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Abstract
Thrombosis is a common complication of end-stage renal disease, particularly in patients on hemodialysis. Although substantial progress has been made in preventing thrombotic complications in various other groups of patients, the mechanisms of thrombosis during hemodialysis require clarification. In this report, we demonstrate that complement activation triggered by hemodialysis biomaterials, and the subsequent generation of the complement anaphylatoxin C5a, results in the expression of functionally active tissue factor (TF) in peripheral blood neutrophils. Because TF is a key initiator of coagulation in vivo, we postulate that the recurring complement activation that occurs during long-term hemodialysis contributes to thrombosis in dialyzed end-stage renal disease patients. Furthermore, we found that complement contributed to the induction of granulocyte colony-stimulating factor, which has been implicated in the pathogenesis of thrombosis in patients treated with the recombinant form of this molecule. Importantly, the inhibition of complement activation attenuated the TF expression and granulocyte colony-stimulating factor induction in blood passing through a hemodialysis circuit, suggesting that the complement system could become a new therapeutic target for preventing thrombosis in patients with chronic renal failure who are maintained on hemodialysis.
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102
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Hutamekalin P, Takeda K, Tani M, Tsuga Y, Ogawa N, Mizutani N, Yoshino S. Effect of the C3a-Receptor Antagonist SB 290157 on Anti-OVA Polyclonal Antibody–Induced Arthritis. J Pharmacol Sci 2010; 112:56-63. [DOI: 10.1254/jphs.09180fp] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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103
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Ali H. Regulation of human mast cell and basophil function by anaphylatoxins C3a and C5a. Immunol Lett 2009; 128:36-45. [PMID: 19895849 DOI: 10.1016/j.imlet.2009.10.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 10/21/2009] [Accepted: 10/23/2009] [Indexed: 12/18/2022]
Abstract
Allergic diseases such as asthma result from inappropriate immunologic responses to common environmental allergens in genetically susceptible individuals. Following allergen exposure, interaction of dendritic cells (DC) with CD4(+) T cells leads to the production of Th2 cytokines, which induce B cells to synthesize IgE molecules (sensitization phase). These IgE molecules bind to their high affinity receptors (FcvarepsilonRI) on the surface of mast cells and basophils and their subsequent cross-linking by allergen results in the release of preformed and newly synthesized mediators, which cause bronchoconstriction, lung inflammation and airway hyperresponsiveness (AHR) in asthma (effector phase). The complement components C3a and C5a levels are increased in the lungs of patients with asthma and are likely generated via the actions of both allergen and mast cell proteases. In vivo studies with rodents have shown that while C3a facilitates allergen sensitization in some models C5a inhibits this response. Despite this difference, both anaphylatoxins promote lung inflammation and AHR in vivo indicating that cells other than DC and T cells likely mediate the functional effects of C3a and C5a in asthma. This review focuses on the contribution of C3a and C5a in the pathogenesis of asthma with a particular emphasis on mast cells and basophils. It discusses the mechanisms by which anaphylatoxins activate mast cells and basophils and the associated signaling pathways via which their receptors are regulated by priming and desensitization.
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Affiliation(s)
- Hydar Ali
- Department of Pathology, University of Pennsylvania School of Dental Medicine, 240 South 40th Street, Philadelphia, PA 19104-6030, USA.
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104
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105
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Anaphylatoxin and formyl peptide. Br J Pharmacol 2009. [DOI: 10.1111/j.1476-5381.2009.00501_10.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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106
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Qu H, Ricklin D, Lambris JD. Recent developments in low molecular weight complement inhibitors. Mol Immunol 2009; 47:185-95. [PMID: 19800693 DOI: 10.1016/j.molimm.2009.08.032] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 08/28/2009] [Indexed: 11/18/2022]
Abstract
As a key part of the innate immune system, complement plays an important role not only in defending against invading pathogens but also in many other biological processes. Inappropriate or excessive activation of complement has been linked to many autoimmune, inflammatory, and neurodegenerative diseases, as well as ischemia-reperfusion injury and cancer. A wide array of low molecular weight complement inhibitors has been developed to target various components of the complement cascade. Their efficacy has been demonstrated in numerous in vitro and in vivo experiments. Though none of these inhibitors has reached the market so far, some of them have entered clinical trials and displayed promising results. This review provides a brief overview of the currently developed low molecular weight complement inhibitors, including short peptides and synthetic small molecules, with an emphasis on those targeting components C1 and C3, and the anaphylatoxin receptors.
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Affiliation(s)
- Hongchang Qu
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd., Philadelphia, PA 19104, USA
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107
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Mizutani N, Nabe T, Yoshino S. Complement C3a regulates late asthmatic response and airway hyperresponsiveness in mice. THE JOURNAL OF IMMUNOLOGY 2009; 183:4039-46. [PMID: 19684087 DOI: 10.4049/jimmunol.0901468] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Allergic asthma is a chronic inflammatory disorder of the airways characterized by biphasic airway obstruction and airway hyperresponsiveness. In this study, we attempted to elucidate the contribution of the complement C3a to these asthmatic symptoms. BALB/c mice sensitized by i.p. injections of OVA plus alum were challenged with OVA intratracheally four times. The fourth challenge caused a biphasic asthmatic response peaking at 10 min and 3-4 h, as well as airway hyperresponsiveness to methacholine. Histological examination revealed increased expression of C3a receptors in the lung on the fourth challenge. Additionally, the C3 level in serum 4 h after the fourth challenge was significantly reduced compared with that before the challenge. When a C3a receptor antagonist, SB290157, was administered i.p. 30 min before the fourth challenge, the late-phase asthmatic response and airway hyperresponsivness induced by the fourth challenge were significantly inhibited, although the early-phase response was not influenced. In bronchoalveolar lavage fluid, neutrophil infiltration 24 h after the fourth challenge was reduced by the treatment. On the other hand, SB290157 suppressed the increased expression of IL-1beta in the lung in this model, and the intratracheal administration of IL-1beta induced airway obstruction, airway hyperresponsiveness, and neutrophil infiltration in normal mice. These results illustrate that C3a is involved in the development of the late asthmatic response and airway hyperresponsiveness. The mechanism leading to the development of these symptoms may correlate with the recruitment of neutrophils and/or the production of IL-1beta induced by C3a.
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Affiliation(s)
- Nobuaki Mizutani
- Department of Pharmacology, Kobe Pharmaceutical University, Kobe, Japan.
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108
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Abstract
Complement has been studied for over a century and its role in promoting the effector side of antibody-mediated immune reactions and of inducing inflammation is well understood. Nevertheless, it has proved surprisingly difficult to translate this information into pharmaceutical agents that can be used to treat immunopathological and inflammatory disease. There are, however, now clear signs that this situation will change. New types of therapeutic agents to interfere with complement function are being developed and it has become apparent quite recently that some common and otherwise untreatable diseases such as age-related macular degeneration are very largely due to mutations in the complement system that leads to a hyperinflammatory state. This has stimulated a renaissance of interest in the complement system as a therapeutic target and in this short review we discuss the possible ways of taking complement to the clinic, and the indications for which this may be carried out.
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Affiliation(s)
- P J Lachmann
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
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109
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Proctor LM, Moore TA, Monk PN, Sanderson SD, Taylor SM, Woodruff TM. Complement factors C3a and C5a have distinct hemodynamic effects in the rat. Int Immunopharmacol 2009; 9:800-6. [DOI: 10.1016/j.intimp.2009.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 02/25/2009] [Accepted: 03/03/2009] [Indexed: 11/17/2022]
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110
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Schraufstatter IU, DiScipio RG, Zhao M, Khaldoyanidi SK. C3a and C5a Are Chemotactic Factors for Human Mesenchymal Stem Cells, Which Cause Prolonged ERK1/2 Phosphorylation. THE JOURNAL OF IMMUNOLOGY 2009; 182:3827-36. [DOI: 10.4049/jimmunol.0803055] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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111
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Arumugam TV, Woodruff TM, Lathia JD, Selvaraj PK, Mattson MP, Taylor SM. Neuroprotection in stroke by complement inhibition and immunoglobulin therapy. Neuroscience 2009; 158:1074-89. [PMID: 18691639 PMCID: PMC2639633 DOI: 10.1016/j.neuroscience.2008.07.015] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 07/08/2008] [Accepted: 07/08/2008] [Indexed: 12/18/2022]
Abstract
Activation of the complement system occurs in a variety of neuroinflammatory diseases and neurodegenerative processes of the CNS. Studies in the last decade have demonstrated that essentially all of the activation components and receptors of the complement system are produced by astrocytes, microglia, and neurons. There is also rapidly growing evidence to indicate an active role of the complement system in cerebral ischemic injury. In addition to direct cell damage, regional cerebral ischemia and reperfusion (I/R) induces an inflammatory response involving complement activation and generation of active fragments, such as C3a and C5a anaphylatoxins, C3b, C4b, and iC3b. The use of specific inhibitors to block complement activation or their mediators such as C5a, can reduce local tissue injury after I/R. Consistent with therapeutic approaches that have been successful in models of autoimmune disorders, many of the same complement inhibition strategies are proving effective in animal models of cerebral I/R injury. One new form of therapy, which is less specific in its targeting of complement than monodrug administration, is the use of immunoglobulins. Intravenous immunoglobulin (IVIG) has the potential to inhibit multiple components of inflammation, including complement fragments, pro-inflammatory cytokine production and leukocyte cell adhesion. Thus, IVIG may directly protect neurons, reduce activation of intrinsic inflammatory cells (microglia) and inhibit transendothelial infiltration of leukocytes into the brain parenchyma following an ischemic stroke. The striking neuroprotective actions of IVIG in animal models of ischemic stroke suggest a potential therapeutic potential that merits consideration for clinical trials in stroke patients.
