PGD2 and its sequential metabolites can occur.
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Affiliation(s)
- C Ward
- Respiratory Medicine Unit, MRC Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK.
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12
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Abstract
The neutrophil granulocyte is a key factor in cellular innate defence mechanisms against infection or tissue damage. Granulocyte apoptosis is now acknowledged to have a critical role in progression of inflammatory responses. Granulocytes are preprogrammed to die with important physiological mechanisms for non-inflammatory clearance. Shutdown of secretory capacity represents an important aspect of the programme of biochemical events that accompany neutrophil apoptosis together with surface molecular changes that serve to identify apoptotic cells as targets for phagocytic removal. Defining the underlying regulatory mechanisms together with the changes in patterns of gene/protein expression associated with granulocyte death remains a challenge. Use of novel strategies for inducing cell death will allow biochemical approaches to dissect the underlying pathways. Although study of granulocyte cell death has especial difficulties when compared with other cell types, there are clearly potential benefits for new therapeutic approaches to treat inflammatory diseases.
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Affiliation(s)
- I Dransfield
- MRC Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK.
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Abstract
Efficient phagocytic clearance of apoptotic cells is crucial in many biological processes. A bewildering array of phagocyte receptors have been implicated in apoptotic cell clearance, but there is little convincing evidence that they act directly as apoptotic cell receptors. Alternatively, apoptotic cells may become opsonized, whereby naturally occurring soluble factors (opsonins) bind to the cell surface and initiate phagocytosis. Evidence is accumulating that antibodies and complement proteins opsonize apoptotic cells, leading to phagocytosis mediated by well-defined 'old-fashioned' receptors for immunoglobulin-Fc and complement. In this review we summarize the evidence that opsonization is necessary for high capacity clearance of apoptotic cells, which would render putative direct apoptotic cell receptors redundant.
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Affiliation(s)
- S P Hart
- MRC Centre for Inflammation Research, University of Edinburgh Medical School, Edinburgh, UK.
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Walker A, Ward C, Dransfield I, Haslett C, Rossi AG. Regulation of Granulocyte Apoptosis by Hemopoietic Growth Factors, Cytokines and Drugs: Potential Relevance to Allergic Inflammation. ACTA ACUST UNITED AC 2003; 2:339-47. [PMID: 14561153 DOI: 10.2174/1568010033484025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has become apparent that the resolution of inflammation depends on the removal of unwanted inflammatory cells, a process governed by physiological apoptosis and non-inflammatory clearance of apoptotic cells. Granulocytes are central to many of the pathophysiological consequences of uncontrolled inflammatory reactions. Hemopoietic factors and cytokines play a critical role in regulating the longevity of these cells in vitro and in vivo. Here we review the progress that has been made in the understanding of granulocyte apoptosis and the implications for immunotherapy and pharmacological strategies in the treatment of allergic inflammatory diseases for therapeutic gain.
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Affiliation(s)
- A Walker
- Respiratory Medicine Unit, Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh, EH8 9AG, Scotland, UK
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Heasman SJ, Giles KM, Ward C, Rossi AG, Haslett C, Dransfield I. Glucocorticoid-mediated regulation of granulocyte apoptosis and macrophage phagocytosis of apoptotic cells: implications for the resolution of inflammation. J Endocrinol 2003; 178:29-36. [PMID: 12844333 DOI: 10.1677/joe.0.1780029] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glucocorticoids represent one of the most effective clinical treatments for a range of inflammatory conditions, including severe acute inflammation. Although glucocorticoids are known to affect processes involved in the initiation of inflammation, the influence of glucocorticoids on the mechanisms by which acute inflammation normally resolves have received less attention. Apoptosis of granulocytes present at inflamed sites leads to their rapid recognition and internalisation by macrophages, a process which may be important for resolution of inflammation. However, if clearance of either eosinophils or neutrophils is impaired, these cells rapidly undergo secondary necrosis leading to release of pro-inflammatory mediators from the phagocyte, potentially prolonging inflammatory responses. Physiologically relevant concentrations of glucocorticoids accelerate eosinophil apoptosis whilst delaying neutrophil apoptosis during in vitro culture. Here we discuss key pathways regulating the granulocyte apoptotic programme and summarise the effects of glucocorticoids on monocyte differentiation and the consequent changes to apoptotic cell clearance capacity. Definition of the mechanisms underlying resolution of inflammatory responses following glucocorticoid treatment may unveil new targets for modulation of inflammatory disease, allowing co-ordinated augmentation of granulocyte apoptosis together with increased macrophage capacity for clearance of apoptotic cells.
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Affiliation(s)
- S J Heasman
- MRC Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK
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Martin MC, Dransfield I, Haslett C, Rossi AG. Cyclic AMP regulation of neutrophil apoptosis occurs via a novel protein kinase A-independent signaling pathway. J Biol Chem 2001; 276:45041-50. [PMID: 11560927 DOI: 10.1074/jbc.m105197200] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The second messenger molecule cyclic AMP dramatically modulates the apoptotic program in a wide variety of cells, accelerating apoptosis in some and delaying the rate of apoptosis in others. Human neutrophil apoptosis, a process that regulates the fate and numbers of these potentially histotoxic cells in inflammatory sites, is profoundly delayed by the cell-permeable analog of cyclic AMP, dibutyryl-cAMP. We have investigated the mechanisms underlying cyclic AMP-mediated delay of neutrophil apoptosis, and we show that cyclic AMP inhibits loss of mitochondrial potential occurring during constitutive neutrophil apoptosis. Furthermore, we demonstrate that cyclic AMP also suppresses caspase activation in these inflammatory cells. Despite increasing protein kinase A activity, this kinase is unlikely to mediate the effect of cyclic AMP on apoptosis because blockade of protein kinase A activation did not influence the survival effects of cyclic AMP. Further investigation of the signaling mechanism demonstrated that the delay of apoptosis is independent of phosphoinositide 3-kinase and MAPK activation. Our results suggest cyclic AMP delays neutrophil apoptosis via a novel, reversible, and transcriptionally independent mechanism. We show that proteasome activity in the neutrophil is vitally involved in this process, and we suggest that a balance of pro-apoptotic and anti-apoptotic proteins plays a key role in the powerful ability of cyclic AMP to delay neutrophil death.
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Affiliation(s)
- M C Martin
- Medical Research Council Centre for Inflammation Research, Respiratory Medicine Unit, University of Edinburgh Medical School, Edinburgh EH8 9AG, United Kingdom.
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Giles KM, Ross K, Rossi AG, Hotchin NA, Haslett C, Dransfield I. Glucocorticoid augmentation of macrophage capacity for phagocytosis of apoptotic cells is associated with reduced p130Cas expression, loss of paxillin/pyk2 phosphorylation, and high levels of active Rac. J Immunol 2001; 167:976-86. [PMID: 11441106 DOI: 10.4049/jimmunol.167.2.976] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Phagocytic clearance of apoptotic granulocytes has a pivotal role in determining an inflammatory outcome, resolution or progression to a chronic state associated with development of fibrotic repair mechanisms, and/or autoimmune responses. In this study, we describe reprogramming of monocyte to macrophage differentiation by glucocorticoids, resulting in a marked augmentation of their capacity for phagocytosis of apoptotic neutrophils. This monocyte/macrophage phenotype was characterized by decreased phosphorylation, and therefore recruitment of paxillin and pyk2 to focal contacts and a down-regulation of p130Cas, a key adaptor molecule in integrin adhesion signaling. Glucocorticoid-treated cells also displayed higher levels of active Rac and cytoskeletal activity, which were mirrored by increases in phagocytic capability for apoptotic neutrophils. We propose that changes in the capacity for reorganization of cytoskeletal elements induced by glucocorticoids are essential for efficient phagocytic uptake of apoptotic cells.
