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Zhang T, Ma N, Wang J, Min X, Wei L, Li K. C5aR2 Deficiency Lessens C5aR1 Distribution and Expression in Neutrophils and Macrophages. J Immunol Res 2024; 2024:2899154. [PMID: 39021433 PMCID: PMC11254461 DOI: 10.1155/2024/2899154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 06/05/2024] [Accepted: 06/20/2024] [Indexed: 07/20/2024] Open
Abstract
As another receptor for complement activation product C5a, C5aR2 has been paid much attention these years. Although controversial and complex, its specific signals or roles in modulating the classic receptor C5aR1 have been investigated and gradually revealed. The hypothesis of the heterodimer of C5aR1 and C5aR2 has also been suggested and observed under extremely high C5a concentrations. In this article, we tried to investigate whether C5aR2 would affect C5aR1 expression under normal or inflammatory conditions in WT and C5ar2 -/- mice of C57BL/6 background. We focused on the innate immune cells-neutrophils and macrophages. The mRNA levels of C5ar1 in normal kidney, liver, and the mRNA or protein levels of naïve-bone marrow and peripheral blood leukocytes and peritoneal Mφs were comparable between WT and C5ar2 -/- mice, indicating the technique of C5aR2 knockout did not affect the transcription of its neighboring gene C5aR1. However, the mean fluorescence intensity of surface C5aR1 on naïve circulating C5ar2 -/- neutrophils detected by FACS was reduced, which might be due to the reduced internalization of C5aR1 on C5ar2 -/- neutrophils. In the peritonitis model induced by i.p. injection of thioglycollate, more neutrophils were raised after 10 hr in C5ar2 -/- peritoneal cavity, indicating the antagonism of C5aR2 on C5aR1 signal in neutrophil chemotaxis. After 3 days of thioglycollate injection, the mainly infiltrating macrophages were comparable between WT and C5ar2 -/- mice, but the C5ar1 mRNA and surface or total C5aR1 protein expression were both reduced in C5ar2 -/- macrophages, combined with our previous study of reduced chemokines and cytokines expression in C5ar2 -/- peritoneal macrophages, indicating that C5aR2 in macrophages may cooperate with C5aR1 inflammatory signals. Our article found C5aR2 deficiency lessened C5aR1 distribution and expression in neutrophils and macrophages with different functions, indicating C5aR2 might function differently in different cells.
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Affiliation(s)
- Ting Zhang
- Department of PathologyThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
- Core Research LaboratoryThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
| | - Ning Ma
- Core Research LaboratoryThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
| | - Jiaxing Wang
- Institute of HematologySchool of MedicineNorthwest University, Xi'an 710069, China
| | - Xiaoyun Min
- Core Research LaboratoryThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
| | - Linlin Wei
- Core Research LaboratoryThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
| | - Ke Li
- Core Research LaboratoryThe Second Affiliated HospitalSchool of MedicineXi'an Jiaotong University, Xi'an 710004, China
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2
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Li XX, Fung JN, Clark RJ, Lee JD, Woodruff TM. Cell-intrinsic C5a synergizes with Dectin-1 in macrophages to mediate fungal killing. Proc Natl Acad Sci U S A 2024; 121:e2314627121. [PMID: 38252818 PMCID: PMC10835034 DOI: 10.1073/pnas.2314627121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
The complement factor C5a is a core effector product of complement activation. C5a, acting through its receptors C5aR1 and C5aR2, exerts pleiotropic immunomodulatory functions in myeloid cells, which is vital for host defense against pathogens. Pattern-recognition receptors (PRRs) are similarly expressed by immune cells as detectors of pathogen-associated molecular patterns. Although there is evidence of cross talk between complement and PRR signaling pathways, knowledge of the full potential for C5a-PRR interaction is limited. In this study, we comprehensively investigated how C5a signaling through C5a receptors can modulate diverse PRR-mediated cytokine responses in human primary monocyte-derived macrophages and observed a powerful, concentration-dependent bidirectional effect of C5a on PRR activities. Unexpectedly, C5a synergized with Dectin-1, Mincle, and STING in macrophages to a much greater extent than TLRs. Notably, we also identified that selective Dectin-1 activation using depleted zymosan triggered macrophages to generate cell-intrinsic C5a, which acted on intracellular and cell surface C5aR1, to help sustain mitochondrial ROS generation, up-regulate TNFα production, and enhance fungal killing. This study adds further evidence to the holistic functions of C5a as a central immunomodulator and important orchestrator of pathogen sensing and killing by phagocytes.
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Affiliation(s)
- Xaria X. Li
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD4072, Australia
| | - Jenny N. Fung
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD4072, Australia
| | - Richard J. Clark
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD4072, Australia
| | - John D. Lee
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD4072, Australia
| | - Trent M. Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD4072, Australia
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3
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Dahmani M, Zhu JC, Cook JH, Riley SP. Anaphylatoxin signaling activates macrophages to control intracellular Rickettsia proliferation. Microbiol Spectr 2023; 11:e0253823. [PMID: 37855623 PMCID: PMC10714731 DOI: 10.1128/spectrum.02538-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/11/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE Pathogenic Rickettsia species are extremely dangerous bacteria that grow within the cytoplasm of host mammalian cells. In most cases, these bacteria are able to overpower the host cell and grow within the protected environment of the cytoplasm. However, a dramatic conflict occurs when Rickettsia encounter innate immune cells; the bacteria can "win" by taking over the host, or the bacteria can "lose" if the host cell efficiently fights the infection. This manuscript examines how the immune complement system is able to detect the presence of Rickettsia and alert nearby cells. Byproducts of complement activation called anaphylatoxins are signals that "activate" innate immune cells to mount an aggressive defensive strategy. This study enhances our collective understanding of the innate immune reaction to intracellular bacteria and will contribute to future efforts at controlling these dangerous infections.
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Affiliation(s)
- Mustapha Dahmani
- Department of Veterinary Medicine, University of Maryland-College Park, College Park, Maryland, USA
| | - Jinyi C. Zhu
- Department of Veterinary Medicine, University of Maryland-College Park, College Park, Maryland, USA
| | - Jack H. Cook
- Department of Veterinary Medicine, University of Maryland-College Park, College Park, Maryland, USA
| | - Sean P. Riley
- Department of Veterinary Medicine, University of Maryland-College Park, College Park, Maryland, USA
- Virginia-Maryland College of Veterinary Medicine, College Park, Maryland, USA
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4
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Wright O, Harris A, Nguyen VD, Zhou Y, Durand M, Jayyaratnam A, Gormley D, O'Neill LAJ, Triantafilou K, Nichols EM, Booty LM. C5aR2 Regulates STING-Mediated Interferon Beta Production in Human Macrophages. Cells 2023; 12:2707. [PMID: 38067135 PMCID: PMC10706378 DOI: 10.3390/cells12232707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/12/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
The complement system mediates diverse regulatory immunological functions. C5aR2, an enigmatic receptor for anaphylatoxin C5a, has been shown to modulate PRR-dependent pro-inflammatory cytokine secretion in human macrophages. However, the specific downstream targets and underlying molecular mechanisms are less clear. In this study, CRISPR-Cas9 was used to generate macrophage models lacking C5aR2, which were used to probe the role of C5aR2 in the context of PRR stimulation. cGAS and STING-induced IFN-β secretion was significantly increased in C5aR2 KO THP-1 cells and C5aR2-edited primary human monocyte-derived macrophages, and STING and IRF3 expression were increased, albeit not significantly, in C5aR2 KO cell lines implicating C5aR2 as a regulator of the IFN-β response to cGAS-STING pathway activation. Transcriptomic analysis by RNAseq revealed that nucleic acid sensing and antiviral signalling pathways were significantly up-regulated in C5aR2 KO THP-1 cells. Altogether, these data suggest a link between C5aR2 and nucleic acid sensing in human macrophages. With further characterisation, this relationship may yield therapeutic options in interferon-related pathologies.
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Affiliation(s)
- Oliver Wright
- Immunology Network, GSK, Stevenage SG1 2NY, UK
- School of Biochemistry and Immunology, Trinity College Dublin, D02 VR66 Dublin, Ireland
| | - Anna Harris
- Immunology Network, GSK, Stevenage SG1 2NY, UK
| | - Van Dien Nguyen
- Systems Immunity Research Institute, Cardiff University, Cardiff CF14 4XW, UK
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XW, UK
| | - You Zhou
- Systems Immunity Research Institute, Cardiff University, Cardiff CF14 4XW, UK
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XW, UK
| | - Maxim Durand
- Immunology Research Unit, GSK, Stevenage SG1 2NY, UK
| | | | | | - Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity College Dublin, D02 VR66 Dublin, Ireland
| | - Kathy Triantafilou
- Immunology Network, GSK, Stevenage SG1 2NY, UK
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff CF14 4XW, UK
| | | | - Lee M Booty
- Immunology Network, GSK, Stevenage SG1 2NY, UK
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Yadav MK, Maharana J, Yadav R, Saha S, Sarma P, Soni C, Singh V, Saha S, Ganguly M, Li XX, Mohapatra S, Mishra S, Khant HA, Chami M, Woodruff TM, Banerjee R, Shukla AK, Gati C. Molecular basis of anaphylatoxin binding, activation, and signaling bias at complement receptors. Cell 2023; 186:4956-4973.e21. [PMID: 37852260 PMCID: PMC7615941 DOI: 10.1016/j.cell.2023.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 07/19/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023]
Abstract
The complement system is a critical part of our innate immune response, and the terminal products of this cascade, anaphylatoxins C3a and C5a, exert their physiological and pathophysiological responses primarily via two GPCRs, C3aR and C5aR1. However, the molecular mechanism of ligand recognition, activation, and signaling bias of these receptors remains mostly elusive. Here, we present nine cryo-EM structures of C3aR and C5aR1 activated by their natural and synthetic agonists, which reveal distinct binding pocket topologies of complement anaphylatoxins and provide key insights into receptor activation and transducer coupling. We also uncover the structural basis of a naturally occurring mechanism to dampen the inflammatory response of C5a via proteolytic cleavage of the terminal arginine and the G-protein signaling bias elicited by a peptide agonist of C3aR identified here. In summary, our study elucidates the innerworkings of the complement anaphylatoxin receptors and should facilitate structure-guided drug discovery to target these receptors in a spectrum of disorders.
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Affiliation(s)
- Manish K Yadav
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Jagannath Maharana
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Ravi Yadav
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA; The Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Shirsha Saha
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Parishmita Sarma
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Chahat Soni
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Vinay Singh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sayantan Saha
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Manisankar Ganguly
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Xaria X Li
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Samanwita Mohapatra
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sudha Mishra
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Htet A Khant
- USC Center of Excellence for Nano-Imaging, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Mohamed Chami
- BioEM Lab, Biozentrum, Universität Basel, Basel, Switzerland
| | - Trent M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ramanuj Banerjee
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
| | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
| | - Cornelius Gati
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA; The Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA; Department of Chemistry, Department of Quantitative and Computational Biology, Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA.
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6
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Santos-López J, de la Paz K, Fernández FJ, Vega MC. Structural biology of complement receptors. Front Immunol 2023; 14:1239146. [PMID: 37753090 PMCID: PMC10518620 DOI: 10.3389/fimmu.2023.1239146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023] Open
Abstract
The complement system plays crucial roles in a wide breadth of immune and inflammatory processes and is frequently cited as an etiological or aggravating factor in many human diseases, from asthma to cancer. Complement receptors encompass at least eight proteins from four structural classes, orchestrating complement-mediated humoral and cellular effector responses and coordinating the complex cross-talk between innate and adaptive immunity. The progressive increase in understanding of the structural features of the main complement factors, activated proteolytic fragments, and their assemblies have spurred a renewed interest in deciphering their receptor complexes. In this review, we describe what is currently known about the structural biology of the complement receptors and their complexes with natural agonists and pharmacological antagonists. We highlight the fundamental concepts and the gray areas where issues and problems have been identified, including current research gaps. We seek to offer guidance into the structural biology of the complement system as structural information underlies fundamental and therapeutic research endeavors. Finally, we also indicate what we believe are potential developments in the field.