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Affiliation(s)
- T V Arumugam
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 Coulter Drive, Amarillo, TX 79106, USA.
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112
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Wenderfer SE, Wang H, Ke B, Wetsel RA, Braun MC. C3a receptor deficiency accelerates the onset of renal injury in the MRL/lpr mouse. Mol Immunol 2009; 46:1397-404. [PMID: 19167760 DOI: 10.1016/j.molimm.2008.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 12/04/2008] [Accepted: 12/07/2008] [Indexed: 12/23/2022]
Abstract
The development and progression of systemic lupus erythematosus (SLE) is strongly associated with complement activation and deposition. The anaphylatoxin C3a is a product of complement activation with immunomodulatory properties, and the receptor for C3a (C3aR) is not only expressed by granulocytes and antigen presenting cell populations, but it is also strongly up-regulated in lupus prone mice with active nephritis. In order to characterize the role of the C3aR in inflammatory nephritis, we bred C3aR knock out mice onto the MRL/lpr genetic background (C3aR KO MRL). Compared to control MRL/lpr mice, C3aR KO MRL mice had elevated auto-antibody titers and an earlier onset of renal injury. At 8 weeks, renal expression of a wide range of chemokines and chemokine receptors was increased in C3aR KO MRL kidneys compared to controls. Only the expression of MCP-1 was significantly decreased in the C3aR KO MRL mice. The increased chemokine and chemokine receptor expression seen in the C3aR KO MRL mice was associated with a more rapid rise in serum creatinine and the acceleration of renal fibrosis. However, loss of the C3aR had little impact on long-term kidney injury and did not alter survival. These findings suggest that activation of the C3aR plays a protective, not pathologic, role in the early phase of inflammatory nephritis in the MRL/lpr model of SLE.
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Affiliation(s)
- Scott E Wenderfer
- The Center for Immunology and Autoimmune Diseases, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
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113
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Khodoun M, Strait R, Orekov T, Hogan S, Karasuyama H, Herbert DR, Köhl J, Finkelman FD. Peanuts can contribute to anaphylactic shock by activating complement. J Allergy Clin Immunol 2009; 123:342-51. [PMID: 19121857 DOI: 10.1016/j.jaci.2008.11.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 11/07/2008] [Accepted: 11/10/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Peanut allergy is the most common food-related cause of lethal anaphylaxis and, unlike other food allergies, typically persists into adulthood. Resistance to digestion and dendritic cell activation by the major peanut allergen Ara h 1 are reported to contribute to its allergenicity. OBJECTIVE We sought to evaluate whether peanut molecules might also promote anaphylaxis through an innate immune mechanism. METHODS Naive mice were treated with a beta-adrenergic receptor antagonist and long-acting IL-4 to increase sensitivity to vasoactive mediators and injected with peanut extract (PE). Shock was detected and quantified by means of rectal thermometry. Gene-deficient mice and specific antagonists were used to determine the roles of specific cell types, complement, Fc receptors, and vasoactive mediators in shock pathogenesis. RESULTS PE induces dose-dependent shock. PE activates complement in vivo in mice and in vitro in mice and human subjects. C3a and, to a lesser extent, stimulatory immunoglobulin receptors contribute to PE-induced shock. PE-induced shock depends more on macrophages and basophils than on mast cells. Platelet-activating factor and, to a lesser extent, histamine contribute to PE-induced shock. PE induces shock in the absence of the adaptive immune system. LPS contamination is not responsible for PE-induced shock. PE and IgE-mediated mast cell degranulation synergistically induce shock. Tree nuts have similar effects to PE, and skim milk and egg white do not. CONCLUSION Peanuts can contribute to shock by causing production of C3a, which stimulates macrophages, basophils, and mast cells to produce platelet-activating factor and histamine.
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Affiliation(s)
- Marat Khodoun
- Cincinnati Veterans Affairs Medical Center, Cincinnati, Ohio; Division of Immunology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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114
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Significant [C3a] Increase in Free Flaps After Prolonged Ischemia. J Surg Res 2008; 150:125-30. [PMID: 18694577 DOI: 10.1016/j.jss.2008.02.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2007] [Revised: 12/19/2007] [Accepted: 02/22/2008] [Indexed: 01/22/2023]
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115
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Brekke OL, Christiansen D, Fure H, Pharo A, Fung M, Riesenfeld J, Mollnes TE. Combined inhibition of complement and CD14 abolish E. coli-induced cytokine-, chemokine- and growth factor-synthesis in human whole blood. Mol Immunol 2008; 45:3804-13. [PMID: 18606453 DOI: 10.1016/j.molimm.2008.05.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/24/2008] [Accepted: 05/25/2008] [Indexed: 10/21/2022]
Abstract
The relative role of complement and CD14 in E. coli-induced cytokine synthesis in an in vitro human whole blood model of sepsis was examined. Fresh lepirudin-anticoagulated whole blood was incubated with E. coli for 2h. Monoclonal antibodies or a C5a receptor antagonist were used to block complement. Inflammatory mediators (n=27) were measured by multiplex technology, selected cytokine mRNA by real time PCR, and CD11b, oxidative burst and phagocytosis by flow cytometry. E. coli significantly increased 18 of the 27 inflammatory mediators, including proinflammatory cytokines (TNF-alpha, IL-6, INF-gamma and IL-1beta), chemokines (IL-8, MCP-1, MIP-1alpha, MIP-1beta, eotaxin and IP-10), growth factors (VEGF, FGF-basic, G-CSF and GM-CSF) and other interleukins (IL-9, IL-15 and IL-17). Notably, the increases in all mediators were abolished by a combined inhibition of CD14 and complement using anti-C2 and anti-factor D in combination, whereas the relative effect of the inhibition of complement and CD14 varied. In comparison, a C5a receptor antagonist and anti-CD14 in combination reduced cytokine synthesis less efficiently. Real time PCR analysis confirmed that the cytokine synthesis was blocked at the mRNA level. Similarly, E. coli-induced CD11b up-regulation, oxidative burst and phagocytosis was totally inhibited by CD14, anti-C2 and anti-factor D in combination after 2h incubation. In conclusion, the combined inhibition of complement using anti-C2, anti-factor D and CD14 almost completely inhibits the E. coli-induced inflammatory response. The combined approach may therefore be a new treatment regimen in Gram-negative sepsis.
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Affiliation(s)
- Ole-Lars Brekke
- Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway.
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116
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Kambas K, Markiewski MM, Pneumatikos IA, Rafail SS, Theodorou V, Konstantonis D, Kourtzelis I, Doumas MN, Magotti P, DeAngelis RA, Lambris JD, Ritis KD. C5a and TNF-alpha up-regulate the expression of tissue factor in intra-alveolar neutrophils of patients with the acute respiratory distress syndrome. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:7368-75. [PMID: 18490736 PMCID: PMC2673518 DOI: 10.4049/jimmunol.180.11.7368] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by the presence of fibrin-rich inflammatory exudates in the intra-alveolar spaces and the extensive migration of neutrophils into alveoli of the lungs. Tissue factor (TF)-dependent procoagulant properties of bronchoalveaolar lavage fluid (BALF) obtained from ARDS patients favor fibrin deposition, and are likely the result of cross-talk between inflammatory mediators and hemostatic mechanisms. However, the regulation of these interactions remains elusive. Prompted by previous findings suggesting that neutrophils, under certain inflammatory conditions, can express functional TF, we investigated the contribution of intra-alveolar neutrophils to the procoagulant properties of BALF from patients with ARDS. Our results confirm that the procoagulant properties of BALF from ARDS patients are the result of TF induction, and further indicate that BALF neutrophils are a main source of TF in intra-alveolar fluid. We also found that BALF neutrophils in these patients express significantly higher levels of TF than peripheral blood neutrophils. These results suggest that the alveolar microenvironment contributes to TF induction in ARDS. Additional experiments indicated that the ability of BALF to induce TF expression in neutrophils from healthy donors can be abolished by inhibiting C5a or TNF-alpha signaling, suggesting a primary role for these inflammatory mediators in the up-regulation of TF in alveolar neutrophils in ARDS. This cross-talk between inflammatory mediators and the induction of TF expression in intra-alveolar neutrophils may be a potential target for novel therapeutic strategies to limit ARDS-associated disturbances of coagulation.
