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Liu J, Guo F, Chen X, Fu P, Ma L. Integrin αM promotes macrophage alternative M2 polarization in hyperuricemia-related chronic kidney disease. MedComm (Beijing) 2024; 5:e580. [PMID: 38911067 PMCID: PMC11193137 DOI: 10.1002/mco2.580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 03/30/2024] [Accepted: 04/01/2024] [Indexed: 06/25/2024] Open
Abstract
Hyperuricemia is an essential risk factor in chronic kidney disease (CKD), while urate-lowering therapy to prevent or delay CKD is controversial. Alternatively activated macrophages in response to local microenvironment play diverse roles in kidney diseases. Here, we aim to investigate whether and how macrophage integrin αM (ITGAM) contributes to hyperuricemia-related CKD. In vivo, we explored dynamic characteristics of renal tissue in hyperuricemia-related CKD mice. By incorporating transcriptomics and phosphoproteomics data, we analyzed gene expression profile, hub genes and potential pathways. In vitro, we validated bioinformatic findings under different conditions with interventions corresponding to core nodes. We found that hyperuricemia-related CKD was characterized by elevated serum uric acid levels, impaired renal function, activation of macrophage alternative (M2) polarization, and kidney fibrosis. Integrated bioinformatic analyses revealed Itgam as the potential core gene, which was associated with focal adhesion signaling. Notably, we confirmed the upregulated expression of macrophage ITGAM, activated pathway, and macrophage M2 polarization in injured kidneys. In vitro, through silencing Itgam, inhibiting p-FAK or p-AKT1 phosphorylation, and concurrent inhibiting of p-FAK while activating p-AKT1 all contributed to the modulation of macrophage M2 polarization. Our results indicated targeting macrophage ITGAM might be a promising therapeutic approach for preventing CKD.
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Affiliation(s)
- Jing Liu
- Division of Nephrology, Institute of Kidney DiseasesWest China Hospital of Sichuan UniversityChengduChina
| | - Fan Guo
- Division of Nephrology, Institute of Kidney DiseasesWest China Hospital of Sichuan UniversityChengduChina
| | - Xiaoting Chen
- Animal Experimental CenterWest China Hospital of Sichuan UniversityChengduChina
| | - Ping Fu
- Division of Nephrology, Institute of Kidney DiseasesWest China Hospital of Sichuan UniversityChengduChina
| | - Liang Ma
- Division of Nephrology, Institute of Kidney DiseasesWest China Hospital of Sichuan UniversityChengduChina
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2
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Klaus T, Hieber C, Bros M, Grabbe S. Integrins in Health and Disease-Suitable Targets for Treatment? Cells 2024; 13:212. [PMID: 38334604 PMCID: PMC10854705 DOI: 10.3390/cells13030212] [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: 12/27/2023] [Revised: 01/13/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024] Open
Abstract
Integrin receptors are heterodimeric surface receptors that play multiple roles regarding cell-cell communication, signaling, and migration. The four members of the β2 integrin subfamily are composed of an alternative α (CD11a-d) subunit, which determines the specific receptor properties, and a constant β (CD18) subunit. This review aims to present insight into the multiple immunological roles of integrin receptors, with a focus on β2 integrins that are specifically expressed by leukocytes. The pathophysiological role of β2 integrins is confirmed by the drastic phenotype of patients suffering from leukocyte adhesion deficiencies, most often resulting in severe recurrent infections and, at the same time, a predisposition for autoimmune diseases. So far, studies on the role of β2 integrins in vivo employed mice with a constitutive knockout of all β2 integrins or either family member, respectively, which complicated the differentiation between the direct and indirect effects of β2 integrin deficiency for distinct cell types. The recent generation and characterization of transgenic mice with a cell-type-specific knockdown of β2 integrins by our group has enabled the dissection of cell-specific roles of β2 integrins. Further, integrin receptors have been recognized as target receptors for the treatment of inflammatory diseases as well as tumor therapy. However, whereas both agonistic and antagonistic agents yielded beneficial effects in animal models, the success of clinical trials was limited in most cases and was associated with unwanted side effects. This unfavorable outcome is most probably related to the systemic effects of the used compounds on all leukocytes, thereby emphasizing the need to develop formulations that target distinct types of leukocytes to modulate β2 integrin activity for therapeutic applications.
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Affiliation(s)
| | | | | | - Stephan Grabbe
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (T.K.); (C.H.); (M.B.)
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3
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Tabata H, Morita H, Kouyama K, Tohyama Y. Complement dependent TNFα production in neutrophil-like HL60 cells. Biochem Biophys Rep 2023; 34:101465. [PMID: 37125077 PMCID: PMC10130347 DOI: 10.1016/j.bbrep.2023.101465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 03/12/2023] [Accepted: 04/03/2023] [Indexed: 05/02/2023] Open
Abstract
Neutrophils develop in the bone marrow (BM) from hematopoietic stem cells (HSCs) through a series of progenitor cells and mature neutrophils play a critical role in the human immune system. Previous studies revealed that tumor necrosis factor α (TNFα) produced by immature neutrophils contributes to HSCs development and vascular regeneration in the BM niche. However, the precise mechanism of TNFα production in immature neutrophils remains unclear. This study aims to assess the relationship between complement C3 activation and TNFα production from immature neutrophils. We investigated the regulatory mechanism of TNFα production by complement components in neutrophil-like HL60 cells. Flow cytometric analysis showed that C3a receptor (C3aR) and C3bi receptor (CR3, Mac-1, CD11b/CD18, integrin αMβ2) are expressed on the surface of neutrophil-like HL60 cells. We found that zymosan-treated human serum leads to TNFα production in neutrophil-like HL60 cells, but not in human polymorphonuclear cells (PMNs). A C3-convertase inhibitor, compstatin suppresses TNFα production. These data suggest that the TNFα production is mediated by complement C3 activation. Furthermore, the TNFα production is enhanced by Ca2+ elevating agents, thapsigargin (TG), but is suppressed by treatment with Ca2+ chelators, EGTA, or BAPTA-AM. In addition, the soluble TNFα production is suppressed by treatment with immobilized-fibrinogen or -fibronectin. Thus, the TNFα production is enhanced by intracellular Ca2+ elevation and is negatively regulated by the interaction between the neutrophil-like HL60 cells and fibrinogen or fibronectin.
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Affiliation(s)
- Hiroyuki Tabata
- Division of Biochemistry, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Hyogo, 670-8524, Japan
- Corresponding author.
| | - Hiroyuki Morita
- Division of Biochemistry, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Hyogo, 670-8524, Japan
| | - Kenichi Kouyama
- Division of Biochemistry, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Hyogo, 670-8524, Japan
| | - Yumi Tohyama
- Division of Biochemistry, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Hyogo, 670-8524, Japan
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4
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Biasella F, Plössl K, Baird PN, Weber BHF. The extracellular microenvironment in immune dysregulation and inflammation in retinal disorders. Front Immunol 2023; 14:1147037. [PMID: 36936905 PMCID: PMC10014728 DOI: 10.3389/fimmu.2023.1147037] [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: 01/18/2023] [Accepted: 02/15/2023] [Indexed: 03/05/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) as well as genetically complex retinal phenotypes represent a heterogenous group of ocular diseases, both on account of their phenotypic and genotypic characteristics. Therefore, overlaps in clinical features often complicate or even impede their correct clinical diagnosis. Deciphering the molecular basis of retinal diseases has not only aided in their disease classification but also helped in our understanding of how different molecular pathologies may share common pathomechanisms. In particular, these relate to dysregulation of two key processes that contribute to cellular integrity, namely extracellular matrix (ECM) homeostasis and inflammation. Pathological changes in the ECM of Bruch's membrane have been described in both monogenic IRDs, such as Sorsby fundus dystrophy (SFD) and Doyne honeycomb retinal dystrophy (DHRD), as well as in the genetically complex age-related macular degeneration (AMD) or diabetic retinopathy (DR). Additionally, complement system dysfunction and distorted immune regulation may also represent a common connection between some IRDs and complex retinal degenerations. Through highlighting such overlaps in molecular pathology, this review aims to illuminate how inflammatory processes and ECM homeostasis are linked in the healthy retina and how their interplay may be disturbed in aging as well as in disease.
