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Ibrahim ST, Abdelhamid MR, Lewis N, Baddour N, Adam AG. Role of fluid-phase complement system regulation in the development of hepatitis C virus-associated glomerulonephritis. PLoS One 2022; 17:e0276017. [PMID: 36227893 PMCID: PMC9560510 DOI: 10.1371/journal.pone.0276017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/28/2022] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES It is not known why only some hepatitis C virus (HCV) infected patients develop glomerulonephritis (GN). Therefore, we investigated the role of soluble complement regulators in the development of HCV associated GN. METHODS Patients with HCV associated GN who were admitted to our nephrology unit between July 2016 and July 2018 were recruited to the study (group 1). Two other age and sex matched groups were studied as control groups: patients with HCV without GN (group 2) and healthy HCV negative volunteers (group 3). There were 26 participants in each of the three groups at the end of the recruitment period. An assay of serum fluid-phase complement regulators was performed using enzyme linked immunosorbent assay technique. Three complement single nucleotide polymorphisms (SNPs) were analyzed using real time polymerase chain reaction (Taqman; thermo fisher scientific): rs2230199 and rs1047286 for complement 3 (C3) and rs800292 for complement factor H (CFH). RESULTS Serum levels of complement 4 binding protein (C4BP) were significantly lower in group 1 (median 70 ng/ml) than in groups 2 (median 88.8 ng/ml) and 3 (median 82.8 ng/ml) with p value of 0.007. The minor allele (allele A) of rs800292 for CFH was significantly higher in group 2 and group 3 (G 54% and A 46%) than in group 1 (G 73% and A 27%), p = 0.04. CONCLUSIONS Low C4BP levels are associated with GN in HCV infected patients. In addition, rs800292 SNP in CFH protects against GN in patients with HCV.
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Affiliation(s)
- Sara T. Ibrahim
- Department of Internal Medicine and Nephrology, Faculty of Medicine, Alexandria University, Alexandria, Egypt,* E-mail:
| | | | - Neveen Lewis
- Department of Clinical Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Nahed Baddour
- Department of Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Ahmed G. Adam
- Department of Internal Medicine and Nephrology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
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Quantitative Plasma Proteomics to Identify Candidate Biomarkers of Relapse in Pediatric/Adolescent Hodgkin Lymphoma. Int J Mol Sci 2022; 23:ijms23179911. [PMID: 36077307 PMCID: PMC9456176 DOI: 10.3390/ijms23179911] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/27/2022] [Accepted: 08/29/2022] [Indexed: 11/29/2022] Open
Abstract
Classical pediatric Hodgkin Lymphoma (HL) is a rare malignancy. Therapeutic regimens for its management may be optimized by establishing treatment response early on. The aim of this study was to identify plasma protein biomarkers enabling the prediction of relapse in pediatric/adolescent HL patients treated under the pediatric EuroNet-PHL-C2 trial. We used untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics at the time of diagnosis—before any therapy—as semiquantitative method to profile plasma proteins specifically associated with relapse in 42 children with nodular sclerosing HL. In both the exploratory and the validation cohorts, six proteins (apolipoprotein E, C4b-binding protein α chain, clusterin, fibrinogen γ chain, prothrombin, and vitronectin) were more abundant in the plasma of patients whose HL relapsed (|fold change| ≥ 1.2, p < 0.05, Student’s t-test). Predicting protein function with the Gene Ontology classification model, the proteins were included in four biological processes (p < 0.01). Using immunoblotting and Luminex assays, we validated two of these candidate biomarkers—C4b-binding protein α chain and clusterin—linked to innate immune response function (GO:0045087). This study identified C4b-binding protein α chain and clusterin as candidate early plasma biomarkers of HL relapse, and important for the purpose of shedding light on the molecular scenario associated with immune response in patients treated under the EuroNet-PHL-C2 trial.
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3
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Sasaki K, Takano S, Tomizawa S, Miyahara Y, Furukawa K, Takayashiki T, Kuboki S, Takada M, Ohtsuka M. C4b-binding protein α-chain enhances antitumor immunity by facilitating the accumulation of tumor-infiltrating lymphocytes in the tumor microenvironment in pancreatic cancer. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:212. [PMID: 34167573 PMCID: PMC8228942 DOI: 10.1186/s13046-021-02019-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 06/17/2021] [Indexed: 01/08/2023]
Abstract
Background Recent studies indicate that complement plays pivotal roles in promoting or suppressing cancer progression. We have previously identified C4b-binding protein α-chain (C4BPA) as a serum biomarker for the early detection of pancreatic ductal adenocarcinoma (PDAC). However, its mechanism of action remains unclear. Here, we elucidated the functional roles of C4BPA in PDAC cells and the tumor microenvironment. Methods We assessed stromal C4BPA, the C4BPA binding partner CD40, and the number of CD8+ tumor-infiltrating lymphocytes in resected human PDAC tissues via immunohistochemical staining. The biological functions of C4BPA were investigated in peripheral blood mononuclear cells (PBMCs) and human PDAC cell lines. Mouse C4BPA (mC4BPA) peptide, which is composed of 30 amino acids from the C-terminus and binds to CD40, was designed for further in vitro and in vivo experiments. In a preclinical experiment, we assessed the efficacy of gemcitabine plus nab-paclitaxel (GnP), dual immune checkpoint blockades (ICBs), and mC4BPA peptide in a mouse orthotopic transplantation model. Results Immunohistochemical analysis revealed that high stromal C4BPA and CD40 was associated with favorable PDAC prognosis (P=0.0005). Stromal C4BPA strongly correlated with the number of CD8+ tumor-infiltrating lymphocytes (P=0.001). In in vitro experiments, flow cytometry revealed that recombinant human C4BPA (rhC4BPA) stimulation increased CD4+ and CD8+ T cell numbers in PBMCs. rhC4BPA also promoted the proliferation of CD40-expressing PDAC cells. By contrast, combined treatment with gemcitabine and rhC4BPA increased PDAC cell apoptosis rate. mC4BPA peptide increased the number of murine T lymphocytes in vitro and the number of CD8+ tumor-infiltrating lymphocytes surrounding PDAC tumors in vivo. In a preclinical study, GnP/ICBs/mC4BPA peptide treatment, but not GnP treatment, led to the accumulation of a greater number of CD8+ T cells in the periphery of PDAC tumors and to greater tumor regression than did control treatment. Conclusions These findings demonstrate that the combination of GnP therapy with C4BPA inhibits PDAC progression by promoting antitumor T cell accumulation in the tumor microenvironment. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-021-02019-0.
