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Duan M, Zhang X, Lou Y, Feng J, Guo P, Ye S, Lv P, Chen Y. Deletion of Tmem268 in mice suppresses anti-infectious immune responses by downregulating CD11b signaling. EMBO Rep 2024; 25:2550-2570. [PMID: 38730209 PMCID: PMC11169502 DOI: 10.1038/s44319-024-00141-6] [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: 05/24/2023] [Revised: 02/25/2024] [Accepted: 04/03/2024] [Indexed: 05/12/2024] Open
Abstract
Transmembrane protein 268 (TMEM268) is a novel, tumor growth-related protein first reported by our laboratory. It interacts with the integrin subunit β4 (ITGB4) and plays a positive role in the regulation of the ITGB4/PLEC signaling pathway. Here, we investigated the effects and mechanism of TMEM268 in anti-infectious immune response in mice. Tmem268 knockout in mice aggravated cecal ligation and puncture-induced sepsis, as evidenced by higher bacterial burden in various tissues and organs, congestion, and apoptosis. Moreover, Tmem268 deficiency in mice inhibited phagocyte adhesion and migration, thus decreasing phagocyte infiltration at the site of infection and complement-dependent phagocytosis. Further findings indicated that TMEM268 interacts with CD11b and inhibits its degradation via the endosome-lysosome pathway. Our results reveal a positive regulatory role of TMEM268 in β2 integrin-associated anti-infectious immune responses and signify the potential value of targeting the TMEM268-CD11b signaling axis for the maintenance of immune homeostasis and immunotherapy for sepsis and related immune disorders.
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Affiliation(s)
- Mengyuan Duan
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Xuan Zhang
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
- Beijing Key Laboratory for Pediatric Diseases of Otolaryngology, Beijing Pediatric Research Institute, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Yaxin Lou
- Medical and Healthy Analytical Center, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Jinqiu Feng
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Pengli Guo
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Shufang Ye
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Ping Lv
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China
| | - Yingyu Chen
- Department of Immunology, Peking University School of Basic Medical Sciences; NHC Key Laboratory of Medical Immunology, Peking University, 38 Xueyuan Road, 100191, Beijing, China.
- Center for Human Disease Genomics, Peking University, 38 Xueyuan Road, 100191, Beijing, China.
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2
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Li Y, Tang C, Vanarsa K, Thai N, Castillo J, Lea GAB, Lee KH, Kim S, Pedroza C, Wu T, Saxena R, Mok CC, Mohan C. Proximity extension assay proteomics and renal single cell transcriptomics uncover novel urinary biomarkers for active lupus nephritis. J Autoimmun 2024; 143:103165. [PMID: 38194790 DOI: 10.1016/j.jaut.2023.103165] [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: 10/16/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024]
Abstract
OBJECTIVE To identify urinary biomarkers that can distinguish active renal involvement in Lupus Nephritis (LN), a severe manifestation of systemic lupus erythematosus (SLE). METHODS Urine from 117 subjects, comprised of inactive SLE, active non-renal lupus, active LN, and healthy controls, were subjected to Proximity Extension Assay (PEA) based comprehensive proteomics followed by ELISA validation in an independent, ethnically diverse cohort. Proteomic data is also cross-referenced to renal transcriptomic data to elucidate cellular origins of biomarkers. RESULTS Systems biology analyses revealed progressive activation of cytokine signaling, chemokine activity and coagulation pathways, with worsening renal disease. In addition to validating 30 previously reported biomarkers, this study uncovers several novel candidates. Following ELISA validation in an independent cohort of different ethnicity, the six most discriminatory biomarkers for active LN were urinary ICAM-2, FABP4, FASLG, IGFBP-2, SELE and TNFSF13B/BAFF, with ROC AUC ≥80%, with most correlating strongly with clinical disease activity. Transcriptomic analyses of LN kidneys mapped the likely origin of these proteins to intra-renal myeloid cells (CXCL16, IL-1RT2, TNFSF13B/BAFF), T/NK cells (FASLG), leukocytes (ICAM2) and endothelial cells (SELE). CONCLUSION In addition to confirming the diagnostic potential of urine ALCAM, CD163, MCP1, SELL, ICAM1, VCAM1, NGAL and TWEAK for active LN, this study adds urine ICAM-2, FABP4, FASLG, IGFBP-2, SELE, and TNFSF13B/BAFF as additional markers that warrant systematic validation in larger cross-sectional and longitudinal cohorts.
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Affiliation(s)
- Yaxi Li
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Chenling Tang
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Kamala Vanarsa
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Nga Thai
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Jessica Castillo
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | | | - Kyung Hyun Lee
- Center for Clinical Research and Evidence-Based Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Soojin Kim
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Claudia Pedroza
- Center for Clinical Research and Evidence-Based Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Tianfu Wu
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Ramesh Saxena
- Department of Internal Medicine, Division of Nephrology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chi Chiu Mok
- Department of Medicine, Tuen Mun Hospital, New Territories, Hong Kong, China
| | - Chandra Mohan
- Department of Biomedical Engineering, University of Houston, Houston, TX, USA.
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3
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Lichtnekert J, Anders HJ, Lech M. Lupus Nephritis: Current Perspectives and Moving Forward. J Inflamm Res 2022; 15:6533-6552. [PMID: 36483271 PMCID: PMC9726217 DOI: 10.2147/jir.s363722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/22/2022] [Indexed: 08/07/2023] Open
Abstract
Lupus nephritis is a severe organ manifestation of systemic lupus erythematosus, and its pathogenesis involves complex etiology and mechanisms. Despite significant knowledge gains and extensive efforts put into understanding the development and relapsing disease activity, lupus nephritis remains a substantial cause of morbidity and mortality in lupus patients. Current therapies retain a significant unmet medical need regarding rates of complete response, preventing relapse of lupus nephritis, progression of chronic kidney disease to kidney failure, drug toxicity, and pill burden-related drug non-adherence. Connected to progression of chronic kidney disease are the associated risks for disabling or even lethal cardiovascular events, as well as chronic kidney disease-related secondary immunodeficiency and serious infections. In this regard, biomarkers are needed that can predict treatment response to specific drugs to enable personalized precision medicine. A series of clinical trials with innovative immunomodulatory drugs are ongoing and raise expectations for improvements in the management of lupus nephritis. Here, we review how new developments in pathogenesis connect with current and future perspectives for the management of lupus nephritis.
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Affiliation(s)
- Julia Lichtnekert
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, München, Germany
| | - Hans-Joachim Anders
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, München, Germany
| | - Maciej Lech
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, München, Germany
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4
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Dupuy A, Ju LA, Chiu J, Passam FH. Mechano-Redox Control of Integrins in Thromboinflammation. Antioxid Redox Signal 2022; 37:1072-1093. [PMID: 35044225 DOI: 10.1089/ars.2021.0265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Significance: How mechanical forces and biochemical cues are coupled remains a miracle for many biological processes. Integrins, well-known adhesion receptors, sense changes in mechanical forces and reduction-oxidation reactions (redox) in their environment to mediate their adhesive function. The coupling of mechanical and redox function is a new area of investigation. Disturbance of normal mechanical forces and the redox balance occurs in thromboinflammatory conditions; atherosclerotic plaques create changes to the mechanical forces in the circulation. Diabetes induces redox changes in the circulation by the production of reactive oxygen species and vascular inflammation. Recent Advances: Integrins sense changes in the blood flow shear stress at the level of focal adhesions and respond to flow and traction forces by increased signaling. Talin, the integrin-actin linker, is a traction force sensor and adaptor. Oxidation and reduction of integrin disulfide bonds regulate their adhesion. A conserved disulfide bond in integrin αlpha IIb beta 3 (αIIbβ3) is directly reduced by the thiol oxidoreductase endoplasmic reticulum protein 5 (ERp5) under shear stress. Critical Issues: The coordination of mechano-redox events between the extracellular and intracellular compartments is an active area of investigation. Another fundamental issue is to determine the spatiotemporal arrangement of key regulators of integrins' mechanical and redox interactions. How thromboinflammatory conditions lead to mechanoredox uncoupling is relatively unexplored. Future Directions: Integrated approaches, involving disulfide bond biochemistry, microfluidic assays, and dynamic force spectroscopy, will aid in showing that cell adhesion constitutes a crossroad of mechano- and redox biology, within the same molecule, the integrin. Antioxid. Redox Signal. 37, 1072-1093.
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Affiliation(s)
- Alexander Dupuy
- Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, Australia.,Heart Research Institute, Newtown, Australia
| | - Lining Arnold Ju
- Charles Perkins Centre, The University of Sydney, Camperdown, Australia.,Heart Research Institute, Newtown, Australia.,School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, Australia
| | - Joyce Chiu
- Charles Perkins Centre, The University of Sydney, Camperdown, Australia.,ACRF Centenary Cancer Research Centre, The Centenary Institute, Camperdown, Australia
| | - Freda H Passam
- Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, Australia.,Heart Research Institute, Newtown, Australia
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5
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Le-Bel G, Desjardins P, Gross C, Cortez Ghio S, Couture C, Germain L, Guérin SL. Influence of the Postmortem/Storage Time of Human Corneas on the Properties of Cultured Limbal Epithelial Cells. Cells 2022; 11:cells11172716. [PMID: 36078126 PMCID: PMC9455001 DOI: 10.3390/cells11172716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/25/2022] Open
Abstract
Besides being a powerful model to study the mechanisms of corneal wound healing, tissue-engineered human corneas (hTECs) are sparking interest as suitable substitutes for grafting purposes. To ensure the histological and physiological integrity of hTECs, the primary cultures generated from human cornea (identified as human limbal epithelial cells (hLECs) that are used to produce them must be of the highest possible quality. The goal of the present study consisted in evaluating the impact of the postmortem/storage time (PM/ST) on their properties in culture. hLECs were isolated from the entire cornea comprising the limbus and central cornea. When grown as monolayers, short PM/ST hLECs displayed increased daily doublings and generated more colonies per seeded cells than long PM/ST hLECs. Moreover, hLECs with a short PM/ST exhibited a markedly faster wound closure kinetic both in scratch wound assays and hTECs. Collectively, these results suggest that short PM/ST hLECs have a greater number of highly proliferative stem cells, exhibit a faster and more efficient wound healing response in vitro, and produce hTECs of a higher quality, making them the best candidates to produce biomaterial substitutes for clinical studies.
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Affiliation(s)
- Gaëtan Le-Bel
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Pascale Desjardins
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Christelle Gross
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Sergio Cortez Ghio
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Camille Couture
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Lucie Germain
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Sylvain L. Guérin
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, and Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1J 1Z4, Canada
- Centre Universitaire d’Ophtalmologie (CUO)-Recherche, Centre de Recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice, Québec, QC G1S 4L8, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada
- Correspondence: ; Tel.: +1-418-682-7565
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6
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Shilts J, Severin Y, Galaway F, Müller-Sienerth N, Chong ZS, Pritchard S, Teichmann S, Vento-Tormo R, Snijder B, Wright GJ. A physical wiring diagram for the human immune system. Nature 2022; 608:397-404. [PMID: 35922511 PMCID: PMC9365698 DOI: 10.1038/s41586-022-05028-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 06/28/2022] [Indexed: 12/14/2022]
Abstract
The human immune system is composed of a distributed network of cells circulating throughout the body, which must dynamically form physical associations and communicate using interactions between their cell-surface proteomes1. Despite their therapeutic potential2, our map of these surface interactions remains incomplete3,4. Here, using a high-throughput surface receptor screening method, we systematically mapped the direct protein interactions across a recombinant library that encompasses most of the surface proteins that are detectable on human leukocytes. We independently validated and determined the biophysical parameters of each novel interaction, resulting in a high-confidence and quantitative view of the receptor wiring that connects human immune cells. By integrating our interactome with expression data, we identified trends in the dynamics of immune interactions and constructed a reductionist mathematical model that predicts cellular connectivity from basic principles. We also developed an interactive multi-tissue single-cell atlas that infers immune interactions throughout the body, revealing potential functional contexts for new interactions and hubs in multicellular networks. Finally, we combined targeted protein stimulation of human leukocytes with multiplex high-content microscopy to link our receptor interactions to functional roles, in terms of both modulating immune responses and maintaining normal patterns of intercellular associations. Together, our work provides a systematic perspective on the intercellular wiring of the human immune system that extends from systems-level principles of immune cell connectivity down to mechanistic characterization of individual receptors, which could offer opportunities for therapeutic intervention. Systematic measurements of the interactions between proteins found on the surfaces of human leukocytes provides a global view of the way that immune cells are dynamically connected by receptors.