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Affiliation(s)
- Fabiola Biasella
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Karolina Plössl
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Paul N. Baird
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
- Department of Surgery, Ophthalmology, University of Melbourne, Melbourne, VIC, Australia
- *Correspondence: Paul N. Baird, ; Bernhard H. F. Weber,
| | - Bernhard H. F. Weber
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
- Institute of Clinical Human Genetics, University Hospital Regensburg, Regensburg, Germany
- *Correspondence: Paul N. Baird, ; Bernhard H. F. Weber,
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5
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Tian Y, Shin K, Aleshin AE, Im W, Marassi FM. Calcium-induced environmental adaptability of the blood protein vitronectin. Biophys J 2022; 121:3896-3906. [PMID: 36056555 PMCID: PMC9674982 DOI: 10.1016/j.bpj.2022.08.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 06/29/2022] [Accepted: 08/29/2022] [Indexed: 11/22/2022] Open
Abstract
The adaptability of proteins to their work environments is fundamental for cellular life. Here, we describe how the hemopexin-like domain of the multifunctional blood glycoprotein vitronectin binds Ca2+ to adapt to excursions of temperature and shear stress. Using X-ray crystallography, molecular dynamics simulations, NMR, and differential scanning fluorimetry, we describe how Ca2+ and its flexible hydration shell enable the protein to perform conformational changes that relay beyond the calcium-binding site and alter the number of polar contacts to enhance conformational stability. By means of mutagenesis, we identify key residues that cooperate with Ca2+ to promote protein stability, and we show that calcium association confers protection against shear stress, a property that is advantageous for proteins that circulate in the vasculature, like vitronectin.
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Affiliation(s)
- Ye Tian
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Kyungsoo Shin
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | | | - Wonpil Im
- Departments of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, Pennsylvania
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Novel Functions of Integrins as Receptors of CD154: Their Role in Inflammation and Apoptosis. Cells 2022; 11:cells11111747. [PMID: 35681441 PMCID: PMC9179867 DOI: 10.3390/cells11111747] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 12/16/2022] Open
Abstract
CD154, an inflammatory mediator also known as CD40 ligand, has been identified as a novel binding partner for some members of the integrin family. The αIIbβ3, specifically expressed on platelets, was the first integrin to be described as a receptor for CD154 after CD40. Its interaction with soluble CD154 (sCD154) highly contributes to thrombus formation and stability. Identifying αIIbβ3 opened the door for investigating other integrins as partners of CD154. The αMβ2 expressed on myeloid cells was shown capable of binding CD154 and contributing as such to cell activation, adhesion, and release of proinflammatory mediators. In parallel, α5β1 communicates with sCD154, inducing pro-inflammatory responses. Additional pathogenic effects involving apoptosis-preventing functions were exhibited by the CD154–α5β1 dyad in T cells, conferring a role for such interaction in the survival of malignant cells, as well as the persistence of autoreactive T cells. More recently, CD154 receptors integrated two new integrin members, αvβ3 and α4β1, with little known as to their biological significance in this context. This article provides an overview of the novel role of integrins as receptors of CD154 and as critical players in pro-inflammatory and apoptotic responses.
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Zuchtriegel G, Uhl B, Pick R, Ramsauer M, Dominik J, Mittmann LA, Canis M, Kanse S, Sperandio M, Krombach F, Reichel CA. Vitronectin stabilizes intravascular adhesion of neutrophils by coordinating β2 integrin clustering. Haematologica 2021; 106:2641-2653. [PMID: 32703799 PMCID: PMC8485676 DOI: 10.3324/haematol.2019.226241] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Indexed: 11/09/2022] Open
Abstract
The recruitment of neutrophils from the microvasculature to the site of injury or infection represents a key event in the inflammatory response. Vitronectin (VN) is a multifunctional macromolecule abundantly present in blood and extracellular matrix. The role of this glycoprotein in the extravasation process of circulating neutrophils remains elusive. Employing advanced in vivo/ex vivo imaging techniques in different mouse models as well as in vitro methods, we uncovered a previously unrecognized function of VN in the transition of dynamic to static intravascular interactions of neutrophils with microvascular endothelial cells. These distinct properties of VN require the heteromerization of this glycoprotein with plasminogen activator inhibitor-1 (PAI- 1) on the activated venular endothelium and subsequent interactions of this protein complex with the scavenger receptor low-density lipoprotein receptor-related protein-1 on intravascularly adhering neutrophils. This induces p38 mitogen-activated protein kinases-dependent intracellular signaling events which, in turn, regulates the proper clustering of the b2 integrin lymphocyte function associated antigen-1 on the surface of these immune cells. As a consequence of this molecular interplay, neutrophils become able to stabilize their adhesion to the microvascular endothelium and, subsequently, to extravasate to the perivascular tissue. Hence, endothelial-bound VN-PAI-1 heteromers stabilize intravascular adhesion of neutrophils by coordinating b2 integrin clustering on the surface of these immune cells, thereby effectively controlling neutrophil trafficking to inflamed tissue. Targeting this protein complex might be beneficial for the prevention and treatment of inflammatory pathologies.