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Affiliation(s)
- Kosuke Sasaki
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Shigetsugu Takano
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan.
| | - Satoshi Tomizawa
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Yoji Miyahara
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Katsunori Furukawa
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Tsukasa Takayashiki
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Satoshi Kuboki
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Mamoru Takada
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
| | - Masayuki Ohtsuka
- Department of General Surgery, Chiba University, Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba City, Chiba, 260-8677, Japan
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Malik A, Thanekar U, Amarachintha S, Mourya R, Nalluri S, Bondoc A, Shivakumar P. "Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma. Front Oncol 2021; 10:627701. [PMID: 33718121 PMCID: PMC7943925 DOI: 10.3389/fonc.2020.627701] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.
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Affiliation(s)
- Astha Malik
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Unmesha Thanekar
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Surya Amarachintha
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Reena Mourya
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Shreya Nalluri
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Alexander Bondoc
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Division of Pediatric General and Thoracic Surgery, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Pranavkumar Shivakumar
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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5
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Reichhardt MP, Meri S. Intracellular complement activation-An alarm raising mechanism? Semin Immunol 2018; 38:54-62. [PMID: 29631809 DOI: 10.1016/j.smim.2018.03.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/26/2018] [Indexed: 12/20/2022]
Abstract
It has become increasingly apparent that the complement system, being an ancient defense mechanism, is not operative only in the extracellular milieu but also intracellularly. In addition to the known synthetic machinery in the liver and by macrophages, many other cell types, including lymphocytes, adipocytes and epithelial cells produce selected complement components. Activation of e.g. C3 and C5 inside cells may have multiple effects ranging from direct antimicrobial defense to cell differentiation and possible influence on metabolism. Intracellular activation of C3 and C5 in T cells is involved in the maintenance of immunological tolerance and promotes differentiation of T helper cells into Th1-type cells that activate cell-mediated immune responses. Adipocytes are unique in producing many complement sensor proteins (like C1q) and Factor D (adipsin), the key enzyme in promoting alternative pathway amplification. The effects of complement activation products are mediated by intracellular and cell membrane receptors, like C3aR, C5aR1, C5aR2 and the complement regulator MCP/CD46, often jointly with other receptors like the T cell receptor, Toll-like receptors and those of the inflammasomes. These recent observations link complement activation to cellular metabolic processes, intracellular defense reactions and to diverse adaptive immune responses. The complement components may thus be viewed as intracellular alarm molecules involved in the cellular danger response.
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Affiliation(s)
- M P Reichhardt
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
| | - S Meri
- Department of Bacteriology and Immunology, Haartman Institute, Immunobiology Research Program, University of Helsinki, Helsinki, Finland; Helsinki University Central Hospital Laboratory (HUSLAB), Helsinki, Finland.
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6
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Lubbers R, van Essen MF, van Kooten C, Trouw LA. Production of complement components by cells of the immune system. Clin Exp Immunol 2017; 188:183-194. [PMID: 28249350 DOI: 10.1111/cei.12952] [Citation(s) in RCA: 302] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2017] [Indexed: 12/14/2022] Open
Abstract
The complement system is an important part of the innate immune defence. It contributes not only to local inflammation, removal and killing of pathogens, but it also assists in shaping of the adaptive immune response. Besides a role in inflammation, complement is also involved in physiological processes such as waste disposal and developmental programmes. The complement system comprises several soluble and membrane-bound proteins. The bulk of the soluble proteins is produced mainly by the liver. While several complement proteins are produced by a wide variety of cell types, other complement proteins are produced by only a few related cell types. As these data suggest that local production by specific cell types may have specific functions, more detailed studies have been employed recently analysing the local and even intracellular role of these complement proteins. Here we review the current knowledge about extrahepatic production and/or secretion of complement components. More specifically, we address what is known about complement synthesis by cells of the human immune system.