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Affiliation(s)
- Jarrod Shilts
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK.
| | - Yannik Severin
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Francis Galaway
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK
| | | | - Zheng-Shan Chong
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK
| | - Sophie Pritchard
- Cellular Genetics Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Sarah Teichmann
- Cellular Genetics Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Roser Vento-Tormo
- Cellular Genetics Programme, Wellcome Sanger Institute, Cambridge, UK
| | - Berend Snijder
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK. .,Department of Biology, Hull York Medical School, York Biomedical Research Institute, University of York, York, UK.
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7
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Villanueva V, Li X, Jimenez V, Faridi HM, Gupta V. CD11b agonists offer a novel approach for treating lupus nephritis. Transl Res 2022; 245:41-54. [PMID: 35288363 PMCID: PMC9167730 DOI: 10.1016/j.trsl.2022.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 12/20/2022]
Abstract
Lupus nephritis (LN) develops in more than a third of all systemic lupus erythematosus (SLE) patients and is the strongest predictor of morbidity and mortality. Increased circulating levels of type I interferon (IFN I) and anti-double stranded DNA (anti-dsDNA) and anti-RNA binding protein (anti-RNP) antibodies lead to increased glomerular injury via leukocyte activation and glomerular infiltration. Uncontrolled Toll-like receptor (TLR) signaling in leukocytes results in increased production of IFN I and anti-dsDNA antibodies. ITGAM gene codes for integrin CD11b, the α-chain of integrin heterodimer CD11b/CD18, that is highly expressed in leukocytes and modulates TLR-dependent pro-inflammatory signaling. Three nonsynonymous SNPs in the ITGAM gene strongly correlate with increased risk for SLE and LN and with IFN I levels. Here we review the literature on the role of CD11b on leukocytes in LN. We also incorporate conclusions from several recent studies that show that these ITGAM SNPs result in a CD11b protein that is less able to suppress TLR-dependent pro-inflammatory pathways in leukocytes, that activation of CD11b via novel small molecule agonists suppresses TLR-dependent pathways, including reductions in circulating levels of IFN I and anti-dsDNA antibodies, and that CD11b activation reduces LN in model systems. Recent data strongly suggest that integrin CD11b is an exciting new therapeutic target in SLE and LN and that allosteric activation of CD11b is a novel therapeutic paradigm for effectively treating such autoimmune diseases.
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Affiliation(s)
- Veronica Villanueva
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Xiaobo Li
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Viviana Jimenez
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Hafeez M Faridi
- Department of Pharmaceutical Sciences, College of Pharmacy, Chicago State University, Chicago, Illinois
| | - Vineet Gupta
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois.
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8
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Jensen RK, Pedersen H, Lorentzen J, Laursen NS, Vorup-Jensen T, Andersen GR. Structural insights into the function-modulating effects of nanobody binding to the integrin receptor α Mβ 2. J Biol Chem 2022; 298:102168. [PMID: 35738398 PMCID: PMC9287160 DOI: 10.1016/j.jbc.2022.102168] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 01/12/2023] Open
Abstract
The integrin receptor αMβ2 mediates phagocytosis of complement-opsonized objects, adhesion to the extracellular matrix, and transendothelial migration of leukocytes. However, the mechanistic aspects of αMβ2 signaling upon ligand binding are unclear. Here, we present the first atomic structure of the human αMβ2 headpiece fragment in complex with the nanobody (Nb) hCD11bNb1 at a resolution of 3.2 Å. We show that the receptor headpiece adopts the closed conformation expected to exhibit low ligand affinity. The crystal structure indicates that in the R77H αM variant, associated with systemic lupus erythematosus, the modified allosteric relationship between ligand binding and integrin outside–inside signaling is due to subtle conformational effects transmitted over a distance of 40 Å. Furthermore, we found the Nb binds to the αI domain of the αM subunit in an Mg2+-independent manner with low nanomolar affinity. Biochemical and biophysical experiments with purified proteins demonstrated that the Nb acts as a competitive inhibitor through steric hindrance exerted on the thioester domain of complement component iC3b attempting to bind the αM subunit. Surprisingly, we show that the Nb stimulates the interaction of cell-bound αMβ2 with iC3b, suggesting that it may represent a novel high-affinity proteinaceous αMβ2-specific agonist. Taken together, our data suggest that the iC3b–αMβ2 complex may be more dynamic than predicted from the crystal structure of the core complex. We propose a model based on the conformational spectrum of the receptor to reconcile these observations regarding the functional consequences of hCD11bNb1 binding to αMβ2.
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Affiliation(s)
- Rasmus K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Henrik Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Josefine Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
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9
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Chen Y, Huang C, Chen X, Cai Y, Li W, Fang X, Zhang W. Bone protein analysis via label-free quantitative proteomics in patients with periprosthetic joint infection. J Proteomics 2022; 252:104448. [PMID: 34883267 DOI: 10.1016/j.jprot.2021.104448] [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: 06/27/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/17/2022]
Abstract
Periprosthetic joint infection (PJI) is a catastrophic complication of arthroplasty. The treatment of PJI often requires multiple operations and long-term use of antibiotics, making PJI a substantial health and economic burden for patients. Therefore, there is an urgent need to elucidate the pathological mechanism of PJI to explore new therapeutic methods. This study aimed to explore proteomics changes in bone tissue around the prosthesis during PJI development, to explain the pathological mechanism and to provide new treatment ideas. Ten patients who underwent revision surgery at our institution were included: 5 patients with Staphylococcus aureus PJI and 5 patients with aseptic failure. The proteomics changes in bone tissues after PJI were investigated by label-free quantitative proteomics, and the pathways affected by the differential proteins were analyzed by GO annotation, GO enrichment analysis, KEGG enrichment analysis and protein-protein interaction network analysis. We identified 435 differentially expressed proteins (DEPs), with 213 upregulated and 222 downregulated proteins. Analysis revealed activation of immune-related pathways, such as complement and coagulation cascades, phagocytosis, and neutrophil activation, and inhibition of energy metabolism pathways represented by the TCA cycle. We also observed an altered balance between osteoblasts and osteoclasts during S. aureus PJI. We hope that these processes will reveal new treatment ideas. SIGNIFICANCE: PJI is a catastrophic complication of arthroplasty. When infection occurs, bacteria may invade periprosthetic bone tissue to escape immunity and cause damage. So far, only few studies focused on the changes of proteomics associated to PJI. This is the first study to describe the proteomics changes of periprosthetic bone tissue of patients with PJI. We found that the pathological process of S. aureus PJI mainly involves activation of the immune system, decreased energy metabolism, and an altered balance of osteoblasts and osteoclasts.
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Affiliation(s)
- Yang Chen
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Changyu Huang
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xiaoqing Chen
- Department of Orthopedic Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University, Quanzhou, China
| | - Yuanqing Cai
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Wenbo Li
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xinyu Fang
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
| | - Wenming Zhang
- Department of Orthopedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
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10
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Zhiping LL, Ong LT, Chatterjee D, Tan SM, Bhattacharjya S. Binary and ternary complexes of FLNa-Ig21 with cytosolic tails of αMß2 integrin reveal dual role of filamin mediated regulation. Biochim Biophys Acta Gen Subj 2021; 1865:130005. [PMID: 34509570 DOI: 10.1016/j.bbagen.2021.130005] [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: 07/01/2021] [Revised: 08/25/2021] [Accepted: 09/07/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Cytoskeletal protein filamin A is critical for the outside-in signaling of integrins. Although molecular mechanisms of filamin-integrin interactions are not fully understood. Mostly, the membrane distal (MD) part of the cytosolic tail (CT) of β subunit of integrin is known to interact with filamin A domain 21 (FLNa-Ig2). However, binary and ternary complexes of full-length CTs of leucocyte specific ß2 integrins with FLNa-Ig21 are yet to be elucidated. METHODS Binding interactions of the CTs of integrin αMß2 with FLNa-Ig21 are extensively investigated by NMR, ITC, cell-based functional assays and computational docking. RESULTS The αM CT demonstrates interactions with FLNa-Ig21 forming a binary complex. Filamin/αM interface is mediated by sidechain-sidechain interactions among non-polar and aromatic residues involving MP helix of αM and the canonical CD face of FLNa-Ig21. Functional assays delineated an interfacial residue Y1137 of αM CT is critical for in-cell binding to FLNa-Ig2. In addition, full-length ß2 CT occupies two distinct binding sites in complex with FLNa-Ig21. A ternary complex of FLNa-Ig21 with CTs has been characterized. In the ternary complex, αM CT moves away to a distal site of FLNa-Ig21 with fewer interactions. CONCLUSION Our findings demonstrate a plausible dual role of filamin in integrin regulation. The molecular interactions of the ternary complex are critical for the resting state of integrins whereas stable FLNa-Ig21/αM CT binary complex perhaps be required for the activated state. GENERAL SIGNIFICANCE Filamin binding to both α and β CTs of other integrins could be essential in regulating bidirectional signaling mechanisms.
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Affiliation(s)
- Lewis Lu Zhiping
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Li-Teng Ong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Deepak Chatterjee
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Suet-Mien Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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11
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Jensen RK, Bajic G, Sen M, Springer TA, Vorup-Jensen T, Andersen GR. Complement Receptor 3 Forms a Compact High-Affinity Complex with iC3b. THE JOURNAL OF IMMUNOLOGY 2021; 206:3032-3042. [PMID: 34117107 DOI: 10.4049/jimmunol.2001208] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 04/13/2021] [Indexed: 11/19/2022]
Abstract
Complement receptor 3 (CR3, also known as Mac-1, integrin αMβ2, or CD11b/CD18) is expressed on a subset of myeloid and certain activated lymphoid cells. CR3 is essential for the phagocytosis of complement-opsonized particles such as pathogens and apoptotic or necrotic cells opsonized with the complement fragment iC3b and, to a lesser extent, C3dg. Although the interaction between the iC3b thioester domain and the ligand binding CR3 αM I-domain is structurally and functionally well characterized, the nature of additional CR3-iC3b interactions required for phagocytosis of complement-opsonized objects remains obscure. In this study, we analyzed the interaction between iC3b and the 150-kDa headpiece fragment of the CR3 ectodomain. Surface plasmon resonance experiments demonstrated a 30 nM affinity of the CR3 headpiece for iC3b compared with 515 nM for the iC3b thioester domain, whereas experiments monitoring binding of iC3b to CR3-expressing cells suggested an affinity of 50 nM for the CR3-iC3b interaction. Small angle x-ray scattering analysis revealed that iC3b adopts an extended but preferred conformation in solution. Upon interaction with CR3, iC3b rearranges to form a compact receptor-ligand complex. Overall, the data suggest that the iC3b-CR3 interaction is of high affinity and relies on minor contacts formed between CR3 and regions outside the iC3b thioester domain. Our results rationalize the more efficient phagocytosis elicited by iC3b than by C3dg and pave the way for the development of specific therapeutics for the treatment of inflammatory and neurodegenerative diseases that do not interfere with the recognition of noncomplement CR3 ligands.