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Affiliation(s)
- K M Giles
- Medical Research Council Centre for Inflammation Research, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, United Kingdom
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Abstract
Thalidomide has significant immunomodulatory properties and has been used successfully in the treatment of oral ulcers and wasting in HIV patients. However, its use is limited by its poor bioavailability due to low solubility and short half life in solution, and teratogenic and neurotoxic side-effects. Recently, water-soluble analogues of thalidomide with significantly greater immunomodulatory activity and reduced side-effects have become available. We examined the effect of thalidomide and one analogue, CC-3052, on neutrophil apoptosis following culture for 20 h in vitro. Apoptosis was assessed by reduced CD16 expression and Annexin V binding using flow cytometry. Thalidomide or CC-3052 alone had no effect on neutrophil apoptosis when used at physiological levels. However, when used together with prostaglandin E2 (10-7 M), a potent adenylate cyclase activator, CC-3052 but not thalidomide (both 10-5 M) reduced apoptosis in neutrophils from normal and HIV+ donors. The reduced apoptosis could not be attributed to the ability of CC-3052 to reduce tumour necrosis factor-alpha (TNF-alpha) production, but may be due to its PDE4 inhibitor properties, as it increased [cAMP]i, and mimicked the effect of increasing [cAMP]i using dibutryl cAMP, a membrane-permeable analogue of cAMP. The results suggest a role for thalidomide analogue CC-3052 in reducing persistent activation of the TNF-alpha system in HIV without markedly impairing neutrophil viability.
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Affiliation(s)
- M Guckian
- Division of Oncology, St George's Hospital Medical School, London, UK
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Ruchaud-Sparagano MH, Walker TR, Rossi AG, Haslett C, Dransfield I. Soluble E-selectin acts in synergy with platelet-activating factor to activate neutrophil beta 2-integrins. Role of tyrosine kinases and Ca2+ mobilization. J Biol Chem 2000; 275:15758-64. [PMID: 10748085 DOI: 10.1074/jbc.m907390199] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Selectins play a critical role in neutrophil recruitment to sites of inflammation, in tethering and rolling of neutrophils on vascular endothelium, as well as triggering beta(2)-integrin-mediated adhesion. We have previously demonstrated potential pro-inflammatory effects of soluble E-selectin upon neutrophil effector functions, using a soluble recombinant molecule (E-zz), which increased beta(2)-integrin-mediated adhesion, decreased beta(2)-integrin-dependent migration, and triggered reactive oxygen species generation and release. In this study, we have examined the intracellular signals following neutrophil activation by soluble E-selectin. We show that exposure of neutrophils to E-selectin and platelet-activating factor (PAF) in combination induced a synergistic effect upon beta(2)-integrin-mediated adhesion. Although soluble E-selectin did not induce Ca(2+) mobilization in neutrophils by itself, elevation of intracellular Ca(2+) was specifically prolonged in response to PAF but not leukotriene B(4) or N-formyl-Met-Leu-Phe. The prolonged Ca(2+) mobilization observed in the presence of E-selectin was dependent on Ca(2+) influx from intracellular stores rather than influx of extracellular Ca(2+) through SKF 96365-sensitive channels. The specific alteration of Ca(2+) mobilization reported here appears not to have a role in the synergistic effects of E-selectin and PAF upon neutrophil O(2) release but may be involved in augmentation of beta(2)-integrin-mediated adhesion.
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Affiliation(s)
- M H Ruchaud-Sparagano
- Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh Medical School, Edinburgh EH8 9AG, United Kingdom.
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Hart SP, Ross JA, Ross K, Haslett C, Dransfield I. Molecular characterization of the surface of apoptotic neutrophils: implications for functional downregulation and recognition by phagocytes. Cell Death Differ 2000; 7:493-503. [PMID: 10800083 DOI: 10.1038/sj.cdd.4400680] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We have used a panel of monoclonal antibodies and lectins to examine the profile of surface molecule expression on human neutrophils that have undergone spontaneous apoptosis during in vitro culture. Neutrophil apoptosis was found to be accompanied by down-regulation of the immunoglobulin superfamily members PECAM-1 (CD31), ICAM-3 (CD50), CD66acde, and CD66b and the integrin-associated proteins CD63 and urokinase plasminogen activator receptor (CD87) that may alter the potential for adhesive interactions. Cellular interactions may be further influenced by the reduction of the expression of surface carbohydrate moieties, including sialic acid. Reduced expression of FcgammaRII (CD32), complement receptor type 1 (CD35) and receptors for pro-inflammatory mediators C5a (CD88) and TNFalpha (CD120b) associated with apoptosis might limit neutrophil responsiveness to stimuli that trigger degranulation responses. Although many of the receptors we have examined are expressed at reduced levels on apoptotic neutrophils, we found that there was differential loss of certain receptors (e.g. CD16, CD15 and CD120b) and increased expression of aminopeptidase-N (CD13). Together with our previous data showing that expression of certain molecules e.g. LFA-3 (CD58) is not altered during neutrophil apoptosis, these data are suggestive of specific changes in receptor mobilisation and shedding associated with apoptosis. Although reduced expression of CD63 (azurophilic granules) and CR1 (specific granules) indicates that granule mobilisation does not accompany apoptosis, a monoclonal antibody (BOB78), that recognises a 90 kDa antigen localised in intracellular granules, defines a subpopulation of apoptotic neutrophils that exhibit nuclear degradation yet retain intact plasma membranes. BOB78 positive neutrophils were found to bind biotinylated thrombospondin, suggesting that this mAb defines surface molecular changes associated with exposure of thrombospondin binding moieties.
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Affiliation(s)
- S P Hart
- The Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh Medical School, Teviot Place, Edinburgh, EH8 9AG, UK
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Affiliation(s)
- K M Giles
- The Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh, Medical School, Teviot Place, Edinburgh, EH8 9AG, UK
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Abstract
Resolution of inflammation involves the clearance of excess or effete inflammatory cells by a process of physiological programmed cell death (apoptosis) and the subsequent recognition and removal of apoptotic cells by phagocytes. The therapeutic induction of apoptosis for the resolution of chronic inflammation and the general pharmacology of apoptosis have become subjects of increasing interest. In this article, some of the unique and important differences in the control of apoptosis of various inflammatory cells (particularly neutrophil and eosinophil granulocytes) are highlighted. It is suggested that apoptosis can be specifically regulated pharmacologically and could be exploited to develop new drug therapies.