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Affiliation(s)
- Gabriele Zuchtriegel
- Walter Brendel Centre of Experimental Medicine and Klinikum der Universität München, Germany
| | - Bernd Uhl
- Walter Brendel Centre of Experimental Medicine and Klinikum der Universität München, Germany
| | - Robert Pick
- Dept. of Otorhinolaryngology, Klinikum der Universität Munchen, Munich, Germany
| | - Michaela Ramsauer
- Walter Brendel Centre of Experimental Medicine and Klinikum der Universität Munchen, Germany
| | - Julian Dominik
- Dept. of Otorhinolaryngology, Klinikum der Universität Munchen, Munich, Germany
| | - Laura A Mittmann
- Walter Brendel Centre of Experimental Medicine and Klinikum der Universität Munchen, Germany
| | | | - Sandip Kanse
- Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Markus Sperandio
- Dept. of Otorhinolaryngology, Klinikum der Universität Munchen, Munich, Germany
| | - Fritz Krombach
- Walter Brendel Centre of Experimental Medicine, Munich, Germany
| | - Christoph A Reichel
- Walter Brendel Centre of Experimental Medicine and Klinikum der Universität Munchen, Germany
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8
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P 2Y 12 receptor blockers are anti-inflammatory drugs inhibiting both circulating monocytes and macrophages including THP-1 cells. Sci Rep 2021; 11:17459. [PMID: 34465804 PMCID: PMC8408182 DOI: 10.1038/s41598-021-95710-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/22/2021] [Indexed: 01/11/2023] Open
Abstract
P2Y12 blockade improves patient outcomes after myocardial infarction. As well as antithrombotic effects, anti-inflammatory effects may contribute to this beneficial clinical outcome. Here we aimed to identify potential anti-inflammatory effects of P2Y12 receptor blockers on monocytes and macrophages. Using flow cytometry, migration assays, flow chambers and RNA microarrays, we investigated the effects of adenosine diphosphate (ADP) and P2Y12 receptor blockers on blood monocytes, THP-1 monocytes and THP-1 monocytes after differentiation to macrophages. P2Y12 -expressing platelets can form aggregates with monocytes in circulating blood. Mediated by platelets, ADP results in activation of the integrin receptor Mac-1 on blood monocytes, as detected by the conformation-specific single-chain antibody MAN-1. Via the same association with platelets, THP-1 monocyte adhesion to the endothelial intercellular adhesion molecule 1 (ICAM-1) is induced by ADP. P2Y12 receptor blockers prevent these ADP effects on monocytes. Interestingly, in contrast to THP-1 monocytes, THP-1 monocytes, after differentiation to macrophages, directly expressed the P2Y12 receptor and consequently ADP was found to be a potent chemoattractant. Again, P2Y12 receptor blockers antagonised this effect. Accordingly, stimulation of THP-1 macrophages with ADP caused a substantial change in gene expression pattern and upregulation of several genes associated with inflammation and atherogenesis. These data establish novel anti-inflammatory effects of P2Y12 receptor blockers on monocytes and macrophages, which are expected to contribute to cardiovascular risk reduction.
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9
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Lamers C, Plüss CJ, Ricklin D. The Promiscuous Profile of Complement Receptor 3 in Ligand Binding, Immune Modulation, and Pathophysiology. Front Immunol 2021; 12:662164. [PMID: 33995387 PMCID: PMC8118671 DOI: 10.3389/fimmu.2021.662164] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/12/2021] [Indexed: 12/19/2022] Open
Abstract
The β2-integrin receptor family has a broad spectrum of physiological functions ranging from leukocyte adhesion, cell migration, activation, and communication to the phagocytic uptake of cells and particles. Among the members of this family, complement receptor 3 (CR3; CD11b/CD18, Mac-1, αMβ2) is particularly promiscuous in its functional profile and ligand selectivity. There are close to 100 reported structurally unrelated ligands for CR3, and while many ligands appear to cluster at the αMI domain, molecular details about binding modes remain largely elusive. The versatility of CR3 is reflected in its functional portfolio, which includes prominent roles in the removal of invaders and cell debris, induction of tolerance and synaptic pruning, and involvement in the pathogenesis of numerous autoimmune and chronic inflammatory pathologies. While CR3 is an interesting therapeutic target for immune modulation due to these known pathophysiological associations, drug development efforts are limited by concerns of potential interference with host defense functions and, most importantly, an insufficient molecular understanding of the interplay between ligand binding and functional impact. Here, we provide a systematic summary of the various interaction partners of CR3 with a focus on binding mechanisms and functional implications. We also discuss the roles of CR3 as an immune receptor in health and disease, as an activation marker in research and diagnostics, and as a therapeutic target.
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Affiliation(s)
- Christina Lamers
- Molecular Pharmacy Unit, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
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10
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Jia C, Malone HM, Keasey MP, Lovins C, Elam J, Hagg T. Blood Vitronectin Induces Detrimental Brain Interleukin-6 and Correlates With Outcomes After Stroke Only in Female Mice. Stroke 2020; 51:1587-1595. [PMID: 32312218 DOI: 10.1161/strokeaha.120.029036] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background and Purpose- Women have worse stroke outcomes than men, especially after menopause. Few studies have focused on female-specific mechanisms, other than hormones. We investigated the role of the blood protein VTN (vitronectin) after ischemic stroke in mice. Methods- Adult male and female VTN knockout and wild-type littermates and C57BL/6 mice received a middle cerebral artery occlusion and the injured brain tissue analyzed 24 hours to 3 weeks later for cell loss and inflammation, as well as neurological function. Blood VTN levels were measured before and after stroke. Results- Intravenously injected VTN leaked extensively from bloodstream into brain infarct and penumbra by 24 hours after stroke. Strikingly, VTN was detrimental in female, but not male, mice, as shown by reduced brain injury (26.2±2.6% versus 13.4±3.8%; P=0.018; n=6 and 5) and forelimb dysfunction in female VTN knockout mice. Stroke increased plasma VTN 2- to 8-fold at 24 hours in females (36±4 versus 145±24 μg/mL; P<0.0001; n=10 and 7), but not males (62±8 versus 68±6; P>0.99; n=10 and 7), and returned to control levels by 7 days. Individually variable VTN levels at 24 hours correlated with stroke-induced brain injury at 7 days only in females. VTN promoted stroke-induced microglia/macrophage activation and leukocyte infiltration in females. Proinflammatory IL (interleukin)-6 greatly increased in the striatum at 24 hours in wild-type mice but was increased ≈60% less in female (739±159 versus 268±111; P=0.02; n=7 and 6), but not male (889±178 versus 1179±295; P=0.73; n=10 and 11), knockout mice. In individual wild-type females, plasma VTN levels correlated with striatal IL-6 expression at 24 hours. The female-specific effect of VTN-induced IL-6 expression following stroke was not due to gonadal hormones, as shown by ovariectomy and castration. Lastly, intrastriatal injection of IL-6 in female mice immediately before stroke reversed the VTN knockout phenotypes of reduced brain injury and microglia/macrophage activation. Conclusions- VTN plays a novel sexually dimorphic detrimental pathophysiological role in females and might ultimately be a therapeutic target to improve stroke outcomes in women.
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Affiliation(s)
- Cuihong Jia
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Hannah M Malone
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Matthew P Keasey
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Chiharu Lovins
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Jacob Elam
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Theo Hagg
- From the Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City
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11
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How Adhesion Molecule Patterns Change While Neutrophils Traffic through the Lung during Inflammation. Mediators Inflamm 2019; 2019:1208086. [PMID: 30944544 PMCID: PMC6421765 DOI: 10.1155/2019/1208086] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023] Open
Abstract
In acute pulmonary inflammation, polymorphonuclear cells (PMNs) pass a transendothelial barrier from the circulation into the lung interstitium followed by a transepithelial migration into the alveolar space. These migration steps are regulated differentially by a concept of adhesion molecules and remain-despite decades of research-incompletely understood. Current knowledge of changes in the expression pattern of adhesion molecules mainly derives from in vitro studies or from studies in extrapulmonary organ systems, where regulation of adhesion molecules differs significantly. In a murine model of lung inflammation, we determined the expression pattern of nine relevant neutrophilic adhesion molecules on their way through the different compartments of the lung. We used a flow cytometry-based technique that allowed describing spatial distribution of the adhesion molecules expressed on PMNs during their migration through the lung in detail. For example, the highest expression of CD29 was found in the intravascular compartment, highlighting its impact on the initial adhesion to the endothelium. CD47 showed its peak of expression on the later phase of transendothelial migration, whereas CD11b and CD54 expression peaked interstitial. A pivotal role for transepithelial migration was found for the adhesion molecule CD172a. Thereby, expression may correlate with functional impact for specific migration steps. In vitro studies further confirmed our in vivo findings. In conclusion, we are the first to determine the changes in expression patterns of relevant adhesion molecules on their migration through the different compartments of the lung. These findings may help to further understand the regulation of neutrophil trafficking in the lung.