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Affiliation(s)
- Konstantinos Kambas
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Maciej M. Markiewski
- Department of Pathology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Laboratory Medicine, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ioannis A. Pneumatikos
- Intensive Care Unit, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Stavros S. Rafail
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Vassiliki Theodorou
- Intensive Care Unit, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Dimitrios Konstantonis
- Intensive Care Unit, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Ioannis Kourtzelis
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Michael N. Doumas
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
| | - Paola Magotti
- Department of Pathology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert A. DeAngelis
- Department of Pathology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - John D. Lambris
- Department of Pathology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Konstantinos D. Ritis
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, Alexandroupolis, Greece
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117
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Jacobson AC, Weis JJ, Weis JH. Complement receptors 1 and 2 influence the immune environment in a B cell receptor-independent manner. THE JOURNAL OF IMMUNOLOGY 2008; 180:5057-66. [PMID: 18354231 DOI: 10.4049/jimmunol.180.7.5057] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The CD21/35 proteins are complement receptors implicated in controlling and interpreting activation states of the innate and acquired immune responses. One defect of CD21/35(-/-) animals is depressed production of Ag-specific IgG3 which we show is evident in vivo but not in vitro. Gene expression profiles obtained from naive wild-type and CD21/35(-/-) splenocytes demonstrated enhanced expression of inflammatory mediators from CD11b(+) splenocytes in the CD21/35(-/-) animals. Splenocyte populations between wild-type and CD21/35(-/-) mice were similar except for a moderate increase in GR1(low)CD31(+) immature myeloid cells. Furthermore, depletion of neutrophils and other GR1-expressing cells alleviates elevated inflammatory gene expression in the CD21/35(-/-) spleen. Complement activation also plays a key role in the differential gene expression observed in the CD21/35-deficient mouse as depletion of C3 or inhibition of C3a receptor signaling within the animal returned inflammatory gene expression within the spleen to wild-type levels. Finally, C3 depletion before immunization allowed for the enhanced production of Ag-specific IgG3 production in the CD21/35(-/-) mouse compared with mock-depleted animals. These data suggest that the overall environment of the CD21/35(-/-) spleen is quite different from that of the wild-type animal perhaps due to altered complement convertase activity. This difference may be responsible for a number of the phenotypes ascribed to the deficiency of CD21/35 proteins on B cells and follicular dendritic cells.
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Affiliation(s)
- Amanda C Jacobson
- Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
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118
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Itoh S, Takeshita K, Susuki C, Shige-Eda K, Tsuji T. Redistribution of P-selectin ligands on neutrophil cell membranes and the formation of platelet-neutrophil complex induced by hemodialysis membranes. Biomaterials 2008; 29:3084-90. [PMID: 18452987 DOI: 10.1016/j.biomaterials.2008.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 04/09/2008] [Indexed: 11/16/2022]
Abstract
The formation of platelet-neutrophil microaggregates and successive activation of neutrophils are closely related to hemodialysis-associated complications. The microaggregate is mediated primarily by the interaction between P-selectin (CD62P) expressed on activated platelets and P-selectin glycoprotein ligand-1 (PSGL-1, CD162) expressed on neutrophils. We previously reported that the clustered distribution of PSGL-1 on the cell membranes of chemokine-treated neutrophils caused upregulation of the microaggregate formation. In this study, we found that neutrophils treated with human plasma that had been incubated with hemodialysis membranes greatly enhanced the microaggregate formation. The membrane-treated plasma also induced PSGL-1 to form a cap-like cluster on the neutrophil surface. Analysis of several hemodialysis membranes with different materials indicated that the inducibility for the cap-like cluster formation of PSGL-1 parallels their ability to activate the complement system. Both the enhancement of microaggregate formation and the redistribution of PSGL-1 induced by the hemodialysis membrane-treated plasma were almost completely abrogated in the presence of a specific antagonist for the complement component C5a receptor, W-54011. These results strongly suggest that the generation of anaphylatoxin C5a through complement activation induced by hemodialysis membranes is responsible for the clustered redistribution of PSGL-1 in neutrophils leading to the increase in the platelet-neutrophil microaggregate formation. The present study indicates the importance of synergistic exacerbation of complement activation and platelet-neutrophil microaggregate formation in developing hemodialysis-associated complications.
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Affiliation(s)
- Saotomo Itoh
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
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119
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C3a receptor modulation of granulocyte infiltration after murine focal cerebral ischemia is reperfusion dependent. J Cereb Blood Flow Metab 2008; 28:1048-58. [PMID: 18197178 DOI: 10.1038/sj.jcbfm.9600608] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The complement anaphylatoxin C3a contributes to injury after cerebral ischemia in mice. This study assesses the effect of C3a receptor antagonist (C3aRA) on leukocyte infiltration into the ischemic zone. Transient or permanent middle cerebral artery occlusion (MCAO) was induced in wild-type C57Bl/6 mice. Intraperitoneal C3aRA or vehicle was administered 45 mins before or 1 h after occlusion. Twenty-four hours after occlusion, we harvested brain tissue and purified inflammatory cells using flow cytometry. Soluble intercellular adhesion molecule (ICAM)-1 protein levels were assessed using enzyme-linked immunosorbent assays, and ICAM-1 and C3a receptor (C3aR) expression was confirmed via immunohistochemistry. In the transient MCAO model, animals receiving C3aRA showed smaller strokes, less upregulation of C3aR-positive granulocytes, and less ICAM-1 protein on endothelial cells than vehicle-treated animals; no significant differences in other inflammatory cell populations were observed. C3a receptor antagonist-treated and vehicle-treated animals showed no differences in stroke volume or inflammatory cell populations after permanent MCAO. These data suggest that blocking the binding of C3a to C3aR modulates tissue injury in reperfused stroke by inhibiting the recruitment of neutrophils to the ischemic zone. It further establishes antagonism of the C3a anaphylatoxin as a promising strategy for ameliorating injury after ischemia/reperfusion.
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120
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Blakeney JS, Reid RC, Le GT, Fairlie DP. Nonpeptidic Ligands for Peptide-Activated G Protein-Coupled Receptors. Chem Rev 2007; 107:2960-3041. [PMID: 17622179 DOI: 10.1021/cr050984g] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jade S Blakeney
- Centre for Drug Design and Development, Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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121
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Denonne F, Binet S, Burton M, Collart P, Dipesa A, Ganguly T, Giannaras A, Kumar S, Lewis T, Maounis F, Nicolas JM, Mansley T, Pasau P, Preda D, Stebbins K, Volosov A, Zou D. Discovery of new C3aR ligands. Part 1: Arginine derivatives. Bioorg Med Chem Lett 2007; 17:3258-61. [PMID: 17467987 DOI: 10.1016/j.bmcl.2007.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 03/31/2007] [Accepted: 04/04/2007] [Indexed: 10/23/2022]
Abstract
The synthesis and in vitro binding of several new arginine-containing C3aR ligands are reported. DMPK properties and functional activities of selected compounds have been evaluated. One compound is shown to be active in an in vivo model of airway inflammation after aerosol administration.
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Affiliation(s)
- Frédéric Denonne
- UCB Global Chemistry, Chemin du Foriest R4, 1420 Braine l'Alleud, Belgium.
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122
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Dillard P, Wetsel RA, Drouin SM. Complement C3a regulates Muc5ac expression by airway Clara cells independently of Th2 responses. Am J Respir Crit Care Med 2007; 175:1250-8. [PMID: 17400733 PMCID: PMC2176092 DOI: 10.1164/rccm.200701-049oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
RATIONALE The factors that control the secretion of epithelial mucins are essential to understanding obstructive airway diseases such as asthma. Although the complement anaphylatoxin C3a and its receptor have been shown to promote many features of allergic lung inflammation, the contribution to mucin expression has not been elucidated. OBJECTIVES To determine if the C3a receptor with its ligand regulates airway epithelial mucin production. METHODS Mice deficient in the C3a receptor were examined in a model of allergic airway disease for the presence of goblet cells and the gel-forming secreted mucin Muc5ac. MEASUREMENTS AND MAIN RESULTS Lungs from antigen-challenged C3a receptor-deficient mice revealed a dramatic decrease in goblet cells and Muc5ac compared with challenged wild-type control animals. These differences were dependent on C3a binding to its receptor since intranasal challenge with C3a induced the formation of goblet cells only in wild-type but not C3a receptor-deficient mice. Increased numbers of goblet cells were also found in C3a-stimulated RAG-1-deficient mice demonstrating a mechanism independent of T lymphocytes and Th2 cytokines, mediators which have been shown to regulate mucin expression. A direct physiological role for C3a in these models was further demonstrated in cultures of airway epithelial Clara cells, which not only express the C3a receptor but also produce Muc5ac in response to C3a. CONCLUSIONS These studies identify a novel C3a receptor-dependent mechanism in the development of airway epithelial goblet cells and regulation of Muc5ac production and implicate C3a as a mediator of airway obstruction in asthma.
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Affiliation(s)
- Patricia Dillard
- The Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, The University of Texas Health Science Center at Houston, 1825 Pressler Street, Houston, TX 77030, USA
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123
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Thurman JM, Lenderink AM, Royer PA, Coleman KE, Zhou J, Lambris JD, Nemenoff RA, Quigg RJ, Holers VM. C3a is required for the production of CXC chemokines by tubular epithelial cells after renal ishemia/reperfusion. THE JOURNAL OF IMMUNOLOGY 2007; 178:1819-28. [PMID: 17237432 DOI: 10.4049/jimmunol.178.3.1819] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The complement system is one of the major ways by which the body detects injury to self cells, and the alternative pathway of complement is rapidly activated within the tubulointerstitium after renal ischemia/reperfusion (I/R). In the current study, we investigate the hypothesis that recognition of tubular injury by the complement system is a major mechanism by which the systemic inflammatory response is initiated. Gene array analysis of mouse kidney following I/R initially identified MIP-2 (CXCL2) and keratinocyte-derived chemokine (KC or CXCL1) as factors that are produced in a complement-dependent fashion. Using in situ hybridization, we next demonstrated that these factors are expressed in tubular epithelial cells of postischemic kidneys. Mouse proximal tubular epithelial cells (PTECs) in culture were then exposed to an intact alternative pathway and were found to rapidly produce both chemokines. Selective antagonism of the C3a receptor significantly attenuated production of MIP-2 and KC by PTECs, whereas C5a receptor antagonism and prevention of membrane attack complex (MAC) formation did not have a significant effect. Treatment of PTECs with an NF-kappaB inhibitor also prevented full expression of these factors in response to an intact alternative pathway. In summary, alternative pathway activation after renal I/R induces production of MIP-2 and KC by PTECs. This innate immune system thereby recognizes hypoxic injury and triggers a systemic inflammatory response through the generation of C3a and subsequent activation of the NF-kappaB system.