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Affiliation(s)
- C Ward
- The Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh Medical School, Teviot Place, Edinburgh, UK EH8 9AG.
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Sethi T, Rintoul RC, Moore SM, MacKinnon AC, Salter D, Choo C, Chilvers ER, Dransfield I, Donnelly SC, Strieter R, Haslett C. Extracellular matrix proteins protect small cell lung cancer cells against apoptosis: a mechanism for small cell lung cancer growth and drug resistance in vivo. Nat Med 1999; 5:662-8. [PMID: 10371505 DOI: 10.1038/9511] [Citation(s) in RCA: 575] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Resistance to chemotherapy is a principal problem in the treatment of small cell lung cancer (SCLC). We show here that SCLC is surrounded by an extensive stroma of extracellular matrix (ECM) at both primary and metastatic sites. Adhesion of SCLC cells to ECM enhances tumorigenicity and confers resistance to chemotherapeutic agents as a result of beta1 integrin-stimulated tyrosine kinase activation suppressing chemotherapy-induced apoptosis. SCLC may create a specialized microenvironment, and the survival of cells bound to ECM could explain the partial responses and local recurrence of SCLC often seen clinically after chemotherapy. Strategies based on blocking beta1 integrin-mediated survival signals may represent a new therapeutic approach to improve the response to chemotherapy in SCLC.
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Affiliation(s)
- T Sethi
- Respiratory Medicine Unit, Rayne Laboratory, University of Edinburgh Medical School, Scotland, UK.
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Liu Y, Cousin JM, Hughes J, Van Damme J, Seckl JR, Haslett C, Dransfield I, Savill J, Rossi AG. Glucocorticoids promote nonphlogistic phagocytosis of apoptotic leukocytes. J Immunol 1999; 162:3639-46. [PMID: 10092825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Phagocyte recognition, uptake, and nonphlogistic degradation of neutrophils and other leukocytes undergoing apoptosis promote the resolution of inflammation. This study assessed the effects of anti-inflammatory glucocorticoids on this leukocyte clearance mechanism. Pretreatment of "semimature" 5-day human monocyte-derived macrophages (M phi) for 24 h with methylprednisolone, dexamethasone, and hydrocortisone, but not the nonglucocorticoid steroids aldosterone, estradiol, and progesterone, potentiated phagocytosis of apoptotic neutrophils. These effects were specific in that the potentiated phagocytosis of apoptotic neutrophils was completely blocked by the glucocorticoid receptor antagonist RU38486, and glucocorticoids did not promote 5-day M phi ingestion of opsonized erythrocytes. Similar glucocorticoid-mediated potentiation was observed with 5-day M phi uptake of alternative apoptotic "targets" (eosinophils and Jurkat T cells) and in uptake of apoptotic neutrophils by alternative phagocytes (human glomerular mesangial cells and murine M phi elicited into the peritoneum or derived from bone marrow). Importantly, methylprednisolone-mediated enhancement of the uptake of apoptotic neutrophils did not trigger the release of the chemokines IL-8 and monocyte chemoattractant protein-1. Furthermore, longer-term potentiation by methylprednisolone was observed in maturing human monocyte-derived M phi, with greater increases in 5-day M phi uptake of apoptotic cells being observed the earlier glucocorticoids were added during monocyte maturation into M phi. We conclude that potentiation of nonphlogistic clearance of apoptotic leukocytes by phagocytes is a hitherto unrecognized property of glucocorticoids that has potential implications for therapies aimed at promoting the resolution of inflammatory diseases.
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Affiliation(s)
- Y Liu
- Division of Renal and Inflammatory Disease, School of Medical and Surgical Sciences, University Hospital, Nottingham, United Kingdom
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25
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Affiliation(s)
- S P Hart
- Rayne Laboratory, University of Edinburgh Medical School, UK
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26
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McCutcheon JC, Hart SP, Canning M, Ross K, Humphries MJ, Dransfield I. Regulation of macrophage phagocytosis of apoptotic neutrophils by adhesion to fibronectin. J Leukoc Biol 1998; 64:600-7. [PMID: 9823764 DOI: 10.1002/jlb.64.5.600] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The potential for leukocyte-mediated host tissue damage during resolution of inflammatory responses is influenced by the rate at which extravasated apoptotic leukocytes are cleared from inflammatory sites. Regulation of macrophage capacity for clearance of apoptotic granulocytes is likely to be an important factor determining whether inflammation ultimately resolves or progresses to a chronic state. In this study we have investigated the molecular basis for rapid augmentation of macrophage phagocytosis of apoptotic neutrophils, which was observed following macrophage adhesion to fibronectin. We used a combination of monoclonal antibodies, blocking peptides, and recombinant fibronectin fragments to investigate the role of beta1 integrins in mediating the fibronectin effects. Blockade of alpha5beta1 or alpha4beta1 alone did not attenuate fibronectin-augmentation of phagocytosis. In addition, adhesion of macrophages to recombinant fibronectins lacking alpha4beta1 recognition motifs failed to promote phagocytosis of apoptotic neutrophils. Our results would be consistent with a model in which multiple fibronectin receptors, including beta1 integrins, act co-operatively to augment macrophage phagocytic responses. Together, these data suggest that the extracellular matrix environment of macrophages may provide regulatory signals that act indirectly to rapidly alter the potential for removal of apoptotic cells and influence the process of resolution of inflammation.
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Affiliation(s)
- J C McCutcheon
- Rayne Laboratory, Edinburgh University Medical School, United Kingdom
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27
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Abstract
Lipopolysaccharide (LPS) is a potent inflammatory agent which augments neutrophil sensitivity to subsequent inflammatory stimuli. In this study, the effects of structurally different LPS types upon neutrophil effector functions were examined. Rough LPS types, which have lost the O-polysaccharide moiety, were found to act more rapidly than smooth LPS types in stimulating neutrophil beta2 integrin activity and fMLP-induced respiratory burst. These findings suggest an involvement of the O-polysaccharide region of LPS in regulating neutrophil responsiveness to different LPS chemotypes with important implications for the mechanisms underlying regulation of the inflammatory response in conditions associated with elevation of LPS in plasma, e.g. septic shock or acute respiratory distress syndrome.
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28
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MacDonald AS, Maizels RM, Lawrence RA, Dransfield I, Allen JE. Requirement for in vivo production of IL-4, but not IL-10, in the induction of proliferative suppression by filarial parasites. J Immunol 1998; 160:4124-32. [PMID: 9558124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Loss of T lymphocyte proliferation and the emergence of a host response that is dominated by a Th2-type profile are well-established features of human filariasis. We have previously reported that adherent peritoneal exudate cells (PEC) from mice transplanted with adult Brugia malayi parasites suppress the proliferation of lymphocytes without blocking Ag-cytokine production in vitro. We now show that infection of mice with the infective larval (L3) stage of B. malayi generates a similar population of PEC. Suppressive cells are generated within 7 days of infection and mediate their effects through a nitric oxide-independent pathway. Both L3 and adult infection elicit high levels of host IL-4 whereas the microfilarial stage of the parasite induces IFN-gamma production and does not generate a similar form of suppression. Production of host IL-4 was necessary to allow the generation of suppressive PEC, given that IL-4-deficient mice implanted with adult parasites failed to induce proliferative block. However, IL-10-deficient mice implanted with adult parasites resulted in T cell suppression, indicating that IL-10 is not essential for the induction of hyporesponsiveness. Neither IL-4 nor IL-10 were directly responsible for ablating cellular proliferation in vitro, as the addition of neutralizing Ab to either cytokine did not reverse the proliferative block. Thus, IL-4 produced in vivo in response to filarial L3 and adult parasites is essential for the induction of proliferative suppression but is not itself the suppressive factor.