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Affiliation(s)
- R Lubbers
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
| | - M F van Essen
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - C van Kooten
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - L A Trouw
- Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands
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7
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Khorooshi R, Asgari N, Mørch MT, Berg CT, Owens T. Hypersensitivity Responses in the Central Nervous System. Front Immunol 2015; 6:517. [PMID: 26500654 PMCID: PMC4595775 DOI: 10.3389/fimmu.2015.00517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/22/2015] [Indexed: 12/29/2022] Open
Abstract
Immune-mediated tissue damage or hypersensitivity can be mediated by autospecific IgG antibodies. Pathology results from activation of complement, and antibody-dependent cellular cytotoxicity, mediated by inflammatory effector leukocytes include macrophages, natural killer cells, and granulocytes. Antibodies and complement have been associated to demyelinating pathology in multiple sclerosis (MS) lesions, where macrophages predominate among infiltrating myeloid cells. Serum-derived autoantibodies with predominant specificity for the astrocyte water channel aquaporin-4 (AQP4) are implicated as inducers of pathology in neuromyelitis optica (NMO), a central nervous system (CNS) demyelinating disease where activated neutrophils infiltrate, unlike in MS. The most widely used model for MS, experimental autoimmune encephalomyelitis, is an autoantigen-immunized disease that can be transferred to naive animals with CD4+ T cells, but not with antibodies. By contrast, NMO-like astrocyte and myelin pathology can be transferred to mice with AQP4–IgG from NMO patients. This is dependent on complement, and does not require T cells. Consistent with clinical observations that interferon-beta is ineffective as a therapy for NMO, NMO-like pathology is significantly reduced in mice lacking the Type I IFN receptor. In MS, there is evidence for intrathecal synthesis of antibodies as well as blood–brain barrier (BBB) breakdown, whereas in NMO, IgG accesses the CNS from blood. Transfer models involve either direct injection of antibody and complement to the CNS, or experimental manipulations to induce BBB breakdown. We here review studies in MS and NMO that elucidate roles for IgG and complement in the induction of BBB breakdown, astrocytopathy, and demyelinating pathology. These studies point to significance of T-independent effector mechanisms in neuroinflammation.
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Affiliation(s)
- Reza Khorooshi
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Nasrin Asgari
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark , Odense , Denmark ; Department of Neurology, Vejle Hospital , Vejle , Denmark
| | - Marlene Thorsen Mørch
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Carsten Tue Berg
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark , Odense , Denmark
| | - Trevor Owens
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark , Odense , Denmark
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8
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Nesargikar PN, Spiller B, Chavez R. The complement system: history, pathways, cascade and inhibitors. Eur J Microbiol Immunol (Bp) 2012; 2:103-11. [PMID: 24672678 DOI: 10.1556/eujmi.2.2012.2.2] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 03/26/2012] [Indexed: 01/20/2023] Open
Abstract
Since its discovery in the 19th century, the complement system has developed into a clinically significant entity. The complement system has been implicated in a variety of clinical conditions, from autoimmune diseases to ischemia-reperfusion injury in transplantation. This article charts the historical progress of our understanding of the complement system and provides a synopsis on the activation pathways and its inherent regulators.
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9
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Fraczek LA, Martin BK. Transcriptional control of genes for soluble complement cascade regulatory proteins. Mol Immunol 2010; 48:9-13. [PMID: 20869772 DOI: 10.1016/j.molimm.2010.08.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 08/29/2010] [Indexed: 11/17/2022]
Abstract
The complement cascade of the immune system is an important mediator of the inflammatory response to infection; however it is crucial that this pathway is tightly regulated to prevent uncontrolled activation, which can lead to damage to host tissues. The complement system has many regulators that control activation; both membrane-bound and soluble factors. This review will focus on what is currently known about the transcriptional regulation of the soluble complement regulatory genes C1-inhibitor, complement factor I, complement factor H and C4-binding protein. The absence or mutation of these regulators is all associated with specific disease, and yet their contribution to disease is often poorly understood. It is through full understanding of these genes that we can comprehend the diseases with which they are implicated, and thus prove why knowledge of the transcriptional regulation of these genes is valuable.
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Affiliation(s)
- Laura A Fraczek
- The Iowa Cancer Research Foundation, Urbandale, IA 50322, USA.
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10
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Zadura AF, Theander E, Blom AM, Trouw LA. Complement Inhibitor C4b-Binding Protein in Primary Sjögren’s Syndrome and its Association With Other Disease Markers. Scand J Immunol 2009; 69:374-80. [DOI: 10.1111/j.1365-3083.2009.02229.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Wenderfer SE, Soimo K, Wetsel RA, Braun MC. Analysis of C4 and the C4 binding protein in the MRL/lpr mouse. Arthritis Res Ther 2008; 9:R114. [PMID: 17971229 PMCID: PMC2212569 DOI: 10.1186/ar2320] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 10/11/2007] [Accepted: 10/30/2007] [Indexed: 11/10/2022] Open
Abstract
Systemic lupus erythematosus is a complement-mediated autoimmune disease. While genetic deficiencies of classical pathway components lead to an increased risk of developing systemic lupus erythematosus, end organ damage is associated with complement activation and immune complex deposition. The role of classical pathway regulators in systemic lupus erythematosus is unknown. C4 binding protein (C4bp) is a major negative regulator of the classical pathway. In order to study the role of C4bp deficiency in an established murine model of lupus nephritis, mice with a targeted deletion in the gene encoding C4bp were backcrossed into the MRL/lpr genetic background. Compared with control MRL/lpr mice, C4bp knockout MLR/lpr mice had similar mortality and similar degrees of lymphoproliferation. There were no differences in the extent of proteinuria or renal inflammation. Staining for complement proteins and immunoglobulins in the kidneys of diseased mice revealed no significant strain differences. Moreover, there was no difference in autoantibody production or in levels of circulating immune complexes. In comparison with C57BL/6 mice, MRL/lpr mice had depressed C4 levels as early as 3 weeks of age. The absence of C4bp did not impact serum C4 levels or alter classical pathway hemolytic activity. Given that immune complex renal injury in the MRL/lpr mouse is independent of Fc receptors as well as the major negative regulator of the classical pathway, new mechanisms for immune-complex-mediated renal injury need to be considered.
