1
|
Ehirchiou D, Bernabei I, Pandian VD, Nasi S, Chobaz V, Castelblanco M, So A, Martinon F, Li X, Acha-Orbea H, Hugle T, Zhang L, Busso N. The integrin CD11b inhibits MSU-induced NLRP3 inflammasome activation in macrophages and protects mice against MSU-induced joint inflammation. Arthritis Res Ther 2024; 26:119. [PMID: 38863059 PMCID: PMC11165854 DOI: 10.1186/s13075-024-03350-5] [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: 02/05/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
OBJECTIVE In gout, monosodium urate crystals are taken up by macrophages, triggering the activation of the NLRP3 inflammasome and the maturation of IL-1β. This study aimed to investigate the role of integrin CD11b in inflammasome activation in macrophages stimulated by MSU. METHODS BMDM from WT and CD11b KO mice were stimulated in vitro with MSU crystals. Cellular supernatants were collected to assess the expression of the inflammatory cytokines by enzyme-linked immunosorbent assay and western blot methods. The role of integrin CD11b in MSU-induced gouty arthritis in vivo was investigated by intra-articular injection of MSU crystals. Real-time extracellular acidification rate and oxygen consumption rate of BMDMs were measured by Seahorse Extracellular Flux Analyzer. RESULTS We demonstrate that CD11b-deficient mice developed exacerbated gouty arthritis with increased recruitment of leukocytes in the joint and higher IL-1β levels in the sera. In macrophages, genetic deletion of CD11b induced a shift of macrophage metabolism from oxidative phosphorylation to glycolysis, thus decreasing the overall generation of intracellular ATP. Upon MSU stimulation, CD11b-deficient macrophages showed an exacerbated secretion of IL-1β. Treating wild-type macrophages with a CD11b agonist, LA1, inhibited MSU-induced release of IL-1β in vitro and attenuated the severity of experimental gouty arthritis. Importantly, LA1, was also effective in human cells as it inhibited MSU-induced release of IL-1β by peripheral blood mononuclear cells from healthy donors. CONCLUSION Our data identified the CD11b integrin as a principal cell membrane receptor that modulates NLRP3 inflammasome activation by MSU crystal in macrophages, which could be a potential therapeutic target to treat gouty arthritis in human patients.
Collapse
Grants
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
- 310030_173134 Fonds National Suisse de la recherche scientifique, Switzerland
Collapse
Affiliation(s)
- Driss Ehirchiou
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Ilaria Bernabei
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Vishnuprabu Durairaj Pandian
- Department of Physiology, Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Sonia Nasi
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Veronique Chobaz
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Mariela Castelblanco
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Alexander So
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Fabio Martinon
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Xiaoyun Li
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland
| | - Hans Acha-Orbea
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Thomas Hugle
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Li Zhang
- Department of Physiology, Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Nathalie Busso
- Service of Rheumatology, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland.
| |
Collapse
|
2
|
Bendapudi PK, Nazeen S, Ryu J, Söylemez O, Robbins A, Rouaisnel B, O’Neil JK, Pokhriyal R, Yang M, Colling M, Pasko B, Bouzinier M, Tomczak L, Collier L, Barrios D, Ram S, Toth-Petroczy A, Krier J, Fieg E, Dzik WH, Hudspeth JC, Pozdnyakova O, Nardi V, Knight J, Maas R, Sunyaev S, Losman JA. Low-frequency inherited complement receptor variants are associated with purpura fulminans. Blood 2024; 143:1032-1044. [PMID: 38096369 PMCID: PMC10950473 DOI: 10.1182/blood.2023021231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/15/2023] [Indexed: 03/16/2024] Open
Abstract
ABSTRACT Extreme disease phenotypes can provide key insights into the pathophysiology of common conditions, but studying such cases is challenging due to their rarity and the limited statistical power of existing methods. Herein, we used a novel approach to pathway-based mutational burden testing, the rare variant trend test (RVTT), to investigate genetic risk factors for an extreme form of sepsis-induced coagulopathy, infectious purpura fulminans (PF). In addition to prospective patient sample collection, we electronically screened over 10.4 million medical records from 4 large hospital systems and identified historical cases of PF for which archived specimens were available to perform germline whole-exome sequencing. We found a significantly increased burden of low-frequency, putatively function-altering variants in the complement system in patients with PF compared with unselected patients with sepsis (P = .01). A multivariable logistic regression analysis found that the number of complement system variants per patient was independently associated with PF after controlling for age, sex, and disease acuity (P = .01). Functional characterization of PF-associated variants in the immunomodulatory complement receptors CR3 and CR4 revealed that they result in partial or complete loss of anti-inflammatory CR3 function and/or gain of proinflammatory CR4 function. Taken together, these findings suggest that inherited defects in CR3 and CR4 predispose to the maladaptive hyperinflammation that characterizes severe sepsis with coagulopathy.