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12
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Wolf D, Anto-Michel N, Blankenbach H, Wiedemann A, Buscher K, Hohmann JD, Lim B, Bäuml M, Marki A, Mauler M, Duerschmied D, Fan Z, Winkels H, Sidler D, Diehl P, Zajonc DM, Hilgendorf I, Stachon P, Marchini T, Willecke F, Schell M, Sommer B, von Zur Muhlen C, Reinöhl J, Gerhardt T, Plow EF, Yakubenko V, Libby P, Bode C, Ley K, Peter K, Zirlik A. A ligand-specific blockade of the integrin Mac-1 selectively targets pathologic inflammation while maintaining protective host-defense. Nat Commun 2018; 9:525. [PMID: 29410422 PMCID: PMC5802769 DOI: 10.1038/s41467-018-02896-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/05/2018] [Indexed: 12/22/2022] Open
Abstract
Integrin-based therapeutics have garnered considerable interest in the medical treatment of inflammation. Integrins mediate the fast recruitment of monocytes and neutrophils to the site of inflammation, but are also required for host defense, limiting their therapeutic use. Here, we report a novel monoclonal antibody, anti-M7, that specifically blocks the interaction of the integrin Mac-1 with its pro-inflammatory ligand CD40L, while not interfering with alternative ligands. Anti-M7 selectively reduces leukocyte recruitment in vitro and in vivo. In contrast, conventional anti-Mac-1 therapy is not specific and blocks a broad repertoire of integrin functionality, inhibits phagocytosis, promotes apoptosis, and fuels a cytokine storm in vivo. Whereas conventional anti-integrin therapy potentiates bacterial sepsis, bacteremia, and mortality, a ligand-specific intervention with anti-M7 is protective. These findings deepen our understanding of ligand-specific integrin functions and open a path for a new field of ligand-targeted anti-integrin therapy to prevent inflammatory conditions.
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Affiliation(s)
- Dennis Wolf
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany.,Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Nathaly Anto-Michel
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Hermann Blankenbach
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Ansgar Wiedemann
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Konrad Buscher
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Jan David Hohmann
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, 8008, VIC, Australia
| | - Bock Lim
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, 8008, VIC, Australia
| | - Marina Bäuml
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Alex Marki
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Maximilian Mauler
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Daniel Duerschmied
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Zhichao Fan
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Holger Winkels
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Daniel Sidler
- Division of Nephrology, Inselspital, Bern University Hospital, Bern, 3010, Switzerland
| | - Philipp Diehl
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Dirk M Zajonc
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Ingo Hilgendorf
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Peter Stachon
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Timoteo Marchini
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Florian Willecke
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Maximilian Schell
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany.,Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Björn Sommer
- Neurosurgery, Medical Faculty of the University of Erlangen, Erlangen, 91054, Germany
| | - Constantin von Zur Muhlen
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Jochen Reinöhl
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Teresa Gerhardt
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Edward F Plow
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Valentin Yakubenko
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Peter Libby
- Brigham and Women's Hospital, Cardiovascular Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Christoph Bode
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
| | - Klaus Ley
- Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, 8008, VIC, Australia.
| | - Andreas Zirlik
- Cardiology and Angiology I, University Heart Center, and Medical Faculty, University of Freiburg, Freiburg, 79106, Germany
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13
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Abstract
Polymorphonuclear neutrophils (PMNs) are innate immune system cells that play an essential role in eradicating invading pathogens. PMN migration to sites of infection/inflammation requires exiting the microcirculation and subsequent crossing of epithelial barriers in mucosa-lined organs such as the lungs and intestines. Although these processes usually occur without significant damage to surrounding host tissues, dysregulated/excessive PMN transmigration and resultant bystander-tissue damage are characteristic of numerous mucosal inflammatory disorders. Mechanisms controlling PMN extravasation have been well characterized, but the molecular details regarding regulation of PMN migration across mucosal epithelia are poorly understood. Given that PMN migration across mucosal epithelia is strongly correlated with disease symptoms in many inflammatory mucosal disorders, enhanced understanding of the mechanisms regulating PMN transepithelial migration should provide insights into clinically relevant tissue-targeted therapies aimed at ameliorating PMN-mediated bystander-tissue damage. This review will highlight current understanding of the molecular interactions between PMNs and mucosal epithelia and the associated functional consequences.
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Affiliation(s)
- Jennifer C Brazil
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Charles A Parkos
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
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14
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Michel NA, Zirlik A, Wolf D. CD40L and Its Receptors in Atherothrombosis-An Update. Front Cardiovasc Med 2017; 4:40. [PMID: 28676852 PMCID: PMC5477003 DOI: 10.3389/fcvm.2017.00040] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/29/2017] [Indexed: 12/30/2022] Open
Abstract
CD40L (CD154), a member of the tumor necrosis factor superfamily, is a co-stimulatory molecule that was first discovered on activated T cells. Beyond its fundamental role in adaptive immunity-ligation of CD40L to its receptor CD40 is a prerequisite for B cell activation and antibody production-evidence from more than two decades has expanded our understanding of CD40L as a powerful modulator of inflammatory pathways. Although inhibition of CD40L with neutralizing antibodies has induced life-threatening side effects in clinical trials, the discovery of cell-specific effects and novel receptors with distinct functional consequences has opened a new path for therapies that specifically target detrimental properties of CD40L. Here, we carefully evaluate the signaling network of CD40L by gene enrichment analysis and its cell-specific expression, and thoroughly discuss its role in cardiovascular pathologies with a specific emphasis on atherosclerotic and thrombotic disease.
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Affiliation(s)
- Nathaly Anto Michel
- Faculty of Medicine, Department of Cardiology and Angiology I, Heart Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Andreas Zirlik
- Faculty of Medicine, Department of Cardiology and Angiology I, Heart Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Dennis Wolf
- Faculty of Medicine, Department of Cardiology and Angiology I, Heart Center Freiburg, University of Freiburg, Freiburg, Germany
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15
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Sprangers S, Schoenmaker T, Cao Y, Everts V, de Vries TJ. Integrin αMβ2 is differently expressed by subsets of human osteoclast precursors and mediates adhesion of classical monocytes to bone. Exp Cell Res 2016; 350:161-168. [PMID: 27889375 DOI: 10.1016/j.yexcr.2016.11.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 02/02/2023]
Abstract
Bone-degrading osteoclasts are formed through fusion of their monocytic precursors. In the population of human peripheral blood monocytes, three distinct subsets have been identified: classical, intermediate and non-classical monocytes. We have previously shown that when the monocyte subsets are cultured on bone, significantly more osteoclasts are formed from classical monocytes than from intermediate or non-classical monocytes. Considering that this difference does not exist when monocyte subsets are cultured on plastic, we hypothesized that classical monocytes adhere better to the bone surface compared to intermediate and non-classical monocytes. To investigate this, the different monocyte subsets were isolated from human peripheral blood and cultured on slices of human bone in the presence of the cytokine M-CSF. We found that classical monocytes adhere better to bone due to a higher expression of the integrin αMβ2 and that their ability to attach to bone is significantly decreased when the integrin is blocked. This suggests that integrin αMβ2 mediates attachment of osteoclast precursors to bone and thereby enables the formation of osteoclasts.
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Affiliation(s)
- Sara Sprangers
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands.
| | - Ton Schoenmaker
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands; Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands.
| | - Yixuan Cao
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands.
| | - Vincent Everts
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands.
| | - Teun J de Vries
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands; Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam The Netherlands.