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Affiliation(s)
- Jorge Santos-López
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Karla de la Paz
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Research & Development, Abvance Biotech SL, Madrid, Spain
| | | | - M. Cristina Vega
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Seiler DL, Kähler KH, Kleingarn M, Sadik CD, Bieber K, Köhl J, Ludwig RJ, Karsten CM. The complement receptor C5aR2 regulates neutrophil activation and function contributing to neutrophil-driven epidermolysis bullosa acquisita. Front Immunol 2023; 14:1197709. [PMID: 37275893 PMCID: PMC10235453 DOI: 10.3389/fimmu.2023.1197709] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/02/2023] [Indexed: 06/07/2023] Open
Abstract
Introduction The function of the second receptor for the complement cleavage product C5a, C5aR2, is poorly understood and often neglected in the immunological context. Using mice with a global deficiency of C5aR2, we have previously reported an important role of this receptor in the pathogenesis of the neutrophil-driven autoimmune disease epidermolysis bullosa acquisita (EBA). Based on in vitro analyses, we hypothesized that the absence of C5aR2 specifically on neutrophils is the cause of the observed differences. Here, we report the generation of a new mouse line with a LysM-specific deficiency of C5aR2. Methods LysM-specific deletion of C5aR2 was achieved by crossing LysMcre mice with tdTomato-C5ar2fl/fl mice in which the tdTomato-C5ar2 gene is flanked by loxP sites. Passive EBA was induced by subcutaneous injection of rabbit anti-mouse collagen type VII IgG. The effects of targeted deletion of C5ar2 on C5a-induced effector functions of neutrophils were examined in in vitro assays. Results We confirm the successful deletion of C5aR2 at both the genetic and protein levels in neutrophils. The mice appeared healthy and the expression of C5aR1 in bone marrow and blood neutrophils was not negatively affected by LysM-specific deletion of C5aR2. Using the antibody transfer mouse model of EBA, we found that the absence of C5aR2 in LysM-positive cells resulted in an overall amelioration of disease progression, similar to what we had previously found in mice with global deficiency of C5aR2. Neutrophils lacking C5aR2 showed decreased activation after C5a stimulation and increased expression of the inhibitory Fcγ receptor FcγRIIb. Discussion Overall, with the data presented here, we confirm and extend our previous findings and show that C5aR2 in neutrophils regulates their activation and function in response to C5a by potentially affecting the expression of Fcγ receptors and CD11b. Thus, C5aR2 regulates the finely tuned interaction network between immune complexes, Fcγ receptors, CD11b, and C5aR1 that is important for neutrophil recruitment and sustained activation. This underscores the importance of C5aR2 in the pathogenesis of neutrophil-mediated autoimmune diseases.
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Affiliation(s)
- Daniel L. Seiler
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Katja H. Kähler
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Marie Kleingarn
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Christian D. Sadik
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany
- Department of Dermatology, Allergology and Venerology, University Hospital Schleswig-Holstein, Lübeck, Germany
| | - Katja Bieber
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany
- Department of Dermatology, Allergology and Venerology, University Hospital Schleswig-Holstein, Lübeck, Germany
- Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Centre, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Ralf J. Ludwig
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany
- Department of Dermatology, Allergology and Venerology, University Hospital Schleswig-Holstein, Lübeck, Germany
- Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Christian M. Karsten
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
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8
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Trambas IA, Coughlan MT, Tan SM. Therapeutic Potential of Targeting Complement C5a Receptors in Diabetic Kidney Disease. Int J Mol Sci 2023; 24:ijms24108758. [PMID: 37240105 DOI: 10.3390/ijms24108758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Diabetic kidney disease (DKD) affects 30-40% of patients with diabetes and is currently the leading cause of end-stage renal disease (ESRD). The activation of the complement cascade, a highly conserved element of the innate immune system, has been implicated in the pathogenesis of diabetes and its complications. The potent anaphylatoxin C5a is a critical effector of complement-mediated inflammation. Excessive activation of the C5a-signalling axis promotes a potent inflammatory environment and is associated with mitochondrial dysfunction, inflammasome activation, and the production of reactive oxygen species. Conventional renoprotective agents used in the treatment of diabetes do not target the complement system. Mounting preclinical evidence indicates that inhibition of the complement system may prove protective in DKD by reducing inflammation and fibrosis. Targeting the C5a-receptor signaling axis is of particular interest, as inhibition at this level attenuates inflammation while preserving the critical immunological defense functions of the complement system. In this review, the important role of the C5a/C5a-receptor axis in the pathogenesis of diabetes and kidney injuries will be discussed, and an overview of the status and mechanisms of action of current complement therapeutics in development will be provided.
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Affiliation(s)
- Inez A Trambas
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Melinda T Coughlan
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Sih Min Tan
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
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9
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Wu KC, Condon ND, Hill TA, Reid RC, Fairlie DP, Lim J. Ras-Related Protein Rab5a Regulates Complement C5a Receptor Trafficking, Chemotaxis, and Chemokine Secretion in Human Macrophages. J Innate Immun 2023; 15:468-484. [PMID: 36882040 PMCID: PMC10105068 DOI: 10.1159/000530012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/01/2023] [Indexed: 03/09/2023] Open
Abstract
Complement activation and Rab GTPase trafficking are commonly observed in inflammatory responses. Recruitment of innate immune cells to sites of infection or injury and secretion of inflammatory chemokines are promoted by complement component 5a (C5a) that activates the cell surface protein C5a receptor1 (C5aR1). Persistent activation can lead to a myriad of inflammatory and autoimmune diseases. Here, we demonstrate that the mechanism of C5a induced chemotaxis of human monocyte-derived macrophages (HMDMs) and their secretion of inflammatory chemokines are controlled by Rab5a. We find that C5a activation of the G protein coupled receptor C5aR1 expressed on the surface of HMDMs, recruits β-arrestin2 via Rab5a trafficking, then activates downstream phosphatidylinositol 3-kinase (PI3K)/Akt signaling that culminates in chemotaxis and secretion of pro-inflammatory chemokines from HMDMs. High-resolution lattice light-sheet microscopy on live cells showed that C5a activates C5aR1-GFP internalization and colocalization with Rab5a-tdTomato but not with dominant negative mutant Rab5a-S34N-tdTomato in HEK293 cells. We found that Rab5a is significantly upregulated in differentiated HMDMs and internalization of C5aR1 is dependent on Rab5a. Interestingly, while knockdown of Rab5a inhibited C5aR1-mediated Akt phosphorylation, it did not affect C5aR1-mediated ERK1/2 phosphorylation or intracellular calcium mobilization in HMDMs. Functional analysis using transwell migration and µ-slide chemotaxis assays indicated that Rab5a regulates C5a-induced chemotaxis of HMDMs. Further, C5aR1 was found to mediate interaction of Rab5a with β-arrestin2 but not with G proteins in HMDMs. Furthermore, C5a-induced secretion of pro-inflammatory chemokines (CCL2, CCL3) from HMDMs was attenuated by Rab5a or β-arrestin2 knockdown or by pharmacological inhibition with a C5aR1 antagonist or a PI3K inhibitor. These findings reveal a C5a-C5aR1-β-arrestin2-Rab5a-PI3K signaling pathway that regulates chemotaxis and pro-inflammatory chemokine secretion in HMDMs and suggests new ways of selectively modulating C5a-induced inflammatory outputs.
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Affiliation(s)
- Kai-Chen Wu
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Nicholas D. Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Timothy A. Hill
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Robert C. Reid
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David P. Fairlie
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Junxian Lim
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
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10
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Mechanism of activation and biased signaling in complement receptor C5aR1. Cell Res 2023; 33:312-324. [PMID: 36806352 PMCID: PMC9937529 DOI: 10.1038/s41422-023-00779-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/13/2023] [Indexed: 02/19/2023] Open
Abstract
The complement system plays an important role in the innate immune response to invading pathogens. The complement fragment C5a is one of its important effector components and exerts diverse physiological functions through activation of the C5a receptor 1 (C5aR1) and associated downstream G protein and β-arrestin signaling pathways. Dysfunction of the C5a-C5aR1 axis is linked to numerous inflammatory and immune-mediated diseases, but the structural basis for activation and biased signaling of C5aR1 remains elusive. Here, we present cryo-electron microscopy structures of the activated wild-type C5aR1-Gi protein complex bound to each of the following: C5a, the hexapeptidic agonist C5apep, and the G protein-biased agonist BM213. The structures reveal the landscape of the C5a-C5aR1 interaction as well as a common motif for the recognition of diverse orthosteric ligands. Moreover, combined with mutagenesis studies and cell-based pharmacological assays, we deciphered a framework for biased signaling using different peptide analogs and provided insight into the activation mechanism of C5aR1 by solving the structure of C5aR1I116A mutant-Gi signaling activation complex induced by C089, which exerts antagonism on wild-type C5aR1. In addition, unusual conformational changes in the intracellular end of transmembrane domain 7 and helix 8 upon agonist binding suggest a differential signal transduction process. Collectively, our study provides mechanistic understanding into the ligand recognition, biased signaling modulation, activation, and Gi protein coupling of C5aR1, which may facilitate the future design of therapeutic agents.
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11
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Li XX, Lee JD, Lee HS, Clark RJ, Woodruff TM. TLQP-21 is a low potency partial C3aR activator on human primary macrophages. Front Immunol 2023; 14:1086673. [PMID: 36776827 PMCID: PMC9909341 DOI: 10.3389/fimmu.2023.1086673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023] Open
Abstract
TLQP-21 is a 21-amino acid neuropeptide derived from the VGF precursor protein. TLQP-21 is expressed in the nervous system and neuroendocrine glands, and demonstrates pleiotropic roles including regulating metabolism, nociception and microglial functions. Several possible receptors for TLQP-21 have been identified, with complement C3a receptor (C3aR) being the most commonly reported. However, few studies have characterised the activity of TLQP-21 in immune cells, which represent the major cell type expressing C3aR. In this study, we therefore aimed to define the activity of both human and mouse TLQP-21 on cell signalling in primary human and mouse macrophages. We first confirmed that TLQP-21 induced ERK signalling in CHO cells overexpressing human C3aR, and did not activate human C5aR1 or C5aR2. TLQP-21 mediated ERK signalling was also observed in primary human macrophages. However, the potency for human TLQP-21 was 135,000-fold lower relative to C3a, and only reached 45% at the highest dose tested (10 μM). Unlike in humans, mouse TLQP-21 potently triggered ERK signalling in murine macrophages, reaching near full activation, but at ~10-fold reduced potency compared to C3a. We further confirmed the C3aR dependency of the TLQP-21 activities. Our results reveal significant discrepancy in TLQP-21 C3aR activity between human and murine receptors, with mouse TLQP-21 being consistently more potent than the human counterpart in both systems. Considering the supraphysiological concentrations of hTLQP-21 needed to only partially activate macrophages, it is likely that the actions of TLQP-21, at least in these immune cells, may not be mediated by C3aR in humans.
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Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - John D Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Han S Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
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12
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Das A, Gupta PK, Rana S. C5aR2 receptor: The genomic twin of the flamboyant C5aR1. J Cell Biochem 2022; 123:1841-1856. [PMID: 35977039 DOI: 10.1002/jcb.30320] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/05/2022] [Indexed: 11/12/2022]
Abstract
The complement fragment C5a is one of the most potent proinflammatory glycoproteins liberated by the activation of the biochemical cascade of the complement system. C5a is established to interact with a set of genomically related transmembrane receptors, like C5aR1 (CD88, C5aR) and C5aR2 (GPR77, C5L2) with comparable affinity. The C5aR1 is a classical G-protein-coupled receptor (GPCR), whereas C5aR2 is a nonclassical GPCR that tailors immune cell activity potentially through β-arrestins rather than G-proteins. Currently, the exact function of the C5aR2 is actively debated in the context of C5aR1, even though both C5aR1 and C5aR2 are coexpressed on myriads of tissues. The functional relevance of C5aR2 appears to be context-dependent compared to the C5aR1, which has received enormous attention for its role in both acute and chronic inflammatory diseases. In addition, the structure of C5aR2 and its interaction specificity toward C5a is not structurally elucidated in the literature so far. The current study has attempted to close the gap by generating highly refined model structures of C5aR2, respectively in free (inactive), complexed to C-terminal peptide of C5a (meta-active) and the C5a (active), embedded to a model palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer. The computational modeling and the 1.5-μs molecular dynamics data presented in the current study are expected to further enrich the understanding of C5a-C5aR2 interaction compared to C5a-C5aR1, which will surely help in elaborating the currently debated biological function of C5aR2 better in the foreseeable future.