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Affiliation(s)
- Joshua M Thurman
- Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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124
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Zhang X, Kimura Y, Fang C, Zhou L, Sfyroera G, Lambris JD, Wetsel RA, Miwa T, Song WC. Regulation of Toll-like receptor-mediated inflammatory response by complement in vivo. Blood 2007; 110:228-36. [PMID: 17363730 PMCID: PMC1896115 DOI: 10.1182/blood-2006-12-063636] [Citation(s) in RCA: 272] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptors (TLRs) and complement are 2 components of innate immunity that are critical for first-line host defense and elicitation of adaptive immune responses. Many pathogen-associated molecular patterns activate both TLR and complement, but whether and how these 2 systems, when coactivated in vivo, interact with each other has not been well studied. We demonstrate here a widespread regulation of TLR signaling by complement in vivo. The TLR ligands lipopolysacharride (TLR4), zymosan (TLR2/6), and CpG oligonucleotide (TLR9) caused, in a complement-dependent manner, strikingly elevated plasma interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and IL-1beta, and/or decreased plasma IL-12 levels in mice deficient in the membrane complement inhibitor decay-accelerating factor (DAF). A similar outcome was observed in wild-type mice cotreated with the TLR ligands and cobra venom factor, a potent complement activator. The regulatory effect of complement on TLR-induced cytokine production in vivo was mediated by the anaphylatoxin receptors C5aR and C3aR. Additionally, changes in lipopolysaccharide (LPS)-induced cytokine production in DAF-deficient mice correlated with increased mitogen-activated protein kinase and nuclear factor-kappaB activation in the spleen. These results reveal a strong interaction between complement and TLR signaling in vivo and suggest a novel mechanism by which complement promotes inflammation and modulates adaptive immunity.
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Affiliation(s)
- Xinhua Zhang
- Institute for Translational Medicine and Therapeutics and Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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125
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Abstract
Complement activation contributes to a pathological process in a number of autoimmune and inflammatory diseases, including rheumatoid arthritis (RA). In this review we summarize current knowledge of complement contribution to RA, based on clinical observations in patients and in vivo animal models, as well as on experiments in vitro aiming at elucidation of underlying molecular mechanisms. There is strong evidence that both the classical and the alternative pathways of complement are pathologically activated during RA as well as in animal models for RA. The classical pathway can be initiated by several triggers present in the inflamed joint such as deposited autoantibodies, dying cells, and exposed cartilage proteins such as fibromodulin. B cells producing autoantibodies, which in turn form immune complexes, contribute to RA pathogenesis partly via activation of complement. It appears that anaphylatoxin C5a is the main product of complement activation responsible for tissue damage in RA although deposition of membrane attack complex as well as opsonization with fragments of C3b are also important. Success of complement inhibition in the experimental models described so far encourages novel therapeutic approaches to the treatment of human RA.
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Affiliation(s)
- Marcin Okroj
- Lund University, Department of Laboratory Medicine, University Hospital Malmö, Malmö, Sweden
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126
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Arumugam TV, Magnus T, Woodruff TM, Proctor LM, Shiels IA, Taylor SM. Complement mediators in ischemia–reperfusion injury. Clin Chim Acta 2006; 374:33-45. [PMID: 16872589 DOI: 10.1016/j.cca.2006.06.010] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 06/08/2006] [Accepted: 06/09/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ischemia-reperfusion (I/R) injury occurs when a tissue is temporarily deprived of blood supply and the return of the blood supply triggers an intense inflammatory response. Pathologically, increased complement activity can cause substantial damage to blood vessels, tissues and also facilitate leukocyte activation and recruitment following I/R injury. Herein, previously published studies are reported and critically reviewed. METHODS Medline and the World Wide Web were searched and the relevant literature was classified under the following categories: (1) Complement pathways; (2) The complement system and the inflammatory response; (3) Complement in ischemia-reperfusion injuries; and (4) Therapeutic approaches against complement in I/R injuries. RESULTS AND CONCLUSIONS I/R injury is a common clinical event with the potential to seriously affect, and sometimes kill, the patient and is a potent inducer of complement activation that results in the production of a number of inflammatory mediators. Complement activation leads to the release of biologically active potent inflammatory complement substances including the anaphylatoxins (C3a and C5a) and the cytolytic terminal membrane attack complement complex C5b-9 (MAC). The use of specific complement inhibitors to block complement activation at various levels of the cascade has been shown to prevent or reduce local tissue injury after I/R. Several agents that inhibit all or part of the complement system, such as soluble complement receptor type 1 (sCR1), C1 inhibitor (C1-INH), C5a monoclonal antibodies, a C5a receptor antagonist and soluble CD59 (sCD59) have been shown to reduce I/R injury of various organs. The novel inhibitors of complement products may eventually find wide clinical application because there are no effective drug therapies currently available to treat I/R injuries.
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Affiliation(s)
- Thiruma V Arumugam
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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127
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Purwar R, Wittmann M, Zwirner J, Oppermann M, Kracht M, Dittrich-Breiholz O, Gutzmer R, Werfel T. Induction of C3 and CCL2 by C3a in keratinocytes: a novel autocrine amplification loop of inflammatory skin reactions. THE JOURNAL OF IMMUNOLOGY 2006; 177:4444-50. [PMID: 16982879 DOI: 10.4049/jimmunol.177.7.4444] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The complement fragment-3a (C3a) acts via a G protein-coupled C3aR and is of importance in allergic and inflammatory diseases. Recent studies suggest the presence of complement proteins in the epidermal compartment and synthesis of some of these proteins (C3, factor B, and factor H) by human primary keratinocytes (KCs) during inflammation. However, expression of C3aR and its role in human KCs is not elucidated thus far. In this study, we demonstrate the expression of C3aR on KCs as detected by quantitative real-time RT-PCR and flow cytometry. IFN-gamma and IFN-alpha strongly up-regulated the surface expression of C3aR on KCs among all other cytokines tested. After up-regulation of C3aR by IFN-gamma and IFN-alpha, we observed the induction of five genes (CCL2, CCL5, CXCL8, CXCL10, and C3) after stimulation of KCs with C3a in microarray analysis. We confirmed the induction of C3 and CCL2 at RNA and protein levels. Furthermore, incubation of C3 with skin mast cells tryptase resulted in the generation of C3 fragments with C3a activity. In conclusion, our data illustrate that epidermal KCs express functional C3aR. The increases of C3 and CCL2 synthesis by C3a and C3 activation by skin mast cell tryptase delineates a novel amplification loop of complement activation and inflammatory responses that may influence the pathogenesis of allergic/inflammatory skin diseases.
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Affiliation(s)
- Rahul Purwar
- Department of Dermatology and Allergology, Hannover Medical University, Ricklinger Strasse 05, D-30449 Hannover, Germany.
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128
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Ritis K, Doumas M, Mastellos D, Micheli A, Giaglis S, Magotti P, Rafail S, Kartalis G, Sideras P, Lambris JD. A novel C5a receptor-tissue factor cross-talk in neutrophils links innate immunity to coagulation pathways. THE JOURNAL OF IMMUNOLOGY 2006; 177:4794-802. [PMID: 16982920 DOI: 10.4049/jimmunol.177.7.4794] [Citation(s) in RCA: 334] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neutrophils and complement are key sentinels of innate immunity and mediators of acute inflammation. Recent studies have suggested that inflammatory processes modulate thrombogenic pathways. To date, the potential cross-talk between innate immunity and thrombosis and the precise molecular pathway by which complement and neutrophils trigger the coagulation process have remained elusive. In this study, we demonstrate that antiphospholipid Ab-induced complement activation and downstream signaling via C5a receptors in neutrophils leads to the induction of tissue factor (TF), a key initiating component of the blood coagulation cascade. TF expression by neutrophils was associated with an enhanced procoagulant activity, as verified by a modified prothrombin time assay inhibited by anti-TF mAb. Inhibition studies using the complement inhibitor compstatin revealed that complement activation is triggered by antiphospholipid syndrome (APS) IgG and leads to the induction of a TF-dependent coagulant activity. Blockade studies using a selective C5a receptor antagonist and stimulation of neutrophils with recombinant human C5a demonstrated that C5a, and its receptor C5aR, mediate the expression of TF in neutrophils and thereby significantly enhance the procoagulant activity of neutrophils exposed to APS serum. These results identify a novel cross-talk between the complement and coagulation cascades that can potentially be exploited therapeutically in the treatment of APS and other complement-associated thrombotic diseases.
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Affiliation(s)
- Konstantinos Ritis
- First Division of Internal Medicine, Medical School, Democritus University of Thrace, 68100 Alexandroupolis, Greece.