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Affiliation(s)
- A S MacDonald
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Scotland, UK
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29
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Rossi AG, McCutcheon JC, Roy N, Chilvers ER, Haslett C, Dransfield I. Regulation of macrophage phagocytosis of apoptotic cells by cAMP. J Immunol 1998; 160:3562-8. [PMID: 9531319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Regulation of macrophage capacity to remove apoptotic cells may control the balance of apoptotic and necrotic leukocytes at inflamed foci and the extent of leukocyte-mediated tissue damage. Although the molecules involved in the phagocytic process are beginning to be defined, little is known about the underlying regulatory and signaling mechanisms controlling this process. In this paper, we have investigated the effects of treatment of human monocyte-derived macrophages with PGs and other agents that elevate intracellular cAMP on phagocytosis. PGE2 and PGD2 specifically reduced the proportion of macrophages that phagocytosed apoptotic cells. Similar results were obtained with the membrane-permeable cAMP analogues dibutyryl-cAMP and 8-bromo-cAMP but not with the cGMP analogue dibutyryl-GMP. Consistent with the observation that phagocytosis was inhibited by cAMP elevation, treatment of monocyte-derived macrophages with PGE2 resulted in rapid, transient increase in levels of intracellular cAMP. These effects were not due to nonspecific inhibition of monocyte-derived macrophage phagocytosis given that ingestion of Ig-opsonized erythrocytes was unaffected. Elevation of cAMP induced morphologic alterations indicative of changes in the adhesive status of the macrophage, including cell rounding and disassembly of structures that represent points of contact with substrate containing actin and talin. These results strongly suggest that rapid activation of cAMP signaling pathways by inflammatory mediators regulates processes that limit tissue injury and that modulation of cAMP levels represents an additional therapeutic target in the control of resolution of inflammation.
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Affiliation(s)
- A G Rossi
- Department of Medicine (RIE), Rayne Laboratory, The University of Edinburgh Medical School, Scotland, UK.
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30
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MacDonald AS, Maizels RM, Lawrence RA, Dransfield I, Allen JE. Requirement for in vivo production of IL-4, but not IL-10, in the induction of proliferative suppression by filarial parasites. J Immunol 1998; 160:1304-12. [PMID: 9570548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Loss of T lymphocyte proliferation and the emergence of a host response that is dominated by a Th2-type profile are well-established features of human filariasis. We have previously reported that adherent peritoneal exudate cells (PEC) from mice transplanted with adult Brugia malayi parasites suppress the proliferation of lymphocytes without blocking Ag-cytokine production in vitro. We now show that infection of mice with the infective larval (L3) stage of B. malayi generates a similar population of PEC. Suppressive cells are generated within 7 days of infection and mediate their effects through a nitric oxide-independent pathway. Both L3 and adult infection elicit high levels of host IL-4 whereas the microfilarial stage of the parasite induces IFN-gamma production and does not generate a similar form of suppression. Production of host IL-4 was necessary to allow the generation of suppressive PEC, given that IL-4-deficient mice implanted with adult parasites failed to induce proliferative block. However, IL-10-deficient mice implanted with adult parasites resulted in T cell suppression, indicating that IL-10 is not essential for the induction of hyporesponsiveness. Neither IL-4 nor IL-10 were directly responsible for ablating cellular proliferation in vitro, as the addition of neutralizing Ab to either cytokine did not reverse the proliferative block. Thus, IL-4 produced in vivo in response to filarial L3 and adult parasites is essential for the induction of proliferative suppression but is not itself the suppressive factor.
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Affiliation(s)
- A S MacDonald
- Institute of Cell, Animal and Population Biology, University of Edinburgh, UK
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31
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Hannah S, Nadra I, Dransfield I, Pryde JG, Rossi AG, Haslett C. Constitutive neutrophil apoptosis in culture is modulated by cell density independently of beta2 integrin-mediated adhesion. FEBS Lett 1998; 421:141-6. [PMID: 9468295 DOI: 10.1016/s0014-5793(97)01551-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although inflammatory mediators modulate the rate of constitutive neutrophil apoptosis in vitro the effects of micro-environmental conditions have not been fully investigated. In this study, we demonstrate that the rate of constitutive neutrophil apoptosis is affected by the number of cells per unit surface area, with enhanced survival at high cell density. Furthermore, the presence of protein or serum in the culture medium also enhances neutrophil survival. These effects were independent of beta2 integrin-mediated adhesion and were not influenced by specific adhesion to extracellular matrix components. Thus, the rate of neutrophil apoptosis is fundamentally influenced by microenvironmental conditions and indicates that factors such as cell density and extracellular protein concentration must be considered when investigating mechanisms regulating inflammatory cell apoptosis in vitro.
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Affiliation(s)
- S Hannah
- Department of Medicine (R.I.E.), University of Edinburgh Medical School, Scotland, UK.
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32
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Abstract
Appropriate recruitment of neutrophils to sites of infection or tissue injury is a key event in the inflammatory response. A number of studies have shown the critical role of selectins in tethering and rolling of neutrophils on vascular endothelium, as well as a more complex regulatory role, since they have the potential to alter leukocyte recruitment by triggering beta2 integrin-mediated adhesion. In this study, we report that in contrast to patients "at risk" of developing acute respiratory disease syndrome (ARDS), elevated plasma levels of soluble E-selectin are found in patients with established disease. Since neutrophil granulocytes are implicated in ARDS pathogenesis, we have investigated the possibility of a link between elevated soluble plasma E-selectin levels and disease progression by examining the effects of soluble recombinant E-selectin (E-zz) upon neutrophil function. In this paper, we describe the novel finding that exposure of neutrophils to E-zz potentiates a number of neutrophil functions which may act to drive inflammatory processes. Although neutrophil deformability, an important parameter determining retention within the lung microvasculature, was not affected by E-zz, neutrophil polarization was observed. In addition, neutrophil beta2 integrin-mediated adhesion was found to be augmented by E-zz without alteration in levels of surface expression of alphaMbeta2 or the "activation" reporter epitope defined by monoclonal antibody 24. Concomitantly with increased beta2 integrin-mediated adhesion, we observed an inhibition of formyl-Met-Leu-Phe-directed chemotaxis. Together with an augmentation of neutrophil reactive oxidant species production and release of superoxide anions, these data raise the possibility that soluble E-selectin exerts pro-inflammatory effects upon neutrophil function at sites of inflammation, thereby exacerbating disease processes.