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Affiliation(s)
- Aurosikha Das
- Chemical Biology Laboratory, School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Odisha, Bhubaneswar, India
| | - Pulkit K Gupta
- Chemical Biology Laboratory, School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Odisha, Bhubaneswar, India
| | - Soumendra Rana
- Chemical Biology Laboratory, School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Odisha, Bhubaneswar, India
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13
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Xu W, Kumar V, Cui CS, Li XX, Whittaker AK, Xu ZP, Smith MT, Woodruff TM, Han FY. Success in navigating hurdles to oral delivery of a bioactive peptide complement antagonist through use of nanoparticles to increase bioavailability and in vivo efficacy. ADVANCED THERAPEUTICS 2022. [DOI: 10.1002/adtp.202200109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Weizhi Xu
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
- Australian Institute for Bioengineering and Nanotechnology The University of Queensland Queensland QLD Australia
| | - Vinod Kumar
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
| | - Cedric S. Cui
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
| | - Xaria X. Li
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
| | - Andrew K. Whittaker
- Australian Institute for Bioengineering and Nanotechnology The University of Queensland Queensland QLD Australia
| | - Zhi Ping Xu
- Australian Institute for Bioengineering and Nanotechnology The University of Queensland Queensland QLD Australia
| | - Maree T. Smith
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
| | - Trent M. Woodruff
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
| | - Felicity Y Han
- School of Biomedical Sciences Faculty of Medicine The University of Queensland Queensland QLD Australia
- Australian Institute for Bioengineering and Nanotechnology The University of Queensland Queensland QLD Australia
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14
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Schäfer N, Grässel S. Involvement of complement peptides C3a and C5a in osteoarthritis pathology. Peptides 2022; 154:170815. [PMID: 35598724 DOI: 10.1016/j.peptides.2022.170815] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/10/2022] [Accepted: 05/17/2022] [Indexed: 12/28/2022]
Abstract
Osteoarthritis (OA) affects more than 500 million people worldwide and is among the five diseases in Germany causing the highest suffering of the patients and cost for the society. The quality of life of OA patients is severely compromised, and adequate therapy is lacking owing to a knowledge gap that acts as a major barrier to finding safe and effective solutions. Chronic, low-grade inflammation plays a central role in OA pathogenesis and is associated with both OA pain and disease progression. Innate immune pathways, such as the complement- and pattern-recognition receptor pathways, are pivotal to the inflammation in OA and key components of the innate immune system implicated in OA include DAMP-TLR signaling, the complement system, carboxypeptidase B (CPB), and mononuclear cells. Anaphylatoxins C3a and C5a are small polypeptides (77 and 74 amino acids, respectively) which are released by proteolytic cleavage of the complement components C3 and C5. The alternative complement pathway seems to play a crucial role in OA pathogenesis as these complement components, mostly C3 and its activation peptide C3a, were detected at high levels in osteoarthritic cartilage, synovial membrane, and cultured chondrocytes. Targeting the complement system by using anti-complement drugs as a therapeutic option bears the risk of major side effects such as increasing the risk of infection, interfering with cell regeneration and metabolism, and suppressing the clearance of immune complexes. Despite those adverse effects, several synthetic complement peptide antagonists show promising effects in ameliorating inflammatory cell responses also in joint tissues.
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Affiliation(s)
- Nicole Schäfer
- Experimental Orthopaedics, Centre for Medical Biotechnology (ZMB), Bio Park 1, University of Regensburg, Germany
| | - Susanne Grässel
- Experimental Orthopaedics, Centre for Medical Biotechnology (ZMB), Bio Park 1, University of Regensburg, Germany; Department of Orthopaedic Surgery, University of Regensburg, Germany.
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15
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Schanzenbacher J, Köhl J, Karsten CM. Anaphylatoxins spark the flame in early autoimmunity. Front Immunol 2022; 13:958392. [PMID: 35958588 PMCID: PMC9358992 DOI: 10.3389/fimmu.2022.958392] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
The complement system (CS) is an ancient and highly conserved part of the innate immune system with important functions in immune defense. The multiple fragments bind to specific receptors on innate and adaptive immune cells, the activation of which translates the initial humoral innate immune response (IR) into cellular innate and adaptive immunity. Dysregulation of the CS has been associated with the development of several autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ANCA-associated vasculitis, and autoimmune bullous dermatoses (AIBDs), where complement drives the inflammatory response in the effector phase. The role of the CS in autoimmunity is complex. On the one hand, complement deficiencies were identified as risk factors to develop autoimmune disorders. On the other hand, activation of complement can drive autoimmune responses. The anaphylatoxins C3a and C5a are potent mediators and regulators of inflammation during the effector phase of autoimmunity through engagement of specific anaphylatoxin receptors, i.e., C3aR, C5aR1, and C5aR2 either on or in immune cells. In addition to their role in innate IRs, anaphylatoxins regulate humoral and cellular adaptive IRs including B-cell and T-cell activation, differentiation, and survival. They regulate B- and T-lymphocyte responses either directly or indirectly through the activation of anaphylatoxin receptors via dendritic cells that modulate lymphocyte function. Here, we will briefly review our current understanding of the complex roles of anaphylatoxins in the regulation of immunologic tolerance and the early events driving autoimmunity and the implications of such regulation for therapeutic approaches that target the CS.
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Affiliation(s)
- Jovan Schanzenbacher
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
- Division of Immunobiology, Cincinnati Childrens Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christian M. Karsten
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
- *Correspondence: Christian M. Karsten,
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16
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Sahu RK, Xavier S, Chauss D, Wang L, Chew C, Taylor RP, Stallcup WB, Ma JZ, Kazemian M, Afzali B, Köhl J, Portilla D. Folic acid-mediated fibrosis is driven by C5a receptor 1-mediated activation of kidney myeloid cells. Am J Physiol Renal Physiol 2022; 322:F597-F610. [PMID: 35379003 DOI: 10.1152/ajprenal.00404.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that increased expression and activation of kidney cell complement components play an important role in the pathogenesis of renal scarring. Here we used floxed green fluorescent protein (GFP)-C5a receptor 1 (C5aR1) knock-in mice (GFP-C5ar1fl/fl) and the model of Folic acid-induced kidney injury to define the cell types and potential mechanisms by which increased C5aR1 activation leads to fibrosis. Using flow cytometry and confocal microscopy we identified macrophages as the major interstitial cell type showing increased expression of C5aR1 in FA-treated mice. C5ar1fl/fl.Lyz2Cre+/- mice, in which C5aR1 has been specifically deleted in lysozyme M (LysM)-expressing myeloid cells, experienced reduced fibrosis when compared to control C5ar1fl/fl mice. Examination of C5aR1-expressing macrophage transcriptomes by gene set enrichment analysis (GSEA) demonstrated that these cells were enriched in pathways corresponding to the complement cascade, collagen formation and the NABA matrisome, strongly pointing to their critical roles in tissue repair/scarring. Since C5aR1 was also detected in a small population of PDGFBR+ GFP+ cells we develop C5ar1fl/fl.Foxd1Cre+/- mice, in which C5aR1 is deleted specifically in pericytes, and found reduced FA-induced fibrosis. Primary cell cultures of platelet-derived growth factor receptor beta (PDGFRβ)+ pericytes isolated from FA-treated C5ar1fl/fl.Foxd1Cre+/- mice showed reduced secretion of several cytokines, including IL-6, and macrophage inflammatory proteins (MIP) 2, when compared to pericytes isolated from FA-treated control GFP-C5ar1fl/fl mice. Collectively, these data imply that the C5a/C5aR1 axis activation primarily in interstitial cells contributes to the development of renal fibrosis.
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Affiliation(s)
- Ranjit K Sahu
- PO Box 800133, grid.27755.32University of Virginia, Charlottesville, VA, United States
| | - Sandhya Xavier
- Department of Medicine, grid.27755.32University of Virginia, Charlottesville, VA, United States
| | - Daniel Chauss
- Immunoregulation Section, Kidney Diseases Branch, grid.419635.cNational Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States
| | - Luopin Wang
- Department of Computer Science, grid.169077.ePurdue University West Lafayette, West Lafayette, IN, United States
| | - Claude Chew
- Flow Cytometry Core, grid.27755.32University of Virginia, Charlottesville, VA, United States
| | | | - William B Stallcup
- Tumor Metastasis and Caner Immunology Program, grid.479509.6Sanford Burnham Prebys Medical Discovery Institute
| | - Jennie Z Ma
- Public Health Sciences, grid.27755.32University of Virginia, Charlottesville, VA, United States
| | - Majid Kazemian
- Departments of Biochemistry and Computer Science, grid.169077.ePurdue University West Lafayette, IN, United States
| | - Behdad Afzali
- Immunoregulation Section, Kidney Diseases Branch, grid.419635.cNational Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States
| | - Jörg Köhl
- Division of Immunobiology, Institute for Systemic Inflammation Research
| | - Didier Portilla
- Medicine/Nephrology, grid.27755.32University of Virginia, Charlottesville, United States
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17
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Seiler DL, Kleingarn M, Kähler KH, Gruner C, Schanzenbacher J, Ehlers-Jeske E, Kenno S, Sadik CD, Schmidt E, Bieber K, Köhl J, Ludwig RJ, Karsten CM. C5aR2 deficiency ameliorates inflammation in murine epidermolysis bullosa acquisita by regulating FcγRIIb expression on neutrophils. J Invest Dermatol 2022; 142:2715-2723.e2. [PMID: 35007559 DOI: 10.1016/j.jid.2021.12.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 12/06/2021] [Accepted: 12/17/2021] [Indexed: 11/26/2022]
Abstract
Epidermolysis bullosa acquisita (EBA) is a rare blistering skin disease induced by autoantibodies directed against type VII collagen (COL7). Transfer of antibodies against murine COL7 (mCOL7) into mice mimics the effector phase of EBA and results in a subepidermal blistering phenotype. Activation of the complement system, and especially the C5a/C5aR1 axis driving neutrophil activation, are critical for EBA pathogenesis. However, the role of the alternative C5a receptor, C5aR2, which is commonly thought to be more immunosuppressive, in the pathogenesis of EBA is still elusive. Therefore, we sought to delineate the functional relevance of C5aR2 during the effector phase of EBA. Unexpectedly, C5aR2-deficient (C5ar2-/-) mice showed an attenuated disease phenotype, suggesting a pathogenic contribution of C5aR2 to disease progression. In vitro, C5ar2-/- neutrophils exhibited significantly reduced (Ca2+)i flux, reactive oxygen species release, and migratory capacity when activated with immune complexes or exposed to C5a. These functions were completely absent when C5ar1-/- neutrophils were activated. Moreover, C5aR2 deficiency more than tripled FcγRIIb expression on neutrophils thus lowering the A/I ratio of FcγRs and impeding the sustainment of inflammation. Collectively, we demonstrate here a pro-inflammatory contribution of C5aR2 to the pathogenesis of antibody-induced tissue damage in experimental EBA.
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Affiliation(s)
- Daniel L Seiler
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany; Complement and Inflammation Research Section (CIRS), National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Marie Kleingarn
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Katja H Kähler
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Caroline Gruner
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Jovan Schanzenbacher
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Elvira Ehlers-Jeske
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Samyr Kenno
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany
| | - Christian D Sadik
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany; Department of Dermatology, Allergy, and Venereology, University of Lübeck, Lübeck, Germany
| | - Enno Schmidt
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany; Department of Dermatology, Allergy, and Venereology, University of Lübeck, Lübeck, Germany; Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Katja Bieber
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany; Department of Dermatology, Allergy, and Venereology, University of Lübeck, Lübeck, Germany; Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany; Division of Immunobiology, Cincinnati Children's Hospital Medical Centre, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Ralf J Ludwig
- Center for Research on Inflammation of the Skin (CRIS), University of Lübeck, Lübeck, Germany; Department of Dermatology, Allergy, and Venereology, University of Lübeck, Lübeck, Germany; Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany
| | - Christian M Karsten
- Institute for Systemic Inflammation Research (ISEF), University of Lübeck, Lübeck, Germany.
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18
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Li XX, Gorman DM, Lee JD, Clark RJ, Woodruff TM. Unexpected Off-Target Activities for Recombinant C5a in Human Macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:133-142. [PMID: 34853076 DOI: 10.4049/jimmunol.2100444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
The anaphylatoxin C5a is core effector of complement activation. C5a exerts potent proinflammatory and immunomodulatory actions through interacting with its C5a receptors, C5aR1 and C5aR2, modulating multiple signaling and functional activities of immune cells. Native C5a contains a large N-linked glycosylation site at Asn64, which accounts for up to 25% of its m.w. To date, the vast majority of published studies examining C5a are performed using Escherichia coli-generated recombinant C5a, which is readily available from numerous commercial suppliers, but lacks this glycosylation moiety. However, a plasma-purified "native" form of C5a is also commercially available. The different size and glycosylation of these two C5a versions could have functional implications. Therefore, the current study aimed to compare recombinant human C5a to purified plasma-derived human C5a in driving the signaling and functional activities of human primary macrophages. We found that both versions of C5a displayed similar potencies at triggering C5aR1- and C5aR2-mediated cell signaling, but elicited distinct functional responses in primary human monocyte-derived macrophages. Multiple commercial sources of recombinant C5a, but not the plasma-purified or a synthetic C5a version, induced human monocyte-derived macrophages to produce IL-6 and IL-10 in a C5a receptor-independent manner, which was driven through Syk and NF-κB signaling and apparently not due to endotoxin contamination. Our results, therefore, offer caution against the sole use of recombinant human C5a, particularly in functional/cytokine assays conducted in human primary immune cells, and suggest studies using recombinant human C5a should be paired with C5aR1 inhibitors or purified/synthetic human C5a to confirm relevant findings.