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Affiliation(s)
- Rasmus K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Goran Bajic
- Laboratory of Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA.,Department of Pediatrics, Harvard Medical School, Boston, MA.,Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Mehmet Sen
- Department of Biology and Biochemistry, University of Houston, Houston, TX
| | - Timothy A Springer
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA; and
| | | | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark;
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12
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Lokki AI, Teirilä L, Triebwasser M, Daly E, Bhattacharjee A, Uotila L, Llort Asens M, Kurki MI, Perola M, Auro K, Salmon JE, Daly M, Atkinson JP, Laivuori H, Fagerholm S, Meri S. Dysfunction of complement receptors CR3 (CD11b/18) and CR4 (CD11c/18) in pre-eclampsia: a genetic and functional study. BJOG 2021; 128:1282-1291. [PMID: 33539617 DOI: 10.1111/1471-0528.16660] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To study genetic variants and their function within genes coding for complement receptors in pre-eclampsia. DESIGN A case-control study. SETTING Pre-eclampsia is a common vascular disease of pregnancy. The clearance of placenta-derived material is one of the functions of the complement system in pregnancy. POPULATION We genotyped 500 women with pre-eclamptic pregnancies and 190 pregnant women without pre-eclampsia, as controls, from the FINNPEC cohort, and 122 women with pre-eclamptic pregnancies and 1905 controls from the national FINRISK cohort. METHODS The functional consequences of genotypes discovered by targeted exomic sequencing were explored by analysing the binding of the main ligand iC3b to mutated CR3 or CR4, which were transiently expressed on the surface of COS-1 cells. MAIN OUTCOME MEASURES Allele frequencies were compared between pre-eclamptic pregnancies and controls in genetic studies. The functional consequences of selected variants were measured by binding assays. RESULTS The most significantly pre-eclampsia-linked CR3 variant M441K (P = 4.27E-4, OR = 1.401, 95% CI = 1.167-1.682) displayed a trend of increased adhesion to iC3b (P = 0.051). The CR4 variant A251T was found to enhance the adhesion of CR4 to iC3b, whereas W48R resulted in a decrease of the binding of CR4 to iC3b. CONCLUSIONS Results suggest that changes in complement-facilitated phagocytosis are associated with pre-eclampsia. Further studies are needed to ascertain whether aberrant CR3 and CR4 activity leads to altered pro- and anti-inflammatory cytokine responses in individuals carrying the associated variants, and the role of these receptors in pre-eclampsia pathogenesis. TWEETABLE ABSTRACT Genetic variants of complement receptors CR3 and CR4 have functional consequences that are associated with pre-eclampsia.
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Affiliation(s)
- A I Lokki
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Department of Obstetrics and Gynecology, Faculty of Medicine and Health Technology, Tampere University Hospital, Tampere University, Tampere, Finland
| | - L Teirilä
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Bacteriology and immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - M Triebwasser
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, Saint Louis, MO, USA
| | - E Daly
- Hospital and Harvard Medical School, Boston, MA, USA
| | - A Bhattacharjee
- Herantis Pharma Plc, Espoo, Finland.,Neuroscience Center, HiLife, University of Helsinki, Helsinki, Finland
| | - L Uotila
- Research Services, University of Helsinki, Helsinki, Finland
| | - M Llort Asens
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - M I Kurki
- Neurosurgery of Neuro Center, Kuopio University Hospital, Finland.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - M Perola
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - K Auro
- Department of Government Services, National Institute for Health and Welfare, Helsinki, Finland
| | - J E Salmon
- Hospital for Special Surgery-Weill Cornell Medicine, Department of Medicine, New York, NY, USA
| | - M Daly
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - J P Atkinson
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, Saint Louis, MO, USA
| | - H Laivuori
- Department of Obstetrics and Gynecology, Faculty of Medicine and Health Technology, Tampere University Hospital, Tampere University, Tampere, Finland.,Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.,Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - S Fagerholm
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - S Meri
- Translational Immunology Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Bacteriology and immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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- Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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13
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Microglia mediated neuroinflammation in autism spectrum disorder. J Psychiatr Res 2020; 130:167-176. [PMID: 32823050 DOI: 10.1016/j.jpsychires.2020.07.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/09/2020] [Accepted: 07/15/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Although the precise pathophysiologies underlying autism spectrum disorder (ASD) has not yet been fully clarified, growing evidence supports the involvement of neuroinflammation in the pathogenesis of this disorder, with microglia being particular relevance in the pathophysiologic processes. OBJECTIVE The present review aimed to systematically characterize existing literature regarding the role of microglia mediated neuroinflammation in the etiology of ASD. METHODS A systematic search was conducted for records indexed within Pubmed, EMBASE, or Web of Science to identify potentially eligible publications. Study selection and data extraction were performed by two authors, and the discrepancies in each step were settled through discussions. RESULTS A total of 14 studies comprising 1007 subjects met the eligibility criteria for this review, including 8 immunohistochemistry (IHC) studies, 5 genetic analysis studies, and 1 positron emission tomography (PET) studies. Although small in quantity, the included studies collectively pointed to a role of microglia mediated neuroinflammation in the pathogenesis of ASD. CONCLUSION Findings generated from this review consistently supported the involvement of neuroinflammation in the development of ASD, confirmed by the activation of microglia in different brain regions, involving increased cell number or cell density, morphological alterations, and phenotypic shifts.
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14
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Abstract
PURPOSE OF REVIEW The aim of this review is to discuss recent developments in our understanding of how systemic lupus erythematosus (SLE)-associated genes contribute to autoimmunity. RECENT FINDINGS Gene-function studies have revealed mechanisms through which SLE-associated alleles of IFIH1, TNFAIP3, IRF5, and PRDM1 likely contribute to the development of autoimmunity. Novel research has identified Mac-1 (encoded by ITGAM), CaMK4, and iRhom2 as plausible therapeutic targets in lupus nephritis. SUMMARY The work discussed in this review has broad implications for our understanding of the pathogenesis of SLE and for the development of novel therapeutic strategies.
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15
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Age-related macular degeneration: A two-level model hypothesis. Prog Retin Eye Res 2019; 76:100825. [PMID: 31899290 DOI: 10.1016/j.preteyeres.2019.100825] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 02/08/2023]
Abstract
Age-related diseases, including age-related macular degeneration (AMD), are of growing importance in a world where population ageing has become a dominant global trend. Although a wide variety of risk factors for AMD have been identified, age itself remains by far the most important risk factor, making it an urgent priority to understand the connections between underlying ageing mechanisms and pathophysiology of AMD. Ageing is both multicausal and variable, so that differences between individuals in biological ageing processes are the focus of a growing number of pathophysiological studies seeking to explain how ageing contributes to chronic, age-related conditions. The aim of this review is to integrate the available knowledge on the pathophysiology of AMD within the framework of the biology of ageing. One highly significant feature of biological ageing is systemic inflammation, which arises as a second-level response to a first level of molecular damage involving oxidative stress, mutations etc. Combining these insights, the various co-existing pathophysiological explanations in AMD arrange themselves according to a two-level hypothesis. Accordingly, we describe how AMD can be considered the consequence of age-related random accumulation of molecular damage at the ocular level and the subsequent systemic inflammatory host response thereof. We summarize evidence and provide original data to enlighten where evidence is lacking. Finally, we discuss how this two-level hypothesis provides a foundation for thoughts and future studies in prevention, prognosis, and intervention.
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16
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Regulation of the complement system and immunological tolerance in pregnancy. Semin Immunol 2019; 45:101337. [PMID: 31757607 DOI: 10.1016/j.smim.2019.101337] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/24/2019] [Indexed: 12/18/2022]
Abstract
Preeclampsia is a serious vascular complication of the human pregnancy, whose etiology is still poorly understood. In preeclampsia, exacerbated apoptosis and fragmentation of the placental tissue occurs due to developmental qualities of the placental trophoblast cells and/or mechanical and oxidative distress to the syncytiotrophoblast, which lines the placental villi. Dysregulation of the complement system is recognized as one of the mechanisms of the disease pathology. Complement has the ability to promote inflammation and facilitate phagocytosis of placenta-derived particles and apoptotic cells by macrophages. In preeclampsia, an overload of placental cell damage or dysregulated complement system may lead to insufficient clearance of apoptotic particles and placenta-derived debris. Excess placental damage may lead to sequestration of microparticles, such as placental vesicles, to capillaries in the glomeruli of the kidney and other vulnerable tissues. This phenomenon could contribute to the manifestations of typical diagnostic symptoms of preeclampsia: proteinuria and new-onset hypertension. In this review we propose that the complement system may serve as a regulator of the complex tolerance and clearance processes that are fundamental in healthy pregnancy. It is therefore recommended that further research be conducted to elucidate the interactions between components of the complement system and immune responses in the context of complicated and healthy pregnancy.
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17
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Mice expressing the variant rs1143679 allele of ITGAM (CD11b) show impaired DC-mediated T cell proliferation. Mamm Genome 2019; 30:245-259. [PMID: 31673770 PMCID: PMC6842653 DOI: 10.1007/s00335-019-09819-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/03/2019] [Indexed: 11/09/2022]
Abstract
Genome-wide association studies (GWAS) and functional genomic analyses have implicated several ITGAM (CD11b) single-nucleotide polymorphisms (SNPs) in the development of SLE and other disorders. ITGAM encodes the αM chain of the β2 integrin Mac-1, a receptor that plays important roles in myeloid cell functions. The ITGAM SNP rs1143679, which results in an arginine to histidine change at amino acid position 77 of the CD11b protein, has been shown to reduce binding to several ligands and to alter Mac-1-mediated cellular response in vitro. Importantly, however, the potential contribution of this SNP variant to the initiation and/or progression of immune and inflammatory processes in vivo remains unexplored. Herein, we describe for the first time the generation and characterization of a mouse line expressing the 77His variant of CD11b. Surprisingly, we found that 77His did not significantly affect Mac-1-mediated leukocyte migration and activation as assessed using thioglycollate-induced peritonitis and LPS/TNF-α-induced dermal inflammation models. In contrast, expression of this variant did alter T cell immunity, as evidenced by significantly reduced proliferation of ovalbumin (OVA)-specific transgenic T cells in 77His mice immunized with OVA. Reduced antigen-specific T cell proliferation was also observed when either 77His splenic dendritic cells (DCs) or bone marrow-derived DCs were used as antigen-presenting cells (APCs). Although more work is necessary to determine how this alteration might influence the development of SLE or other diseases, these in vivo findings suggest that the 77His variant of CD11b can compromise the ability of DCs to induce antigen-driven T cell proliferation.