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16
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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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17
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Rosetti F, Chen Y, Sen M, Thayer E, Azcutia V, Herter JM, Luscinskas FW, Cullere X, Zhu C, Mayadas TN. A Lupus-Associated Mac-1 Variant Has Defects in Integrin Allostery and Interaction with Ligands under Force. Cell Rep 2015; 10:1655-1664. [PMID: 25772353 DOI: 10.1016/j.celrep.2015.02.037] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/26/2014] [Accepted: 02/11/2015] [Indexed: 01/23/2023] Open
Abstract
Leukocyte CD18 integrins increase their affinity for ligand by transmitting allosteric signals to and from their ligand-binding αI domain. Mechanical forces induce allosteric changes that paradoxically slow dissociation by increasing the integrin/ligand bond lifetimes, referred to as catch bonds. Mac-1 formed catch bonds with its ligands. However, a Mac-1 gene (ITGAM) coding variant (rs1143679, R77H), which is located in the β-propeller domain and is significantly associated with systemic lupus erythematosus risk, exhibits a marked impairment in 2D ligand affinity and affinity maturation under mechanical force. Targeted mutations and activating antibodies reveal that the failure in Mac-1 R77H allostery is rescued by induction of cytoplasmic tail separation and full integrin extension. These findings demonstrate roles for R77, and the β-propeller in which it resides, in force-induced allostery relay and integrin bond stabilization. Defects in these processes may have pathological consequences, as the Mac-1 R77H variant is associated with increased susceptibility to lupus.
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Affiliation(s)
- Florencia Rosetti
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Immunology Graduate Program, Division of Medical Sciences, Harvard Graduate School of Arts and Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Yunfeng Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Mehmet Sen
- Program in Cellular and Molecular Medicine, Department of Pediatrics, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth Thayer
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Veronica Azcutia
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jan M Herter
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - F William Luscinskas
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Xavier Cullere
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA; Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Tanya N Mayadas
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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18
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Alturaihi H, Hassan GS, Al-Zoobi L, Salti S, Darif Y, Yacoub D, El Akoum S, Oudghiri M, Merhi Y, Mourad W. Interaction of CD154 with different receptors and its role in bidirectional signals. Eur J Immunol 2014; 45:592-602. [PMID: 25403978 DOI: 10.1002/eji.201444941] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/16/2014] [Accepted: 11/11/2014] [Indexed: 11/09/2022]
Abstract
In addition to its classical receptor, CD40, it is now well established that CD154 also binds αIIbβ3, α5β1, and αMβ2 integrins. Although these integrins are all members of the same family, they bind CD154 differently. The current investigation aims to analyze the interaction of CD154 with α5β1 and αMβ2 and investigate its role in bidirectional signals in various human cell lines. Results obtained herein indicate that the CD154 residues involved in the interaction with α5β1 are N151 and Q166, whereas those involved in αMβ2 binding are common to residues required for CD40, namely Y145 and R203. Soluble CD40/CD154 or αMβ2/CD154 complexes do not interfere with the binding of CD154 to α5β1-positive cells, but inhibit the binding of CD154 to CD40- or αMβ2-positive cells, respectively. Ligation of CD154 on CD154-positive cells with soluble CD40, αIIbβ3, α5β1, or αMβ2 stimulates intracellular signaling, including MAPK phosphorylation. Given that CD154 exists as a trimer, our data strongly suggest that CD154 may bind concomitantly to two receptors of the same or different family, and biologically activate cells expressing both receptors. The characterization of CD154/receptor interactions helps the identification of new therapeutic targets for the prevention and/or treatment of CD154-associated autoimmune and inflammatory diseases.
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Affiliation(s)
- Haydar Alturaihi
- Laboratoire d'immunologie cellulaire et moléculaire, Centre de Recherche-Centre Hospitalier de l'Université de Montréal (CR-CHUM), Montréal, Canada
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19
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Zaveri TD, Lewis JS, Dolgova NV, Clare-Salzler MJ, Keselowsky BG. Integrin-directed modulation of macrophage responses to biomaterials. Biomaterials 2014; 35:3504-15. [PMID: 24462356 PMCID: PMC3970928 DOI: 10.1016/j.biomaterials.2014.01.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 01/07/2014] [Indexed: 01/08/2023]
Abstract
Macrophages are the primary mediator of chronic inflammatory responses to implanted biomaterials, in cases when the material is either in particulate or bulk form. Chronic inflammation limits the performance and functional life of numerous implanted medical devices, and modulating macrophage interactions with biomaterials to mitigate this response would be beneficial. The integrin family of cell surface receptors mediates cell adhesion through binding to adhesive proteins nonspecifically adsorbed onto biomaterial surfaces. In this work, the roles of integrin Mac-1 (αMβ2) and RGD-binding integrins were investigated using model systems for both particulate and bulk biomaterials. Specifically, the macrophage functions of phagocytosis and inflammatory cytokine secretion in response to a model particulate material, polystyrene microparticles were investigated. Opsonizing proteins modulated microparticle uptake, and integrin Mac-1 and RGD-binding integrins were found to control microparticle uptake in an opsonin-dependent manner. The presence of adsorbed endotoxin did not affect microparticle uptake levels, but was required for the production of inflammatory cytokines in response to microparticles. Furthermore, it was demonstrated that integrin Mac-1 and RGD-binding integrins influence the in vivo foreign body response to a bulk biomaterial, subcutaneously implanted polyethylene terephthalate. A thinner foreign body capsule was formed when integrin Mac-1 was absent (~30% thinner) or when RGD-binding integrins were blocked by controlled release of a blocking peptide (~45% thinner). These findings indicate integrin Mac-1 and RGD-binding integrins are involved and may serve as therapeutic targets to mitigate macrophage inflammatory responses to both particulate and bulk biomaterials.
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Affiliation(s)
- Toral D Zaveri
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Jamal S Lewis
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Natalia V Dolgova
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Michael J Clare-Salzler
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Benjamin G Keselowsky
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
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20
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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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21
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Oehmcke S, Westman J, Malmström J, Mörgelin M, Olin AI, Kreikemeyer B, Herwald H. A novel role for pro-coagulant microvesicles in the early host defense against streptococcus pyogenes. PLoS Pathog 2013; 9:e1003529. [PMID: 23935504 PMCID: PMC3731245 DOI: 10.1371/journal.ppat.1003529] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 06/15/2013] [Indexed: 01/30/2023] Open
Abstract
Previous studies have shown that stimulation of whole blood or peripheral blood mononuclear cells with bacterial virulence factors results in the sequestration of pro-coagulant microvesicles (MVs). These particles explore their clotting activity via the extrinsic and intrinsic pathway of coagulation; however, their pathophysiological role in infectious diseases remains enigmatic. Here we describe that the interaction of pro-coagulant MVs with bacteria of the species Streptococcus pyogenes is part of the early immune response to the invading pathogen. As shown by negative staining electron microscopy and clotting assays, pro-coagulant MVs bind in the presence of plasma to the bacterial surface. Fibrinogen was identified as a linker that, through binding to the M1 protein of S. pyogenes, allows the opsonization of the bacteria by MVs. Surface plasmon resonance analysis revealed a strong interaction between pro-coagulant MVs and fibrinogen with a KD value in the nanomolar range. When performing a mass-spectrometry-based strategy to determine the protein quantity, a significant up-regulation of the fibrinogen-binding integrins CD18 and CD11b on pro-coagulant MVs was recorded. Finally we show that plasma clots induced by pro-coagulant MVs are able to prevent bacterial dissemination and possess antimicrobial activity. These findings were confirmed by in vivo experiments, as local treatment with pro-coagulant MVs dampens bacterial spreading to other organs and improved survival in an invasive streptococcal mouse model of infection. Taken together, our data implicate that pro-coagulant MVs play an important role in the early response of the innate immune system in infectious diseases. The coagulation system is much more than a passive bystander in our defense against exogenous microorganisms. Over the last years there has been a growing body of evidence pointing to an integral part of coagulation in innate immunity and a special focus has been on bacterial entrapment in a fibrin network. However, thus far, pro-coagulant MVs have not been discussed in this context, though it is known that their numbers can dramatically increase in many pathological conditions, including severe infectious diseases. In the present study we see a significant increase of pro-coagulant MVs in an invasive streptococcal mouse model, suggesting that their release is an immune response to the infection. We find that pro-coagulant MVs bind to Streptococcus pyogenes and promote clotting, entrapment, and killing of the bacteria in a fibrin network. As a proof of concept pro-coagulant MVs were applied as local treatment in the streptococcal infection model, and it was demonstrated that this led to a significantly improved survival in mice.