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Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Declan M Gorman
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - John D Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
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19
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Gorman D, Li XX, Payne CD, Cui CS, Lee JD, Rosengren KJ, Woodruff TM, Clark RJ. Development of Synthetic Human and Mouse C5a: Application to Binding and Functional Assays In Vitro and In Vivo. ACS Pharmacol Transl Sci 2021; 4:1808-1817. [PMID: 34927012 PMCID: PMC8669711 DOI: 10.1021/acsptsci.1c00199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 11/28/2022]
Abstract
The complement activation peptide C5a is a key mediator of inflammation that is associated with numerous immune disorders. C5a binds and activates two seven-transmembrane receptors, C5aR1 and C5aR2. Experimentally, C5a is utilized to investigate C5a receptor biology and to screen for potential C5aR1/C5aR2 therapeutics. Currently, laboratory sources of C5a stem from either isolation of endogenous C5a from human serum or most predominantly via recombinant expression. An alternative approach to C5a production is chemical synthesis, which has several advantages, including the ability to introduce non-natural amino acids and site-specific modifications whilst also maintaining a lower probability of C5a being contaminated with microbial molecules or other endogenous proteins. Here, we describe the efficient synthesis of both human (hC5a) and mouse C5a (mC5a) without the need for ligation chemistry. We validate the synthetic peptides by comparing pERK1/2 signaling in CHO-hC5aR1 cells and primary human macrophages (for hC5a) and in RAW264.7 cells (for mC5a). C5aR2 activation was confirmed by measuring β-arrestin recruitment in C5aR2-transfected HEK293 cells. We also demonstrate the functionalization of synthetic C5a through the introduction of a lanthanide chelating cage to facilitate a screen for the binding of ligands to C5aR1. Finally, we verify that the synthetic ligands are functionally similar to recombinant or native C5a by assessing hC5a-induced neutrophil chemotaxis in vitro and mC5a-mediated neutrophil mobilization in vivo. We propose that the synthetic hC5a and mC5a described herein are valuable alternatives to recombinant or purified C5a for in vitro and in vivo applications and add to the growing complement reagent toolbox.
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Affiliation(s)
- Declan
M. Gorman
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - Xaria X. Li
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - Colton D. Payne
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - Cedric S. Cui
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - John D. Lee
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - K. Johan Rosengren
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
| | - Trent M. Woodruff
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
- Queensland
Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Richard J. Clark
- School
of Biomedical Sciences, The University of
Queensland, Brisbane, Queensland 4072, Australia
- Institute
for Molecular Bioscience, The University
of Queensland, Brisbane, Queensland 4072, Australia
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20
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Pandey S, Kumari P, Baidya M, Kise R, Cao Y, Dwivedi-Agnihotri H, Banerjee R, Li XX, Cui CS, Lee JD, Kawakami K, Maharana J, Ranjan A, Chaturvedi M, Jhingan GD, Laporte SA, Woodruff TM, Inoue A, Shukla AK. Intrinsic bias at non-canonical, β-arrestin-coupled seven transmembrane receptors. Mol Cell 2021; 81:4605-4621.e11. [PMID: 34582793 PMCID: PMC7612807 DOI: 10.1016/j.molcel.2021.09.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/13/2021] [Accepted: 09/02/2021] [Indexed: 12/31/2022]
Abstract
G-protein-coupled receptors (GPCRs), also known as seven transmembrane receptors (7TMRs), typically interact with two distinct signal-transducers, i.e., G proteins and β-arrestins (βarrs). Interestingly, there are some non-canonical 7TMRs that lack G protein coupling but interact with barrs, although an understanding of their transducer coupling preference, downstream signaling, and structural mechanism remains elusive. Here, we characterize two such non-canonical 7TMRs, namely, the decoy D6 receptor (D6R) and the complement C5a receptor subtype 2 (C5aR2), in parallel with their canonical GPCR counterparts. We discover that D6R and C5aR2 efficiently couple to βarrs, exhibit distinct engagement of GPCR kinases (GRKs), and activate non-canonical downstream signaling pathways. We also observe that βarrs adopt distinct conformations for D6R and C5aR2, compared to their canonical GPCR counterparts, in response to common natural agonists. Our study establishes D6R and C5aR2 as βarr-coupled 7TMRs and provides key insights into their regulation and signaling with direct implication for biased agonism.
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Affiliation(s)
- Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Punita Kumari
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Mithu Baidya
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Ryoji Kise
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Yubo Cao
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada
| | - Hemlata Dwivedi-Agnihotri
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Ramanuj Banerjee
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Xaria X Li
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia
| | - Cedric S Cui
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia
| | - John D Lee
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Jagannath Maharana
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Ashutosh Ranjan
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Madhu Chaturvedi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | | | - Stéphane A Laporte
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada; Department of Medicine, McGill University Health Center, McGill University, Montréal, QC H4A 3J1, Canada
| | - Trent M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
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21
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Anaphylatoxin receptor promiscuity for commonly used complement C5a peptide agonists. Int Immunopharmacol 2021; 100:108074. [PMID: 34454293 DOI: 10.1016/j.intimp.2021.108074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/30/2021] [Accepted: 08/11/2021] [Indexed: 11/22/2022]
Abstract
The complement system is an essential component of innate immunity. Its activation generates the effector cleavage proteins, anaphylatoxins C3a and C5a, that exert activity by interacting with three structurally related seven-transmembrane receptors. C3a activates C3aR, whilst C5a interacts with both C5aR1 and C5aR2 with equal potency. Of the three receptors, C5aR1 in particular is considered the most functionally potent inflammatory driver and has been the major target for pharmacological development. Multiple peptidic C5a agonists have been developed to target C5aR1, with the full agonists EP54 (YSFKPMPLaR) and EP67 (YSFKDMP(MeL)aR), and the partial agonist C028 (C5apep, NMe-FKPdChaChadR) being the most commonly utilised in research. Recent studies have indicated that small complement peptide ligands may lack selectivity amongst the three anaphylatoxin receptors, however this has not been uniformly confirmed for these commonly used C5a agonists. In the present study, we therefore characterised the pharmacological activity of EP54, EP67, and C5apep at human C5aR1, C5aR2 and C3aR, by conducting signalling assays in transfected cell lines, and in human primary macrophages. Our results revealed that none of the compounds tested were selective for human C5aR1. Both EP54 and EP67 were potent, full C3aR agonists, and EP54 and C5apep potently and partially activated human C5aR2. Therefore, we caution against the usage of these ligands, particularly EP54 and EP67, as C5a surrogates in C5a/ C5aR research.
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22
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O’Brien RM, Cannon A, Reynolds JV, Lysaght J, Lynam-Lennon N. Complement in Tumourigenesis and the Response to Cancer Therapy. Cancers (Basel) 2021; 13:1209. [PMID: 33802004 PMCID: PMC7998562 DOI: 10.3390/cancers13061209] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 12/16/2022] Open
Abstract
In recent years, our knowledge of the complement system beyond innate immunity has progressed significantly. A modern understanding is that the complement system has a multifaceted role in malignancy, impacting carcinogenesis, the acquisition of a metastatic phenotype and response to therapies. The ability of local immune cells to produce and respond to complement components has provided valuable insights into their regulation, and the subsequent remodeling of the tumour microenvironment. These novel discoveries have advanced our understanding of the immunosuppressive mechanisms supporting tumour growth and uncovered potential therapeutic targets. This review discusses the current understanding of complement in cancer, outlining both direct and immune cell-mediated roles. The role of complement in response to therapies such as chemotherapy, radiation and immunotherapy is also presented. While complement activities are largely context and cancer type-dependent, it is evident that promising therapeutic avenues have been identified, in particular in combination therapies.
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Affiliation(s)
- Rebecca M. O’Brien
- Department of Surgery, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland; (R.M.O.); (A.C.); (J.V.R.); (J.L.)
- Cancer Immunology and Immunotherapy Group, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland
| | - Aoife Cannon
- Department of Surgery, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland; (R.M.O.); (A.C.); (J.V.R.); (J.L.)
| | - John V. Reynolds
- Department of Surgery, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland; (R.M.O.); (A.C.); (J.V.R.); (J.L.)
| | - Joanne Lysaght
- Department of Surgery, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland; (R.M.O.); (A.C.); (J.V.R.); (J.L.)
- Cancer Immunology and Immunotherapy Group, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland
| | - Niamh Lynam-Lennon
- Department of Surgery, Trinity St. James’s Cancer Institute, Trinity Translational Medicine Institute, Trinity College Dublin and St. James’s Hospital, Dublin 8, Ireland; (R.M.O.); (A.C.); (J.V.R.); (J.L.)
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23
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Vandendriessche S, Cambier S, Proost P, Marques PE. Complement Receptors and Their Role in Leukocyte Recruitment and Phagocytosis. Front Cell Dev Biol 2021; 9:624025. [PMID: 33644062 PMCID: PMC7905230 DOI: 10.3389/fcell.2021.624025] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/15/2021] [Indexed: 12/21/2022] Open
Abstract
The complement system is deeply embedded in our physiology and immunity. Complement activation generates a multitude of molecules that converge simultaneously on the opsonization of a target for phagocytosis and activation of the immune system via soluble anaphylatoxins. This response is used to control microorganisms and to remove dead cells, but also plays a major role in stimulating the adaptive immune response and the regeneration of injured tissues. Many of these effects inherently depend on complement receptors expressed on leukocytes and parenchymal cells, which, by recognizing complement-derived molecules, promote leukocyte recruitment, phagocytosis of microorganisms and clearance of immune complexes. Here, the plethora of information on the role of complement receptors will be reviewed, including an analysis of how this functionally and structurally diverse group of molecules acts jointly to exert the full extent of complement regulation of homeostasis.
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Affiliation(s)
- Sofie Vandendriessche
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
| | - Seppe Cambier
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
| | - Paul Proost
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
| | - Pedro E Marques
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
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24
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Jackson WD, Gulino A, Fossati-Jimack L, Castro Seoane R, Tian K, Best K, Köhl J, Belmonte B, Strid J, Botto M. C3 Drives Inflammatory Skin Carcinogenesis Independently of C5. J Invest Dermatol 2021; 141:404-414.e6. [PMID: 32682912 PMCID: PMC8150327 DOI: 10.1016/j.jid.2020.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/30/2020] [Accepted: 06/10/2020] [Indexed: 11/17/2022]
Abstract
Nonmelanoma skin cancer such as cutaneous squamous cell carcinoma (cSCC) is the most common form of cancer and can occur as a consequence of DNA damage to the epithelium by UVR or chemical carcinogens. There is growing evidence that the complement system is involved in cancer immune surveillance; however, its role in cSCC remains unclear. Here, we show that complement genes are expressed in tissue from patients with cSCC, and C3 activation fragments are present in cSCC biopsies, indicating complement activation. Using a range of complement-deficient mice in a two-stage mouse model of chemically-induced cSCC, where a subclinical dose of 7,12-dimethylbenz[a]anthracene causes oncogenic mutations in epithelial cells and 12-O-tetradecanoylphorbol-13-acetate promotes the outgrowth of these cells, we found that C3-deficient mice displayed a significantly reduced tumor burden, whereas an opposite phenotype was observed in mice lacking C5aR1, C5aR2, and C3a receptor. In addition, in mice unable to form the membrane attack complex, the tumor progression was unaltered. C3 deficiency did not affect the cancer response to 7,12-dimethylbenz[a]anthracene treatment alone but reduced the epidermal hyperplasia during 12-O-tetradecanoylphorbol-13-acetate-induced inflammation. Collectively, these data indicate that C3 drives tumorigenesis during chronic skin inflammation, independently of the downstream generation of C5a or membrane attack complex.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene/administration & dosage
- 9,10-Dimethyl-1,2-benzanthracene/toxicity
- Animals
- Carcinogens/administration & dosage
- Carcinogens/toxicity
- Carcinoma, Squamous Cell/chemically induced
- Carcinoma, Squamous Cell/immunology
- Carcinoma, Squamous Cell/pathology
- Complement Activation/genetics
- Complement Activation/immunology
- Complement C3/genetics
- Complement C3/metabolism
- Complement C5/metabolism
- Complement Membrane Attack Complex/metabolism
- Disease Models, Animal
- Disease Progression
- Humans
- Mice
- Mice, Knockout
- Mice, Transgenic
- Neoplasms, Experimental/blood
- Neoplasms, Experimental/chemically induced
- Neoplasms, Experimental/immunology
- Neoplasms, Experimental/pathology
- Receptor, Anaphylatoxin C5a/genetics
- Receptor, Anaphylatoxin C5a/metabolism
- Receptors, Complement/genetics
- Receptors, Complement/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- Skin/drug effects
- Skin/immunology
- Skin/pathology
- Skin Neoplasms/chemically induced
- Skin Neoplasms/immunology
- Skin Neoplasms/pathology
- Tumor Escape
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Affiliation(s)
- William D Jackson
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom
| | - Alessandro Gulino
- Tumor Immunology Unit, Department of Health Sciences, University of Palermo School of Medicine, Palermo, Italy
| | - Liliane Fossati-Jimack
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom
| | - Rocio Castro Seoane
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom
| | - Kunyuan Tian
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom
| | - Katie Best
- Department of Dermatology, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany; Division of Immunobiology, Cincinnati Children's Hospital and College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Beatrice Belmonte
- Tumor Immunology Unit, Department of Health Sciences, University of Palermo School of Medicine, Palermo, Italy
| | - Jessica Strid
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom.