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129
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Proctor LM, Strachan AJ, Woodruff TM, Mahadevan IB, Williams HM, Shiels IA, Taylor SM. Complement inhibitors selectively attenuate injury following administration of cobra venom factor to rats. Int Immunopharmacol 2006; 6:1224-32. [PMID: 16782534 DOI: 10.1016/j.intimp.2006.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Accepted: 03/02/2006] [Indexed: 11/23/2022]
Abstract
Systemic activation of complement is a pathophysiological response common to severe disturbances such as hemorrhagic shock, major burn injury and sepsis. Intravenous infusion of cobra venom factor (CVF) has been used as an animal model of acute respiratory distress syndrome (ARDS), and reliably and selectively induces rapid intravascular activation of the complement system, leading to acute organ damage. In the present study, we have used different complement inhibitors to investigate the roles of complement products in CVF-induced responses in the rat. Rats were treated with either a C5a receptor antagonist (C5aRA, AcF-[OP(d-Cha)WR], 1 mg/kg i.v. or 10 mg/kg p.o.), a C3a receptor antagonist (C3aRA, N(2)-[(2,2-diphenylethoxy)acetyl]-l-arginine, 0.1 mg/kg i.v.) or a convertase inhibitor, rosmarinic acid (RMA, 10 mg/kg i.v.), prior to CVF-induced complement challenge. Intravenous CVF resulted in hallmark events evident in the development of ARDS, including systemic neutropenia followed by neutrophil migration to the lung and bronchoalveolar vascular leakage, blood pressure alterations, and an increase in TNFalpha levels in both serum and bronchoalveolar lavage fluid. These hemodynamic changes were differentially inhibited by antagonism of C5a receptors, C3a receptors or by inhibition of the entire complement cascade using RMA. This evidence strongly implicates complement factors in the development of lung injury associated with systemic complement activation and identifies complement inhibition as a potential therapeutic target for acute syndromes such as ARDS and other severe systemic shock states mediated by activation of complement.
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Affiliation(s)
- Lavinia M Proctor
- Promics Ltd., PO Box 4578, Eight Mile Plains, Queensland 4113, Australia.
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130
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Mocco J, Mack WJ, Ducruet AF, Sosunov SA, Sughrue ME, Hassid BG, Nair MN, Laufer I, Komotar RJ, Claire M, Holland H, Pinsky DJ, Connolly ES. Complement component C3 mediates inflammatory injury following focal cerebral ischemia. Circ Res 2006; 99:209-17. [PMID: 16778128 DOI: 10.1161/01.res.0000232544.90675.42] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The complement cascade has been implicated in ischemia/reperfusion injury, and recent studies have shown that complement inhibition is a promising treatment option for acute stroke. The development of clinically useful therapies has been hindered, however, by insufficient understanding of which complement subcomponents contribute to post-ischemic injury. To address this issue, we subjected mice deficient in selected complement proteins (C1q, C3, C5) to transient focal cerebral ischemia. Of the strains investigated, only C3-/- mice were protected, as demonstrated by 34% reductions in both infarct volume (P<0.01) and neurological deficit score (P<0.05). C3-deficient mice also manifested decreased granulocyte infiltration (P<0.02) and reduced oxidative stress (P<0.05). Finally, administration of a C3a-receptor antagonist resulted in commensurate neurological improvement and stroke volume reduction (P<0.05). Together, these results establish C3 activation as the key constituent in complement-related inflammatory tissue injury following stroke and suggest a C3a anaphylatoxin-mediated mechanism.
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Affiliation(s)
- J Mocco
- Department of Neurosurgery, Columbia University, 710 W 168th St, New York, NY 10032, USA
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131
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Huber-Lang M, Sarma JV, Zetoune FS, Rittirsch D, Neff TA, McGuire SR, Lambris JD, Warner RL, Flierl MA, Hoesel LM, Gebhard F, Younger JG, Drouin SM, Wetsel RA, Ward PA. Generation of C5a in the absence of C3: a new complement activation pathway. Nat Med 2006; 12:682-7. [PMID: 16715088 DOI: 10.1038/nm1419] [Citation(s) in RCA: 724] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Accepted: 04/21/2006] [Indexed: 11/09/2022]
Abstract
Complement-mediated tissue injury in humans occurs upon deposition of immune complexes, such as in autoimmune diseases and acute respiratory distress syndrome. Acute lung inflammatory injury in wild-type and C3-/- mice after deposition of IgG immune complexes was of equivalent intensity and was C5a dependent, but injury was greatly attenuated in Hc-/- mice (Hc encodes C5). Injury in lungs of C3-/- mice and C5a levels in bronchoalveolar lavage (BAL) fluids from these mice were greatly reduced in the presence of antithrombin III (ATIII) or hirudin but were not reduced in similarly treated C3+/+ mice. Plasma from C3-/- mice contained threefold higher levels of thrombin activity compared to plasma from C3+/+ mice. There were higher levels of F2 mRNA (encoding prothrombin) as well as prothrombin and thrombin protein in liver of C3-/- mice compared to C3+/+ mice. A potent solid-phase C5 convertase was generated using plasma from either C3+/+ or C3-/- mice. Human C5 incubated with thrombin generated C5a that was biologically active. These data suggest that, in the genetic absence of C3, thrombin substitutes for the C3-dependent C5 convertase. This linkage between the complement and coagulation pathways may represent a new pathway of complement activation.
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Affiliation(s)
- Markus Huber-Lang
- Department of Traumatology, Hand and Reconstructive Surgery, University of Ulm Medical School, Steinhoevelstrasse 9, D-89075 Ulm, Germany
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132
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Abstract
The involvement of complement in the pathogenesis of a great number of partly life threatening diseases defines the importance to develop inhibitors which specifically interfere with its deleterious action. Endogenous soluble complement-inhibitors, antibodies or low molecular weight antagonists, either blocking key proteins of the cascade reaction or neutralizing the action of the complement-derived anaphylatoxins have successfully been tested in various animal models over the past years. Promising results consequently led to first clinical trials. This review is focused on different approaches for the development of inhibitors, on their site of action in the cascade, on possible indications for complement inhibition based on experimental animal data, and on potential side effects of such treatment.
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Affiliation(s)
- Tom E Mollnes
- Institute of Immunology, Rikshospitalet University Hospital and University of Oslo, N-0027 Oslo, Norway.
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133
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Alexander SPH, Mathie A, Peters JA. Anaphylatoxin and chemotactic peptide. Br J Pharmacol 2006. [DOI: 10.1038/sj.bjp.0706519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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134
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Rahpeymai Y, Hietala MA, Wilhelmsson U, Fotheringham A, Davies I, Nilsson AK, Zwirner J, Wetsel RA, Gerard C, Pekny M, Pekna M. Complement: a novel factor in basal and ischemia-induced neurogenesis. EMBO J 2006; 25:1364-74. [PMID: 16498410 PMCID: PMC1422160 DOI: 10.1038/sj.emboj.7601004] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Accepted: 01/24/2006] [Indexed: 12/16/2022] Open
Abstract
Through its involvement in inflammation, opsonization, and cytolysis, the complement protects against infectious agents. Although most of the complement proteins are synthesized in the central nervous system (CNS), the role of the complement system in the normal or ischemic CNS remains unclear. Here we demonstrate for the first time that neural progenitor cells and immature neurons express receptors for complement fragments C3a and C5a (C3a receptor (C3aR) and C5a receptor). Mice that are deficient in complement factor C3 (C3(-/-)) lack C3a and are unable to generate C5a through proteolytic cleavage of C5 by C5-convertase. Intriguingly, basal neurogenesis is decreased both in C3(-/-) mice and in mice lacking C3aR or mice treated with a C3aR antagonist. The C3(-/-) mice had impaired ischemia-induced neurogenesis both in the subventricular zone, the main source of neural progenitor cells in adult brain, and in the ischemic region, despite normal proliferative response and larger infarct volumes. Thus, in the adult mammalian CNS, complement activation products promote both basal and ischemia-induced neurogenesis.
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Affiliation(s)
- Yalda Rahpeymai
- Institute of Biomedicine, Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
| | - Max Albert Hietala
- Institute of Biomedicine, Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
| | - Ulrika Wilhelmsson
- The Arvid Carlsson Institute for Neuroscience, Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
| | - Andrew Fotheringham
- School of Medicine and School of Biological Sciences, University of Manchester, Manchester, UK
| | - Ioan Davies
- School of Medicine and School of Biological Sciences, University of Manchester, Manchester, UK
| | - Ann-Katrin Nilsson
- Institute of Biomedicine, Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
| | - Jörg Zwirner
- Department of Immunology, Georg-August-University Göttingen, Göttingen, Germany
| | - Rick A Wetsel
- Research Center for Immunology and Autoimmune Diseases, Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas-Houston, Houston, TX, USA
| | - Craig Gerard
- Pulmonary Division, Department of Pediatrics, Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Milos Pekny
- The Arvid Carlsson Institute for Neuroscience, Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
| | - Marcela Pekna
- Institute of Biomedicine, Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
- Department of Medical Chemistry and Cell Biology, Sahlgrenska Academy at Göteborg University, Box 440, 405 30 Göteborg, Sweden. Tel.: +46 31 773 3581; Fax: +46 31 416 108; E-mail:
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135
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Nozaki M, Raisler BJ, Sakurai E, Sarma JV, Barnum SR, Lambris JD, Chen Y, Zhang K, Ambati BK, Baffi JZ, Ambati J. Drusen complement components C3a and C5a promote choroidal neovascularization. Proc Natl Acad Sci U S A 2006; 103:2328-33. [PMID: 16452172 PMCID: PMC1413680 DOI: 10.1073/pnas.0408835103] [Citation(s) in RCA: 474] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in industrialized nations, affecting 30-50 million people worldwide. The earliest clinical hallmark of AMD is the presence of drusen, extracellular deposits that accumulate beneath the retinal pigmented epithelium. Although drusen nearly always precede and increase the risk of choroidal neovascularization (CNV), the late vision-threatening stage of AMD, it is unknown whether drusen contribute to the development of CNV. Both in patients with AMD and in a recently described mouse model of AMD, early subretinal pigmented epithelium deposition of complement components C3 and C5 occurs, suggesting a contributing role for these inflammatory proteins in the development of AMD. Here we provide evidence that bioactive fragments of these complement components (C3a and C5a) are present in drusen of patients with AMD, and that C3a and C5a induce VEGF expression in vitro and in vivo. Further, we demonstrate that C3a and C5a are generated early in the course of laser-induced CNV, an accelerated model of neovascular AMD driven by VEGF and recruitment of leukocytes into the choroid. We also show that genetic ablation of receptors for C3a or C5a reduces VEGF expression, leukocyte recruitment, and CNV formation after laser injury, and that antibody-mediated neutralization of C3a or C5a or pharmacological blockade of their receptors also reduces CNV. Collectively, these findings establish a mechanistic basis for the clinical observation that drusen predispose to CNV, revealing a role for immunological phenomena in angiogenesis and providing therapeutic targets for AMD.