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Affiliation(s)
- Sonja Oehmcke
- University Medicine, Institute of Medical Microbiology, Virology and Hygiene, Rostock University, Rostock, Germany.
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22
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Bzowska M, Nogieć A, Skrzeczyńska-Moncznik J, Mickowska B, Guzik K, Pryjma J. Oxidized LDLs inhibit TLR-induced IL-10 production by monocytes: a new aspect of pathogen-accelerated atherosclerosis. Inflammation 2013; 35:1567-84. [PMID: 22556042 PMCID: PMC3397235 DOI: 10.1007/s10753-012-9472-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It is widely accepted that oxidized low-density lipoproteins and local infections or endotoxins in circulation contribute to chronic inflammatory process at all stages of atherosclerosis. The hallmark cells of atherosclerotic lesions-monocytes and macrophages-are able to detect and integrate complex signals derived from lipoproteins and pathogens, and respond with a spectrum of immunoregulatory cytokines. In this study, we show strong inhibitory effect of oxLDLs on anti-inflammatory interleukin-10 production by monocytes responding to TLR2 and TLR4 ligands. In contrast, pro-inflammatory tumor necrosis factor secretion was even slightly increased, when stimulated with lipopolysaccharide from Porphyromonas gingivalis-an oral pathogen associated with atherosclerosis. The oxLDLs modulatory activity may be explained by altered recognition of pathogen-associated molecular patterns, which involves serum proteins, particularly vitronectin. We also suggest an interaction between vitronectin receptor, CD11b, and TLR2. The presented data support a novel pathway for pathogen-accelerated atherosclerosis, which relies on oxidized low-density lipoprotein-mediated modulation of anti-inflammatory response to TLR ligands.
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Affiliation(s)
- Małgorzata Bzowska
- Department of Immunology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Anna Nogieć
- Department of Immunology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Joanna Skrzeczyńska-Moncznik
- Department of Immunology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Barbara Mickowska
- Malopolska Centre of Food Monitoring and Certification, Faculty of Food Technology, Agricultural University, Balicka 122, 30-149 Kraków, Poland
| | - Krzysztof Guzik
- Department of Immunology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Juliusz Pryjma
- Department of Immunology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
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23
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Oxidized LDLs inhibit TLR-induced IL-10 production by monocytes: a new aspect of pathogen-accelerated atherosclerosis. Inflammation 2013. [PMID: 22556042 DOI: 10.1007/s110753-012-9472-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It is widely accepted that oxidized low-density lipoproteins and local infections or endotoxins in circulation contribute to chronic inflammatory process at all stages of atherosclerosis. The hallmark cells of atherosclerotic lesions-monocytes and macrophages-are able to detect and integrate complex signals derived from lipoproteins and pathogens, and respond with a spectrum of immunoregulatory cytokines. In this study, we show strong inhibitory effect of oxLDLs on anti-inflammatory interleukin-10 production by monocytes responding to TLR2 and TLR4 ligands. In contrast, pro-inflammatory tumor necrosis factor secretion was even slightly increased, when stimulated with lipopolysaccharide from Porphyromonas gingivalis-an oral pathogen associated with atherosclerosis. The oxLDLs modulatory activity may be explained by altered recognition of pathogen-associated molecular patterns, which involves serum proteins, particularly vitronectin. We also suggest an interaction between vitronectin receptor, CD11b, and TLR2. The presented data support a novel pathway for pathogen-accelerated atherosclerosis, which relies on oxidized low-density lipoprotein-mediated modulation of anti-inflammatory response to TLR ligands.
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24
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Fink K, Busch HJ, Bourgeois N, Schwarz M, Wolf D, Zirlik A, Peter K, Bode C, von Zur Muhlen C. Mac-1 directly binds to the endothelial protein C-receptor: a link between the protein C anticoagulant pathway and inflammation? PLoS One 2013; 8:e53103. [PMID: 23408932 PMCID: PMC3567096 DOI: 10.1371/journal.pone.0053103] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 11/23/2012] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE The endothelial protein C-receptor (EPCR) is an endothelial transmembrane protein that binds protein C and activated protein C (APC) with equal affinity, thereby facilitating APC formation. APC has anticoagulant, antiapoptotic and antiinflammatory properties. Soluble EPCR, released by the endothelium, may bind activated neutrophils, thereby modulating cell adhesion. EPCR is therefore considered as a possible link between the anticoagulant properties of protein C and the inflammatory response of neutrophils. In the present study, we aimed to provide proof of concept for a direct binding of EPCR to the β2-integrin Mac-1 on monocytic cells under static and physiological flow conditions. MEASUREMENTS AND MAIN RESULTS Under static conditions, human monocytes bind soluble EPCR in a concentration dependent manner, as demonstrated by flow cytometry. Binding can be inhibited by specific antibodies (anti-EPCR and anti-Mac-1). Specific binding was confirmed by a static adhesion assay, where a transfected Mac-1 expressing CHO cell line (Mac-1+ cells) bound significantly more recombinant EPCR compared to Mac-1+ cells blocked by anti-Mac-1-antibody and native CHO cells. Under physiological flow conditions, monocyte binding to the endothelium could be significantly blocked by both, anti-EPCR and anti-Mac-1 antibodies in a dynamic adhesion assay at physiological flow conditions. Pre-treatment of endothelial cells with APC (drotrecogin alfa) diminished monocyte adhesion significantly in a comparable extent to anti-EPCR. CONCLUSIONS In the present study, we demonstrate a direct binding of Mac-1 on monocytes to the endothelial protein C receptor under static and flow conditions. This binding suggests a link between the protein C anticoagulant pathway and inflammation at the endothelium side, such as in acute vascular inflammation or septicaemia.
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Affiliation(s)
- Katrin Fink
- Department of Cardiology and Angiology I, University Heart Center Freiburg, Freiburg, Germany.