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18
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Fagerholm SC, Guenther C, Llort Asens M, Savinko T, Uotila LM. Beta2-Integrins and Interacting Proteins in Leukocyte Trafficking, Immune Suppression, and Immunodeficiency Disease. Front Immunol 2019; 10:254. [PMID: 30837997 PMCID: PMC6389632 DOI: 10.3389/fimmu.2019.00254] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/29/2019] [Indexed: 12/21/2022] Open
Abstract
Beta2-integrins are complex leukocyte-specific adhesion molecules that are essential for leukocyte (e.g., neutrophil, lymphocyte) trafficking, as well as for other immunological processes such as neutrophil phagocytosis and ROS production, and T cell activation. Intriguingly, however, they have also been found to negatively regulate cytokine responses, maturation, and migratory responses in myeloid cells such as macrophages and dendritic cells, revealing new, and unexpected roles of these molecules in immunity. Because of their essential role in leukocyte function, a lack of expression or function of beta2-integrins causes rare immunodeficiency syndromes, Leukocyte adhesion deficiency type I, and type III (LAD-I and LAD-III). LAD-I is caused by reduced or lost expression of beta2-integrins, whilst in LAD-III, beta2-integrins are expressed but dysfunctional because a major integrin cytoplasmic regulator, kindlin-3, is mutated. Interestingly, some LAD-related phenotypes such as periodontitis have recently been shown to be due to an uncontrolled inflammatory response rather than to an uncontrolled infection, as was previously thought. This review will focus on the recent advances concerning the regulation and functions of beta2-integrins in leukocyte trafficking, immune suppression, and immune deficiency disease.
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Affiliation(s)
- Susanna C Fagerholm
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Carla Guenther
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Marc Llort Asens
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | | | - Liisa M Uotila
- Research Services, University of Helsinki, Helsinki, Finland
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19
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Exploring the etiopathogenesis of systemic lupus erythematosus: a genetic perspective. Immunogenetics 2019; 71:283-297. [DOI: 10.1007/s00251-019-01103-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/07/2019] [Indexed: 12/27/2022]
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20
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Gupta V, Kumar S, Pratap A, Singh R, Kumari R, Kumar S, Aggarwal A, Misra R. Association of ITGAM, TNFSF4, TNFAIP3 and STAT4 gene polymorphisms with risk of systemic lupus erythematosus in a North Indian population. Lupus 2018; 27:1973-1979. [DOI: 10.1177/0961203318786432] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several susceptibility genes have been associated with systemic lupus erythematosus (SLE) across different populations worldwide. However, data on association between genetic polymorphisms and SLE from Indian population is scarce. We aimed to replicate the association of single nucleotide polymorphisms (SNPs) in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes with susceptibility to SLE in a North Indian population. Three hundred and ninety-four SLE patients and 583 unrelated healthy controls of the same ethnic background were enrolled. All samples were genotyped for SNPs in ITGAM (rs1143679), TNFSF4 (rs2205960), TNFAIP3 (rs5029939) and STAT4 (rs7574865) using TaqMan genotyping assay. At allele level, significant association with susceptibility to SLE was detected with polymorphisms in ITGAM (A vs. G, odds ratio (OR) = 1.73, 95% confidence interval (CI) = 1.30–2.30, p < 0.001), TNFSF4 (T vs. G, OR = 1.33, 95% CI = 1.08–1.64, p < 0.01), TNFAIP3 (G vs. C, OR = 1.91, 95% CI = 1.27–2.85, p < 0.01) and STAT4 (T vs. G, OR = 1.38, 95% CI = 1.13–1.69, p < 0.01). All four SNPs were associated with SLE under a dominant model with an OR of 1.47 (95% CI = 1.07–2.04, p < 0.05) for ITGAM, 1.30 (95% CI = 1.01–1.69, p < 0.05) for TNFSF4, 1.90 (95% CI = 1.25–2.90, p < 0.01) for TNFAIP3 and 1.38 (95% CI = 1.06–1.78, p < 0.05) for STAT4. Under a recessive model, significant association was found with ITGAM (OR = 4.87, 95% CI = 2.17–10.91, p < 0.001), TNFSF4 (OR = 1.84, 95% CI = 1.13–3.00, p < 0.05) and STAT4 (OR = 1.82, 95% CI = 1.19–2.77, p < 0.01). In conclusion, single nucleotide polymorphisms in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes are associated with susceptibility to SLE in a North Indian population.
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Affiliation(s)
- V Gupta
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - S Kumar
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - A Pratap
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - R Singh
- Department of Biochemistry, King George’s Medical University, Lucknow, India
| | - R Kumari
- Department of Biochemistry, King George’s Medical University, Lucknow, India
| | - S Kumar
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - A Aggarwal
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - R Misra
- Department of Clinical Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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21
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Timóteo RP, Silva AF, Micheli DC, Candido Murta EF, Freire M, Teodoro RB, Lima FM, Martins Tavares Murta B, Bertoncello D. Increased flexibility, pain reduction and unaltered levels of IL-10 and CD11b + lymphocytes in patients with systemic lupus erythematosus were associated with kinesiotherapy. Lupus 2018; 27:1159-1168. [DOI: 10.1177/0961203318768880] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of physical activity on the immune system is still poorly understood in cases of systemic lupus erythematosus (SLE). Therefore, our aim was to investigate differences in the serum levels of cytokines (IL-2, IL-5, IL-6, IL-8, IL-10 and TNF-α) and the numbers of CD11b + and CXCR2 + neutrophils and lymphocytes in women with SLE undergoing drug treatment, without ( n = 9) or with ( n = 5) 4 months of kinesiotherapy. Parameters related to functional capacity were also analyzed. In the case of the patients who were not submitted to kinesiotherapy, there were reductions in the levels of IL-5, IL-6 and IL-10, and an increase in the number of CD11b + leukocytes, in addition to an increase in abdominal circumference after the monitoring time. Patients submitted to kinesiotherapy did not present changes in serum cytokines or in the numbers of CD11b + and CXCR2 + neutrophils and lymphocytes, but there were increases of flexibility and strength, as well as a reduction in pain sensation after the monitoring time. In conclusion, kinesiotherapy was able to increase flexibility and reduce pain in SLE patients without influencing immune parameters.
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Affiliation(s)
- R Pessato Timóteo
- Discipline of Special Pathology, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - A Ferreira Silva
- Department of Applied Physical Therapy, Institute of Health Sciences, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - D Côbo Micheli
- Department of Biochemistry, Pharmacology and Physiology, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - E F Candido Murta
- Research Institute of Oncology (IPON)/Discipline of Gynecology and Obstetrics, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - M Freire
- Discipline of Rheumatology, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - R Botelho Teodoro
- Discipline of Rheumatology, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - F M Lima
- Department of Applied Physical Therapy, Institute of Health Sciences, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - B Martins Tavares Murta
- Department of Biochemistry, Pharmacology and Physiology, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
| | - D Bertoncello
- Department of Applied Physical Therapy, Institute of Health Sciences, Universidade Federal do Triangulo Mineiro, Uberaba, Brazil
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22
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Khan SQ, Khan I, Gupta V. CD11b Activity Modulates Pathogenesis of Lupus Nephritis. Front Med (Lausanne) 2018; 5:52. [PMID: 29600248 PMCID: PMC5862812 DOI: 10.3389/fmed.2018.00052] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 02/13/2018] [Indexed: 01/01/2023] Open
Abstract
Lupus nephritis (LN) is a common complication of systemic lupus erythematosus (SLE) with unclear etiology and limited treatment options. Immune cell infiltration into the kidneys, a hallmark of LN, triggers tissue damage and proteinuria. CD11b, the α-chain of integrin receptor CD11b/CD18 (also known as αMβ2, Mac-1, and CR3), is highly expressed on the surface of innate immune cells, including macrophages and neutrophils. Genetic variants in the human ITGAM gene, which encodes for CD11b, are strongly associated with susceptibility to SLE, LN, and other complications of SLE. CD11b modulates several key biological functions in innate immune cells, including cell adhesion, migration, and phagocytosis. CD11b also modulates other signaling pathways in these cells, such as the Toll-like receptor signaling pathways, that mediate generation of type I interferons, a key proinflammatory cytokine and circulating biomarker in SLE and LN patients. However, how variants in ITGAM gene contribute to disease pathogenesis has not been completely established. Here, we provide an overview of CD11b modulated mechanisms and the functional consequences of the genetic variants that can drive disease pathogenesis. We also present recent insights from studies after pharmacological activation of CD11b. These studies offer novel mechanisms for development of therapeutics for LN, SLE and other autoimmune diseases.
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Affiliation(s)
- Samia Q Khan
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, IL, United States
| | - Imran Khan
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, IL, United States
| | - Vineet Gupta
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical School, Chicago, IL, United States
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23
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Li C, Tong F, Ma Y, Qian K, Zhang J, Chen X. Association of the CD11b rs1143679 polymorphism with systemic lupus erythematosus in the Han Chinese population. J Int Med Res 2017; 46:1008-1014. [PMID: 29207897 PMCID: PMC5972232 DOI: 10.1177/0300060517719210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Objective To investigate the association of the CD11b single nucleotide polymorphism (SNP) rs1143679 with systemic lupus erythematosus (SLE) in Han Chinese patients, and to clarify this association with SLE clinical manifestations. Methods PCR–restriction fragment length polymorphism and direct sequencing of CD11b rs1143679 were conducted in 584 patients with SLE and 628 healthy controls in this case–control study to compare genotype and allele frequency distributions. Correlations between CD11b genotypes and clinical manifestations were also determined. Results The frequency of the CD11b rs1143679 GA genotype was 1.89% in Han Chinese patients with SLE, which was much lower than that of European and American populations, but close to the frequency observed in individuals from Hong Kong and Thailand. The CD11b rs1143679 GA genotype was also shown to confer susceptibility to SLE (odds ratio = 4.00, 95% confidence interval = 1.11–14.41). CD11b rs1143679 was found to be significantly associated with nephritis, but not with age of disease onset, arthritis, hematological involvement, or neural lesions. Conclusion CD11b rs1143679 appears to be associated with risk for SLE in the Han Chinese population, and may play an important role in the development of lupus nephritis.
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Affiliation(s)
- Chunmei Li
- 1 Department of Rheumatology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | | | - Yi Ma
- 1 Department of Rheumatology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Kai Qian
- 1 Department of Rheumatology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Junyu Zhang
- 1 Department of Rheumatology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Xingguo Chen
- 1 Department of Rheumatology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
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Non-identical twins: Different faces of CR3 and CR4 in myeloid and lymphoid cells of mice and men. Semin Cell Dev Biol 2017; 85:110-121. [PMID: 29174917 DOI: 10.1016/j.semcdb.2017.11.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 01/08/2023]
Abstract
Integrins are cell membrane receptors that are involved in essential physiological and serious pathological processes. Their main role is to ensure a closely regulated link between the extracellular matrix and the intracellular cytoskeletal network enabling cells to react to environmental stimuli. Complement receptor type 3 (CR3, αMβ2, CD11b/CD18) and type 4 (CR4, αXβ2, CD11c/CD18) are members of the β2-integrin family expressed on most white blood cells. Both receptors bind multiple ligands like iC3b, ICAM, fibrinogen or LPS. β2-integrins are accepted to play important roles in cellular adhesion, migration, phagocytosis, ECM rearrangement and inflammation. Several pathological conditions are linked to the impaired functions of these receptors. CR3 and CR4 are generally thought to mediate overlapping functions in monocytes, macrophages and dendritic cells, therefore the potential distinctive role of these receptors has not been investigated so far in satisfactory details. Lately it has become clear that a functional segregation has evolved between the two receptors regarding phagocytosis, cellular adhesion and podosome formation. In addition to their tasks on myeloid cells, the expression and function of CR3 and CR4 on lymphocytes have also gained interest recently. The picture is further complicated by the fact that while these β2-integrins are expressed by immune cells both in mice and humans, there are significant differences in their expression level, functions and the pathological consequences of genetic defects. Here we aim to summarize our current knowledge on CR3 and CR4 and highlight the functional differences between these receptors, involving their expression in myeloid and lymphoid cells of both men and mice.