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Affiliation(s)
- Scott E Wenderfer
- Center for Immunology and Autoimmune Diseases, Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, USA
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12
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Williams KT, Young SP, Negus A, Young LS, Adams DH, Afford SC. C4b binding protein binds to CD154 preventing CD40 mediated cholangiocyte apoptosis: a novel link between complement and epithelial cell survival. PLoS One 2007; 2:e159. [PMID: 17225862 PMCID: PMC1764644 DOI: 10.1371/journal.pone.0000159] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 12/15/2006] [Indexed: 02/08/2023] Open
Abstract
Activation of CD40 on hepatocytes and cholangiocytes is critical for amplifying Fas-mediated apoptosis in the human liver. C4b-Binding Protein (C4BP) has been reported to act as a potential surrogate ligand for CD40, suggesting that it could be involved in modulating liver epithelial cell survival. Using surface plasmon resonance (BiaCore) analysis supported by gel filtration we have shown that C4BP does not bind CD40, but it forms stable high molecular weight complexes with soluble CD40 ligand (sCD154). These C4BP/sCD154 complexes bound efficiently to immobilised CD40, but when applied to cholangiocytes they failed to induce apoptosis or proliferation or to activate NFkB, AP-1 or STAT 3, which are activated by sCD154 alone. Thus C4BP can modulate CD40/sCD154 interactions by presenting a high molecular weight multimeric sCD154/C4BP complex that suppresses critical intracellular signalling pathways, permitting cell survival without inducing proliferation. Immunohistochemistry demonstrated co-localisation and enhanced expression of C4BP and CD40 in human liver cancers. These findings suggest a novel pathway whereby components of the complement system and TNF ligands and receptors might be involved in modulating epithelial cell survival in chronic inflammation and malignant disease.
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Affiliation(s)
- Kevin T. Williams
- The Liver Research Group and MRC Centre for Immune Regulation, Institute of Biomedical Research, The University of Birmingham, Birmingham, United Kingdom
| | - Steven P. Young
- Department of Rheumatology, University of Birmingham Medical School, Birmingham, United Kingdom
| | - Alison Negus
- The Liver Research Group and MRC Centre for Immune Regulation, Institute of Biomedical Research, The University of Birmingham, Birmingham, United Kingdom
| | - Lawrence S. Young
- Cancer Research UK Institute for Cancer Studies, University of Birmingham Medical School, Birmingham, United Kingdom
| | - David H. Adams
- The Liver Research Group and MRC Centre for Immune Regulation, Institute of Biomedical Research, The University of Birmingham, Birmingham, United Kingdom
| | - Simon C. Afford
- The Liver Research Group and MRC Centre for Immune Regulation, Institute of Biomedical Research, The University of Birmingham, Birmingham, United Kingdom
- * To whom correspondence should be addressed. E-mail:
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13
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Reis ES, Barbuto JAM, Isaac L. Complement components, regulators and receptors are produced by human monocyte-derived dendritic cells. Immunobiology 2007; 212:151-7. [PMID: 17412282 DOI: 10.1016/j.imbio.2006.11.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 11/14/2006] [Accepted: 11/27/2006] [Indexed: 01/19/2023]
Abstract
Complement and dendritic cells (DCs) are essential components of innate immunity. Both participate in local inflammation and moreover have roles in the initiation of the acquired immunity response and in the maintenance of tolerance. Recent studies have demonstrated the ability of DCs to synthesize C1q, C3, Factor I, Factor B and complement receptors 3 and 4. In this study, we demonstrate that human DCs are a source of other soluble complement proteins including C1q, C4b binding protein (C4BP), C7 and C8. Complement receptors (CR)1 and the CD18 chain (common for CR3 and CR4) were also present on DCs while CR2 was not detected.
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Affiliation(s)
- Edimara S Reis
- Laboratório de Complemento, Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes 1730, 05508-900 São Paulo, Brazil
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14
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Blom AM, Villoutreix BO, Dahlbäck B. Complement inhibitor C4b-binding protein-friend or foe in the innate immune system? Mol Immunol 2004; 40:1333-46. [PMID: 15072852 DOI: 10.1016/j.molimm.2003.12.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Revised: 12/09/2003] [Accepted: 12/11/2003] [Indexed: 01/15/2023]
Abstract
The complement system constitutes an important component of the defence against foreign organisms, functioning both in innate and adaptive immune systems. It is potentially harmful also to the own organism and is therefore tightly regulated by a number of membrane-bound and soluble factors. C4b-binding protein (C4BP) is a potent circulating soluble inhibitor of the classical and lectin pathways of complement. In recent years, the relationships between the structure of C4BP and its functions have been elucidated using a combination of computer-based molecular analysis and recombinant DNA technologies. Moreover, two novel functions have recently been ascribed to C4BP. One is the ability of C4BP to localize complement regulatory activity to the surface of apoptotic cells via its interaction with the membrane-binding vitamin K-dependent protein S. The other is the ability of C4BP to act as a survival factor for B cells due to an interaction with CD40. The complement regulatory activity of C4BP is not only beneficial because it is also explored by pathogens such as Neisseria gonorrhoeae, Bordetella pertussis, Streptococcus pyogenes, Escherichia coli K1, and Candida albicans, that bind C4BP to their surfaces. This contributes to the serum resistance and the pathogenicity of these bacteria. In this review, the structural requirements and functional importance of the interactions between C4BP and its various ligands are discussed.
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Affiliation(s)
- Anna M Blom
- The Wallenberg Laboratory, Department of Clinical Chemistry, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden.