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Li R, Ren M, Chen N, Luo M, Zhang Z, Wu J. Vitronectin increases vascular permeability by promoting VE-cadherin internalization at cell junctions. PLoS One 2012; 7:e37195. [PMID: 22606350 PMCID: PMC3350505 DOI: 10.1371/journal.pone.0037195] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 04/17/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cross-talk between integrins and cadherins regulates cell function. We tested the hypothesis that vitronectin (VN), a multi-functional adhesion molecule present in the extracellular matrix and plasma, regulates vascular permeability via effects on VE-cadherin, a critical regulator of endothelial cell (EC) adhesion. METHODOLOGY/PRINCIPAL FINDINGS Addition of multimeric VN (mult VN) significantly increased VE-cadherin internalization in human umbilical vein EC (HUVEC) monolayers. This effect was blocked by the anti-α(V)β(3) antibody, pharmacological inhibition and knockdown of Src kinase. In contrast to mult VN, monomeric VN did not trigger VE-cadherin internalization. In a modified Miles assay, VN deficiency impaired vascular endothelial growth factor-induced permeability. Furthermore, ischemia-induced enhancement of vascular permeability, expressed as the ratio of FITC-dextran leakage from the circulation into the ischemic and non-ischemic hindlimb muscle, was significantly greater in the WT mice than in the Vn(-/-) mice. Similarly, ischemia-mediated macrophage infiltration was significantly reduced in the Vn(-/-) mice vs. the WT controls. We evaluated changes in the multimerization of VN in ischemic tissue in a mouse hindlimb ischemia model. VN plays a previously unrecognized role in regulating endothelial permeability via conformational- and integrin-dependent effects on VE-cadherin trafficking. CONCLUSION/SIGNIFICANCE These results have important implications for the regulation of endothelial function and angiogenesis by VN under normal and pathological conditions.
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Affiliation(s)
- Rong Li
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
| | - Meiping Ren
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
| | - Ni Chen
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
| | - Mao Luo
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
| | - Zhuo Zhang
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
| | - Jianbo Wu
- Drug Discovery Research Center of Luzhou Medical College, Luzhou Medical College, Luzhou, Sichuan, People's Republic of China
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America
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Wolf D, Hohmann JD, Wiedemann A, Bledzka K, Blankenbach H, Marchini T, Gutte K, Zeschky K, Bassler N, Hoppe N, Rodriguez AO, Herr N, Hilgendorf I, Stachon P, Willecke F, Dürschmied D, von zur Mühlen C, Soloviev DA, Zhang L, Bode C, Plow EF, Libby P, Peter K, Zirlik A. Binding of CD40L to Mac-1's I-domain involves the EQLKKSKTL motif and mediates leukocyte recruitment and atherosclerosis--but does not affect immunity and thrombosis in mice. Circ Res 2011; 109:1269-79. [PMID: 21998326 PMCID: PMC3291815 DOI: 10.1161/circresaha.111.247684] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 09/26/2011] [Indexed: 01/05/2023]
Abstract
RATIONALE CD40L figures prominently in chronic inflammatory diseases such as atherosclerosis. However, since CD40L potently regulates immune function and hemostasis by interaction with CD40 receptor and the platelet integrin GPIIb/IIIa, its global inhibition compromises host defense and generated thromboembolic complications in clinical trials. We recently reported that CD40L mediates atherogenesis independently of CD40 and proposed Mac-1 as an alternate receptor. OBJECTIVE Here, we molecularly characterized the CD40L-Mac-1 interaction and tested whether its selective inhibition by a small peptide modulates inflammation and atherogenesis in vivo. METHODS AND RESULTS CD40L concentration-dependently bound to Mac-1 I-domain in solid phase binding assays, and a high-affinity interaction was revealed by surface-plasmon-resonance analysis. We identified the motif EQLKKSKTL, an exposed loop between the α1 helix and the β-sheet B, on Mac-1 as binding site for CD40L. A linear peptide mimicking this sequence, M7, specifically inhibited the interaction of CD40L and Mac-1. A cyclisized version optimized for in vivo use, cM7, decreased peritoneal inflammation and inflammatory cell recruitment in vivo. Finally, LDLr(-/-) mice treated with intraperitoneal injections of cM7 developed smaller, less inflamed atherosclerotic lesions featuring characteristics of stability. However, cM7 did not interfere with CD40L-CD40 binding in vitro and CD40L-GPIIb/IIIa-mediated thrombus formation in vivo. CONCLUSIONS We present the novel finding that CD40L binds to the EQLKKSKTL motif on Mac-1 mediating leukocyte recruitment and atherogenesis. Specific inhibition of CD40L-Mac-1 binding may represent an attractive anti-inflammatory treatment strategy for atherosclerosis and other inflammatory conditions, potentially avoiding the unwanted immunologic and thrombotic effects of global inhibition of CD40L.
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Affiliation(s)
- Dennis Wolf
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | | | - Ansgar Wiedemann
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Kamila Bledzka
- Cleveland Clinic, Department of Molecular Cardiology, Ohio, USA
| | - Hermann Blankenbach
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Timoteo Marchini
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Katharina Gutte
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Katharina Zeschky
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Nicole Bassler
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Natalie Hoppe
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | | | - Nadine Herr
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Ingo Hilgendorf
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Peter Stachon
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Florian Willecke
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Daniel Dürschmied
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | | | | | - Li Zhang
- Center for Vascular and Inflammatory Diseases, University of Maryland, Baltimore, USA
| | - Christoph Bode
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
| | - Edward F. Plow
- Cleveland Clinic, Department of Molecular Cardiology, Ohio, USA
| | - Peter Libby
- Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, USA
| | - Karlheinz Peter
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Andreas Zirlik
- Atherogenesis Research Group, Department of Cardiology, University of Freiburg, Freiburg, Germany
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CD154: an immunoinflammatory mediator in systemic lupus erythematosus and rheumatoid arthritis. Clin Dev Immunol 2011; 2012:490148. [PMID: 22110533 PMCID: PMC3202102 DOI: 10.1155/2012/490148] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 08/17/2011] [Indexed: 01/17/2023]
Abstract
Systemic lupus erythematosus and rheumatoid arthritis are two major chronic inflammatory autoimmune diseases with significant prevalence rates among the population. Although the etiology of these diseases remains unresolved, several evidences support the key role of CD154/CD40 interactions in initiating and/or propagating these diseases. The discovery of new receptors (αIIbβ3, α5β1, and αMβ2) for CD154 has expanded our understanding about the precise role of this critical immune mediator in the physiopathology of chronic inflammatory autoimmune diseases in general, and in systemic lupus erythematosus and rheumatoid arthritis in particular. This paper presents an overview of the interaction of CD154 with its various receptors and outlines its role in the pathogenesis of systemic lupus erythematosus and rheumatoid arthritis. Moreover, the potential usefulness of various CD154-interfering agents in the treatment and prevention of these diseases is also discussed.