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25
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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: 91] [Impact Index Per Article: 13.0] [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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26
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Faridi MH, Khan SQ, Zhao W, Lee HW, Altintas MM, Zhang K, Kumar V, Armstrong AR, Carmona-Rivera C, Dorschner JM, Schnaith AM, Li X, Ghodke-Puranik Y, Moore E, Purmalek M, Irizarry-Caro J, Zhang T, Day R, Stoub D, Hoffmann V, Khaliqdina SJ, Bhargava P, Santander AM, Torroella-Kouri M, Issac B, Cimbaluk DJ, Zloza A, Prabhakar R, Deep S, Jolly M, Koh KH, Reichner JS, Bradshaw EM, Chen J, Moita LF, Yuen PS, Li Tsai W, Singh B, Reiser J, Nath SK, Niewold TB, Vazquez-Padron RI, Kaplan MJ, Gupta V. CD11b activation suppresses TLR-dependent inflammation and autoimmunity in systemic lupus erythematosus. J Clin Invest 2017; 127:1271-1283. [PMID: 28263189 PMCID: PMC5373862 DOI: 10.1172/jci88442] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 01/13/2017] [Indexed: 12/16/2022] Open
Abstract
Genetic variations in the ITGAM gene (encoding CD11b) strongly associate with risk for systemic lupus erythematosus (SLE). Here we have shown that 3 nonsynonymous ITGAM variants that produce defective CD11b associate with elevated levels of type I interferon (IFN-I) in lupus, suggesting a direct link between reduced CD11b activity and the chronically increased inflammatory status in patients. Treatment with the small-molecule CD11b agonist LA1 led to partial integrin activation, reduced IFN-I responses in WT but not CD11b-deficient mice, and protected lupus-prone MRL/Lpr mice from end-organ injury. CD11b activation reduced TLR-dependent proinflammatory signaling in leukocytes and suppressed IFN-I signaling via an AKT/FOXO3/IFN regulatory factor 3/7 pathway. TLR-stimulated macrophages from CD11B SNP carriers showed increased basal expression of IFN regulatory factor 7 (IRF7) and IFN-β, as well as increased nuclear exclusion of FOXO3, which was suppressed by LA1-dependent activation of CD11b. This suggests that pharmacologic activation of CD11b could be a potential mechanism for developing SLE therapeutics.
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Affiliation(s)
- Mohd Hafeez Faridi
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Samia Q. Khan
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Wenpu Zhao
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Ha Won Lee
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Mehmet M. Altintas
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Kun Zhang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Vinay Kumar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Andrew R. Armstrong
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Carmelo Carmona-Rivera
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | | | | | - Xiaobo Li
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | | | - Erica Moore
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Monica Purmalek
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Jorge Irizarry-Caro
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Tingting Zhang
- Department of Chemistry, University of Miami, Coral Gables, Florida, USA
| | - Rachael Day
- Department of Chemistry and Biochemistry, Dordt College, Sioux Center, Iowa, USA
| | - Darren Stoub
- Department of Chemistry and Biochemistry, Dordt College, Sioux Center, Iowa, USA
| | - Victoria Hoffmann
- Pathology Branch, Division of Veterinary Resources, Office of the Director, NIH, Bethesda, Maryland, USA
| | | | - Prachal Bhargava
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Ana M. Santander
- Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Marta Torroella-Kouri
- Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Biju Issac
- Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - David J. Cimbaluk
- Department of Pathology, Rush University Medical School, Chicago, Illinois, USA
| | - Andrew Zloza
- Section of Surgical Oncology Research, Rutgers Cancer Institute of New Jersey, and Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, Coral Gables, Florida, USA
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Meenakshi Jolly
- Division of Rheumatology, Department of Internal Medicine, Rush University Medical School, Chicago, Illinois, USA
| | - Kwi Hye Koh
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Jonathan S. Reichner
- Division of Surgical Research, Department of Surgery, Rhode Island Hospital, Providence, Rhode Island, USA
| | - Elizabeth M. Bradshaw
- Division of Immunology, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - JianFeng Chen
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Luis F. Moita
- Innate Immune and Inflammation Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Peter S. Yuen
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, USA
| | - Wanxia Li Tsai
- Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Bhupinder Singh
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - Jochen Reiser
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Swapan K. Nath
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | | | | | - Mariana J. Kaplan
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Vineet Gupta
- Drug Discovery Center, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA
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27
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Ong LT, Tan HF, Feng C, Qu J, Loh SC, Bhattacharyya S, Tan SM. The Systemic Lupus Erythematosus–Associated Single Nucleotide Polymorphism rs1143678 in Integrin αMCytoplasmic Tail Generates a 14-3-3ζ Binding Site That Is Proinflammatory. THE JOURNAL OF IMMUNOLOGY 2016; 198:883-894. [DOI: 10.4049/jimmunol.1601447] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/16/2016] [Indexed: 02/02/2023]
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28
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Kröger W, Mapiye D, Entfellner JBD, Tiffin N. A meta-analysis of public microarray data identifies gene regulatory pathways deregulated in peripheral blood mononuclear cells from individuals with Systemic Lupus Erythematosus compared to those without. BMC Med Genomics 2016; 9:66. [PMID: 27846842 PMCID: PMC5111272 DOI: 10.1186/s12920-016-0227-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 10/21/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Systemic Lupus Erythematosus (SLE) is a complex, multi-systemic, autoimmune disease for which the underlying aetiological mechanisms are poorly understood. The genetic and molecular processes underlying lupus have been extensively investigated using a variety of -omics approaches, including genome-wide association studies, candidate gene studies and microarray experiments of differential gene expression in lupus samples compared to controls. METHODS This study analyses a combination of existing microarray data sets to identify differentially regulated genetic pathways that are dysregulated in human peripheral blood mononuclear cells from SLE patients compared to unaffected controls. Two statistical approaches, quantile discretisation and scaling, are used to combine publicly available expression microarray datasets and perform a meta-analysis of differentially expressed genes. RESULTS Differentially expressed genes implicated in interferon signaling were identified by the meta-analysis, in agreement with the findings of the individual studies that generated the datasets used. In contrast to the individual studies, however, the meta-analysis and subsequent pathway analysis additionally highlighted TLR signaling, oxidative phosphorylation and diapedesis and adhesion regulatory networks as being differentially regulated in peripheral blood mononuclear cells (PBMCs) from SLE patients compared to controls. CONCLUSION Our analysis demonstrates that it is possible to derive additional information from publicly available expression data using meta-analysis techniques, which is particularly relevant to research into rare diseases where sample numbers can be limiting.
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Affiliation(s)
- Wendy Kröger
- South African National Bioinformatics Institute/Medical Research Council of South Africa Bioinformatics Capacity Development Unit, University of the Western Cape, Cape Town, South Africa
| | - Darlington Mapiye
- South African National Bioinformatics Institute/Medical Research Council of South Africa Bioinformatics Capacity Development Unit, University of the Western Cape, Cape Town, South Africa
| | - Jean-Baka Domelevo Entfellner
- South African National Bioinformatics Institute/Medical Research Council of South Africa Bioinformatics Capacity Development Unit, University of the Western Cape, Cape Town, South Africa
| | - Nicki Tiffin
- South African National Bioinformatics Institute/Medical Research Council of South Africa Bioinformatics Capacity Development Unit, University of the Western Cape, Cape Town, South Africa
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29
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Caracterização de marcadores inflamatórios associados a pacientes com lúpus eritematoso sistêmico em tratamento. REVISTA BRASILEIRA DE REUMATOLOGIA 2016. [DOI: 10.1016/j.rbr.2015.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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30
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Fan Z, Ley K. Leukocyte arrest: Biomechanics and molecular mechanisms of β2 integrin activation. Biorheology 2016; 52:353-77. [PMID: 26684674 DOI: 10.3233/bir-15085] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Integrins are a group of heterodimeric transmembrane receptors that play essential roles in cell-cell and cell-matrix interaction. Integrins are important in many physiological processes and diseases. Integrins acquire affinity to their ligand by undergoing molecular conformational changes called activation. Here we review the molecular biomechanics during conformational changes of integrins, integrin functions in leukocyte biorheology (adhesive functions during rolling and arrest) and molecules involved in integrin activation.
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Affiliation(s)
- Zhichao Fan
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.,Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
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31
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Abstract
Mac-1 (CD11b/CD18) is a β2 integrin classically regarded as a pro-inflammatory molecule because of its ability to promote phagocyte cytotoxic functions and enhance the function of several effector molecules such as FcγR, uPAR, and CD14. Nevertheless, recent reports have revealed that Mac-1 also plays significant immunoregulatory roles, and genetic variants in ITGAM, the gene that encodes CD11b, confer risk for the autoimmune disease systemic lupus erythematosus (SLE). This has renewed interest in the physiological roles of this integrin and raised new questions on how its seemingly opposing biological functions may be regulated. Here, we provide an overview of the CD18 integrins and how their activation may be regulated as this may shed light on how the opposing roles of Mac-1 may be elicited. We then discuss studies that exemplify Mac-1's pro-inflammatory versus regulatory roles particularly in the context of IgG immune complex-mediated inflammation. This includes a detailed examination of molecular mechanisms that could explain the risk-conferring effect of rs1143679, a single nucleotide non-synonymous Mac-1 polymorphism associated with SLE.
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Affiliation(s)
- Florencia Rosetti
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Tanya N Mayadas
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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32
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Sándor N, Lukácsi S, Ungai-Salánki R, Orgován N, Szabó B, Horváth R, Erdei A, Bajtay Z. CD11c/CD18 Dominates Adhesion of Human Monocytes, Macrophages and Dendritic Cells over CD11b/CD18. PLoS One 2016; 11:e0163120. [PMID: 27658051 PMCID: PMC5033469 DOI: 10.1371/journal.pone.0163120] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/03/2016] [Indexed: 12/13/2022] Open
Abstract
Complement receptors CR3 (CD11b/CD18) and CR4 (CD11c/CD18) belong to the family of beta2 integrins and are expressed mainly by myeloid cell types in humans. Previously, we proved that CR3 rather than CR4 plays a key role in phagocytosis. Here we analysed how CD11b and CD11c participate in cell adhesion to fibrinogen, a common ligand of CR3 and CR4, employing human monocytes, monocyte-derived macrophages (MDMs) and monocyte-derived dendritic cells (MDDCs) highly expressing CD11b as well as CD11c. We determined the exact numbers of CD11b and CD11c on these cell types by a bead-based technique, and found that the ratio of CD11b/CD11c is 1.2 for MDDCs, 1.7 for MDMs and 7.1 for monocytes, suggesting that the function of CD11c is preponderant in MDDCs and less pronounced in monocytes. Applying state-of-the-art biophysical techniques, we proved that cellular adherence to fibrinogen is dominated by CD11c. Furthermore, we found that blocking CD11b significantly enhances the attachment of MDDCs and MDMs to fibrinogen, demonstrating a competition between CD11b and CD11c for this ligand. On the basis of the cell surface receptor numbers and the measured adhesion strength we set up a model, which explains the different behavior of the three cell types.