| | - Marina Botto
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, United Kingdom
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25
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Aviel YB, Ofir A, Ben-Izhak O, Vlodavsky E, Karbian N, Brik R, Mevorach D, Magen D. A novel loss-of-function mutation in LACC1 underlies hereditary juvenile arthritis with extended intra-familial phenotypic heterogeneity. Rheumatology (Oxford) 2021; 60:4888-4898. [PMID: 33493343 DOI: 10.1093/rheumatology/keab017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 11/19/2020] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE To investigate phenotypic and molecular characteristics of a consanguineous family with autosomal-recessive, polyarticular, juvenile idiopathic arthritis (JIA) with extra-articular manifestations, including renal amyloidosis and Crohn's disease, associated with a novel homozygous truncating variant in LACC1. METHODS Whole exome sequencing (WES) or targeted Sanger verification were performed in 15 participants. LACC1 expression and cytokine array were analyzed in patient-derived and CRISPR/Cas9-generated LACC1-knockout macrophages (Mϕ). RESULTS A homozygous truncating variant (p.Glu348Ter) in LACC1 was identified in three affected and one asymptomatic family member, and predicted harmful by causing premature stop of the LACC1 protein sequences, and by absence from ethnically-matched controls and public variation databases. Expression studies in patient-derived macrophages (Mϕ) showed no endogenous p. Glu348Ter-LACC1 RNA transcription or protein expression, compatible with nonsense-mediated mRNA decay. WES analysis in the asymptomatic homozygous subject for p. Glu348Ter-LACC1 detected an exclusive heterozygous variant (p.Arg928Gln) in complement component C5. Further complement activity analysis suggested a protective role for the p. Arg928Gln-C5 variant as a phenotypic modifier of LACC1-associated disease. Finally, cytokine profile analysis indicated increased levels of pro-inflammatory cytokines in LACC1-disrupted as compared with wild-type Mϕ. CONCLUSIONS Our findings reinforce the role of LACC1 disruption in autosomal-recessive JIA, extend the clinical spectrum and intra-familial heterogeneity of the disease-associated phenotype, indicate a modulatory effect of complement factor C5 on phenotypic severity, and suggest an inhibitory role for wild-type LACC1 on pro-inflammatory pathways.
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Affiliation(s)
- Yonatan Butbul Aviel
- Department of Pediatrics and Pediatric Rheumatology Service, Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ayala Ofir
- Laboratory of Molecular Medicine, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ofer Ben-Izhak
- Department of Pathology, Rambam Health Care Campus, Haifa, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Euvgeni Vlodavsky
- Department of Pathology, Rambam Health Care Campus, Haifa, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Netanel Karbian
- Rheumatology Research Center, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Riva Brik
- Department of Pediatrics and Pediatric Rheumatology Service, Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Dror Mevorach
- Rheumatology Research Center, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Daniella Magen
- Laboratory of Molecular Medicine, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Pediatric Nephrology Institute, Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel
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26
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Li XX, Kumar V, Clark RJ, Lee JD, Woodruff TM. The "C3aR Antagonist" SB290157 is a Partial C5aR2 Agonist. Front Pharmacol 2021; 11:591398. [PMID: 33551801 PMCID: PMC7859635 DOI: 10.3389/fphar.2020.591398] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/02/2020] [Indexed: 12/29/2022] Open
Abstract
Innate immune complement activation generates the C3 and C5 protein cleavage products C3a and C5a, defined classically as anaphylatoxins. C3a activates C3aR, while C5a activates two receptors (C5aR1 and C5aR2) to exert their immunomodulatory activities. The non-peptide compound, SB290157, was originally reported in 2001 as the first C3aR antagonist. In 2005, the first report on the non-selective nature of SB290157 was published, where the compound exerted clear agonistic, not antagonistic, activity in variety of cells. Other studies also documented the non-selective activities of this drug in vivo. These findings severely hamper data interpretation regarding C3aR when using this compound. Unfortunately, given the dearth of C3aR inhibitors, SB290157 still remains widely used to explore C3aR biology (>70 publications to date). Given these issues, in the present study we aimed to further explore SB290157's pharmacological selectivity by screening the drug against three human anaphylatoxin receptors, C3aR, C5aR1 and C5aR2, using cell models. We identified that SB290157 exerts partial agonist activity at C5aR2 by mediating β-arrestin recruitment at higher compound doses. This translated to a functional outcome in both human and mouse primary macrophages, where SB290157 significantly dampened C5a-induced ERK signaling. We also confirmed that SB290157 acts as a potent agonist at human C3aR in transfected cells, but as an antagonist in primary human macrophages. Our results therefore provide even more caution against using SB290157 as a research tool to explore C3aR function. Given the reported immunomodulatory and anti-inflammatory activities of C5aR2 agonism, any function observed with SB290157 could be due to these off-target activities.
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Affiliation(s)
| | | | | | | | - Trent M. Woodruff
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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27
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Li XX, Lee JD, Massey NL, Guan C, Robertson AAB, Clark RJ, Woodruff TM. Pharmacological characterisation of small molecule C5aR1 inhibitors in human cells reveals biased activities for signalling and function. Biochem Pharmacol 2020; 180:114156. [PMID: 32682759 DOI: 10.1016/j.bcp.2020.114156] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 12/17/2022]
Abstract
The complement fragment C5a is a core effector of complement activation. C5a, acting through its major receptor C5aR1, exerts powerful pro-inflammatory and immunomodulatory functions. Dysregulation of the C5a-C5aR1 axis has been implicated in numerous immune disorders, and the therapeutic inhibition of this axis is therefore imperative for the treatment of these diseases. A myriad of small-molecule C5aR1 inhibitors have been developed and independently characterised over the past two decades, however the pharmacological properties of these compounds has been difficult to directly compare due to the wide discrepancies in the model, read-out, ligand dose and instrumentation implemented across individual studies. Here, we performed a systematic characterisation of the most commonly reported and clinically advanced small-molecule C5aR1 inhibitors (peptidic: PMX53, PMX205 and JPE1375; non-peptide: W545011, NDT9513727, DF2593A and CCX168). Through signalling assays measuring C5aR1-mediated cAMP and ERK1/2 signalling, and β-arrestin 2 recruitment, this study highlighted the signalling-pathway dependence of the rank order of potencies of the C5aR1 inhibitors. Functional experiments performed in primary human macrophages demonstrated the high insurmountable antagonistic potencies for the peptidic inhibitors as compared to the non-peptide compounds. Finally, wash-out studies provided novel insights into the duration of inhibition of the C5aR1 inhibitors, and confirmed the long-lasting antagonistic properties of PMX53 and CCX168. Overall, this study revealed the potent and prolonged antagonistic activities of selected peptidic C5aR1 inhibitors and the unique pharmacological profile of CCX168, which thus represent ideal candidates to fulfil diverse C5aR1 research and clinical therapeutic needs.
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Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, Australia
| | - John D Lee
- School of Biomedical Sciences, Australia
| | | | - Carolyn Guan
- The University of Queensland, St Lucia 4072, Australia; Department of Chemistry, Princeton University, Princeton, NJ 08544, United States
| | | | | | - Trent M Woodruff
- School of Biomedical Sciences, Australia; Queensland Brain Institute, Australia.
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28
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Li XX, Clark RJ, Woodruff TM. C5aR2 Activation Broadly Modulates the Signaling and Function of Primary Human Macrophages. THE JOURNAL OF IMMUNOLOGY 2020; 205:1102-1112. [PMID: 32611725 DOI: 10.4049/jimmunol.2000407] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023]
Abstract
The complement activation fragment C5a is a potent proinflammatory mediator that is increasingly recognized as an immune modulator. C5a acts through two C5a receptors, C5aR1 (C5aR, CD88) and C5aR2 (C5L2, GPR77), to powerfully modify multiple aspects of immune cell function. Although C5aR1 is generally acknowledged to be proinflammatory and immune-activating, the potential roles played by C5aR2 remain poorly defined. Despite studies demonstrating C5aR2 can modulate C5aR1 in human cells, it is not yet known whether C5aR2 functionality is limited to, or requires, C5aR1 activation or influences immune cells more broadly. The present study, therefore, aimed to characterize the roles of C5aR2 on the signaling and function of primary human monocyte-derived macrophages, using a C5aR2 agonist (Ac-RHYPYWR-OH; P32) to selectively activate the receptor. We found that although C5aR2 activation with P32 by itself was devoid of any detectable MAPK signaling activities, C5aR2 agonism significantly dampened C5aR1-, C3aR-, and chemokine-like receptor 1 (CMKLR1)-mediated ERK signaling and altered intracellular calcium mobilization mediated by these receptors. Functionally, selective C5aR2 activation also downregulated cytokine production triggered by various TLRs (TLR2, TLR3, TLR4, and TLR7), C-type lectin receptors (Dectin-1, Dectin-2, and Mincle), and the cytosolic DNA sensor stimulator of IFN genes (STING). Surprisingly, activity at the C-type lectin receptors was particularly powerful, with C5aR2 activation reducing Mincle-mediated IL-6 and TNF-α generation by 80-90%. In sum, this study demonstrates that C5aR2 possesses pleiotropic functions in primary human macrophages, highlighting the role of C5aR2 as a powerful regulator of innate immune function.
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Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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29
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Pandey S, Maharana J, Li XX, Woodruff TM, Shukla AK. Emerging Insights into the Structure and Function of Complement C5a Receptors. Trends Biochem Sci 2020; 45:693-705. [PMID: 32402749 DOI: 10.1016/j.tibs.2020.04.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/06/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022]
Abstract
Complement factor C5a is an integral constituent of the complement cascade critically involved in the innate immune response, and it exerts its functions via two distinct receptors, C5aR1 and C5aR2. While C5aR1 is a prototypical G-protein-coupled receptor (GPCR), C5aR2 lacks functional coupling to heterotrimeric G proteins, although both receptors efficiently recruit β arrestins (βarrs). Here, we discuss the recent studies providing direct structural details of ligand-receptor interactions, and a framework of functional bias in this system, including the differences in terms of structural motifs and transducer coupling. We also discuss the functional analogy of C5aR2 with the atypical chemokine receptors (ACKRs), and highlight the future directions to elucidate the mechanistic basis of the functional divergence of these receptors activated by a common natural agonist.
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Affiliation(s)
- Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Jagannath Maharana
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Xaria X Li
- The School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia
| | - Trent M Woodruff
- The School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane 4072, Australia.
| | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
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30
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Li XX, Lee JD, Kemper C, Woodruff TM. The Complement Receptor C5aR2: A Powerful Modulator of Innate and Adaptive Immunity. THE JOURNAL OF IMMUNOLOGY 2020; 202:3339-3348. [PMID: 31160390 DOI: 10.4049/jimmunol.1900371] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/07/2019] [Indexed: 01/01/2023]
Abstract
Complement activation generates the core effector protein C5a, a potent immune molecule that is linked to multiple inflammatory diseases. Two C5a receptors, C5aR1 (C5aR, CD88) and C5aR2 (C5L2, GPR77), mediate the biological activities of C5a. Although C5aR1 has broadly acknowledged proinflammatory roles, C5aR2 remains at the center of controversy, with existing findings supporting both immune-activating and immune-dampening functions. Recent progress has been made toward resolving these issues. Instead of being a pure recycler and sequester of C5a, C5aR2 is capable of mediating its own set of signaling events and through these events exerting significant immunomodulatory effects not only toward C5aR1 but also other pattern recognition receptors and innate immune systems, such as NLRP3 inflammasomes. This review highlights the existing knowns and unknowns concerning C5aR2 and provides a timely update on recent breakthroughs which are expected to have a substantial impact on future fundamental and translational C5aR2 research.
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Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia; and
| | - John D Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia; and
| | - Claudia Kemper
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia; and
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31
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Nabizadeh JA, Manthey HD, Panagides N, Steyn FJ, Lee JD, Li XX, Akhir FNM, Chen W, Boyle GM, Taylor SM, Woodruff TM, Rolfe BE. C5a receptors C5aR1 and C5aR2 mediate opposing pathologies in a mouse model of melanoma. FASEB J 2019; 33:11060-11071. [PMID: 31298935 DOI: 10.1096/fj.201800980rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The canonical complement component 5a (C5a) receptor (C5aR) 1 has well-described roles in tumorigenesis but the contribution of the second receptor, C5aR2, is unclear. The present study demonstrates that B16.F0 melanoma cells express mRNA for both C5aR1 and C5aR2 and signal through ERK and p38 MAPKs in response to C5a. Despite this, C5a had no impact on melanoma cell proliferation or migration in vitro. In vivo studies demonstrated that the growth of B16.F0 melanoma tumors was increased in C5aR2-/- mice but reduced in C5aR1-/- mice and wild-type mice treated with a C5aR1 antagonist. Analysis of tumor-infiltrating leukocyte populations showed no significant differences between wild-type and C5aR2-/- mice. Conversely, percentages of myeloid-derived suppressor cells, macrophages, and regulatory T lymphocytes were lower in tumors from C5aR1-/- mice, whereas total (CD3+) T lymphocytes and CD4+ subsets were higher. Analysis of cytokine and chemokine levels also showed plasma IFN-γ was higher and tumor C-C motif chemokine ligand 2 was lower in the absence of C5aR1. The results suggest that C5aR1 signaling supports melanoma growth by promoting infiltration of immunosuppressive leukocyte populations into the tumor microenvironment, whereas C5aR2 has a more restricted but beneficial role in limiting tumor growth. Overall, these data support the potential of C5aR1-inhibitory therapies for melanoma.-Nabizadeh, J. A., Manthey, H. D., Panagides, N., Steyn, F. J., Lee, J. D., Li, X. X., Akhir, F. N. M., Chen, W., Boyle, G. M., Taylor, S. M., Woodruff, T. M., Rolfe, B. E. C5a receptors C5aR1 and C5aR2 mediate opposing pathologies in a mouse model of melanoma.