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33
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Murray J, Barbara JA, Dunkley SA, Lopez AF, Van Ostade X, Condliffe AM, Dransfield I, Haslett C, Chilvers ER. Regulation of neutrophil apoptosis by tumor necrosis factor-alpha: requirement for TNFR55 and TNFR75 for induction of apoptosis in vitro. Blood 1997; 90:2772-83. [PMID: 9326245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Granulocyte apoptosis is an important mechanism underlying the removal of redundant neutrophils from an inflammatory focus. The ability of many proinflammatory agents to impede this event suggests that such agents act not only in a priming or secretagogue capacity but also increase neutrophil longevity by delaying apoptosis. We have examined whether this hypothesis holds true for all neutrophil priming agents, in particular tumor necrosis factor-alpha (TNF-alpha), which has been variably reported to either induce, delay, or have no effect on neutrophil apoptosis. After 20 hours coincubation TNF-alpha inhibited neutrophil apoptosis; however, more detailed analysis demonstrated its ability to promote apoptosis in a subpopulation of cells at earlier (2 to 8 hours) times. Formyl-Met-Leu-Phe, platelet-activating factor, inositol hexakisphosphate, lipopolysaccharide, leukotriene B4, and granulocyte-macrophage colony-stimulating factor all inhibited apoptosis at 6 and 20 hours. The early proapoptotic effect of TNF-alpha was concentration-dependent (EC50 2.8 ng/mL), abolished by TNF-alpha neutralizing antibody, and was not associated with any change in cell viability or recovery. Of relevance to the inflamed site, the ability of TNF-alpha to accelerate apoptosis was lost if neutrophils were primed with 1 micromol/L PAF or aged for 6 hours before TNF-alpha addition. The TNFR55-selective TNF-alpha mutants (E146K, R32W-S86T) induced neutrophil apoptosis but with a potency 14-fold lower than wild-type TNF-alpha. Although the TNFR75-selective mutant (D143F) did not induce apoptosis, blocking antibodies to both receptor subtypes abolished TNF-alpha-stimulated apoptosis. Hence, TNF-alpha has the unique ability to induce apoptosis in human neutrophils via a mechanism where TNFR75 facilitates the dominant TNFR55 death effect. This may be an important mechanism controlling neutrophil longevity and clearance in vivo.
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Affiliation(s)
- J Murray
- Department of Medicine (RIE), University of Edinburgh, Medical School, UK
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34
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Ruchaud-Sparagano MH, Stocks SC, Turley H, Dransfield I. Activation of neutrophil function via CD66: differential effects upon beta 2 integrin mediated adhesion. Br J Haematol 1997; 98:612-20. [PMID: 9332316 DOI: 10.1046/j.1365-2141.1997.2523070.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To further define the role of CD66 glycoproteins in the regulation of neutrophil function, we analysed the effects of a CD66 monoclonal antibody, Kat4c, which recognizes an epitope present on AB domains of CD66a, CD66b and CD66c. Intact Kat4c and F(ab')2 fragments were found to augment fMLP-induced oxidation of 1,2,3-dihydrorhodamine (oxidant species production) and beta 2 integrin-mediated adhesion to fibrinogen but did not promote beta 2 integrin-mediated binding of albumin coated latex beads. Since the latter assay is a sensitive indicator of neutrophil CD11b/CD18 functional activation, these results imply CD66 may exert differential effects upon beta 2 integrin activity. Neutrophil oxidant species production and spreading on fibrinogen substrates were further potentiated by cross-linking of Kat4c F(ab')2, in keeping with the suggestion that ligation of CD66 regulates neutrophil function. However, although intact Kat4c promoted beta 2 integrin-dependent homotypic neutrophil adhesion, F(ab')2 fragments were without effect, implying a role for Fc receptors in this effect which has previously been attributed to CD66. Together these data define more clearly the role of CD66 in regulation of neutrophil function and further suggest that augmented beta 2 integrin-mediated adhesion following CD66 ligation occurs independently of affinity regulation.
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Affiliation(s)
- M H Ruchaud-Sparagano
- Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh Medical School, U.K
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35
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Hart SP, Dougherty GJ, Haslett C, Dransfield I. CD44 regulates phagocytosis of apoptotic neutrophil granulocytes, but not apoptotic lymphocytes, by human macrophages. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.159.2.919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Phagocytosis of apoptotic neutrophil granulocytes by macrophages at inflammatory sites is an important determinant of the process by which inflammation resolves. We demonstrate that phagocytosis of apoptotic neutrophils, but not apoptotic lymphocytes, by human monocyte-derived macrophages is augmented rapidly following ligation of CD44 by bivalent Abs in vitro. Previously defined inhibitors of apoptotic cell recognition did not affect CD44-augmented phagocytosis of apoptotic neutrophils, suggesting that unique molecular recognition pathways are involved. These observations, together with the lack of effect of CD44 Abs upon macrophage phagocytosis of zymosan or Ig-opsonized erythrocytes, imply that CD44 may regulate the differential clearance of apoptotic leukocytes during evolution of inflammatory responses. This represents a novel role for CD44 in inflammation and tissue repair.
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Affiliation(s)
- S P Hart
- Department of Medicine (RIE), University of Edinburgh Medical School, United Kingdom
| | - G J Dougherty
- Department of Medicine (RIE), University of Edinburgh Medical School, United Kingdom
| | - C Haslett
- Department of Medicine (RIE), University of Edinburgh Medical School, United Kingdom
| | - I Dransfield
- Department of Medicine (RIE), University of Edinburgh Medical School, United Kingdom
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36
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Hart SP, Dougherty GJ, Haslett C, Dransfield I. CD44 regulates phagocytosis of apoptotic neutrophil granulocytes, but not apoptotic lymphocytes, by human macrophages. J Immunol 1997; 159:919-25. [PMID: 9218612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Phagocytosis of apoptotic neutrophil granulocytes by macrophages at inflammatory sites is an important determinant of the process by which inflammation resolves. We demonstrate that phagocytosis of apoptotic neutrophils, but not apoptotic lymphocytes, by human monocyte-derived macrophages is augmented rapidly following ligation of CD44 by bivalent Abs in vitro. Previously defined inhibitors of apoptotic cell recognition did not affect CD44-augmented phagocytosis of apoptotic neutrophils, suggesting that unique molecular recognition pathways are involved. These observations, together with the lack of effect of CD44 Abs upon macrophage phagocytosis of zymosan or Ig-opsonized erythrocytes, imply that CD44 may regulate the differential clearance of apoptotic leukocytes during evolution of inflammatory responses. This represents a novel role for CD44 in inflammation and tissue repair.