Collapse
Affiliation(s)
- Pavan K. Bendapudi
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
- Division of Hematology and Blood Transfusion Service, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - Sumaiya Nazeen
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Justine Ryu
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Onuralp Söylemez
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Alissa Robbins
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Betty Rouaisnel
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Jillian K. O’Neil
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Ruchika Pokhriyal
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Moua Yang
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Meaghan Colling
- Division of Hematology and Blood Transfusion Service, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - Bryce Pasko
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO
| | - Michael Bouzinier
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Lindsay Tomczak
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
| | - Lindsay Collier
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
| | - David Barrios
- Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA
| | - Agnes Toth-Petroczy
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Joel Krier
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Elizabeth Fieg
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Walter H. Dzik
- Division of Hematology and Blood Transfusion Service, Massachusetts General Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - James C. Hudspeth
- Department of Medicine, Boston Medical Center, Boston, MA
- Boston University School of Medicine, Boston, MA
| | - Olga Pozdnyakova
- Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | - Valentina Nardi
- Harvard Medical School, Boston, MA
- Department of Pathology, Massachusetts General Hospital, Boston, MA
| | - James Knight
- Yale Center for Genome Analysis, Yale University, New Haven, CT
| | - Richard Maas
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Shamil Sunyaev
- Harvard Medical School, Boston, MA
- Division of Genomic Medicine, Brigham and Women’s Hospital, Boston, MA
| | - Julie-Aurore Losman
- Harvard Medical School, Boston, MA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Division of Hematology, Brigham and Women’s Hospital, Boston, MA
| |
Collapse
|
3
|
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: 10] [Impact Index Per Article: 5.0] [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.
Collapse
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.
| |
Collapse
|
4
|
Martinez L, Li X, Ramos-Echazabal G, Faridi H, Zigmond ZM, Santos Falcon N, Hernandez DR, Shehadeh SA, Velazquez OC, Gupta V, Vazquez-Padron RI. A Genetic Model of Constitutively Active Integrin CD11b/CD18. THE JOURNAL OF IMMUNOLOGY 2020; 205:2545-2553. [PMID: 32938725 DOI: 10.4049/jimmunol.1901402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/23/2020] [Indexed: 01/31/2023]
Abstract
Pharmacological activation of integrin CD11b/CD18 (αMβ2, Mac-1, and CR3) shows anti-inflammatory benefits in a variety of animal models of human disease, and it is a novel therapeutic strategy. Reasoning that genetic models can provide an orthogonal and direct system for the mechanistic study of CD11b agonism, we present in this study, to our knowledge, a novel knock-in model of constitutive active CD11b in mice. We genetically targeted the Itgam gene (which codes for CD11b) to introduce a point mutation that results in the I332G substitution in the protein. The I332G mutation in CD11b promotes an active, higher-affinity conformation of the ligand-binding I/A-domain (CD11b αA-domain). In vitro, this mutation increased adhesion of knock-in neutrophils to fibrinogen and decreased neutrophil chemotaxis to a formyl-Met-Leu-Phe gradient. In vivo, CD11bI332G animals showed a reduction in recruitment of neutrophils and macrophages in a model of sterile peritonitis. This genetic activation of CD11b also protected against development of atherosclerosis in the setting of hyperlipidemia via reduction of macrophage recruitment into atherosclerotic lesions. Thus, our animal model of constitutive genetic activation of CD11b can be a useful tool for the study of integrin activation and its potential contribution to modulating leukocyte recruitment and alleviating different inflammatory diseases.
Collapse
Affiliation(s)
- Laisel Martinez
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Xiaobo Li
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612
| | - Gioser Ramos-Echazabal
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Hafeez Faridi
- Department of Pharmaceutical Sciences, College of Pharmacy, Chicago State University, Chicago, IL 60612; and
| | - Zachary M Zigmond
- Department of Molecular and Cellular Pharmacology, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Nieves Santos Falcon
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Diana R Hernandez
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Serene A Shehadeh
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Omaida C Velazquez
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Vineet Gupta
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612;
| | - Roberto I Vazquez-Padron
- DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136;
| |
Collapse
|
5
|
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: 61] [Impact Index Per Article: 10.2] [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.