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Affiliation(s)
- Jamileh A Nabizadeh
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Helga D Manthey
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Nadya Panagides
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Frederik J Steyn
- Centre for Clinical Research, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - John D Lee
- School of Biomedical Science, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Xaria X Li
- School of Biomedical Science, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Fazrena N M Akhir
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Weiyu Chen
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Glen M Boyle
- Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
| | - Stephen M Taylor
- School of Biomedical Science, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Trent M Woodruff
- School of Biomedical Science, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Barbara E Rolfe
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
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32
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Pio R, Ajona D, Ortiz-Espinosa S, Mantovani A, Lambris JD. Complementing the Cancer-Immunity Cycle. Front Immunol 2019; 10:774. [PMID: 31031765 PMCID: PMC6473060 DOI: 10.3389/fimmu.2019.00774] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/25/2019] [Indexed: 12/12/2022] Open
Abstract
Reactivation of cytotoxic CD8+ T-cell responses has set a new direction for cancer immunotherapy. Neutralizing antibodies targeting immune checkpoint programmed cell death protein 1 (PD-1) or its ligand (PD-L1) have been particularly successful for tumor types with limited therapeutic options such as melanoma and lung cancer. However, reactivation of T cells is only one step toward tumor elimination, and a substantial fraction of patients fails to respond to these therapies. In this context, combination therapies targeting more than one of the steps of the cancer-immune cycle may provide significant benefits. To find the best combinations, it is of upmost importance to understand the interplay between cancer cells and all the components of the immune response. This review focuses on the elements of the complement system that come into play in the cancer-immunity cycle. The complement system, an essential part of innate immunity, has emerged as a major regulator of cancer immunity. Complement effectors such as C1q, anaphylatoxins C3a and C5a, and their receptors C3aR and C5aR1, have been associated with tolerogenic cell death and inhibition of antitumor T-cell responses through the recruitment and/or activation of immunosuppressive cell subpopulations such as myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), or M2 tumor-associated macrophages (TAMs). Evidence is provided to support the idea that complement blocks many of the effector routes associated with the cancer-immunity cycle, providing the rationale for new therapeutic combinations aimed to enhance the antitumor efficacy of anti-PD-1/PD-L1 checkpoint inhibitors.
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Affiliation(s)
- Ruben Pio
- Program in Solid Tumors (CIMA) and Department of Biochemistry and Genetics (School of Medicine), University of Navarra, Pamplona, Spain
- Navarra Institute for Health Research (IDISNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
| | - Daniel Ajona
- Program in Solid Tumors (CIMA) and Department of Biochemistry and Genetics (School of Medicine), University of Navarra, Pamplona, Spain
- Navarra Institute for Health Research (IDISNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
| | - Sergio Ortiz-Espinosa
- Program in Solid Tumors (CIMA) and Department of Biochemistry and Genetics (School of Medicine), University of Navarra, Pamplona, Spain
| | - Alberto Mantovani
- Humanitas Clinical and Research Center, Humanitas University, Milan, Italy
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - John D. Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Yu S, Wang D, Huang L, Zhang Y, Luo R, Adah D, Tang Y, Zhao K, Lu B. The complement receptor C5aR2 promotes protein kinase R expression and contributes to NLRP3 inflammasome activation and HMGB1 release from macrophages. J Biol Chem 2019; 294:8384-8394. [PMID: 30971430 DOI: 10.1074/jbc.ra118.006508] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/31/2019] [Indexed: 01/21/2023] Open
Abstract
The NLR family pyrin domain-containing 3 (NLRP3) inflammasome is a multimeric protein complex that mediates maturation of the cytokines IL-1β and IL-18 as well as release of the proinflammatory protein high-mobility group box 1 (HMGB1) and contributes to several inflammatory diseases, including sepsis, gout, and type 2 diabetes. In this context, the well-studied active complement fragment C5a and its receptor C5aR1 or C5aR2 orchestrate the inflammatory responses in many diseases. Although a C5a-C5aR interaction in NLRP3-associated diseases has been suggested, little is known about the details of C5a-C5aR cross-talk with the NLRP3 inflammasome in macrophages. In this study, using mice and murine macrophages and cytokines, immunoblotting, siRNA, and quantitative real-time PCR assays, we demonstrate that C5aR2 deficiency restricts activation of the NLRP3 inflammasome and release of HMGB1 both in vitro and in vivo Mechanistically, we found that C5aR2 promotes NLRP3 activation by amplifying dsRNA-dependent PKR expression, which is an important NLRP3-activating factor. We also observed that elevation of PKR expression because of the C5a-C5aR2 interaction depends on the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase pathway and type I IFN signaling. In conclusion, these findings reveal that C5aR2 contributes to NLRP3 inflammasome activation and HMGB1 release from macrophages.
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Affiliation(s)
- Songlin Yu
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China; Postdoctoral Research Station of Clinical Medicine, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Dan Wang
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Lingmin Huang
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Yening Zhang
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Ruiheng Luo
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China
| | - Dickson Adah
- Laboratory of Pathogen Biology, State Key Laboratory of Respiratory Disease, Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510632, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiting Tang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410000, China
| | - Kai Zhao
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China.
| | - Ben Lu
- Department of Hematology and Key Laboratory of Non-resolving Inflammation and Cancer of Hunan Province, Third Xiangya Hospital, Central South University, Changsha, Hunan 410000, China; Key Laboratory of Medical Genetics, School of Biological Science and Technology, Central South University, Changsha, Hunan 410000, China; Key Laboratory of Sepsis and Translational Medicine, School of Basic Medical Science, Central South University, Changsha, Hunan 410000, China; Department of Pathophysiology, School of Basic Medical Science, Jinan University, Guangzhou, Guangdong 510632, China.
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34
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Zaal A, van Ham SM, Ten Brinke A. Differential effects of anaphylatoxin C5a on antigen presenting cells, roles for C5aR1 and C5aR2. Immunol Lett 2019; 209:45-52. [PMID: 30959077 DOI: 10.1016/j.imlet.2019.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 12/24/2022]
Abstract
The anaphylatoxin C5a is well-known for its role as chemoattractant and contributes to immune cell recruitment into inflamed tissue and local inflammation. C5a has recently been implicated in modulation of antigen presenting cell function, such as macrophages and dendritic cells, which are pivotal for T cell activation and final T cell effector function. The published data on the effect of C5a on APC function and subsequent adaptive immune responses are in part conflicting, as both pro and anti-inflammatory effects have been described. In this review the opposing effects of C5a on APC function in mice and human are summarized and discussed in relation to origin of the involved APC subset, being either of the monocyte-derived lineage or dendritic cell lineage. In addition, the current knowledge on the expression of C5aR1 and C5aR2 on the different APC subsets is summarized. Based on the combined data, we propose that the differential effects of C5a on APC function may be attributed to absence or presence of co-expression of C5aR2 and C5aR1 on the specific APC.
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Affiliation(s)
- Anouk Zaal
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - S Marieke van Ham
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands; Swammerdam Institute for Life Sciences, University of Amsterdam, the Netherlands
| | - Anja Ten Brinke
- Department of Immunopathology, Sanquin Research, Amsterdam, the Netherlands and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.
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35
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Ma Y, Liu Y, Zhang Z, Yang GY. Significance of Complement System in Ischemic Stroke: A Comprehensive Review. Aging Dis 2019; 10:429-462. [PMID: 31011487 PMCID: PMC6457046 DOI: 10.14336/ad.2019.0119] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/19/2019] [Indexed: 12/14/2022] Open
Abstract
The complement system is an essential part of innate immunity, typically conferring protection via eliminating pathogens and accumulating debris. However, the defensive function of the complement system can exacerbate immune, inflammatory, and degenerative responses in various pathological conditions. Cumulative evidence indicates that the complement system plays a critical role in the pathogenesis of ischemic brain injury, as the depletion of certain complement components or the inhibition of complement activation could reduce ischemic brain injury. Although multiple candidates modulating or inhibiting complement activation show massive potential for the treatment of ischemic stroke, the clinical availability of complement inhibitors remains limited. The complement system is also involved in neural plasticity and neurogenesis during cerebral ischemia. Thus, unexpected side effects could be induced if the systemic complement system is inhibited. In this review, we highlighted the recent concepts and discoveries of the roles of different kinds of complement components, such as C3a, C5a, and their receptors, in both normal brain physiology and the pathophysiology of brain ischemia. In addition, we comprehensively reviewed the current development of complement-targeted therapy for ischemic stroke and discussed the challenges of bringing these therapies into the clinic. The design of future experiments was also discussed to better characterize the role of complement in both tissue injury and recovery after cerebral ischemia. More studies are needed to elucidate the molecular and cellular mechanisms of how complement components exert their functions in different stages of ischemic stroke to optimize the intervention of targeting the complement system.
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Affiliation(s)
- Yuanyuan Ma
- 1Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yanqun Liu
- 3Department of Neurology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhijun Zhang
- 2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- 1Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,2Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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36
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Wood AJT, Vassallo A, Summers C, Chilvers ER, Conway-Morris A. C5a anaphylatoxin and its role in critical illness-induced organ dysfunction. Eur J Clin Invest 2018; 48:e13028. [PMID: 30229880 DOI: 10.1111/eci.13028] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022]
Abstract
Critical illness is an aetiologically and clinically heterogeneous syndrome that is characterised by organ failure and immune dysfunction. Mortality in critically ill patients is driven by inflammation-associated organ damage and a profound vulnerability to nosocomial infection. Both factors are influenced by the activated complement protein C5a, released by unbridled activation of the complement system during critical illness. C5a exerts deleterious effects on organ systems directly and suppresses antimicrobial functions of key immune cells. Whilst several recent reports have added key knowledge of the cellular signalling pathways triggered by C5a, there remain a number of areas that are incompletely understood and therapeutic opportunities are still being evaluated. In this review, we summarise the cellular basis for C5a-induced vulnerability to nosocomial infection and organ dysfunction. We focus on cells of the innate immune system, highlighting the major areas in need of further research and potential avenues for targeted therapies.
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Affiliation(s)
| | | | | | | | - Andrew Conway-Morris
- Department of Medicine, University of Cambridge, Cambridge, UK.,Signaling Programme, Babraham Institute, Cambridge, UK
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37
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Tenner AJ, Stevens B, Woodruff TM. New tricks for an ancient system: Physiological and pathological roles of complement in the CNS. Mol Immunol 2018; 102:3-13. [PMID: 29958698 DOI: 10.1016/j.molimm.2018.06.264] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 06/12/2018] [Indexed: 12/11/2022]
Abstract
While the mechanisms underlying the functions of the complement system in the central nervous system (CNS) and systemically, namely opsonization, chemotaxis, membrane lysis, and regulation of inflammation are the same, the plethora of functions that complement orchestrates in the central nervous system (CNS) is complex. Strictly controlled expression of complement effector molecules, regulators and receptors across the gamut of life stages (embryogenesis, development and maturation, aging and disease) dictate fascinating contributions for this ancient system. Furthermore, it is becoming apparent that complement functions differ widely across distinct brain regions. This review provides a comprehensive overview of the newly identified roles for complement in the brain, including its roles in CNS development and function, during aging and in the processes of neurodegeneration. The diversity and selectively of beneficial and detrimental activities of complement, while challenging, should lead to precision targeting of specific components to provide disease modifying treatments for devastating psychiatric and neurodegenerative disorders that are still without effective treatment.