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de Paula PF, Barbosa JE, Junior PR, Ferriani VPL, Latorre MRDO, Nudelman V, Isaac L. Ontogeny of complement regulatory proteins - concentrations of factor h, factor I, c4b-binding protein, properdin and vitronectin in healthy children of different ages and in adults. Scand J Immunol 2003; 58:572-7. [PMID: 14629629 DOI: 10.1046/j.1365-3083.2003.01326.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previous studies of human in vivo complement protein levels have only compared data for neonates with that from adult sera. Here, we establish the normal concentration ranges of the following complement regulatory proteins in healthy Brazilian children of different age groups (neonates: 1 month-1 year, 1-6 years and 6-13 years) and in adults: factor H (fH), factor I (fI), C4b-binding protein (C4 BP), properdin and vitronectin. We found that the concentrations of fH, fI, properdin and vitronectin in neonates are significantly lower than in adults. Remarkably, the concentration of C4 BP is below the method resolution (<50 micro g/ml) in 76% of the sera from neonates, while adults presented 199-532 microg/ml of C4 BP in their sera. The concentration of properdin in the sera from neonates and up to 1-year-old children was less than that observed in older children. Adults presented vitronectin levels significantly higher than all the other age groups in the study. No significant sex differences in the concentrations of all the studied regulatory proteins were detected. This study reveals the ontogeny of complement system in greater detail than previously available and may point to the reasons why neonates have higher susceptibility to develop life-threatening pyogenic infections. These reference values will be of use in clinical and laboratory investigations of disorders associated with low levels of these regulatory proteins.
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Affiliation(s)
- P F de Paula
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
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16
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Brodeur SR, Angelini F, Bacharier LB, Blom AM, Mizoguchi E, Fujiwara H, Plebani A, Notarangelo LD, Dahlback B, Tsitsikov E, Geha RS. C4b-binding protein (C4BP) activates B cells through the CD40 receptor. Immunity 2003; 18:837-48. [PMID: 12818164 DOI: 10.1016/s1074-7613(03)00149-3] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We demonstrate that the alpha chain of human C4b binding protein (C4BP) binds directly to CD40 on human B cells at a site that differs from that used by CD40 ligand. C4BP induces proliferation, upregulation of CD54 and CD86 expression, and IL4-dependent IgE isotype switching in normal B cells but not in B cells from patients with CD40 or IKKgamma/NEMO deficiencies. Furthermore, C4BP colocalized with B cells in the germinal centers of human tonsils. These observations suggest that C4BP is an activating ligand for CD40 and establish a novel interface between complement and B cell activation.
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Affiliation(s)
- Scott R Brodeur
- Division of Immunology, Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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17
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Friese MA, Hellwage J, Jokiranta TS, Meri S, Müller-Quernheim HJ, Peter HH, Eibel H, Zipfel PF. Different regulation of factor H and FHL-1/reconectin by inflammatory mediators and expression of the two proteins in rheumatoid arthritis (RA). Clin Exp Immunol 2000; 121:406-15. [PMID: 10931160 PMCID: PMC1905714 DOI: 10.1046/j.1365-2249.2000.01285.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Factor H and the FHL-1/reconectin protein are two human plasma proteins that act as important regulators of the alternative complement pathway. Each protein is encoded by a unique transcript, but both mRNAs are derived from the factor H gene by means of alternative processing. In order to address potential functional differences between the two proteins we analysed their expression in hepatic and non-hepatic cells and studied their regulation by inflammatory mediators. We demonstrate that factor H and FHL-1/reconectin transcripts which are regulated by the same gene promoter and are initiated at the same transcription start site are differently expressed. Expression of the molecules is induced and regulated by the inflammatory mediators interferon-gamma (IFN-gamma) and the anti-inflammatory glucocorticoid dexamethasone. Both factor H and FHL-1/reconectin are expressed and secreted by synovial fibroblasts and are present in synovial fluid derived from patients suffering from rheumatoid or reactive arthritis. The local synthesis in synovial fibroblasts and their induction by IFN-gamma and dexamethasone, but not by tumour necrosis factor-alpha, suggests for each of the two complement regulators a protective role in RA.
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Affiliation(s)
- M A Friese
- Research Group of Biomolecular Medicine, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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18
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Interferon-gamma improves splicing efficiency of CYBB gene transcripts in an interferon-responsive variant of chronic granulomatous disease due to a splice site consensus region mutation. Blood 2000. [DOI: 10.1182/blood.v95.11.3548.011k36_3548_3554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
X-linked chronic granulomatous disease (CGD) derives from defects in the CYBB gene, which encodes the gp91-phox component of NADPH oxidase. We studied the molecular basis of the disease in a kindred with variant CGD, due to a single base substitution at the sixth position of CYBB first intron. The patients' phagocytes have been shown previously to greatly increase superoxide release in response to interferon-gamma (IFN-γ) in vitro and in vivo. We examined CYBB gene expression in an Epstein-Barr virus (EBV)-transformed B-cell line from 1 patient in this kindred. These cells showed markedly decreased levels of CYBB transcripts in total RNA (5% of normal) and nuclear RNA (1.4% of normal), despite equal CYBB transcription rates in the CGD and control cells. Incubation with IFN-γ produced a 3-fold increase in CYBBtotal messenger RNA (mRNA) levels in the patient's cells, and decreased nuclear transcripts to undetectable levels. Reverse transcriptase–polymerase chain reaction analysis of RNA splicing revealed a preponderance of unspliced CYBB transcripts in the patient's nuclear RNA. In vitro incubation with IFN-γ increased by 40% the ratio of spliced relative to unspliced CYBB mRNA in nuclei from the CGD B-cell line. Total RNA harvested from the same patient's monocytes, on and off therapy with IFN-γ, showed a similar improvement in splicing. We conclude that IFN-γ partially corrects a nuclear processing defect due to the intronic mutation in theCYBB gene in this kindred, most likely by augmentation of nuclear export of normal transcripts, and improvement in the fidelity of splicing at the first intron.