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Affiliation(s)
- Miho Nozaki
- *Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536
| | - Brian J. Raisler
- *Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536
| | - Eiji Sakurai
- *Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536
| | - J. Vidya Sarma
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Scott R. Barnum
- Department of Microbiology, University of Alabama, Birmingham, AL 35294
| | - John D. Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Yali Chen
- Department of Ophthalmology and Visual Science, Moran Eye Center and Program in Human Molecular Biology and Genetics, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84132; and
| | - Kang Zhang
- Department of Ophthalmology and Visual Science, Moran Eye Center and Program in Human Molecular Biology and Genetics, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84132; and
| | | | - Judit Z. Baffi
- *Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536
| | - Jayakrishna Ambati
- *Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536
- To whom correspondence should be addressed. E-mail:
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136
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Schaefer M, Konrad S, Thalmann J, Rheinheimer C, Johswich K, Sohns B, Klos A. The transcription factors AP-1 and Ets are regulators of C3a receptor expression. J Biol Chem 2005; 280:42113-23. [PMID: 16253992 DOI: 10.1074/jbc.m508146200] [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: 01/21/2023] Open
Abstract
The anaphylatoxin C3a is a proinflammatory mediator generated during complement activation. The tight control of C3a receptor (C3aR) expression is crucial for the regulation of anaphylatoxin-mediated effects. Key factors regulating constitutive expression of the C3aR in the mast cell line HMC-1 and receptor induction by dibutyryl-cAMP in monomyeloblastic U937 cells were determined by functional characterization of the C3aR promoter. Nucleotides -18 to -285 upstream of the translational start site proved to be critical for promoter activity in HMC-1 cells. Binding sites for the transcription factors AP-1 and Ets could be located. Overexpressed c-Jun/c-Fos (AP-1) and Ets-1 led synergistically to increased promoter activity that was substantially reduced by site-directed mutagenesis of the corresponding elements within the C3aR promoter. In HMC-1 cells, Ets interacted directly with the predicted binding motif of the C3aR promoter as determined by electromobility shift assays. AP-1 binding to the C3aR promoter was augmented during C3aR induction in U937 cells. A retroviral gene transfer system was used to express a dominant negative mutant of Ets-1 in these cells. The resulting cells failed to up-regulate the C3aR after stimulation with dibutyryl-cAMP and showed decreased AP-1 binding, suggesting that Ets acts here indirectly. Thus, it was established that Ets and the AP-1 element mediates dibutyryl-cAMP induction of C3aR promoter activity, hence providing a mechanistic explanation of dibutyryl-cAMP-dependent up-regulation of C3aR expression. In conclusion, this study demonstrates an important role of AP-1 and a member of the Ets family in the transcriptional regulation of C3aR expression, a prerequisite for the ability of C3a to participate in immunomodulation and inflammation.
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Affiliation(s)
- Myriam Schaefer
- Department of Medical Microbiology, Medical School Hannover (MHH), Carl-Neubergstrasse 1, D-30625 Hannover, Germany
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137
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Bao L, Osawe I, Haas M, Quigg RJ. Signaling through up-regulated C3a receptor is key to the development of experimental lupus nephritis. THE JOURNAL OF IMMUNOLOGY 2005; 175:1947-55. [PMID: 16034139 DOI: 10.4049/jimmunol.175.3.1947] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Signaling of the C3a anaphylatoxin through its G protein-coupled receptor, C3aR, is relevant in a variety of inflammatory diseases, but its role in lupus nephritis is undefined. In this study, we show that expression of C3aR was significantly increased in prediseased and diseased kidneys of MRL/lpr lupus mice compared with MRL/+ controls. To investigate the role of C3aR in experimental lupus, a small molecule antagonist of C3aR (C3aRa) was administered continuously to MRL/lpr mice from 13 to 19 wk of age. All 13 C3aRa-treated mice survived during the 6-wk treatment compared with 9 of 14 (64.3%) control animals given vehicle (p = 0.019). Relative to controls, C3aRa-treated animals were protected from renal disease as measured by albuminuria (p = 0.040) and blood urea nitrogen (p = 0.021). In addition, there were fewer neutrophils, monocytes, and apoptotic cells in the kidneys of C3aRa-treated mice. C3aRa treatment also led to reduced renal IL-1beta and RANTES mRNA and phosphorylated phosphatase and tensin homologue deleted on chromosome 10 protein, whereas the mass of phosphorylated protein kinase B/Akt was increased by C3aRa. Thus, C3aR antagonism significantly reduces renal disease in MRL/lpr mice, which further translates into prolonged survival. These data illustrate that C3aR is relevant in experimental lupus nephritis and may be a target for therapeutic intervention in the human disease.
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MESH Headings
- Animals
- Antibodies, Antinuclear/biosynthesis
- Apoptosis/drug effects
- Apoptosis/immunology
- Arginine/administration & dosage
- Arginine/analogs & derivatives
- Benzhydryl Compounds/administration & dosage
- Complement C3a/metabolism
- Complement C3a/physiology
- Complement Inactivator Proteins/administration & dosage
- Fluorescent Antibody Technique, Indirect
- Inflammation Mediators/metabolism
- Kidney/drug effects
- Kidney/immunology
- Kidney/metabolism
- Kidney/pathology
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/metabolism
- Lupus Erythematosus, Systemic/mortality
- Lupus Erythematosus, Systemic/pathology
- Male
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/biosynthesis
- Membrane Proteins/genetics
- Membrane Proteins/physiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred MRL lpr
- PTEN Phosphohydrolase
- Phosphoric Monoester Hydrolases/metabolism
- Phosphorylation/drug effects
- RNA, Messenger/biosynthesis
- Receptors, Complement/antagonists & inhibitors
- Receptors, Complement/biosynthesis
- Receptors, Complement/genetics
- Receptors, Complement/physiology
- Signal Transduction/genetics
- Signal Transduction/immunology
- Tumor Suppressor Proteins/metabolism
- Up-Regulation/genetics
- Up-Regulation/immunology
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Affiliation(s)
- Lihua Bao
- Section of Nephrology, University of Chicago, Chicago, IL 60637, USA.
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138
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Honczarenko M, Ratajczak MZ, Nicholson-Weller A, Silberstein LE. Complement C3a Enhances CXCL12 (SDF-1)-Mediated Chemotaxis of Bone Marrow Hematopoietic Cells Independently of C3a Receptor. THE JOURNAL OF IMMUNOLOGY 2005; 175:3698-706. [PMID: 16148115 DOI: 10.4049/jimmunol.175.6.3698] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Complement C3a promotes CXCL12-induced migration and engraftment of human and murine hemopoietic progenitor cells, suggesting a cross-influence between anaphylatoxin and chemokine axes. Here we have explored the underlying mechanism(s) of complement anaphylatoxin and chemokine cooperation. In addition to C3a, C3a-desArg and C4a but not C5a, are potent enhancers of CXCL12-induced chemotaxis of human and murine bone marrow (BM) stem/progenitor cells and B lineage cells. C3a enhancement of chemotaxis is chemokine specific because it is also observed for chemotaxis to CCL19 but not to CXCL13. The potentiating effect of C3a on CXCL12 is independent of the classical C3a receptor (C3aR). First, human BM CD34(+) and B lineage cells do not express C3aR by flow cytometry. Second, the competitive C3aR inhibitor SB290157 does not affect C3a-mediated enhancement of CXCL12-induced chemotaxis. Third, enhancement of chemotaxis of hemopoietic cells is also mediated by C3a-desArg, which does not bind to C3aR. Finally, C3a enhances CXCL12-induced chemotaxis of BM cells from C3aR knockout mice similar to BM cells from wild-type mice. Subsequent studies revealed that C3a increased the binding affinity of CXCL12 to human CXCR4(+)/C3aR(-), REH pro-B cells, which is compatible with a direct interaction between C3a and CXCL12. BM stromal cells were able to generate C3a, C3a-desArg, C4a, as well as CXCL12, suggesting that this pathway could function in vivo. Taken together, we demonstrate a C3a-CXCL12 interaction independent of the C3aR, which may provide a mechanism to modulate the function of CXCL12 in the BM microenvironment.