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Affiliation(s)
- S P Hart
- Department of Medicine (RIE), University of Edinburgh Medical School, United Kingdom
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37
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Abstract
Neutrophils express several heavily glycosylated carcinoembryonic antigen (CEA)-related glycoproteins (CD66 antigens) which have been implicated in adhesion to E-selectin and as receptors for the lectins galectin 3 and bacterial type-1 fimbriae. The role of the CD66 antigens in neutrophil effector function was examined using non-cross-reacting and cross-reacting domain-mapped CD66 monoclonal antibody (mAb), which recognize epitopes on biliary glycoprotein (BGP; CD66a), CEA gene family member 6 (CGM6; CD66b), nonspecific cross-reacting antigen 90 (NCA90; CD66c) or CGM1 (CD66d). We show that BGP-specific mAb which recognize an AB-domain epitope strongly augment adhesion to fibrinogen by an Fc receptor- and beta2 integrin-dependent mechanism. Co-ligation of BGP with the glycophosphatidylinositol (GPI)-anchored CGM6 and NCA90 also caused increased beta2 integrin-mediated adhesion, receptor clustering and priming of formyl-Met-Leu-Phe (fMLP)-induced oxidant production by neutrophils, but only a small change in expression of L-selectin and CR3 compared to the chemotactic peptide fMLP. Ligation of CGM6 or NCA90 alone did not cause activation of the neutrophil in any of the assays used and did not cause priming of fMLP-induced oxidant production even when a secondary cross-linking reagent was used. We propose that specific cross-linking of neutrophil BGP with CGM6 and NCA90 contributes significantly to the regulation of neutrophil function during neutrophil recruitment.
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Affiliation(s)
- S C Stocks
- Unit of Respiratory Medicine, University of Edinburgh Medical School, Scotland
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38
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Abstract
Effective removal of dying cells is crucial to a variety of processes in health and disease. Cells undergoing apoptosis are recognized and ingested intact by phagocytes, which are not stimulated to release inflammatory mediators. The alternative uncontrolled form of cell death, necrosis, is associated with release of cell contents with the potential to cause tissue damage and inflammation. Four distinct molecular mechanisms have been identified to date which mediate recognition by phagocytes of mammalian cells undergoing apoptosis, but further mechanisms remain to be discovered. The capacity for phagocyte removal of cells undergoing apoptosis may be closely regulated, for example by local cytokines.
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Affiliation(s)
- S P Hart
- Respiratory Medicine Unit, Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
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39
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Tallett A, Chilvers ER, Hannah S, Dransfield I, Lawson MF, Haslett C, Sethi T. Inhibition of neuropeptide-stimulated tyrosine phosphorylation and tyrosine kinase activity stimulates apoptosis in small cell lung cancer cells. Cancer Res 1996; 56:4255-63. [PMID: 8797601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Small cell lung cancer (SCLC) cell growth is sustained by multiple autocrine and paracrine growth loops involving neuropeptides. The bombesin family of peptides are autocrine growth factors in H345 SCLC cells and provide a paradigm for the study of growth factors and mitogenic signaling in SCLC cells. We show that bombesin (and other neuropeptides) stimulates protein tyrosine phosphorylation (particularly focal adhesion kinase) and protein tyrosine kinase (PTK) activity in intact SCLC cells. Furthermore, the broad spectrum neuropeptide receptor antagonist [D-Arg, D = Phe, D-Trp, Leu11]substance P inhibits all neuropeptide-mediated signals (including PTK activation), SCLC cell growth in vivo and in vitro, and also increases the natural rate of apoptosis seen in growing SCLC cell lines. Hence the effect of selective PTK inhibition on SCLC cell growth and apoptosis was examined. We show that selective inhibition of PTK activity, with genistein and (3,4,5-tri-hydroxyphenyl)-methylene(-propanedinitrile) tyrphostin-25 inhibits basal and neuropeptide-stimulated SCLC cell growth. Genistein and tyrphostin-25 also stimulate apoptosis in SCLC cells. Inhibition of proliferation in these cells is intimately linke to apoptosis, because these changes occurred without any effect on SCLC cell cycle kinetics, suggesting that apoptosis occurs independently of the cell cycle and that failure to progress through the cell cycle results in apoptosis. Because tyrphostin-25 fails to influence p53 or Bcl-2 expression in these cells, this mode of programmed cell death appears to be via a p53- and Bcl-2-independent mechanism. These results provide evidence that tyrosine phosphorylation is a mitogenic signal in SCLC cells and suggest that regulation of the level of protein tyrosine phosphorylation represents a critical determinant of whether SCLC cells survive and proliferate or die by apoptosis. Thus PTK inhibition may provide a novel therapeutic option in SCLC that has become resistant to conventional chemotherapeutic agents.
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Affiliation(s)
- A Tallett
- Department of Medicine (RIE), Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
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40
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Bellingan GJ, Caldwell H, Howie SE, Dransfield I, Haslett C. In vivo fate of the inflammatory macrophage during the resolution of inflammation: inflammatory macrophages do not die locally, but emigrate to the draining lymph nodes. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.157.6.2577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The resolution of acute inflammation requires bulk clearance of extravasated inflammatory cells in an ordered manner. Neutrophils undergo apoptosis and are ingested by macrophages (M psi) via a novel recognition mechanism that fails to provoke proinflammatory responses. Thereafter, the fate of inflammatory M psi themselves remains unclear. We investigated this in vivo, developing a semiallogeneic adoptive transfer system to track the fate of inflammatory M psi in a murine model of resolving peritonitis. Fluorescently labeled M psi from H-2k/d mice were transferred into the peritoneal cavity of H-2k mice at the same stage of resolving inflammation as the donor mice. Dual color flow cytometry permitted discrimination among donor cells, recipient cells, and donor cells that had been phagocytosed by recipient M psi. Despite the absence of significant local phagocytosis, the number of transferred M psi free in the peritoneum of recipient mice declined rapidly, being undetectable by 96 h. These data suggest that inflammatory M psi normally emigrate rapidly from the peritoneal cavity during the resolution of inflammation, contrasting with resident M psi, which persist in the noninflamed peritoneum for weeks. Accordingly, labeled nonphagocytosed cells were detected in the draining lymph nodes, but not in a variety of other tissues. Thus, unlike the polymorphonuclear leukocyte, which dies by apoptosis and is ingested by M psi, the inflammatory M psi itself does not die locally. Having performed its acute inflammatory and scavenging roles, it emigrates in a nonrandom fashion to the draining lymph node, where it may play an important part in the presentation of Ags from the inflamed site.
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Affiliation(s)
- G J Bellingan
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
| | - H Caldwell
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
| | - S E Howie
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
| | - I Dransfield
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
| | - C Haslett
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
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41
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Bellingan GJ, Caldwell H, Howie SE, Dransfield I, Haslett C. In vivo fate of the inflammatory macrophage during the resolution of inflammation: inflammatory macrophages do not die locally, but emigrate to the draining lymph nodes. J Immunol 1996; 157:2577-85. [PMID: 8805660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The resolution of acute inflammation requires bulk clearance of extravasated inflammatory cells in an ordered manner. Neutrophils undergo apoptosis and are ingested by macrophages (M psi) via a novel recognition mechanism that fails to provoke proinflammatory responses. Thereafter, the fate of inflammatory M psi themselves remains unclear. We investigated this in vivo, developing a semiallogeneic adoptive transfer system to track the fate of inflammatory M psi in a murine model of resolving peritonitis. Fluorescently labeled M psi from H-2k/d mice were transferred into the peritoneal cavity of H-2k mice at the same stage of resolving inflammation as the donor mice. Dual color flow cytometry permitted discrimination among donor cells, recipient cells, and donor cells that had been phagocytosed by recipient M psi. Despite the absence of significant local phagocytosis, the number of transferred M psi free in the peritoneum of recipient mice declined rapidly, being undetectable by 96 h. These data suggest that inflammatory M psi normally emigrate rapidly from the peritoneal cavity during the resolution of inflammation, contrasting with resident M psi, which persist in the noninflamed peritoneum for weeks. Accordingly, labeled nonphagocytosed cells were detected in the draining lymph nodes, but not in a variety of other tissues. Thus, unlike the polymorphonuclear leukocyte, which dies by apoptosis and is ingested by M psi, the inflammatory M psi itself does not die locally. Having performed its acute inflammatory and scavenging roles, it emigrates in a nonrandom fashion to the draining lymph node, where it may play an important part in the presentation of Ags from the inflamed site.