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19
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Interferon-gamma improves splicing efficiency of CYBB gene transcripts in an interferon-responsive variant of chronic granulomatous disease due to a splice site consensus region mutation. Blood 2000. [DOI: 10.1182/blood.v95.11.3548] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractX-linked chronic granulomatous disease (CGD) derives from defects in the CYBB gene, which encodes the gp91-phox component of NADPH oxidase. We studied the molecular basis of the disease in a kindred with variant CGD, due to a single base substitution at the sixth position of CYBB first intron. The patients' phagocytes have been shown previously to greatly increase superoxide release in response to interferon-gamma (IFN-γ) in vitro and in vivo. We examined CYBB gene expression in an Epstein-Barr virus (EBV)-transformed B-cell line from 1 patient in this kindred. These cells showed markedly decreased levels of CYBB transcripts in total RNA (5% of normal) and nuclear RNA (1.4% of normal), despite equal CYBB transcription rates in the CGD and control cells. Incubation with IFN-γ produced a 3-fold increase in CYBBtotal messenger RNA (mRNA) levels in the patient's cells, and decreased nuclear transcripts to undetectable levels. Reverse transcriptase–polymerase chain reaction analysis of RNA splicing revealed a preponderance of unspliced CYBB transcripts in the patient's nuclear RNA. In vitro incubation with IFN-γ increased by 40% the ratio of spliced relative to unspliced CYBB mRNA in nuclei from the CGD B-cell line. Total RNA harvested from the same patient's monocytes, on and off therapy with IFN-γ, showed a similar improvement in splicing. We conclude that IFN-γ partially corrects a nuclear processing defect due to the intronic mutation in theCYBB gene in this kindred, most likely by augmentation of nuclear export of normal transcripts, and improvement in the fidelity of splicing at the first intron.
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20
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Friese MA, Hellwage J, Jokiranta TS, Meri S, Peter HH, Eibel H, Zipfel PF. FHL-1/reconectin and factor H: two human complement regulators which are encoded by the same gene are differently expressed and regulated. Mol Immunol 1999; 36:809-18. [PMID: 10698334 DOI: 10.1016/s0161-5890(99)00101-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
FHL-1/reconectin and factor H are two human complement regulators which are encoded by a single gene. FHL-1/reconectin contains the first 7 of 20 SCR protein domains of factor H and has four unique residues attached to its C-terminal end. The overlapping region of 445 amino acids explains the related complement regulatory functions of the two proteins. However, unique biological functions have also been reported for FHL-1/reconectin, such as cell adhesion and binding to microbial surfaces. Both proteins are synthesised and secreted by the liver. Extrahepatic synthesis occurs in a wide variety of cells, e.g. in monocytes, fibroblasts or neuronal cells. Unexpectedly, FHL-1/reconectin and factor H exhibit distinct expression patterns. This is also observed in disease situations such as in rheumatoid arthritis or malignancies. In rheumatoid arthritis a potentially protective role is suggested by the local synthesis of both FHL-1/reconectin and factor H in synovial fibroblasts and their induction by the anti-inflammatory agent dexamethasone and the cytokine IFN-gamma, but not by TNF-alpha. FHL-1/reconectin is overexpressed in certain tumor cells such as glioblastoma, conferring an exceptional resistance to such cells against complement mediated lysis. Although FHL-1/reconectin and factor H are encoded by a single gene, regulated by the same gene promoter and initiate transcription at the same start site, their transcripts are differently regulated. The putative control levels, which are responsible for this complex regulation, include transcript elongation, RNA processing, alternative splicing and differential poly(A) site selection.
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Affiliation(s)
- M A Friese
- Research Group of Biomolecular Medicine, Bernard Nocht Institute for Tropical Medicine, Hamburg, Germany
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21
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Kain SJ, Maldonado MJ, Vik DP. Analysis of the promoter region of the murine complement factor H gene. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1397:241-6. [PMID: 9582427 DOI: 10.1016/s0167-4781(98)00036-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have used the luciferase system to assay basal promoter activity of the murine factor H gene. Based on the results from luciferase assays with clones of 13 nested deletions, a 242-bp region that appeared to contain an enhancer element was subcloned upstream of a heterologous promoter and was shown to enhance transcription. A 26-bp fragment from this region was shifted in electrophoretic mobility assays, and this fragment contains a consensus sequence for the adenovirus major late transcription factor/upstream stimulatory factor (MLTF/USF). This fragment had enhancing activity in a minimal factor H promoter construct, demonstrating that it is a major enhancer of the factor H gene in murine liver cells.
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Affiliation(s)
- S J Kain
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM 87131-5276, USA
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22
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Collins T, Winkelstein JA, Sullivan KE. Regulation of early complement components C3 and C4 in the synovium. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1996; 3:5-9. [PMID: 8770496 PMCID: PMC170239 DOI: 10.1128/cdli.3.1.5-9.1996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To determine the cytokine inducibility of early complement component (C3 and C4) expression in the synovium, explant tissue was maintained in culture for 7 days. C3 and C4 production was measured by specific enzyme-linked immunosorbent assay, and RNA was evaluated by semiquantitative PCR. The effects of leukemia inhibitory factor (LIF), gamma interferon (IFN-gamma), IFN-alpha, and estrogen on C3 and C4 expression were evaluated. C3 levels were unaffected by 7 days of LIF, IFN-gamma, or IFN-alpha treatment. In contrast, C4 levels were significantly induced in synovial samples treated for 7 days with either IFN-gamma or IFN-alpha. LIF had no effect on C4 levels in this system. Estrogen was found to down-modulate the induction of expression due to IFN-gamma. These data provide evidence for cytokine regulation of C4 expression in the synovium and for estrogen modulation of those effects.