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Affiliation(s)
- Marek Honczarenko
- Joint Program in Transfusion Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
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139
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Therien AG. Agonist Activity of the Small Molecule C3aR Ligand SB 290157. THE JOURNAL OF IMMUNOLOGY 2005; 174:7479; author reply 7479-80. [PMID: 15944244 DOI: 10.4049/jimmunol.174.12.7479] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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140
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Mathieu MC, Sawyer N, Greig GM, Hamel M, Kargman S, Ducharme Y, Lau CK, Friesen RW, O'Neill GP, Gervais FG, Therien AG. The C3a receptor antagonist SB 290157 has agonist activity. Immunol Lett 2005; 100:139-45. [PMID: 16154494 DOI: 10.1016/j.imlet.2005.03.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 03/02/2005] [Accepted: 03/10/2005] [Indexed: 10/25/2022]
Abstract
The anaphylatoxin C3a is an important immune regulator with a number of distinct functions in both innate and adaptive immunity. Many of these roles have been ascribed to C3a based on studies in mice genetically modified to lack its precursor, C3, or its receptor, C3aR. However, other presumed functions of C3a are based on results obtained with a recently described small molecule ligand of C3aR, SB 290157. Although this compound was originally described as an antagonist and appears to act as such in some systems, it has recently been shown to have effects that cannot be explained by simple antagonism of C3aR. In the current study, SB 290157 is shown to have full agonist activity on C3aR in a variety of cell systems, including a calcium mobilization assay in transfected RBL cells, a beta-lactamase assay in CHO-NFAT-bla-Galpha(16) cells and an enzyme-release assay in differentiated U-937 cells. On the other hand, the compound lacks agonist activity in guinea pig platelets, cells known to express C3aR at very low levels. SB 290157 agonism of C3aR is consistent with recent discrepant data obtained using this molecule. These results caution against attributing novel roles to C3a based on data obtained with SB 290157 and highlight a continuing need for the identification of true small molecule C3aR antagonists.
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Affiliation(s)
- Marie-Claude Mathieu
- Department of Biochemistry and Molecular Biology, Merck Frosst Center for Therapeutic Research, Kirkland, Quebec, Canada H9H 3L1
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141
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Baelder R, Fuchs B, Bautsch W, Zwirner J, Köhl J, Hoymann HG, Glaab T, Erpenbeck V, Krug N, Braun A. Pharmacological targeting of anaphylatoxin receptors during the effector phase of allergic asthma suppresses airway hyperresponsiveness and airway inflammation. THE JOURNAL OF IMMUNOLOGY 2005; 174:783-9. [PMID: 15634899 DOI: 10.4049/jimmunol.174.2.783] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Airway hyperresponsiveness and airway inflammation are hallmarks of allergic asthma, the etiology of which is crucially linked to the presence of Th2 cytokines. A role for the complement anaphylatoxins C3a and C5a in allergic asthma was suggested, as deficiencies of the C3a receptor (C3aR) and of complement factor C5 modulate airway hyperresponsiveness, airway inflammation, and Th2 cytokine levels. However, such models do not allow differentiation of effects on the sensitization phase and the effector phase of the allergic response, respectively. In this study, we determined the role of the anaphylatoxins on the effector phase of asthma by pharmacological targeting of the anaphylatoxin receptors. C3aR and C5a receptor (C5aR) signaling was blocked using the nonpeptidic C3aR antagonist SB290157 and the neutralizing C5aR mAb 20/70 in a murine model of Aspergillus fumigatus extract induced pulmonary allergy. Airway hyperresponsiveness was substantially improved after C5aR blockade but not after C3aR blockade. Airway inflammation was significantly reduced in mice treated with the C3aR antagonist or the anti-C5aR mAb, as demonstrated by reduced numbers of neutrophils and eosinophils in bronchoalveolar lavage fluid. Of note, C5aR but not C3aR inhibition reduced lymphocyte numbers in bronchoalveolar lavage fluid. Cytokine levels of IL-5 and IL-13 in bronchoalveolar lavage fluid were not altered by C3aR or C5aR blockade. However, blockade of both anaphylatoxin receptors markedly reduced IL-4 levels. These data suggest an important and exclusive role for C5aR signaling on the development of airway hyperresponsiveness during pulmonary allergen challenge, whereas both anaphylatoxins contribute to airway inflammation and IL-4 production.
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Affiliation(s)
- Ralf Baelder
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany.
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142
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Abstract
Stem cell transplantation, whether autologous or allogeneic, improves the outcome of patients with a number of hematologic malignancies or solid tumors. A relevant proportion of these patients are excluded from this treatment because sufficient numbers of hematopoietic stem cells cannot be obtained by standard cytokine-assisted mobilization. In this article we review the physiology of peripheral blood progenitor cell (PBPC) mobilization and discuss the role of adhesion molecules, such as integrins and selectins, chemokines and their ligands, such as SDF-1alpha and CXCR4, and proteolytic enzymes. Based on this knowledge, several innovative pharmacologic approaches have been proposed to boost the stem cell harvest. Some of them (CTCE, C3a receptor agonist and GrobetaT) are still subject of pre-clinical development, others, such as chemokine receptor ligand AMD3100, have recently been introduced in clinical trials and already deliver promising results. It appears possible to harvest PBPC successfully in poor mobilizers and to cut down the number of collections required in the remaining PBPC donors.
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Affiliation(s)
- S Fruehauf
- Department of Internal Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
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143
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Godau J, Heller T, Hawlisch H, Trappe M, Howells E, Best J, Zwirner J, Verbeek JS, Hogarth PM, Gerard C, Van Rooijen N, Klos A, Gessner JE, Köhl J. C5a initiates the inflammatory cascade in immune complex peritonitis. THE JOURNAL OF IMMUNOLOGY 2004; 173:3437-45. [PMID: 15322209 DOI: 10.4049/jimmunol.173.5.3437] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immune complex (IC)-induced inflammation is integral to the pathogenesis of several autoimmune diseases. ICs activate the complement system and interact with IgG FcgammaR. In this study, we demonstrate that activation of the complement system, specifically generation of C5a, initiates the neutrophilic inflammation in IC peritonitis. We show that ablation of C5a receptor signaling abrogates neutrophil recruitment in wild-type mice and prevents the enhancement of neutrophil migration seen in FcgammaRIIB(-/-) mice, suggesting that C5aR signaling is the crucial initial event upstream of FcgammaR signaling. We also provide evidence that C5a initiates the inflammatory cascade both directly, through C5aR-mediated effector functions on infiltrating and resident peritoneal cells, and indirectly, through shifting the balance between activating and inhibitory FcgammaRs on resident cells toward an inflammatory phenotype. We conclude that complement activation and C5a generation are prerequisites for IC-induced inflammation through activating FcgammaR, which amplifies complement-induced inflammation in autoimmunity.
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Affiliation(s)
- Jeanne Godau
- Institute of Medical Microbiology, Medical School Hannover, Germany
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144
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Proctor LM, Arumugam TV, Shiels I, Reid RC, Fairlie DP, Taylor SM. Comparative anti-inflammatory activities of antagonists to C3a and C5a receptors in a rat model of intestinal ischaemia/reperfusion injury. Br J Pharmacol 2004; 142:756-64. [PMID: 15159277 PMCID: PMC1575041 DOI: 10.1038/sj.bjp.0705819] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1. Complement activation is implicated in the pathogenesis of intestinal ischaemia-reperfusion injury (I/R), although the relative importance of individual complement components is unclear. A C3a receptor antagonist N(2)-[(2,2-diphenylethoxy)acetyl]-l-arginine (C3aRA) has been compared with a C5a receptor antagonist (C5aRA), AcF-[OPdChaWR], in a rat model of intestinal I/R. 2. C3aRA (IC(50)=0.15 microm) and C5aRA (IC(50)=0.32 microm) bound selectively to human polymorphonuclear leukocyte (PMN) C3a and C5a receptors, respectively. Effects on circulating neutrophils and blood pressure in the rat were also assessed. 3. Anaesthetised rats, subjected to intestinal ischaemia (30 min) and reperfusion (120 min), were administered intravenously with either (A) the C3aRA (0.1-1.0 mg x kg(-1)); the C5aRA (1.0 mg x kg(-1)); the C3aRA+C5aRA (each 1.0 mg x kg(-1)); or vehicle, 45 min prior, or (B) the C3aRA (1.0 mg x kg(-1)) or vehicle, 120 min prior to reperfusion. 4. The C3aRA and C5aRA, administered 45 min prior to reperfusion, displayed similar efficacies at ameliorating several disease markers (increased oedema, elevated ALT levels and mucosal damage) of rat intestinal I/R. The combination drug treatment did not result in greater injury reduction than either antagonist alone. However, doses of the C3aRA (0.01-10 mg x kg(-1)) caused transient neutropaenia, and the highest dose (10 mg x kg(-1)) also caused a rapid and transient hypertension. 5. The C3aRA (1.0 mg x kg(-1)), delivered 120 min prior to reperfusion to remove the global effect of C3aRA-induced neutrophil sequestration, did not attenuate the markers of intestinal I/R, despite persistent C3aR antagonism at this time. 6. C3aR antagonism does not appear to be responsible for the anti-inflammatory actions of this C3aRA in intestinal I/R in the rat. Instead, C3aRA-mediated global neutrophil tissue sequestration during ischaemia and early reperfusion may account for the protective effects observed.