Collapse
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
| |
Collapse
|
6
|
Garbers C, Rose-John S. The balance between Treg and TH 17 cells: CD11b and interleukin-6. Eur J Immunol 2017; 47:629-632. [PMID: 28387942 DOI: 10.1002/eji.201746988] [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: 02/24/2017] [Accepted: 03/06/2017] [Indexed: 01/03/2023]
Abstract
One of the gold standards for animal models of rheumatoid arthritis is the murine collagen-induced arthritis model. Native type II collagen together with CFA is injected into susceptible mouse strains. Unfortunately, only mice with H-2q or H-2r MHC haplotypes are susceptible, making the widely used C57BL/6 mouse strain, which carries the H-2b haplotype, resistant against the disease. In this issue of the European Journal of Immunology, Stevanin et al. [Eur. J. Immunol. 2017. 47: 637-645] now convincingly show that although WT C57BL/6 mice are resistant to collagen-induced arthritis, mice with a homozygous deletion of CD11b on the same genetic background are fully susceptible in this important animal model of rheumatoid arthritis. They clearly demonstrate that the injection of type II collagen together with CFA leads to early onset of the disease with high incidence and with sustained severity. The authors further characterize this disease with an increase of leukocyte infiltration and enhanced TH17 differentiation.
Collapse
|
7
|
Stevanin M, Busso N, Chobaz V, Pigni M, Ghassem-Zadeh S, Zhang L, Acha-Orbea H, Ehirchiou D. CD11b regulates the Treg/Th17 balance in murine arthritis via IL-6. Eur J Immunol 2017; 47:637-645. [PMID: 28191643 DOI: 10.1002/eji.201646565] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 01/07/2017] [Accepted: 02/09/2017] [Indexed: 12/28/2022]
Abstract
Th17 cells are often associated with autoimmunity and been shown to be increased in CD11b-/- mice. Here, we examined the role of CD11b in murine collagen-induced arthritis (CIA). C57BL/6 and CD11b-/- resistant mice were immunized with type II collagen. CD11b-/- mice developed arthritis with early onset, high incidence, and sustained severity compared with C57BL/6 mice. We observed a marked leukocyte infiltration, and histological examinations of the arthritic paws from CD11b-/- mice revealed that the cartilage was destroyed in association with strong lymphocytic infiltration. The CD11b deficiency led to enhanced Th17-cell differentiation. CD11b-/- dendritic cells (DCs) induced much stronger IL-6 production and hence Th17-cell differentiation than wild-type DCs. Treatment of CD11b-/- mice after establishment of the Treg/Th17 balance with an anti-IL-6 receptor mAb significantly suppressed the induction of Th17 cells and reduced arthritis severity. Finally, the severe phenotype of arthritis in CD11b-/- mice was rescued by adoptive transfer of CD11b+ DCs. Taken together, our results indicate that the resistance to CIA in C57BL/6 mice is regulated by CD11b via suppression of IL-6 production leading to reduced Th17-cell differentiation. Therefore, CD11b may represent a susceptibility factor for autoimmunity and could be a target for future therapy.
Collapse
Affiliation(s)
- Mathias Stevanin
- Department of Biochemistry CIIL, University of Lausanne, Epalinges, Switzerland
| | - Nathalie Busso
- DAL, Service of Rheumatology, Laboratory of Rheumatology, University of Lausanne, CHUV, Epalinges, Switzerland
| | - Véronique Chobaz
- DAL, Service of Rheumatology, Laboratory of Rheumatology, University of Lausanne, CHUV, Epalinges, Switzerland
| | - Matteo Pigni
- Department of Biochemistry CIIL, University of Lausanne, Epalinges, Switzerland
| | - Sahar Ghassem-Zadeh
- Department of Biochemistry CIIL, University of Lausanne, Epalinges, Switzerland
| | - Li Zhang
- Center for Vascular and Inflammatory Diseases, Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Hans Acha-Orbea
- Department of Biochemistry CIIL, University of Lausanne, Epalinges, Switzerland
| | - Driss Ehirchiou
- Department of Biochemistry CIIL, University of Lausanne, Epalinges, Switzerland
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Mechanisms of antibody-mediated acute and chronic rejection of kidney allografts. Curr Opin Organ Transplant 2016; 21:7-14. [PMID: 26575854 DOI: 10.1097/mot.0000000000000262] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW Antibody-mediated rejection is responsible for up to half of acute rejection episodes in kidney transplant patients and more than half of late graft failures. Antibodies cause acute graft abnormalities that are distinct from T cell-mediated rejection and at later times posttransplant, a distinct pathologic lesion is associated with capillary basement membrane multilayering and glomerulopathy. Despite the importance of donor-reactive antibodies as the leading cause of kidney graft failure, mechanisms underlying antibody-mediated acute and chronic kidney graft injury are poorly understood. Here, we review recent insights provided from clinical studies as well as from animal models that may help to identify new targets for therapy. RECENT FINDINGS Studies of biopsies from kidney grafts in patients with donor-specific antibody versus those without have utilized analysis of pathologic lesions and gene expression to identify the distinct characteristics of antibody-mediated rejection. These analyses have indicated the presence of natural killer cells and their activation during antibody-mediated rejection. The impact of studies of antibody-mediated allograft injury in animal models have lagged behind these clinical studies, but have been useful in testing the activation of innate immune components within allografts in the presence of donor-specific antibodies. SUMMARY Most insights into processes of antibody-mediated rejection of kidney grafts have come from carefully designed clinical studies. However, several new mouse models of antibody-mediated kidney allograft rejection may replicate the abnormalities observed in clinical kidney grafts and may be useful in directly testing mechanisms that underlie acute and chronic antibody-mediated graft injury.