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Affiliation(s)
- T Collins
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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23
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Abstract
Cytokines secreted from antigen-specific T lymphocytes provide important positive and negative control of inflammation through their effects on non-antigen-specific inflammatory leukocytes. These effects often involve modulation of gene expression. Lymphokine-inducible macrophage gene expression is largely controlled at the level of transcription. Multiple cis-acting sequence motifs cooperate with one another to produce patterns of expression that are relatively unique to individual genes. Members of trans-acting transcription factor families, which recognize related regulatory sequence elements, participate frequently in complex protein-protein interactions that generate remarkable complexity in terms of the number of potential combinations and the consequential functional differences exhibited by each combination. Thus, the remarkable plasticity of immune-mediated inflammation derives from combinations of finite numbers of options at several points in the cellular and molecular sequence.
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Affiliation(s)
- Y Ohmori
- Cleveland Clinic Foundation, Department of Immunology, OH 44195
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24
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Schwaeble W, Huemer HP, Möst J, Dierich MP, Ströbel M, Claus C, Reid KB, Ziegler-Heitbrock HW. Expression of properdin in human monocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 219:759-64. [PMID: 8112326 DOI: 10.1111/j.1432-1033.1994.tb18555.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Properdin is the only known positive regulator of the alternative pathway of complement activation. Northern blot analysis of cell lines derived from fibroblasts, B-cells, hepatoma cells, and cells of the monocyte-macrophage lineage revealed properdin expression only in the myelomonocytic cell line HL-60, in the monoblastic cell line U-937 and in the monocytic line Mono Mac 6. Culture of Mono Mac 6 cells for 24 h with phorbol 12-myristate 13-acetate, bacterial lipopolysaccharide and the cytokines interleukin-1 beta and tumour necrosis factor-alpha enhanced mRNA abundance, with the strongest effect (tenfold) being observed with the lipopolysaccharide. In contrast, recombinant interferon-gamma consistently halved properdin mRNA abundance. The same pattern was found for the secretion of properdin as detected by ELISA of Mono Mac 6 supernatants. The suppressive effect of interferon-gamma on properdin mRNA abundance was also demonstrated for primary blood monocytes. The data suggest that the expression and secretion of this complement regulatory protein by monocytes is differentially regulated by cytokines and link the immune response with alternative pathway activation.
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Affiliation(s)
- W Schwaeble
- Department of Immunology, University of Leicester, England
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25
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Abstract
Mononuclear phagocytes are an important in vivo source of a wide range of complement components. They are able to rapidly up-regulate or down-regulate complement synthesis in response to many different pharmacological and biological stimuli. This ability is likely to make a significant contribution to maintaining host defences particularly in peripheral tissues. The important role of molecular biology in the study of complement biosynthesis by mononuclear phagocytes will be emphasised.
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Affiliation(s)
- A R McPhaden
- Department of Cardiovascular Pathology, Texas Heart Institute, Houston 77201
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26
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Seelen MA, Brooimans RA, van der Woude FJ, van Es LA, Daha MR. IFN-gamma mediates stimulation of complement C4 biosynthesis in human proximal tubular epithelial cells. Kidney Int 1993; 44:50-7. [PMID: 8355466 DOI: 10.1038/ki.1993.212] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The liver has been presumed to be the main source of complement deposited in inflammatory lesions such as in glomerulonephritis. In a previous study, however, it was demonstrated that renal tubular cells synthesize C3 in vitro. Furthermore, it was shown by others that C4 gene transcripts were detectable in situ in renal tubular cells. Therefore studies were initiated to investigate the synthesis of C4 by proximal tubular epithelial cells (PTEC) in vitro. Biosynthetic labeling experiments showed de novo synthesis of C4 by PTEC. The synthesis of C4 by PTEC and its regulation by IFN-gamma was fully inhibitable by the addition of cycloheximide, indicating that protein synthesis is required for an increase in C4 secretion. Addition of increasing concentrations of IFN-gamma enhanced the production of C4 by PTEC in a dose dependent fashion, with a 2.5-fold maximum. Kinetic experiments demonstrated higher levels of C4 production when stimulated with IFN-gamma for up to 72 hours. The hemolytic activity of C4 present in culture supernatants of PTEC decreased during the culture period as assessed by hemolytic titration. Northern blot analysis showed no enhancement of C4 mRNA in IFN-gamma treated PTEC, indicating that IFN-gamma regulates C4 production at a post-transcriptional level. Antibody blocking experiments confirmed that regulation of C4 production was directly mediated by IFN-gamma. From this study it was concluded that renal cells are able to synthesize complement components that could possibly play a role in inflammatory responses evolving in the kidney.