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Affiliation(s)
- Noémi Sándor
- MTA-ELTE Immunology Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Szilvia Lukácsi
- Department of Immunology, Institute of Biology, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
| | - Rita Ungai-Salánki
- Department of Biological Physics, Institute of Physics, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
| | - Norbert Orgován
- Nanobiosensorics “Lendület” Group, Institute of Technical Physics and Material Sciences, Centre for Energy Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Bálint Szabó
- Department of Biological Physics, Institute of Physics, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
| | - Róbert Horváth
- Nanobiosensorics “Lendület” Group, Institute of Technical Physics and Material Sciences, Centre for Energy Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Immunology, Institute of Biology, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
| | - Zsuzsa Bajtay
- Department of Immunology, Institute of Biology, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
- * E-mail:
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Abstract
Systemic lupus erythematosus is a heterogeneous autoimmune disease marked by the presence of pathogenic autoantibodies, immune dysregulation, and chronic inflammation that may lead to increased morbidity and early mortality from end-organ damage. More than half of all systemic lupus erythematosus patients will develop lupus nephritis. Genetic-association studies have identified more than 50 polymorphisms that contribute to lupus nephritis pathogenesis, including genetic variants associated with altered programmed cell death and defective immune clearance of programmed cell death debris. These variants may support the generation of autoantibody-containing immune complexes that contribute to lupus nephritis. Genetic variants associated with lupus nephritis also affect the initial phase of innate immunity and the amplifying, adaptive phase of the immune response. Finally, genetic variants associated with the kidney-specific effector response may influence end-organ damage and the progression to end-stage renal disease and death. This review discusses genetic insights of key pathogenic processes and pathways that may lead to lupus nephritis, as well as the clinical implications of these findings as they apply to recent advances in biologic therapies.
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34
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Teruel M, Alarcón-Riquelme ME. The genetic basis of systemic lupus erythematosus: What are the risk factors and what have we learned. J Autoimmun 2016; 74:161-175. [PMID: 27522116 DOI: 10.1016/j.jaut.2016.08.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 08/02/2016] [Indexed: 12/19/2022]
Abstract
The genome-wide association study is a free-hypothesis approach based on screening of thousands or even millions of genetic variants distributed throughout the whole human genome in relation to a phenotype. The relevant role of the genome-wide association studies in the last decade is undisputed because it has permitted to elucidate multiple risk genetic factors associated with the susceptibility to several human complex diseases. Regarding systemic lupus erythematosus (SLE) this approach has allowed to identify more than 60 risk loci for SLE susceptibility across populations to date, increasing our understanding on the pathogenesis of this disease. We present the latest findings in the genetic of SLE across populations using genome-wide approaches. These studies revealed that most of the genetic risk is shared across borders and ethnicities. Finally, we focus on describing the most important risk loci for SLE attempting to cover the genetic findings in relation to functional polymorphisms, such as missense single nucleotide polymorphisms (SNPs) or regulatory variants involved in the development of the disease. The functional studies try to identify the causality of some GWAS-associated variants, many of which fall in non-coding regions of the genome, suggesting a regulatory role. Many loci show an environmental interaction, another aspect revealed by the studies of epigenetic modifications and those associated with genetic variants. Finally, new-generation sequencing technologies can open other paths in the research on SLE genetics, the role of rare variants and the detailed identification of causal regulatory variation. The clinical relevance of the genetic factors will be shown when we are able to use them or in combination with other molecular measurements to re-classify a heterogeneous disease such as SLE.
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Affiliation(s)
- Maria Teruel
- Center for Genomics and Oncological Research, GENYO, Pfizer/University of Granada/Andalusian Government, PTS, Granada, 18016, Spain.
| | - Marta E Alarcón-Riquelme
- Center for Genomics and Oncological Research, GENYO, Pfizer/University of Granada/Andalusian Government, PTS, Granada, 18016, Spain; Institute of Environmental Medicine, Karolinska Institute, Stockholm, 171 67, Sweden.
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35
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Roberts AL, Fürnrohr BG, Vyse TJ, Rhodes B. The complement receptor 3 (CD11b/CD18) agonist Leukadherin-1 suppresses human innate inflammatory signalling. Clin Exp Immunol 2016; 185:361-71. [PMID: 27118513 PMCID: PMC4991522 DOI: 10.1111/cei.12803] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 04/19/2016] [Accepted: 04/21/2016] [Indexed: 01/14/2023] Open
Abstract
Complement receptor 3 (CR3, CD11b/CD18) is a multi‐functional receptor expressed predominantly on myeloid and natural killer (NK) cells. The R77H variant of CD11b, encoded by the ITGAM rs1143679 polymorphism, is associated robustly with development of the autoimmune disease systemic lupus erythematosus (SLE) and impairs CR3 function, including its regulatory role on monocyte immune signalling. The role of CR3 in NK cell function is unknown. Leukadherin‐1 is a specific small‐molecule CR3 agonist that has shown therapeutic promise in animal models of vascular injury and inflammation. We show that Leukadherin‐1 pretreatment reduces secretion of interferon (IFN)‐γ, tumour necrosis factor (TNF) and macrophage inflammatory protein (MIP)‐1β by monokine‐stimulated NK cells. It was associated with a reduction in phosphorylated signal transducer and activator of transcription (pSTAT)‐5 following interleukin (IL)‐12 + IL‐15 stimulation (P < 0·02) and increased IL‐10 secretion following IL‐12 + IL‐18 stimulation (P < 0·001). Leukadherin‐1 pretreatment also reduces secretion of IL‐1β, IL‐6 and TNF by Toll‐like receptor (TLR)‐2 and TLR‐7/8‐stimulated monocytes (P < 0·01 for all). The R77H variant did not affect NK cell response to Leukadherin‐1 using ex‐vivo cells from homozygous donors; nor did the variant influence CR3 expression by these cell types, in contrast to a recent report. These data extend our understanding of CR3 biology by demonstrating that activation potently modifies innate immune inflammatory signalling, including a previously undocumented role in NK cell function. We discuss the potential relevance of this to the pathogenesis of SLE. Leukadherin‐1 appears to mediate its anti‐inflammatory effect irrespective of the SLE‐risk genotype of CR3, providing further evidence to support its evaluation of Leukadherin‐1 as a potential therapeutic for autoimmune disease.
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Affiliation(s)
- A L Roberts
- Division of Genetics and Molecular Medicine and Division of Infection, Immunity and Inflammatory Disease, King's College London, London, UK
| | - B G Fürnrohr
- Division of Genetics and Molecular Medicine and Division of Infection, Immunity and Inflammatory Disease, King's College London, London, UK.,Division of Biological Chemistry, Innrain 80/IV, Medical University Innsbruck, Innsbruck, Austria
| | - T J Vyse
- Division of Genetics and Molecular Medicine and Division of Infection, Immunity and Inflammatory Disease, King's College London, London, UK
| | - B Rhodes
- Division of Genetics and Molecular Medicine and Division of Infection, Immunity and Inflammatory Disease, King's College London, London, UK.,Department of Rheumatology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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36
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Characterization of inflammatory markers associated with systemic lupus erythematosus patients undergoing treatment. REVISTA BRASILEIRA DE REUMATOLOGIA 2016; 56:497-503. [PMID: 27914596 DOI: 10.1016/j.rbre.2016.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 12/20/2015] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE To characterize the inflammatory profiles of patients with systemic lupus erythematosus receiving standard treatment compared to healthy controls. PATIENTS AND METHODS Peripheral venous blood was collected from systemic lupus erythematosus patients (n=14) and controls (n=18) at enrollment. Blood samples were used for quantification, by flow cytometry, of CD11b (integrin) and Chemokine receptor CXCR2 expression surface antigen in neutrophils and lymphocytes, while cytokines were assayed in serum samples. Purified neutrophils were assayed by their ability to phagocytize human plasma-opsonized zymosan. RESULTS Patients had a median (interquartile range) disease activity index of 1.0 (0-2.0) characteristic of patients in remission. Interleukin-6 and interleukin-10 serum concentrations were significantly higher in the patient group compared to controls and the phagocytic index of circulating neutrophils was significantly reduced in patients compared to controls. The levels of interleukin-2, interleukin-5, interleukin-8 and tumor necrosis factor alpha did not significantly differ between patients and controls. Flow cytometric analysis revealed that the integrin expression levels were reduced in lymphocytes (but not in neutrophils) obtained from systemic lupus erythematosus patients, while surface expression of the chemokine receptor 2 was similar in both neutrophils and lymphocytes. CONCLUSION Systemic lupus erythematosus patients receiving standard treatment presented with elevated systemic levels of interleukin-6 and interleukin-10, reduced neutrophil phagocytic capacity, and reduced lymphocyte expression of integrin even when symptoms were in remission. These alterations to innate immune components may put these individuals at a greater risk for acquiring infections.
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Prechl J, Papp K, Hérincs Z, Péterfy H, Lóránd V, Szittner Z, Estonba A, Rovero P, Paolini I, Del Amo J, Uribarri M, Alcaro MC, Ruiz-Larrañaga O, Migliorini P, Czirják L. Serological and Genetic Evidence for Altered Complement System Functionality in Systemic Lupus Erythematosus: Findings of the GAPAID Consortium. PLoS One 2016; 11:e0150685. [PMID: 26950932 PMCID: PMC4780778 DOI: 10.1371/journal.pone.0150685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/18/2016] [Indexed: 11/30/2022] Open
Abstract
Systemic lupus erythematosus is a chronic autoimmune disease with multifactorial ethiopathogenesis. The complement system is involved in both the early and late stages of disease development and organ damage. To better understand autoantibody mediated complement consumption we examined ex vivo immune complex formation on autoantigen arrays. We recruited patients with SLE (n = 211), with other systemic autoimmune diseases (n = 65) and non-autoimmune control subjects (n = 149). Standard clinical and laboratory data were collected and serum complement levels were determined. The genotype of SNP rs1143679 in the ITGAM gene was also determined. Ex vivo formation of immune complexes, with respect to IgM, IgG, complement C4 and C3 binding, was examined using a functional immunoassay on autoantigen microarray comprising nucleic acids, proteins and lipids. Complement consumption of nucleic acids increased upon binding of IgM and IgG even when serum complement levels were decreased due to consumption in SLE patients. A negative correlation between serum complement levels and ex vivo complement deposition on nucleic acid autoantigens is demonstrated. On the contrary, complement deposition on tested protein and lipid autoantigens showed positive correlation with C4 levels. Genetic analysis revealed that the non-synonymous variant rs1143679 in complement receptor type 3 is associated with an increased production of anti-dsDNA IgG antibodies. Notwithstanding, homozygous carriers of the previously reported susceptible allele (AA) had lower levels of dsDNA specific IgM among SLE patients. Both the non-synonymous variant rs1143679 and the high ratio of nucleic acid specific IgG/IgM were associated with multiple organ involvement. In summary, secondary complement deficiency in SLE does not impair opsonization of nucleic-acid-containing autoantigens but does affect other antigens and potentially other complement dependent processes. Dysfunction of the receptor recognizing complement opsonized immune complexes promotes the development of class-switched autoantibodies targeting nucleic acids.