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Affiliation(s)
- G J Bellingan
- The Rayne Laboratory, University of Edinburgh Medical School, United Kingdom
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42
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Abstract
Lung injury in a variety of disease states is critically dependent on neutrophil-mediated inflammatory responses. Neutrophil recruitment to sites of infection or tissue damage requires co-ordinated regulation of neutrophil adhesion and activation status. We have examined the effects of treatment of human peripheral blood neutrophils with priming agents [lipopolysaccharide (LPS). tumor necrosis factor-alpha (TNF-alpha) and platelet-activating factor (PAF)] upon expression of CD11a. CD11b. CD11c. CD35 and CD62-1 and CD11b function to assess whether subtle regulation of neutrophil adhesion potential accompanies augmented formyl-methionyl-leucyl-phenylalanine-stimulated superoxide production. We have found that there are differential effects of priming concentrations of these agents. For LPS. CD62L loss occurs in the absence of changes in CD11b, whereas for PAF. CD11b up-regulation occurs in the absence of detectable loss of CD62-L. However, for TNF-2, decreased expression of CD62-L occurs concomitantly with increased expression of CD11b. In addition, we have shown that priming agents augment CD11b functional activity in a manner that parallels the priming of the respiratory burst. Thus, priming agents may differentially regulate neutrophil adhesive capacity and data presented in this manuscript suggest that the increased effector cell function observed in primed cells may be associated with a distinct repertoire of potential adhesive interactions.
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Affiliation(s)
- A M Condliffe
- Department of Medicine, Rayne Laboratory, University Medical School Edinburgh, UK
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43
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Abstract
Neutrophil apoptosis, determined after 20 h in culture using standard criteria and shedding of cell surface CD16 (Fc gamma RIII), is dramatically inhibited, in a concentration-dependent manner, by the cAMP analogs, dibutyryl-cAMP and 8-Br-cAMP, and the adenylyl cyclase activator, forskolin. Furthermore, the stable receptor-directed PGD2 mimetic, ZK 118.182, and the PGE2 mimetic, 11-deoxy PGE1, similarly inhibited apoptosis. The DP-receptor antagonist BW A868C blocked the effect of ZK 118.182 and the protein kinase A inhibitor H-89 reversed the inhibition of apoptosis induced by dibutyryl-cAMP. These results clearly show that neutrophil apoptosis is markedly attenuated by cAMP elevating agents. This nucleotide second messenger may play a fundamental role in controlling neutrophil longevity and pharmacological regulation of cAMP levels or actions may influence neutrophil apoptosis in vivo.
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Affiliation(s)
- A G Rossi
- Department of Medicine, Rayne Laboratory, University of Edinburgh Medical School, UK
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44
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Dransfield I. Granulocyte adhesion molecules--structure/function relationships. Semin Cell Biol 1995; 6:337-44. [PMID: 8748141 DOI: 10.1016/s1043-4682(05)80004-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Neutrophil responses are regulated by cellular adhesion events, including interaction with extracellular matrix and other cell types. The diversity of molecular structures which are included in the repertoire of cell adhesion molecules expressed by neutrophils and their subtle regulation allow fine tuning of cell adhesion processes to suit environmental demands. This article reviews some of the recent findings using biochemical, immunochemical and molecular techniques that allow the relationship between adhesion molecule structure and function to be examined. Understanding the molecular basis of cell adhesion events will allow development of novel strategies that allow manipulation of adhesion processes in a clinical setting.
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Affiliation(s)
- I Dransfield
- Department of Medicine, University of Edinburgh Medical School, UK
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45
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Stocks SC, Kerr MA, Haslett C, Dransfield I. CD66-dependent neutrophil activation: a possible mechanism for vascular selectin-mediated regulation of neutrophil adhesion. J Leukoc Biol 1995; 58:40-8. [PMID: 7542306 DOI: 10.1002/jlb.58.1.40] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have examined the role of CD66 in the modulation of neutrophil adhesion and effector function. Engagement of neutrophil CD66 with anti-carcinoembryonic antigen (anti-CEA) Ig results in activation-associated phenomena including shape change, activation of beta 2-integrins, and priming of the respiratory burst. Anti-CEA Ig-treated neutrophils underwent transient shape change distinct from that induced by formyl-Met-Leu-Phe (fMLP). fMLP stimulated beta 2-integrin up-regulation and 70% loss of L-selectin, whereas only low-level up-regulation of the beta 2-integrins, without loss of L-selectin, occurred with anti-CEA Ig. Anti-CEA F(ab')2 fragments and whole Ig augmented beta 2-integrin-dependent adhesion. Anti-CEA Ig-induced beta 2-integrin activation was transient, whereas fMLP-induced activation persisted longer. Although they did not cause a significant increase in respiratory burst activity, CEA Ig and F(ab')2 fragments of antibody primed neutrophils so that the subsequent fMLP-induced respiratory burst was significantly increased.
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Affiliation(s)
- S C Stocks
- Department of Respiratory Medicine, University of Edinburgh Medical School, United Kingdom
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46
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Dransfield I, Stocks SC, Haslett C. Regulation of cell adhesion molecule expression and function associated with neutrophil apoptosis. Blood 1995; 85:3264-73. [PMID: 7538822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have investigated the adhesive capacity of neutrophils after spontaneous apoptosis, which occurs during in vitro culture. Apoptotic neutrophils show reduced adhesion to E selectin and the CD18 integrin ligand fibrinogen. Neutrophil apoptosis is associated with changes in the levels of surface expression of key receptors that mediate neutrophil adhesion events. Notably, apoptotic neutrophils show reduced expression of L-selectin/selectin ligand. In contrast, CD11b/CD18 and CD11c/CD18 integrins are expressed at increased levels. The reduced capacity for adhesion of apoptotic neutrophils may be achieved by very different mechanisms. Regulation of the levels of surface expression of receptors/ligand may control selectin-mediated adhesion, possibly as a result of protease/sialidase activity. In contrast, modulation of integrin-mediated adhesion may involve functional uncoupling of receptors present on the surface of the apoptotic cell without alteration in levels of surface expression. The altered adhesive potential of the apoptotic neutrophil may serve to limit release of its histotoxic contents and reduce inappropriate tissue injury.