Collapse
|
10
|
Brar JE, Quigg RJ. Complement activation in the tubulointerstitium: AKI, CKD, and in between. Kidney Int 2015; 86:663-6. [PMID: 25265946 DOI: 10.1038/ki.2014.168] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Complement activation is actively regulated to prevent injudicious activation, such as on peritubular endothelia and basolateral aspects of tubules. Miao et al. studied mice in which the key complement regulator, Crry, was deleted from tubular cells. This lacked functional consequence in unmanipulated animals. Yet, following ischemia-reperfusion, there was greater injury due to alternative pathway activation of C5. When the balance between complement activation and regulation is tipped towards the former, pathologic complement activation can ensue.
Collapse
Affiliation(s)
- Jyoti E Brar
- Division of Nephrology, Department of Medicine, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Richard J Quigg
- Division of Nephrology, Department of Medicine, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| |
Collapse
|
11
|
Alexander JJ, Chaves LD, Chang A, Jacob A, Ritchie M, Quigg RJ. CD11b is protective in complement-mediated immune complex glomerulonephritis. Kidney Int 2015; 87:930-9. [PMID: 25565310 PMCID: PMC4424815 DOI: 10.1038/ki.2014.373] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 09/03/2014] [Accepted: 09/18/2014] [Indexed: 12/22/2022]
Abstract
In chronic serum sickness, glomerular immune complexes form, yet C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CfH) is absent, indicating the relevance of complement regulation. Complement receptor 3 (CD11b) and Fcγ receptors on leukocytes, and CfH on platelets, can bind immune complexes. Here we induced immune complex–mediated glomerulonephritis in CfH−/− mice chimeric for wild-type, CfH−/−, CD11b−/−, or FcRγ−/− bone marrow stem cells. Glomerulonephritis was worse in CD11b−/− chimeras compared with all others, whereas disease in FcRγ−/− and wild-type chimeras was comparable. Disease tracked strongly with humoral immune responses, but not glomerular immune complex deposits. Interstitial inflammation with M1 macrophages strongly correlated with glomerulonephritis scores. CD11b−/− chimeras had significantly more M1 macrophages and CD4+ T cells. The renal dendritic cell populations originating from bone marrow–derived CD11c+ cells were similar in all experimental groups. CD11b+ cells bearing colony-stimulating factor 1 receptor were present in kidneys, including CD11b−/− chimeras; these cells correlated negatively with glomerulonephritis scores. Thus, experimental immune complex–mediated glomerulonephritis is associated with accumulation of M1 macrophages and CD4+ T cells in kidneys and functional renal insufficiency. Hence, CD11b on mononuclear cells is instrumental in generating an anti-inflammatory response in the inflamed kidney.
Collapse
Affiliation(s)
- Jessy J Alexander
- Division of Nephrology, Department of Medicine, Clinical and Translational Research Center, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Lee D Chaves
- Division of Nephrology, Department of Medicine, Clinical and Translational Research Center, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Anthony Chang
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA
| | - Alexander Jacob
- Division of Nephrology, Department of Medicine, Clinical and Translational Research Center, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Maria Ritchie
- Division of Nephrology, Department of Medicine, Clinical and Translational Research Center, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Richard J Quigg
- Division of Nephrology, Department of Medicine, Clinical and Translational Research Center, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| |
Collapse
|