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Affiliation(s)
- M A Seelen
- Department of Nephrology, University Hospital Leiden, The Netherlands
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27
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Complete structure of the murine C4b-binding protein gene and regulation of its expression by dexamethasone. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)88715-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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28
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Tsukamoto H, Nagasawa K, Yoshizawa S, Tada Y, Ueda A, Ueda Y, Niho Y. Synthesis and regulation of the fourth component of complement (C4) in the human monocytic cell line U937: comparison with that of the third component of complement (C3). Immunol Suppl 1992; 75:565-9. [PMID: 1592431 PMCID: PMC1384831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Production of the fourth component of complement (C4) by the human monocytic cell line U937 and its regulation were investigated in comparison with the production of the third component of complement (C3) in a cell culture system. Although no detectable C4 was produced by U937 without stimulation, U937 was induced by recombinant interferon-gamma (IFN-gamma) to synthesize C4 in a dose- and time-dependent fashion. The production of C4 was reversibly inhibited by cycloheximide, indicating that it resulted from de novo synthesis. The C4 synthesized by U937 cells was functionally active as assessed by haemolytic assay. SDS-PAGE following biosynthetic labelling showed that subunit structure of C4 synthesized by U937 cells was identical with that of plasma C4 but that molecular weight of alpha-chain was greater than that of plasma C4. We compared the regulation of C4 synthesis with that of C3 synthesis. Although C3 synthesis by U937 cells was enhanced by IFN-gamma, lipopolysaccharide (LPS) and phorbol myristate acetate (PMA), C4 synthesis was induced only by IFN-gamma. LPS and IFN-gamma induced a synergistic increase in C3 synthesis by U937 cells. U937 cells incubated with LPS and IFN-gamma synthesized a greater amount of C4 than those incubated with IFN-gamma alone. Thus it was demonstrated that the synthesis of C3 and C4 was independently regulated. This study shows that the U937 cell line provides a useful model for studies on the synthesis of complement proteins and on the regulation of complement production.
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Affiliation(s)
- H Tsukamoto
- First Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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29
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Lemercier C, Julen N, Coulpier M, Dauchel H, Ozanne D, Fontaine M, Ripoche J. Differential modulation by glucocorticoids of alternative complement protein secretion in cells of the monocyte/macrophage lineage. Eur J Immunol 1992; 22:909-15. [PMID: 1532362 DOI: 10.1002/eji.1830220405] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of the synthetic glucocorticoid dexamethasone (DXM) on the secretion by human monocytes of alternative complement proteins C3, factor B and factor H was investigated. Results indicated that DXM modulates this secretion in a direction which would be consistent with its anti-inflammatory properties. DXM, at therapeutic concentrations, had a suppressive effect on C3 and factor B secretion and a stimulatory effect on factor H secretion by monocytes. This differential modulation on C3, factor B and factor H secretion was similar in mature macrophages. Together with previous studies showing that DXM had a suppressive effect on C3 and factor B secretion and a stimulatory effect on factor H secretion by human endothelial cells, our results indicate that DXM appears to have the general property of regulating local production of complement components so as to control complement activation.
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30
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Lappin DF, Guc D, Hill A, McShane T, Whaley K. Effect of interferon-gamma on complement gene expression in different cell types. Biochem J 1992; 281 ( Pt 2):437-42. [PMID: 1531292 PMCID: PMC1130704 DOI: 10.1042/bj2810437] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have studied the expression of the complement components C2, C3, factor B, C1 inhibitor (C1-inh), C4-binding protein (C4-bp) and factor H in human peripheral blood monocytes, skin fibroblasts, umbilical vein endothelial cells (HUVEC) and the human hepatoma cell line G2 (Hep G2) in the absence and the presence of interferon-gamma (IFN-gamma). E.l.i.s.a. performed on culture fluids, run-on transcription assays, Northern blot and double-dilution dot-blot techniques confirmed that monocytes expressed all six components, whereas fibroblasts, HUVEC and HepG2 each expressed five of the six components. Fibroblasts and HUVEC did not synthesize C4-bp, and Hep G2 did not produce factor H. In addition to these differences, the synthesis rates of C3, C1-inh and factor H were not the same in all cell types. However, the synthesis rates of C2 and factor B were similar in all four cell types. The half-lives of the mRNAs were shorter in monocytes than in other cell types. Monocyte factor H mRNA had a half-life of 12 min in monocytes, compared with over 3 h in fibroblasts and HUVEC. The instability of factor H mRNA in monocytes may contribute to their low factor H secretion rate. IFN-gamma produced dose-dependent stimulation of C2, factor B, C1-inh, C4-bp and factor H synthesis by all cell types expressing these proteins, but decreased C3 synthesis in all four cell types. Cell-specific differences in the response to IFN-gamma were observed. The increased rates of transcription of the C1-inh and factor H genes in HUVEC were greater than in other cell types, while the increased rate of transcription of the C2, factor B and C1-inh genes in Hep G2 cells was less than in other cell types. IFN-gamma did not affect the stability of C3, factor H or C4 bp mRNAs, but increased the stability of factor B and C1-inh mRNAs and decreased the stability of C2 mRNA. Although these changes occurred in all four cell types studied, the half-life of C1-inh mRNA in monocytes was increased almost 4-fold, whereas the increases in the other cell types were less than 30%. These data show that the constitutive synthesis rates of complement components may vary in the different cell types. They also show that the degree of change in synthesis rates in response to IFN-gamma in each of the cell types often varies due to differences in transcriptional response, sometimes in association with changes in mRNA stability.
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Affiliation(s)
- D F Lappin
- Department of Pathology, Western Infirmary, Glasgow, U.K
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31
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Hessing M. The interaction between complement component C4b-binding protein and the vitamin K-dependent protein S forms a link between blood coagulation and the complement system. Biochem J 1991; 277 ( Pt 3):581-92. [PMID: 1831349 PMCID: PMC1151280 DOI: 10.1042/bj2770581] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- M Hessing
- Department of Haematology, University Hospital Utrecht, The Netherlands
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