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Affiliation(s)
- Andrea J Tenner
- Departments of Molecular Biology and Biochemistry, Neurobiology and Behavior, and Pathology and Laboratory Medicine, University of California, Irvine, CA, United States.
| | - Beth Stevens
- F.M. Kirby Center for Neurobiology, Boston Children's Hospital, Department of Neurobiology, Harvard Medical School, Boston, MA, United States; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Trent M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
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38
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Abstract
The complement system is an evolutionarily ancient key component of innate immunity required for the detection and removal of invading pathogens. It was discovered more than 100 years ago and was originally defined as a liver-derived, blood-circulating sentinel system that classically mediates the opsonization and lytic killing of dangerous microbes and the initiation of the general inflammatory reaction. More recently, complement has also emerged as a critical player in adaptive immunity via its ability to instruct both B and T cell responses. In particular, work on the impact of complement on T cell responses led to the surprising discoveries that the complement system also functions within cells and is involved in regulating basic cellular processes, predominantly those of metabolic nature. Here, we review current knowledge about complement's role in T cell biology, with a focus on the novel intracellular and noncanonical activities of this ancient system.
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Affiliation(s)
- Erin E West
- Laboratory of Molecular Immunology and Immunology Center, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892, United States; ,
| | - Martin Kolev
- Division of Transplant Immunology and Mucosal Biology, King's College London, London SE1 9RT, United Kingdom;
| | - Claudia Kemper
- Laboratory of Molecular Immunology and Immunology Center, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892, United States; ,
- Division of Transplant Immunology and Mucosal Biology, King's College London, London SE1 9RT, United Kingdom;
- Institute for Systemic Inflammation Research, University of Lübeck, 23562 Lübeck, Germany
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39
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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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40
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Abstract
B-1 cells constitute a unique subpopulation of lymphocytes residing mainly in body cavities like the peritoneal cavity (PerC) but are also found in spleen and bone marrow (BM). As innate-like B cells, they mediate first line immune defense through low-affinity natural IgM (nIgM) antibodies. PerC B-1 cells can egress to the spleen and differentiate into nIgM antibody-secreting plasma cells that recognize conserved exogenous and endogenous cellular structures. Homing to and homeostasis within the PerC are regulated by the chemokine CXCL13 released by PerC macrophages and stroma cells. However, the exact mechanisms underlying the regulation of CXCL13 and B-1 homeostasis are not fully explored. B-1 cells play important roles in the inflammatory response to infection, autoimmunity, ischemia/reperfusion injury, obesity, and atherosclerosis. Remarkably, this list of inflammatory entities has a strong overlap with diseases that are regulated by complement suggesting a link between B-1 cells and the complement system. Interestingly, up to now, no data exist regarding the role of complement in B-1 cell biology. Here, we demonstrate for the first time that C5a regulates B-1 cell steady-state dynamics within the peritoneum, the spleen, and the BM. We found decreased B-1a cell numbers in the peritoneum and the spleen of C5aR1−/− mice associated with increased B1-a and B1-b numbers in the spleen and high serum titers of nIgM antibodies directed against phosphorylcholine and several pneumococcal polysaccharides. Similarly, peritoneal B-1a cells were decreased in the peritoneum and splenic B-1a and B-1b cells were increased in C5aR2−/− mice. The decrease in peritoneal B-1 cell numbers was associated with decreased peritoneal CXCL13 levels in C5aR1−/− and C5aR2−/− mice. In search for mechanisms, we found that combined TLR2 and IL-10 receptor activation in PerC macrophages induced strong CXCL13 production, which was significantly reduced in cells from C5aR1- and C5aR2-deficient mice and after combined C5aR-targeting. Such stimulation also induced marked local C5 production by PerC macrophages and C5a generation. Importantly, peritoneal in vivo administration of C5a increased CXCL13 production. Taken together, our findings suggest that local non-canonical C5 activation in PerC macrophages fuels CXCL13 production as a novel mechanism to control B-1 cell homeostasis.
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Affiliation(s)
- Katharina Bröker
- Brandenburg Medical School, University Hospital Brandenburg, Center of Internal Medicine II, Brandenburg a. d. Havel, Germany
| | - Julia Figge
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Albert F Magnusen
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Rudolf A Manz
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Christian M Karsten
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
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41
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A Verghese D, Demir M, Chun N, Fribourg M, Cravedi P, Llaudo I, Woodruff TM, Yadav P, Lira SA, Medof ME, Heeger PS. T Cell Expression of C5a Receptor 2 Augments Murine Regulatory T Cell (T REG) Generation and T REG-Dependent Cardiac Allograft Survival. THE JOURNAL OF IMMUNOLOGY 2018; 200:2186-2198. [PMID: 29436411 DOI: 10.4049/jimmunol.1701638] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/11/2018] [Indexed: 12/26/2022]
Abstract
C5aR2 (C5L2/gp77) is a seven-transmembrane spanning receptor that binds to C5a but lacks motifs essential for G protein coupling and associated signal transduction. C5aR2 is expressed on immune cells, modulates various inflammatory diseases in mice, and has been shown to facilitate murine and human regulatory T cell (TREG) generation in vitro. Whether and how C5aR2 impacts in vivo TREG generation and pathogenic T cell-dependent disease models have not been established. In this article, we show that murine T cells express and upregulate C5aR2 during induced TREG (iTREG) generation and that the absence of T cell-expressed C5aR2 limits in vivo iTREG generation following adoptive transfer of naive CD4+ T cells into Rag1-/- recipients. Using newly generated C5aR2-transgenic mice, we show that overexpression of C5aR2 in naive CD4+ T cells augments in vivo iTREG generation. In a model of TREG-dependent cardiac allograft survival, recipient C5aR2 deficiency accelerates graft rejection associated with lower TREG/effector T cell ratios, whereas overexpression of C5aR2 in immune cells prolongs graft survival associated with an increase in TREG/effector T cell ratios. T cell-expressed C5aR2 modulates TREG induction without altering effector T cell proliferation or cytokine production. Distinct from reported findings in neutrophils and macrophages, TREG-expressed C5aR2 does not interact with β-arrestin or inhibit ERK1/2 signaling. Rather, cumulative evidence supports the conclusion that C5aR2 limits C5aR1-initiated signals known to inhibit TREG induction. Together, the data expand the role of C5aR2 in adaptive immunity by providing in vivo evidence that T cell-expressed C5aR2 physiologically modulates iTREG generation and iTREG-dependent allograft survival.
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Affiliation(s)
- Divya A Verghese
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Markus Demir
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Nicholas Chun
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Miguel Fribourg
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Paolo Cravedi
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ines Llaudo
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, Brisbane St. Lucia, Brisbane, Queensland 4072, Australia; and
| | - Pragya Yadav
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Sergio A Lira
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - M Edward Medof
- Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106
| | - Peter S Heeger
- Nephrology Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029; .,Translational Transplant Research Center, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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42
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Colley CS, Popovic B, Sridharan S, Debreczeni JE, Hargeaves D, Fung M, An L, Edwards B, Arnold J, England E, Eghobamien L, Sivars U, Flavell L, Renshaw J, Wickson K, Warrener P, Zha J, Bonnell J, Woods R, Wilkinson T, Dobson C, Vaughan TJ. Structure and characterization of a high affinity C5a monoclonal antibody that blocks binding to C5aR1 and C5aR2 receptors. MAbs 2018; 10:104-117. [PMID: 28952876 PMCID: PMC5800367 DOI: 10.1080/19420862.2017.1384892] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
C5a is a potent anaphylatoxin that modulates inflammation through the C5aR1 and C5aR2 receptors. The molecular interactions between C5a-C5aR1 receptor are well defined, whereas C5a-C5aR2 receptor interactions are poorly understood. Here, we describe the generation of a human antibody, MEDI7814, that neutralizes C5a and C5adesArg binding to the C5aR1 and C5aR2 receptors, without affecting complement-mediated bacterial cell killing. Unlike other anti-C5a mAbs described, this antibody has been shown to inhibit the effects of C5a by blocking C5a binding to both C5aR1 and C5aR2 receptors. The crystal structure of the antibody in complex with human C5a reveals a discontinuous epitope of 22 amino acids. This is the first time the epitope for an antibody that blocks C5aR1 and C5aR2 receptors has been described, and this work provides a basis for molecular studies aimed at further understanding the C5a-C5aR2 receptor interaction. MEDI7814 has therapeutic potential for the treatment of acute inflammatory conditions in which both C5a receptors may mediate inflammation, such as sepsis or renal ischemia-reperfusion injury.
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MESH Headings
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Antibody Affinity
- Antibody Specificity
- Binding Sites, Antibody
- Complement C5a/antagonists & inhibitors
- Complement C5a/chemistry
- Complement C5a/immunology
- Complement C5a/metabolism
- Epitope Mapping/methods
- Epitopes
- HEK293 Cells
- Humans
- Protein Binding
- Protein Conformation
- Protein Engineering
- Receptor, Anaphylatoxin C5a/antagonists & inhibitors
- Receptor, Anaphylatoxin C5a/chemistry
- Receptor, Anaphylatoxin C5a/immunology
- Receptor, Anaphylatoxin C5a/metabolism
- Receptors, Chemokine/antagonists & inhibitors
- Receptors, Chemokine/chemistry
- Receptors, Chemokine/immunology
- Receptors, Chemokine/metabolism
- Structure-Activity Relationship
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Affiliation(s)
- Caroline S. Colley
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
- CONTACT Caroline S. Colley Antibody Discovery and Protein Engineering, MedImmune Ltd, Granta Park, Cambridge, CB21 6GH, UK
| | - Bojana Popovic
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | | | | | | | - Michael Fung
- Respiratory, Inflammation and Autoimmunity, MedImmune LLC, Gaithersburg, MD, USA
| | - Ling–Ling An
- Respiratory, Inflammation and Autoimmunity, MedImmune LLC, Gaithersburg, MD, USA
| | - Bryan Edwards
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | - Joanne Arnold
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | - Elizabeth England
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | - Laura Eghobamien
- Respiratory, Inflammation and Autoimmunity, MedImmune Ltd, Cambridge, UK
| | - Ulf Sivars
- Translational Biology, IMED RIA Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Liz Flavell
- Discovery Sciences, AstraZeneca R&D, Cambridge, UK
| | | | - Kate Wickson
- Discovery Sciences, AstraZeneca R&D, Cambridge, UK
| | - Paul Warrener
- Infectious Diseases, MedImmune LLC, Gaithersburg, MD, USA
| | - Jingying Zha
- Infectious Diseases, MedImmune LLC, Gaithersburg, MD, USA
| | | | - Rob Woods
- Antibody Discovery and Protein Engineering, MedImmune LLC, Gaithersburg, MD, USA
| | - Trevor Wilkinson
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | - Claire Dobson
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
| | - Tristan J. Vaughan
- Antibody Discovery and Protein Engineering, MedImmune Ltd, Cambridge, UK
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43
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Ajona D, Ortiz-Espinosa S, Pio R. Complement anaphylatoxins C3a and C5a: Emerging roles in cancer progression and treatment. Semin Cell Dev Biol 2017; 85:153-163. [PMID: 29155219 DOI: 10.1016/j.semcdb.2017.11.023] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/07/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Recent insights into the role of complement anaphylatoxins C3a and C5a in cancer provide new opportunities for the development of innovative biomarkers and therapeutic strategies. These two complement activation products can maintain chronic inflammation, promote an immunosuppressive microenvironment, induce angiogenesis, and increase the motility and metastatic potential of cancer cells. Still, the diverse heterogeneity of responses mediated by these peptides poses a challenge both to our understanding of the role played by these molecules in cancer progression and to the development of effective treatments. This review attempts to summarize the evidence surrounding the involvement of anaphylatoxins in the biological contexts associated with tumor progression. We also describe the recent developments that support the inhibition of anaphylatoxins, or their cognate receptors C3aR and C5aR1, as a treatment option for maximizing the clinical efficacy of current immunotherapies that target the PD-1/PD-L1 immune checkpoint.
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Affiliation(s)
- Daniel Ajona
- University of Navarra, Center for Applied Medical Research (CIMA), Program in Solid Tumors and Biomarkers, Pamplona, Spain; Navarra's Health Research Institute (IdiSNA), Pamplona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Spain; University of Navarra, School of Sciences, Department of Biochemistry and Genetics, Pamplona, Spain
| | - Sergio Ortiz-Espinosa
- University of Navarra, Center for Applied Medical Research (CIMA), Program in Solid Tumors and Biomarkers, Pamplona, Spain; University of Navarra, School of Sciences, Department of Biochemistry and Genetics, Pamplona, Spain
| | - Ruben Pio
- University of Navarra, Center for Applied Medical Research (CIMA), Program in Solid Tumors and Biomarkers, Pamplona, Spain; Navarra's Health Research Institute (IdiSNA), Pamplona, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Spain; University of Navarra, School of Sciences, Department of Biochemistry and Genetics, Pamplona, Spain.