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Affiliation(s)
- I Dransfield
- Department of Medicine, University of Edinburgh, UK
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47
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Haslett C, Savill JS, Whyte MK, Stern M, Dransfield I, Meagher LC. Granulocyte apoptosis and the control of inflammation. Philos Trans R Soc Lond B Biol Sci 1994; 345:327-33. [PMID: 7846130 DOI: 10.1098/rstb.1994.0113] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We have described a novel pathway available for the clearance of extravasated granulocytes from inflamed tissues whereby aging granulocytes undergo apoptosis, a process which leads to their phagocytosis by inflammatory macrophages. By contrast with necrosis, which may also be seen at inflamed sites, apoptosis represents a granulocyte fate which by a number of mechanisms would tend to limit inflammatory tissue injury and promote resolution rather than progression of inflammation: (i) apoptosis is responsible for macrophage recognition of senescent neutrophils with intact cell membranes which exclude vital dyes and retain their potentially histotoxic granule contents; (ii) the apoptotic neutrophil loses its ability to secrete granule enzymes on deliberate external stimulation; (iii) the macrophage possesses a huge phagocytic capacity for apoptotic neutrophils which it rapidly ingests and degrades without disgorging neutrophil contents; and (iv) the macrophage utilizes a novel phagocytic recognition mechanism which fails to trigger the release of pro-inflammatory macrophage mediators during the phagocytosis of apoptotic neutrophils. Preliminary characterization of the recognition mechanism implicates the integrin alpha v beta 3 (vitronectin receptor) and CD36 (thrombospondin receptor) on the macrophage surface. Macrophage phagocytosis of apoptotic neutrophils is greatly influenced by the microenvironmental pH and by the presence of cationic molecules. Moreover, it can be specifically modulated by external cytokines and intracellular second messenger systems. By controlling the functional longevity of neutrophil and eosinophil granulocytes and their subsequent removal by macrophages, granulocyte apoptosis, with its potential for modulation by external mediators, is likely to play a key dynamic role in the control of the 'tissue load' of granulocytes at inflamed sites.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C Haslett
- Department of Medicine (RIE), University of Edinburgh Royal Infirmary, U.K
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48
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Dransfield I, Buckle AM, Savill JS, McDowall A, Haslett C, Hogg N. Neutrophil apoptosis is associated with a reduction in CD16 (Fc gamma RIII) expression. The Journal of Immunology 1994. [DOI: 10.4049/jimmunol.153.3.1254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Resolution of inflammation involves removal of recruited neutrophils from inflamed sites via a noninflammatory mechanism, possibly involving neutrophil apoptosis and engulfment/phagocytosis by macrophages. In this study, we describe the reduction in surface expression (> 90%) of the neutrophil molecule Fc gamma RIII (CD16) during in vitro culture at 37 degrees C, which was found to be temporally associated with the appearance of neutrophils with apoptotic morphology during in vitro culture and inhibitable by granulocyte-macrophage colony-stimulating factor (GM-CSF), which postpones apoptosis in the neutrophil. By using dual fluorescence analysis, CD16 "low" expressing neutrophils showed reduced staining with the DNA-binding dye propidium iodide, suggesting that CD16 low expressing neutrophils were apoptotic. Separation of CD16 "high" and CD16 "low" expressing neutrophils by fluorescence-activated cell sorting revealed that morphologically apoptotic cells exhibited the CD16 low phenotype. We did not observe similar marked changes in expression of other neutrophil surface molecules (including other phosphatidylinositol (PI)-linked molecules), indicating that generalized loss of surface molecules does not occur during apoptosis. We believe this to be the first reported cell type-specific membrane alteration in a surface glycoprotein associated with apoptosis, suggesting that the program of cell death in the neutrophil, in addition to morphologic and nuclear changes, includes alterations in expression of surface receptors.
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Affiliation(s)
- I Dransfield
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
| | - A M Buckle
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
| | - J S Savill
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
| | - A McDowall
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
| | - C Haslett
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
| | - N Hogg
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
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49
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Dransfield I, Buckle AM, Savill JS, McDowall A, Haslett C, Hogg N. Neutrophil apoptosis is associated with a reduction in CD16 (Fc gamma RIII) expression. J Immunol 1994; 153:1254-63. [PMID: 8027553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Resolution of inflammation involves removal of recruited neutrophils from inflamed sites via a noninflammatory mechanism, possibly involving neutrophil apoptosis and engulfment/phagocytosis by macrophages. In this study, we describe the reduction in surface expression (> 90%) of the neutrophil molecule Fc gamma RIII (CD16) during in vitro culture at 37 degrees C, which was found to be temporally associated with the appearance of neutrophils with apoptotic morphology during in vitro culture and inhibitable by granulocyte-macrophage colony-stimulating factor (GM-CSF), which postpones apoptosis in the neutrophil. By using dual fluorescence analysis, CD16 "low" expressing neutrophils showed reduced staining with the DNA-binding dye propidium iodide, suggesting that CD16 low expressing neutrophils were apoptotic. Separation of CD16 "high" and CD16 "low" expressing neutrophils by fluorescence-activated cell sorting revealed that morphologically apoptotic cells exhibited the CD16 low phenotype. We did not observe similar marked changes in expression of other neutrophil surface molecules (including other phosphatidylinositol (PI)-linked molecules), indicating that generalized loss of surface molecules does not occur during apoptosis. We believe this to be the first reported cell type-specific membrane alteration in a surface glycoprotein associated with apoptosis, suggesting that the program of cell death in the neutrophil, in addition to morphologic and nuclear changes, includes alterations in expression of surface receptors.
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Affiliation(s)
- I Dransfield
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, U.K
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50
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Abstract
The acute lung injury of adult respiratory distress syndrome (ARDS) is characterised by inflammatory cell accumulation and activation in the lung. Selectins are a family of adhesion molecules implicated in leucocyte-endothelial adhesion, whose receptors can exist in a cleaved, soluble form. We investigated whether circulating soluble selectin adhesion molecules, obtained from ARDS at-risk patients, were associated with subsequent ARDS development. 82 patients, at risk of ARDS, were enrolled from three well-defined groups (multiple trauma, pancreatitis, perforated bowel). Plasma samples were obtained on hospital presentation and soluble L, E, and P, selectins were quantified with a sandwich enzyme-linked immunosorbent assay (ELISA). 14 patients subsequently developed ARDS. Initial plasma soluble L-selectin (sL-selectin) levels were significantly lower in patients who progressed to ARDS compared to those who did not (p = 0.0001; 95% Cl for mean in ARDS patients as percent of that in non-ARDS patients, 27-61%). Moreover concentrations were lower than in 62 normal volunteers (range 0.37-6.55, median 1.83 micrograms/mL, n = 62), suggesting that a selective reduction of sL-selectin correlates with susceptibility. In addition, a significant correlation was found between low values of sL-selectin and indices of subsequent lung injury including requirement for ventilation (p = 0.0001) and degree of respiratory failure (p = 0.0001). A significant correlation was also found between low values of sL-selectin and patient mortality (p = 0.002). These results elucidate the inflammatory cell endothelial interactions in the early stages of ARDS and may be of prognostic value.
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Affiliation(s)
- S C Donnelly
- Respiratory Medicine Unit, Rayne Laboratory, University of Edinburgh, UK
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