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Affiliation(s)
- József Prechl
- Diagnosticum Zrt, Budapest, Hungary.,MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary
| | - Krisztián Papp
- MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary
| | | | | | - Veronika Lóránd
- Department of Rheumatology and Immunology, Clinic Center, University of Pécs, Pécs, Hungary
| | - Zoltán Szittner
- MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary
| | - Andone Estonba
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, Bilbao, Spain
| | - Paolo Rovero
- Department of NeuroFarBa, University of Florence, Florence, Italy
| | | | - Jokin Del Amo
- Progenika Biopharma S.A., a Grifols Company, Derio, Bizkaia, Spain
| | - Maria Uribarri
- Progenika Biopharma S.A., a Grifols Company, Derio, Bizkaia, Spain
| | | | - Otsanda Ruiz-Larrañaga
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country, Bilbao, Spain
| | - Paola Migliorini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - László Czirják
- Department of Rheumatology and Immunology, Clinic Center, University of Pécs, Pécs, Hungary
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Interferon-gamma and nitric oxide synthase 2 mediate the aggregation of resident adherent peritoneal exudate cells: implications for the host response to pathogens. PLoS One 2015; 10:e0128301. [PMID: 26029930 PMCID: PMC4452304 DOI: 10.1371/journal.pone.0128301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 04/27/2015] [Indexed: 12/28/2022] Open
Abstract
Interferon-gamma (Ifnγ), a key macrophage activating cytokine, plays pleiotropic roles in host immunity. In this study, the ability of Ifnγ to induce the aggregation of resident mouse adherent peritoneal exudate cells (APECs), consisting primarily of macrophages, was investigated. Cell-cell interactions involve adhesion molecules and, upon addition of Ifnγ, CD11b re-localizes preferentially to the sites of interaction on APECs. A functional role of CD11b in enhancing aggregation is demonstrated using Reopro, a blocking reagent, and siRNA to Cd11b. Studies with NG-methyl-L-arginine (LNMA), an inhibitor of Nitric oxide synthase (Nos), NO donors, e.g., S-nitroso-N-acetyl-DL-penicillamine (SNAP) or Diethylenetriamine/nitric oxide adduct (DETA/NO), and Nos2-/- mice identified Nitric oxide (NO) induced by Ifnγ as a key regulator of aggregation of APECs. Further studies with Nos2-/- APECs revealed that some Ifnγ responses are independent of NO: induction of MHC class II and CD80. On the other hand, Nos2 derived NO is important for other functions: motility, phagocytosis, morphology and aggregation. Studies with cytoskeleton depolymerizing agents revealed that Ifnγ and NO mediate the cortical stabilization of Actin and Tubulin which contribute to aggregation of APECs. The biological relevance of aggregation of APECs was delineated using infection experiments with Salmonella Typhimurium (S. Typhimurium). APECs from orally infected, but not uninfected, mice produce high amounts of NO and aggregate upon ex vivo culture in a Nos2-dependent manner. Importantly, aggregated APECs induced by Ifnγ contain fewer intracellular S. Typhimurium compared to their single counterparts post infection. Further experiments with LNMA or Reopro revealed that both NO and CD11b are important for aggregation; in addition, NO is bactericidal. Overall, this study elucidates novel roles for Ifnγ and Nos2 in regulating Actin, Tubulin, CD11b, motility and morphology during the aggregation response of APECs. The implications of aggregation or “group behavior” of APECs are discussed in the context of host resistance to infectious organisms.
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Maggadottir SM, Li J, Glessner JT, Li YR, Wei Z, Chang X, Mentch FD, Thomas KA, Kim CE, Zhao Y, Hou C, Wang F, Jørgensen SF, Perez EE, Sullivan KE, Orange JS, Karlsen TH, Chapel H, Cunningham-Rundles C, Hakonarson H. Rare variants at 16p11.2 are associated with common variable immunodeficiency. J Allergy Clin Immunol 2015; 135:1569-77. [PMID: 25678086 PMCID: PMC4461447 DOI: 10.1016/j.jaci.2014.12.1939] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 12/24/2014] [Accepted: 12/31/2014] [Indexed: 12/27/2022]
Abstract
BACKGROUND Common variable immunodeficiency (CVID) is characterized clinically by inadequate quantity and quality of serum immunoglobulins with increased susceptibility to infections, resulting in significant morbidity and mortality. Only a few genes have been uncovered, and the genetic background of CVID remains elusive to date for the majority of patients. OBJECTIVE We sought to seek novel associations of genes and genetic variants with CVID. METHODS We performed association analyses in a discovery cohort of 164 patients with CVID and 19,542 healthy control subjects genotyped on the Immuno BeadChip from Illumina platform; replication of findings was examined in an independent cohort of 135 patients with CVID and 2,066 healthy control subjects, followed by meta-analysis. RESULTS We identified 11 single nucleotide polymorphisms (SNPs) at the 16p11.2 locus associated with CVID at a genome-wide significant level in the discovery cohort. The most significant SNP, rs929867 (P = 6.21 × 10(-9)), is in the gene fused-in-sarcoma (FUS), with 4 other SNPs mapping to integrin CD11b (ITGAM). Results were confirmed in our replication cohort. Conditional association analysis suggests a single association signal at the 16p11.2 locus. A strong trend of association was also seen for 38 SNPs (P < 5 × 10(-5)) in the MHC region, supporting that this is a genuine CVID locus. Interestingly, we found that 80% of patients with the rare ITGAM variants have reduced switched memory B-cell counts. CONCLUSION We report a novel association of CVID with rare variants at the FUS/ITGAM (CD11b) locus on 16p11.2. The association signal is enriched for promoter/enhancer markers in the ITGAM gene. ITGAM encodes the integrin CD11b, a part of complement receptor 3, a novel candidate gene implicated here for the first time in the pathogenesis of CVID.
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Affiliation(s)
- S Melkorka Maggadottir
- Division of Allergy and Immunology, Children's Hospital of Philadelphia, Philadelphia, Pa; Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Jin Li
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Joseph T Glessner
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Yun Rose Li
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa; Medical Scientist Training Program, Perelman School of Medicine Philadelphia, University of Pennsylvania, Philadelphia, Pa
| | - Zhi Wei
- Department of Computer Science, New Jersey Institute of Technology, Newark, NJ
| | - Xiao Chang
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Frank D Mentch
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Kelly A Thomas
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Cecilia E Kim
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Yan Zhao
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Cuiping Hou
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Fengxiang Wang
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Silje F Jørgensen
- K.G. Jebsen Inflammation Research Centre, Research Institute of Internal Medicine, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Elena E Perez
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, University of South Florida, St Petersburg, Fla
| | - Kathleen E Sullivan
- Division of Allergy and Immunology, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Jordan S Orange
- Section of Immunology, Allergy and Rheumatology, Texas Children's Hospital, Houston, Tex
| | - Tom H Karlsen
- K.G. Jebsen Inflammation Research Centre, Research Institute of Internal Medicine, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Helen Chapel
- Nuffield Department of Medicine, University of Oxford and Oxford Radcliffe Hospital, Oxford, United Kingdom
| | | | - Hakon Hakonarson
- Center for Applied Genomics, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, Pa; Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, Pa; Department of Pediatrics, Perelman School of Medicine Philadelphia, University of Pennsylvania, Philadelphia, Pa.
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Prechl J, Czirják L. The endothelial deprotection hypothesis for lupus pathogenesis: the dual role of C1q as a mediator of clearance and regulator of endothelial permeability. F1000Res 2015; 4:24. [DOI: 10.12688/f1000research.6075.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/26/2015] [Indexed: 11/20/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a heterogeneous multifactorial systemic autoimmune disease affecting several organs. SLE can start relatively early in life and results in impaired quality of life and shortened life expectancy because of a gradual disease progression leading to cardiovascular, renal and neoplastic disease. The basic mechanisms of the pathogenesis of the disease still remain to be clarified. It is clear that complement proteins play a key and complex role in the development of SLE. Complement component C1q has been known to be a fundamental component of lupus development, but most explanations focus on its role in apoptotic debris removal. Importantly, C1q was recently found to play a key role in the maintenance of vascular endothelial integrity.We suggest that apoptotic products, endothelial cells and extracellular matrix components, which display negatively charged moieties, compete for binding to molecules of the innate humoral immune response, like C1q. Genetic or acquired factors leading to an increased load of apoptotic cell debris and decrease or absence of C1q therefore interfere with the regulation of endothelial permeability and integrity. Furthermore, we suggest that lupus is the net result of an imbalance between the two functions of immune clearance and vascular endothelial integrity maintenance, an imbalance triggered and sustained by autoimmunity, which skews C1q consumption by IgG-mediated complement classical pathway activation on autoantigens. In this triangle of innate clearance, autoimmunity and endothelial integrity, C1q plays a central role.Hence, we interpret the pathogenesis of lupus by identifying three key components, namely innate immune clearance, autoimmunity and endothelial integrity and we establish a link between these components based on the protective role that innate clearance molecules play in endothelial renewal. By including the vasoprotective role of C1q in the interpretation of SLE development we attempt to provide novel explanations for the symptoms, organ damage, diagnostic and therapeutic difficulties of the disease.
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Prechl J, Czirják L. The endothelial deprotection hypothesis for lupus pathogenesis: the dual role of C1q as a mediator of clearance and regulator of endothelial permeability. F1000Res 2015; 4:24. [PMID: 25901277 PMCID: PMC4392829 DOI: 10.12688/f1000research.6075.2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/08/2015] [Indexed: 12/31/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a heterogeneous multifactorial systemic autoimmune disease affecting several organs. SLE can start relatively early in life and results in impaired quality of life and shortened life expectancy because of a gradual disease progression leading to cardiovascular, renal and neoplastic disease. The basic mechanisms of the pathogenesis of the disease still remain to be clarified. It is clear that complement proteins play a key and complex role in the development of SLE. Complement component C1q has been known to be a fundamental component of lupus development, but most explanations focus on its role in apoptotic debris removal. Importantly, C1q was recently found to play a key role in the maintenance of vascular endothelial integrity. We suggest that apoptotic products, endothelial cells and extracellular matrix components, which display negatively charged moieties, compete for binding to molecules of the innate humoral immune response, like C1q. Genetic or acquired factors leading to an increased load of apoptotic cell debris and decrease or absence of C1q therefore interfere with the regulation of endothelial permeability and integrity. Furthermore, we suggest that lupus is the net result of an imbalance between the two functions of immune clearance and vascular endothelial integrity maintenance, an imbalance triggered and sustained by autoimmunity, which skews C1q consumption by IgG-mediated complement classical pathway activation on autoantigens. In this triangle of innate clearance, autoimmunity and endothelial integrity, C1q plays a central role. Hence, we interpret the pathogenesis of lupus by identifying three key components, namely innate immune clearance, autoimmunity and endothelial integrity and we establish a link between these components based on the protective role that innate clearance molecules play in endothelial renewal. By including the vasoprotective role of C1q in the interpretation of SLE development we attempt to provide novel explanations for the symptoms, organ damage, diagnostic and therapeutic difficulties of the disease.
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Affiliation(s)
- József Prechl
- Diagnosticum Zrt, Budapest, 1047, Hungary ; MTA-ELTE Immunology Research Group, Budapest, 1117, Hungary
| | - László Czirják
- Department of Rheumatology and Immunology, Clinic Center, University of Pécs, Pécs, 7632, Hungary
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43
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Kottyan L, Kelly JA, Harley JB. Genetics of lupus. Rheumatology (Oxford) 2015. [DOI: 10.1016/b978-0-323-09138-1.00127-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Lee YH, Bae SC. Association between the functional ITGAM rs1143679 G/A polymorphism and systemic lupus erythematosus/lupus nephritis or rheumatoid arthritis: an update meta-analysis. Rheumatol Int 2014; 35:815-23. [PMID: 25315704 DOI: 10.1007/s00296-014-3156-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/08/2014] [Indexed: 02/06/2023]
Abstract
The aim of this study was to determine whether the functional integrin-α-M (ITGAM) rs1143679 polymorphism is associated with susceptibility to systemic lupus erythematosus (SLE), lupus nephritis (LN), and rheumatoid arthritis (RA). A series of meta-analyses were conducted to test for associations between the ITGAM rs1143679 polymorphism and SLE, LN, or RA. A total of 24 comparisons involving 7,738 patients and 8,309 controls for SLE, and 2,663 patients and 2,694 controls in RA were considered. Meta-analysis showed a significant association between the ITGAM rs1143679 A allele and SLE in all subjects (OR 1.773, 95 % CI 1.656, 1.901, p < 1.0 × 10(-9)). After stratification by ethnicity, the A allele was found to be significantly associated with SLE in European, Latin American, and Asian. A significant association was also found between the ITGAM A allele and lupus nephritis in Europeans (OR 2.131, 95 % CI 1.565, 2.903, p = 1.6 × 10(-7)). However, no association was found between RA and the ITGAM rs1143679 polymorphism. Our meta-analyses confirm that the ITGAM rs1143679 polymorphism is associated with SLE susceptibility in different ethnic groups and demonstrate that the polymorphism is associated with LN in European.