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44
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Martin IV, Bohner A, Boor P, Shagdarsuren E, Raffetseder U, Lammert F, Floege J, Ostendorf T, Weber SN. Complement C5a receptors C5L2 and C5aR in renal fibrosis. Am J Physiol Renal Physiol 2017; 314:F35-F46. [PMID: 28903945 DOI: 10.1152/ajprenal.00060.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Complement factor C5a has two known receptors, C5aR, which mediates proinflammatory effects, and C5L2, a potential C5a decoy receptor. We previously identified C5a/C5aR signaling as a potent profibrotic pathway in the kidney. Here we tested for the first time the role of C5L2 in renal fibrosis. In unilateral ureteral obstruction (UUO)-induced kidney fibrosis, the expression of C5aR and C5L2 increased similarly and gradually as fibrosis progressed and was particularly prominent in injured dilated tubules. Genetic deficiency of either C5aR or C5L2 significantly reduced UUO-induced tubular injury. Expression of key proinflammatory mediators, however, significantly increased in C5L2- compared with C5aR-deficient mice, but this had no effect on the number of renal infiltrating macrophages or T cells. Moreover, in C5L2-/- mice, the cytokine and matrix metalloproteinase-inhibitor tissue inhibitor of matrix metalloproteinase-1 was specifically enhanced. Consequently, in C5L2-/- mice the degree of renal fibrosis was similar to wild type (WT), albeit with reduced mRNA expression of some fibrosis-related genes. In contrast, C5aR-/- mice had significantly reduced renal fibrosis compared with WT and C5L2-/- mice in UUO. In vitro experiments with primary tubular cells demonstrated that deficiency for either C5aR or C5L2 led to a significantly reduced expression of tubular injury and fibrosis markers. Vice versa, stimulation of WT tubular cells with C5a significantly induced the expression of these markers, whereas the absence of either receptor abolished this induction. In conclusion, in experimental renal fibrosis C5L2 and C5aR both contribute to tubular injury, and, while C5aR acts profibrotic, C5L2 does not play a role in extracellular matrix accumulation, arguing against C5L2 functioning simply as a decoy receptor.
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Affiliation(s)
- Ina V Martin
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule (RWTH) University of Aachen , Aachen , Germany
| | - Annika Bohner
- Division of Gastroenterology, Saarland University Medical Center , Homburg , Germany
| | - Peter Boor
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule (RWTH) University of Aachen , Aachen , Germany.,Institute of Pathology, RWTH University of Aachen , Aachen , Germany
| | | | - Ute Raffetseder
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule (RWTH) University of Aachen , Aachen , Germany
| | - Frank Lammert
- Division of Gastroenterology, Saarland University Medical Center , Homburg , Germany
| | - Jürgen Floege
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule (RWTH) University of Aachen , Aachen , Germany
| | - Tammo Ostendorf
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule (RWTH) University of Aachen , Aachen , Germany
| | - Susanne N Weber
- Division of Gastroenterology, Saarland University Medical Center , Homburg , Germany
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45
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Karsten CM, Wiese AV, Mey F, Figge J, Woodruff TM, Reuter T, Scurtu O, Kordowski A, Almeida LN, Briukhovetska D, Quell KM, Sun J, Ender F, Schmudde I, Vollbrandt T, Laumonnier Y, Köhl J. Monitoring C5aR2 Expression Using a Floxed tdTomato-C5aR2 Knock-In Mouse. THE JOURNAL OF IMMUNOLOGY 2017; 199:3234-3248. [PMID: 28864475 DOI: 10.4049/jimmunol.1700710] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/10/2017] [Indexed: 12/23/2022]
Abstract
The biological significance of C5a receptor [(C5aR)2/C5L2], a seven-transmembrane receptor binding C5a and C5adesArg, remains ill-defined. Specific ligation of C5aR2 inhibits C5a-induced ERK1/2 activation, strengthening the view that C5aR2 regulates C5aR1-mediated effector functions. Although C5aR2 and C5aR1 are often coexpressed, a detailed picture of C5aR2 expression in murine cells and tissues is still lacking. To close this gap, we generated a floxed tandem dye (td)Tomato-C5aR2 knock-in mouse that we used to track C5aR2 expression in tissue-residing and circulating immune cells. We found the strongest C5aR2 expression in the brain, bone marrow, and airways. All myeloid-derived cells expressed C5aR2, although with different intensities. C5aR2 expression in blood and tissue neutrophils was strong and homogeneous. Specific ligation of C5aR2 in neutrophils from tdTomato-C5aR2 mice blocked C5a-driven ERK1/2 phosphorylation, demonstrating functionality of C5aR2 in the reporter mice. In contrast to neutrophils, we found tissue-specific differences in C5aR2 expression in eosinophils, macrophages, and dendritic cell subsets. Naive and activated T cells stained negative for C5aR2, whereas B cells from different tissues homogeneously expressed C5aR2. Also, NK cell subsets in blood and spleen strongly expressed C5aR2. Activation of C5aR2 in NK cells suppressed IL-12/IL-18-induced IFN-γ production. Intratracheal IL-33 challenge resulted in decreased C5aR2 expression in pulmonary eosinophils and monocyte-derived dendritic cells. In summary, we provide a detailed map of murine C5aR2 immune cell expression in different tissues under steady-state conditions and upon pulmonary inflammation. The C5aR2 knock-in mouse will help to reliably track and conditionally delete C5aR2 expression in experimental models of inflammation.
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Affiliation(s)
- Christian M Karsten
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany;
| | - Anna V Wiese
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Fabian Mey
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Julia Figge
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tom Reuter
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Olga Scurtu
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Anna Kordowski
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Larissa N Almeida
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Daria Briukhovetska
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Katharina M Quell
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Jing Sun
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Fanny Ender
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Inken Schmudde
- Institute of Anatomy, University of Lübeck, Lübeck 23562, Germany
| | - Tillman Vollbrandt
- Cell Analysis Core Facility, University of Lübeck, Lübeck 23562, Germany; and
| | - Yves Laumonnier
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck 23562, Germany; .,Division of Immunobiology, Cincinnati Children's Hospital and College of Medicine, University of Cincinnati, Cincinnati, OH 45229
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46
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Hajishengallis G, Lambris JD. More than complementing Tolls: complement-Toll-like receptor synergy and crosstalk in innate immunity and inflammation. Immunol Rev 2017; 274:233-244. [PMID: 27782328 DOI: 10.1111/imr.12467] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Complement and Toll-like receptors (TLRs) play key roles in the host immune response and are swiftly activated by infection or other types of immunological stress. This review focuses on the capacity of complement and TLRs to engage in signaling crosstalk, ostensibly to coordinate immune and inflammatory responses through synergistic or antagonistic (regulatory) interactions. However, overactivation or dysregulation of either system may lead-often synergistically-to exaggerated inflammation and host tissue injury. Intriguingly, moreover, certain pathogens can manipulate complement-TLR crosstalk pathways in ways that undermine host immunity and favor their persistence. In the setting of polymicrobial inflammatory disease, subversion of complement-TLR crosstalk by keystone pathogens can promote dysbiosis. Knowledge of the molecular mechanisms underlying complement-TLR crosstalk pathways can, therefore, be used productively for tailored therapeutic approaches, such as, to enhance host immunity, mitigate destructive inflammation, or counteract microbial subversion of the host response.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA.
| | - John D Lambris
- Perelman School of Medicine, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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47
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The Controversial C5a Receptor C5aR2: Its Role in Health and Disease. J Immunol Res 2017; 2017:8193932. [PMID: 28706957 PMCID: PMC5494583 DOI: 10.1155/2017/8193932] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/11/2017] [Indexed: 01/24/2023] Open
Abstract
After the discovery of the C5a receptor C5aR1, C5aR2 is the second receptor found to bind C5a and its des-arginine form. As a heptahelical G protein-coupled receptor but devoid of the intracellular Gα signal, C5aR2 is special and confusing. Ramifications and controversies about C5aR2 are under debate since its identification, from putative ligands and cellular localization to intracellular signals and pathological roles in inflammation and immunity. The ruleless and even conflicting pro- or anti-inflammatory role of C5aR2 in animal models of diverse diseases makes one bewildered. This review summarizes reports on C5aR2, tries to clear up available evidence on these four controversial aspects, and delineates C5aR2 function(s). It also summarizes available toolboxes for C5aR2 study.
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48
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Intracellular complement - the complosome - in immune cell regulation. Mol Immunol 2017; 89:2-9. [PMID: 28601357 PMCID: PMC7112704 DOI: 10.1016/j.molimm.2017.05.012] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 05/14/2017] [Accepted: 05/19/2017] [Indexed: 12/18/2022]
Abstract
The complement system was defined over a century ago based on its ability to "complement" the antibody-mediated and cell-mediated immune responses against pathogens. Today our understanding of this ancient part of innate immunity has changed substantially and we know now that complement plays an undisputed pivotal role in the regulation of both innate and adaptive immunity. The complement system consists of over 50 blood-circulating, cell-surface expressed and intracellular proteins. It is key in the recognition and elimination of invading pathogens, also in the removal of self-derived danger such as apoptotic cells, and it supports innate immune responses and the initiation of the general inflammatory reactions. The long prevailing classic view of complement was that of a serum-operative danger sensor and first line of defence system, however, recent experimental and clinical evidences have demonstrated that "local" tissue and surprisingly intracellular complement (the complosome) activation impacts on normal cell physiology. This review will focus on novel aspects of intracellular complement activation and its unexpected roles in basic cell processes such as metabolism. We also discuss what the existence of the complosome potentially means for how the host handles intracellular pathogens such as viruses.
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49
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Novel insights into the expression pattern of anaphylatoxin receptors in mice and men. Mol Immunol 2017; 89:44-58. [PMID: 28600003 DOI: 10.1016/j.molimm.2017.05.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 02/06/2023]
Abstract
The anaphylatoxins (AT) C3a and C5a play important roles as mediators of inflammation. Further, they regulate and control multiple innate and adaptive immune responses through binding and activation of their cognate G protein-coupled receptors, i.e. C3a receptor (C3aR), C5a receptor 1 (C5aR1) and C5a receptor 2 (C5aR2), although the latter lacks important sequence motifs for G protein-coupling. Based on their pleiotropic functions, they contribute not only to tissue homeostasis but drive, perpetuate and resolve immune responses in many inflammatory diseases including infections, malignancies, autoimmune as well as allergic diseases. During the past few years, transcriptome expression data provided detailed insights into AT receptor tissue mRNA expression. In contrast, our understanding of cellular AT receptor expression in human and mouse tissues under steady and inflammatory conditions is still sketchy. Ligand binding studies, flow cytometric and immunohistochemical analyses convincingly demonstrated tissue-specific C5aR1 expression in various cells of myeloid origin. However, a detailed map for C3aR or C5aR2 expression in human or mouse tissue cells is still lacking. Also, reports about AT expression in lymphoid cells is still controversial. To understand the multiple roles of the ATs in the innate and adaptive immune networks, a detailed understanding of their receptor expression in health and disease is required. Recent findings obtained with novel GFP or tdTomato AT-receptor knock-in mice provide detailed insights into their expression pattern in tissue immune and stroma cells. Here, we will provide an update about our current knowledge of AT receptor expression pattern in humans and mice.
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50
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Biggins PJC, Brennan FH, Taylor SM, Woodruff TM, Ruitenberg MJ. The Alternative Receptor for Complement Component 5a, C5aR2, Conveys Neuroprotection in Traumatic Spinal Cord Injury. J Neurotrauma 2017; 34:2075-2085. [PMID: 28173736 DOI: 10.1089/neu.2016.4701] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
This study investigated the role of the alternative receptor for complement activation fragment C5a, C5aR2, in secondary inflammatory pathology after contusive spinal cord injury (SCI) in mice. C5ar2-/- mice exhibited decreased intraparenchymal tumor necrosis factor alpha and interleukin-6 acutely post-injury, but these reductions did not translate into improved outcomes. We show that loss of C5aR2 leads to increased lesion volumes, reduced myelin sparing, and significantly worsened recovery from SCI in C5ar2-/- animals compared to wild-type (WT) controls. Loss of C5aR2 did not alter leukocyte mobilization from the bone marrow in response to SCI, and neutrophil recruitment/presence at the lesion site was also not different between genotypes. Acute treatment of SCI mice with the selective C5aR1 antagonist, PMX205, improved SCI outcomes, compared to vehicle controls, and, importantly, fully alleviated the worsened recovery of C5ar2-/- mice compared to their WT counterparts. Collectively, these findings indicate that C5aR2 is neuroprotective and a novel target to restrain injurious C5a signaling after a major neurotraumatic event.
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Affiliation(s)
- Patrick J C Biggins
- 1 School of Biomedical Sciences, The University of Queensland , Brisbane, Australia
| | - Faith H Brennan
- 1 School of Biomedical Sciences, The University of Queensland , Brisbane, Australia
| | - Stephen M Taylor
- 1 School of Biomedical Sciences, The University of Queensland , Brisbane, Australia
| | - Trent M Woodruff
- 1 School of Biomedical Sciences, The University of Queensland , Brisbane, Australia
| | - Marc J Ruitenberg
- 1 School of Biomedical Sciences, The University of Queensland , Brisbane, Australia .,2 Queensland Brain Institute, The University of Queensland , Brisbane, Australia .,3 Trauma, Critical Care and Recovery, Brisbane Diamantina Health Partners , Brisbane, Australia
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