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MESH Headings
- Alanine Transaminase/blood
- Animals
- Anti-Inflammatory Agents/administration & dosage
- Anti-Inflammatory Agents/chemical synthesis
- Anti-Inflammatory Agents/therapeutic use
- Arginine/administration & dosage
- Arginine/analogs & derivatives
- Arginine/chemical synthesis
- Arginine/therapeutic use
- Australia
- Benzhydryl Compounds/administration & dosage
- Benzhydryl Compounds/chemical synthesis
- Benzhydryl Compounds/therapeutic use
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Combinations
- Female
- Humans
- Injections, Intravenous
- Intestinal Mucosa/drug effects
- Intestinal Mucosa/pathology
- Intestinal Mucosa/ultrastructure
- Membrane Proteins/administration & dosage
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/therapeutic use
- Neutropenia/chemically induced
- Neutropenia/complications
- Neutrophils/drug effects
- Neutrophils/metabolism
- Peptides, Cyclic/administration & dosage
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/therapeutic use
- Rats
- Rats, Wistar
- Receptor, Anaphylatoxin C5a/administration & dosage
- Receptor, Anaphylatoxin C5a/antagonists & inhibitors
- Receptor, Anaphylatoxin C5a/therapeutic use
- Receptors, Complement/administration & dosage
- Receptors, Complement/antagonists & inhibitors
- Receptors, Complement/therapeutic use
- Reperfusion Injury/complications
- Reperfusion Injury/drug therapy
- Reperfusion Injury/metabolism
- Time Factors
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Affiliation(s)
- Lavinia M Proctor
- School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia
| | - Thiruma V Arumugam
- School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia
| | - Ian Shiels
- School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia
| | - Robert C Reid
- Institute for Molecular Bioscience, University of Queensland, Brisbane QLD 4072, Australia
| | - David P Fairlie
- Institute for Molecular Bioscience, University of Queensland, Brisbane QLD 4072, Australia
| | - Stephen M Taylor
- School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia
- Author for correspondence:
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145
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Ratajczak J, Reca R, Kucia M, Majka M, Allendorf DJ, Baran JT, Janowska-Wieczorek A, Wetsel RA, Ross GD, Ratajczak MZ. Mobilization studies in mice deficient in either C3 or C3a receptor (C3aR) reveal a novel role for complement in retention of hematopoietic stem/progenitor cells in bone marrow. Blood 2004; 103:2071-8. [PMID: 14604969 DOI: 10.1182/blood-2003-06-2099] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Abstract
The mechanisms regulating the homing/mobilization of hematopoietic stem/progenitor cells (HSPCs) are not fully understood. In our previous studies we showed that the complement C3 activation peptide, C3a, sensitizes responses of HSPCs to stromal-derived factor 1 (SDF-1). In this study, mobilization was induced with granulocyte colony-stimulating factor (G-CSF) in both C3-deficient (C3–/–) and C3a receptor–deficient (C3aR–/–) mice as well as in wild-type (wt) mice in the presence or absence of a C3aR antagonist, SB 290157. The data indicated (1) significantly increased G-CSF–induced mobilization in C3–/– and C3aR–/– mice compared with wt mice, (2) significantly accelerated and enhanced G-CSF–induced mobilization in wt, but not in C3–/– or C3aR–/–, mice treated with SB 290157, and (3) deposition of C3b/iC3b fragments onto the viable bone marrow (BM) cells of G-CSF–treated animals. Furthermore, mobilization studies performed in chimeric mice revealed that wt mice reconstituted with C3aR–/– BM cells, but not C3aR–/– mice reconstituted with wt BM cells, are more sensitive to G-CSF–induced mobilization, suggesting that C3aR deficiency on graft-derived cells is responsible for this increased mobilization. Hence we suggest that C3 is activated in mobilized BM into C3a and C3b, and that the C3a-C3aR axis plays an important and novel role in retention of HSPCs (by counteracting mobilization) by increasing their responsiveness to SDF-1, the concentration of which is reduced in BM during mobilization. The C3a-C3aR axis may prevent an uncontrolled release of HSPCs into peripheral blood. These data further suggest that the C3aR antagonist SB 290157 could be developed as a drug to mobilize HSPCs for transplantation.
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Affiliation(s)
- Janina Ratajczak
- Stem Cell Biology Program, James Graham Brown Cancer Center, University of Louisville, 529 South Jackson St, KY 40202, USA.
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146
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Ismail HF, Zhang J, Lynch RG, Wang Y, Berg DJ. Role for complement in development of Helicobacter-induced gastritis in interleukin-10-deficient mice. Infect Immun 2003; 71:7140-8. [PMID: 14638805 PMCID: PMC308887 DOI: 10.1128/iai.71.12.7140-7148.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Revised: 05/07/2003] [Accepted: 08/11/2003] [Indexed: 12/28/2022] Open
Abstract
The mechanisms by which the immune response can eradicate gastric Helicobacter infection are unknown. We hypothesized that Helicobacter-induced activation of the complement system could promote both inflammation and eradication of Helicobacter from the stomach. In vitro studies demonstrated that Helicobacter felis activates complement in normal mouse serum but not in serum from Rag2(-/-) mice, indicating that H. felis activates complement through the classical pathway. Next, we infected complement-depleted wild-type control and interleukin-10-deficient (IL-10(-/-)) mice with H. felis. Helicobacter infection of wild-type mice elicited a mild, focal gastritis and did not alter serum complement levels. Infection of IL-10(-/-) mice with H. felis elicited severe gastritis. After the initial colonization, the IL-10(-/-) mice completely cleared Helicobacter from the stomach by day 8. In contrast to wild-type mice, H. felis-infected IL-10(-/-) mice had a marked increase in serum complement levels. Complement depletion of wild-type mice did not affect the intensity of gastric inflammation or the extent of Helicobacter colonization compared to that for the wild-type control mice. In contrast, complement depletion of Helicobacter-infected IL-10(-/-) mice decreased the severity of gastritis, decreased the Helicobacter-induced infiltration of neutrophils into the stomach, and delayed the clearance of bacteria. In vitro studies of stimulated splenocytes and neutrophils from IL-10(-/-) mice produced a twofold increase in complement production compared to that for wild-type mice. Pretreatment with IL-10 inhibited this increase. These studies identify a role for complement in the local immune response to gastric Helicobacter in IL-10(-/-) mice and suggest a role for IL-10 in the regulation of complement production.
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Affiliation(s)
- Hanan F Ismail
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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147
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Affiliation(s)
- V Michael Holers
- Department of Medicine and Immunology, Health Science Center, University of Colorado, Denver, CO 80262, USA.
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148
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Reca R, Mastellos D, Majka M, Marquez L, Ratajczak J, Franchini S, Glodek A, Honczarenko M, Spruce LA, Janowska-Wieczorek A, Lambris JD, Ratajczak MZ. Functional receptor for C3a anaphylatoxin is expressed by normal hematopoietic stem/progenitor cells, and C3a enhances their homing-related responses to SDF-1. Blood 2003; 101:3784-93. [PMID: 12511407 DOI: 10.1182/blood-2002-10-3233] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Complement has recently been implicated in developmental pathways and noninflammatory processes. The expression of various complement components and receptors has been shown in a wide range of circulating myeloid and lymphoid cells, but their role in normal hematopoiesis and stem cell homing has not yet been investigated. We report that normal human CD34(+) cells and lineage-differentiated hematopoietic progenitors express the complement anaphylatoxin C3a receptor (C3aR) and respond to C3a. Moreover, C3a, but not the biologically inactive desArg-C3a, induces calcium flux in these cells. Furthermore, we found that C3 is secreted by bone marrow stroma and that, although C3a does not influence directly the proliferation/survival of hematopoietic progenitors, it (1) potentiates the stromal cell-derived factor 1 (SDF-1)-dependent chemotaxis of human CD34(+) cells and lineage-committed myeloid, erythroid, and megakaryocytic progenitors; (2) primes SDF-1-dependent trans-Matrigel migration; and (3) stimulates matrix metalloproteinase-9 secretion and very late antigen 4 (VLA-4)-mediated adhesion to vascular cell adhesion molecule 1 (VCAM-1). Furthermore, we found that murine Sca-1(+) cells primed by C3a engrafted faster in lethally irradiated animals. These results indicate that normal human hematopoietic stem and progenitor cells express functional C3aR and that the C3aR-C3a axis sensitizes the responses of these cells to SDF-1 and thus may be involved in promoting their homing into the bone marrow via cross talk with the SDF-CXC chemokine receptor-4 (CXCR4) signaling axis. C3a is the first positive regulator of this axis to be identified.
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Affiliation(s)
- Ryan Reca
- Stem Cell Biology Program, University of Louisville, Louisville, KY 40202, USA
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149
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Affiliation(s)
- Tom E Mollnes
- Institute of Immunology, The National Hospital, University of Oslo, Norway.
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150
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Welch TR, Frenzke M, Carroll MC, Witte DP. Evidence of a role for C4 in modulating interstitial inflammation in experimental glomerulonephritis. Clin Immunol 2001; 101:366-70. [PMID: 11726230 DOI: 10.1006/clim.2001.5125] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of C4 releases into the fluid phase a fragment of the alpha chain, C4a. Unlike the analogous fragments of C3 and C2, there is no evidence for an anaphylatoxic effect of C4a. There is actually some in vitro evidence that it could have a modulating effect on inflammation by inhibiting monocyte chemotaxis. We induced an immune complex glomerulonephritis in wild-type (WT) and C4 knock out (C4KO) mice. Although the glomerular component of the disease did not differ in the two groups of animals, there were marked differences in the accompanying tubulo-interstitial injury. Compared to WT animals, the C4KO mice had significantly more infiltrating interstitial cells (1910 vs 2720/mm(2)), foci of tubular atrophy (6.3 vs 14.8/section), and interstitial space (22 vs 30% of cortex). C4 is expressed constitutively by renal tubular epithelial cells. These data support a role for such local C4 in modulating interstitial inflammation, consistent with in vitro experiments.
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Affiliation(s)
- T R Welch
- Division of Nephrology and Hypertension, Children's Hospital Research Foundation, Cincinnati, Ohio 45229, USA
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