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Affiliation(s)
- Young Ho Lee
- Division of Rheumatology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, 126-1, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-705, Korea,
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Integrin CD11b negatively regulates BCR signalling to maintain autoreactive B cell tolerance. Nat Commun 2014; 4:2813. [PMID: 24264377 DOI: 10.1038/ncomms3813] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 10/24/2013] [Indexed: 12/14/2022] Open
Abstract
A variant of the integrin-α-M (CD11b) gene has been linked to the pathogenesis of systemic lupus erythematosus. However, how this genotype results in the lupus phenotype is not fully understood. Here we show that autoreactive B cells lacking CD11b exhibit a hyperproliferative response to B cell receptor (BCR) crosslinking and enhanced survival. In vivo engagement of BCR in CD11b-deficient mice leads to increased autoAb production and kidney Ig deposition. In addition, CD11b-deficient autoreactive B cells have decreased tyrosine phosphorylation including Lyn and CD22 with decreased phosphatase SHP-1 recruitment but increased calcium influx. Results obtained using B cells transfected with the wild type or rs1143679 lupus-associated variant of CD11b suggest that this mutation completely abrogates the regulatory effect of CD11b on BCR signalling. This is through disruption of CD22-CD11b direct binding. These results reveal a previously unrecognized role of CD11b in maintaining autoreactive B cell tolerance.
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James JA. Clinical perspectives on lupus genetics: advances and opportunities. Rheum Dis Clin North Am 2014; 40:413-32, vii. [PMID: 25034154 DOI: 10.1016/j.rdc.2014.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In recent years, genome-wide association studies have led to an expansion in the identification of regions containing confirmed genetic risk variants within complex human diseases, such as systemic lupus erythematosus (SLE). Many of the strongest SLE genetic associations can be divided into groups based on their potential roles in different processes implicated in lupus pathogenesis, including ubiquitination, DNA degradation, innate immunity, cellular immunity, lymphocyte development, and antigen presentation. Recent advances have also shown several genetic associations with SLE subphenotypes and subcriteria. Many areas for further exploration remain to move lupus genetic studies toward clinically informative end points.
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Affiliation(s)
- Judith A James
- Oklahoma Clinical & Translational Science Institute, University of Oklahoma Health Sciences Center, 920 Stanton L Young Boulevard, Oklahoma City, OK 73104, USA; Departments of Medicine, Pathology, Microbiology & Immunology, University of Oklahoma Health Sciences Center, 920 Stanton L Young Boulevard, Oklahoma City, OK 73104, USA.
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Resequencing the susceptibility gene, ITGAM, identifies two functionally deleterious rare variants in systemic lupus erythematosus cases. Arthritis Res Ther 2014; 16:R114. [PMID: 24886912 PMCID: PMC4060450 DOI: 10.1186/ar4566] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 05/07/2014] [Indexed: 12/16/2022] Open
Abstract
Introduction The majority of the genetic variance of systemic lupus erythematosus (SLE) remains unexplained by the common disease-common variant hypothesis. Rare variants, which are not detectable by genome-wide association studies because of their low frequencies, are predicted to explain part of this ”missing heritability.” However, recent studies identifying rare variants within known disease-susceptibility loci have failed to show genetic associations because of their extremely low frequencies, leading to the questioning of the contribution of rare variants to disease susceptibility. A common (minor allele frequency = 17.4% in cases) nonsynonymous coding variant rs1143679 (R77H) in ITGAM (CD11b), which forms half of the heterodimeric integrin receptor, complement receptor 3 (CR3), is robustly associated with SLE and has been shown to impair CR3-mediated phagocytosis. Methods We resequenced ITGAM in 73 SLE cases and identified two previously unidentified, case-specific nonsynonymous variants, F941V and G1145S. Both variants were genotyped in 2,107 and 949 additional SLE cases, respectively, to estimate their frequencies in a disease population. An in vitro model was used to assess the impact of F941V and G1145S, together with two nonsynonymous ITGAM polymorphisms, A858V (rs1143683) and M441T (rs11861251), on CR3-mediated phagocytosis. A paired two-tailed t test was used to compare the phagocytic capabilities of each variant with that of wild-type CR3. Results Both rare variants, F941V and G1145S, significantly impair CR3-mediated phagocytosis in an in vitro model (61% reduction, P = 0.006; 26% reduction, P = 0.0232). However, neither of the common variants, M441T and A858V, had an effect on phagocytosis. Neither rare variant was observed again in the genotyping of additional SLE cases, suggesting that there frequencies are extremely low. Conclusions Our results add further evidence to the functional importance of ITGAM in SLE pathogenesis through impaired phagocytosis. Additionally, this study provides a new example of the identification of rare variants in common-allele-associated loci, which, because of their extremely low frequencies, are not statistically associated. However, the demonstration of their functional effects adds support to their contribution to disease risk, and questions the current notion of dismissing the contribution of very rare variants on purely statistical analyses.
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Leffler J, Bengtsson AA, Blom AM. The complement system in systemic lupus erythematosus: an update. Ann Rheum Dis 2014; 73:1601-6. [PMID: 24845390 DOI: 10.1136/annrheumdis-2014-205287] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complement system plays a major role in the autoimmune disease, systemic lupus erythematosus (SLE). However, the role of complement in SLE is complex since it may both prevent and exacerbate the disease. In this review, we explore the latest findings in complement-focused research in SLE. C1q deficiency is the strongest genetic risk factor for SLE, although such deficiency is very rare. Various recently discovered genetic associations include mutations in the complement receptors 2 and 3 as well as complement inhibitors, the latter related to earlier onset of nephritis. Further, autoantibodies are a distinct feature of SLE that are produced as the result of an adaptive immune response and how complement can affect that response is also being reviewed. SLE generates numerous disease manifestations involving contributions from complement such as glomerulonephritis and the increased risk of thrombosis. Furthermore, since most of the complement system is present in plasma, complement is very accessible and may be suitable as biomarker for diagnosis or monitoring of disease activity. This review highlights the many roles of complement for SLE pathogenesis and how research has progressed during recent years.
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Affiliation(s)
- Jonatan Leffler
- Division of Medical Protein Chemistry, Department of Laboratory Medicine Malmö, Lund University, Malmö, Sweden Division of Cell Biology and Immunology, Telethon Kids Institute, University of Western Australia, Subiaco, Australia
| | - Anders A Bengtsson
- Department of Clinical Sciences, Section of Rheumatology, Lund University, Skåne University Hospital Lund, Lund, Sweden
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Laboratory Medicine Malmö, Lund University, Malmö, Sweden
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Maiti AK, Kim-Howard X, Motghare P, Pradhan V, Chua KH, Sun C, Arango-Guerrero MT, Ghosh K, Niewold TB, Harley JB, Anaya JM, Looger LL, Nath SK. Combined protein- and nucleic acid-level effects of rs1143679 (R77H), a lupus-predisposing variant within ITGAM. Hum Mol Genet 2014; 23:4161-76. [PMID: 24608226 DOI: 10.1093/hmg/ddu106] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Integrin alpha M (ITGAM; CD11b) is a component of the macrophage-1 antigen complex, which mediates leukocyte adhesion, migration and phagocytosis as part of the immune system. We previously identified a missense polymorphism, rs1143679 (R77H), strongly associated with systemic lupus erythematosus (SLE). However, the molecular mechanisms of this variant are incompletely understood. A meta-analysis of published and novel data on 28 439 individuals with European, African, Hispanic and Asian ancestries reinforces genetic association between rs1143679 and SLE [Pmeta = 3.60 × 10(-90), odds ratio (OR) = 1.76]. Since rs1143679 is in the most active region of chromatin regulation and transcription factor binding in ITGAM, we quantitated ITGAM RNA and surface protein levels in monocytes from patients with each rs1143679 genotype. We observed that transcript levels significantly decreased for the risk allele ('A') relative to the non-risk allele ('G'), in a dose-dependent fashion: ('AA' < 'AG' < 'GG'). CD11b protein levels in patients' monocytes were directly correlated with RNA levels. Strikingly, heterozygous individuals express much lower (average 10- to 15-fold reduction) amounts of the 'A' transcript than 'G' transcript. We found that the non-risk sequence surrounding rs1143679 exhibits transcriptional enhancer activity in vivo and binds to Ku70/80, NFKB1 and EBF1 in vitro, functions that are significantly reduced with the risk allele. Mutant CD11b protein shows significantly reduced binding to fibrinogen and vitronectin, relative to non-risk, both in purified protein and in cellular models. This two-pronged contribution (nucleic acid- and protein-level) of the rs1143679 risk allele to decreasing ITGAM activity provides insight into the molecular mechanisms of its potent association with SLE.
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Affiliation(s)
- Amit K Maiti
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Xana Kim-Howard
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Prasenjeet Motghare
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | | | - Kek Heng Chua
- Department of Biomedical Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Celi Sun
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - María Teresa Arango-Guerrero
- Center for Autoimmune Diseases Research (CREA), School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | | | - Timothy B Niewold
- Division of Rheumatology and Department of Immunology, Mayo Clinic, Rochester, MN, USA
| | - John B Harley
- Cincinnati Children's Hospital Medical Center and the US Department of Veterans Affairs Medical Center, Cincinnati, OH, USA
| | - Juan-Manual Anaya
- Center for Autoimmune Diseases Research (CREA), School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Loren L Looger
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA, USA
| | - Swapan K Nath
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
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Fagerholm SC, MacPherson M, James MJ, Sevier-Guy C, Lau CS. The CD11b-integrin (ITGAM) and systemic lupus erythematosus. Lupus 2014; 22:657-63. [PMID: 23753600 DOI: 10.1177/0961203313491851] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Variations at the ITGAM gene, which encodes for the CD11b chain of the Mac-1 (alphaMbeta2; CD11b/CD18; complement receptor-3) integrin, is one of the strongest genetic risk factors for systemic lupus erythematosus (SLE). More specifically, a genetic variant (rs1143679) which results in an arginine to histidine substitution at position 77 in the extracellular portion of the integrin is associated with disease. It has recently been shown that this amino acid substitution results in a dysfunctional integrin, which is deficient in mediating cell adhesion to integrin ligands, phagocytosis and in addition cannot restrict inflammatory cytokine production in macrophages. In this review, we discuss immunological functions of the Mac-1 integrin and how defects in the genetic variant of Mac-1 may relate to SLE development.
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Affiliation(s)
- S C Fagerholm
- Medical Research Institute, Ninewells Hospital and Medical School, Institute of Biotechnology, University of Helsinki, Finland.
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