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28
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Yang Y, Friggeri A, Banerjee S, Bdeir K, Cines DB, Liu G, Abraham E. Urokinase-type plasminogen activator inhibits efferocytosis of neutrophils. Am J Respir Crit Care Med 2010; 182:1516-23. [PMID: 20656938 DOI: 10.1164/rccm.201003-0452oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
RATIONALE Phagocytosis of apoptotic cells, also called efferocytosis, plays an essential role in the resolution of inflammation. Urokinase-type plasminogen activator (uPA) is a multifunctional protein that has been implicated in inflammatory conditions, including pneumonia and severe infection, which are often accompanied by the development of acute lung injury. However, the role of uPA in modulating efferocytosis of apoptotic neutrophils has not been defined. OBJECTIVES To characterize the role of uPA in regulation of efferocytosis and to delineate the underlying mechanisms involved in this process. METHODS In vitro and in vivo phagocytosis, immunoprecipitation, and Western blotting assays. MEASUREMENTS AND MAIN RESULTS The phagocytosis of apoptotic neutrophils by macrophages was significantly inhibited by uPA. Mutant uPA lacking the growth factor domain and catalytically inactive uPA had similar inhibitory effects on efferocytosis, as did wild-type uPA. In contrast, absence of the kringle domain abrogated the ability of uPA to diminish efferocytosis. Both the α(V)β₃ integrin and vitronectin seemed to be involved in the inhibition of efferocytosis by uPA. Incubation of macrophages with uPA also diminished activation of the small GTPase Rac-1, which normally occurs during ingestion of apoptotic neutrophils. Under in vivo conditions in the lungs, uPA decreased the uptake of apoptotic neutrophils by alveolar macrophages. CONCLUSIONS Our data demonstrate a novel role for uPA in which it is able to diminish the uptake of apoptotic neutrophils by macrophages under both in vitro and in vivo conditions.
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Affiliation(s)
- Yanping Yang
- Department of Medicine, University of Alabama at Birmingham, 35294, USA
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29
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von zur Muhlen C, Fink-Petri A, Salaklang J, Paul D, Neudorfer I, Berti V, Merkle A, Peter K, Bode C, von Elverfeldt D. Imaging monocytes with iron oxide nanoparticles targeted towards the monocyte integrin MAC-1 (CD11b/CD18) does not result in improved atherosclerotic plaque detection by in vivo MRI. CONTRAST MEDIA & MOLECULAR IMAGING 2010; 5:268-75. [DOI: 10.1002/cmmi.384] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Singh B, Janardhan KS, Kanthan R. EXPRESSION OF ANGIOSTATIN, INTEGRINαvβ3, AND VITRONECTIN IN HUMAN LUNGS IN SEPSIS. Exp Lung Res 2009; 31:771-82. [PMID: 16368651 DOI: 10.1080/01902140500324901] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Angiostatin, integrin alphavbeta3, and vitronectin play important roles in inflammation. However, there is very little information on expression of these molecules in the lungs of humans with sepsis. Therefore, as a first step to eventually study the function of these molecules, the authors conducted an immunohistochemical study to evaluate their expression in lungs of normal (N = 8) and sepsis patients (N = 8). In normal lungs, angiostatin expression was minimal in the alveolar septa and alveolar macrophages, and absent in large blood vessels, bronchioles, and interstitium. In sepsis patients, the staining was intense in the septa, neutrophils, alveolar macrophages, and large blood vessels. Integrin alphavbeta3 staining was observed in occasional bronchiolar epithelial cells and a few alveolar macrophages in the normal lungs. The integrin was expressed extensively and intensely in bronchiolar epithelium and alveolar macrophages, and with lesser intensity in large blood vessels in inflamed lungs. Compared to the normal lung, vitronectin expression was increased in alveolar macrophages and in vascular smooth muscles in inflamed lungs. These data show cell-specific increase in the expression of integrin alphavbeta3, angiostatin, and vitronectin in inflamed lungs of sepsis patients. Because all these molecules can have significant influence on inflammation, the data reported in this manuscript create a need for further investigation.
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Affiliation(s)
- Baljit Singh
- Immunology Research Group and Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Canada. baljit@
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31
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Abstract
At sites of inflammation, infection or vascular injury local proinflammatory or pathogen-derived stimuli render the luminal vascular endothelial surface attractive for leukocytes. This innate immunity response consists of a well-defined and regulated multi-step cascade involving consecutive steps of adhesive interactions between the leukocytes and the endothelium. During the initial contact with the activated endothelium leukocytes roll along the endothelium via a loose bond which is mediated by selectins. Subsequently, leukocytes are activated by chemokines presented on the luminal endothelial surface, which results in the activation of leukocyte integrins and the firm leukocyte arrest on the endothelium. After their firm adhesion, leukocytes make use of two transmigration processes to pass the endothelial barrier, the transcellular route through the endothelial cell body or the paracellular route through the endothelial junctions. In addition, further circulating cells, such as platelets arrive early at sites of inflammation contributing to both coagulation and to the immune response in parts by facilitating leukocyte-endothelial interactions. Platelets have thereby been implicated in several inflammatory pathologies. This review summarizes the major mechanisms and molecules involved in leukocyte-endothelial and leukocyte-platelet interactions in inflammation.
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Affiliation(s)
- Harald F Langer
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD, USA.
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Eniola-Adefeso O, Huang RB, Smith CW. Kinetics of LFA-1 mediated adhesion of human neutrophils to ICAM-1--role of E-selectin signaling post-activation. Ann Biomed Eng 2009; 37:737-48. [PMID: 19184433 DOI: 10.1007/s10439-009-9647-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 01/20/2009] [Indexed: 12/01/2022]
Abstract
LFA-1 and Mac-1 are the two integrins involved in the arrest and firm adhesion of neutrophils. LFA-1 plays a role in the early stage of cell arrest while Mac-1 stabilizes firm adhesion. Here, we further elucidated the kinetics of LFA-1 activation and its role in mediating neutrophil adhesion to ICAM-1 in the presence of E-selectin interaction. We confirm that LFA-1 activation to high affinity is transient in nature, decaying back to low affinity within 1 min after chemotactic stimulation. However, we show for the first time that this downshift in LFA-1 affinity does not return back to the low affinity state when E-selectin interaction is present and active, but rather E-selectin signals an intermediate LFA-1 conformation through PI3-Kinase that maintains an intermediate level of neutrophil firm adhesion. We further show that this E-selectin signaling is capable of returning LFA-1 to the intermediate affinity conformation outside the 1-min window previously reported for LFA-1 functionality. While our work confirms a role for PI3-Kinase in neutrophil firm adhesion, we show that PI3-Kinase may not be important in the initial transition from rolling to firm arrest (i.e. LFA-1 shift from low to high affinity conformation occurring within seconds of chemotactic stimulation).
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Affiliation(s)
- Omolola Eniola-Adefeso
- Department of Chemical Engineering, University of Michigan, 2300 Hayward Street, 3074 H. H. Dow Building, Ann Arbor, MI 48109-2136, USA.
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McNally AK, Jones JA, Macewan SR, Colton E, Anderson JM. Vitronectin is a critical protein adhesion substrate for IL-4-induced foreign body giant cell formation. J Biomed Mater Res A 2008; 86:535-43. [PMID: 17994558 PMCID: PMC4227597 DOI: 10.1002/jbm.a.31658] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
An in vitro system of interleukin (IL)-4-induced foreign body giant cell (FBGC) formation was utilized to define the adhesion protein substrate(s) that promotes this aspect of the foreign body reaction on biomedical polymers. Human monocytes were cultured on cell culture polystyrene surfaces that had been pre-adsorbed with a synthetic arginine-glycine-aspartate peptide previously found to support optimal FBGC formation, or with various concentrations of potential physiological protein substrates, i.e. complement C3bi, collagen types I or IV, fibrinogen, plasma fibronectin, fibroblast fibronectin, laminin, thrombospondin, vitronectin, or von Willebrand factor. Cultures were evaluated on days 0 (1.5 h), 3, and 7 by May-Grünwald/Giemsa staining. Initial monocyte adhesion occurred on all adsorbed proteins. However, by day 7 of culture, only vitronectin was striking in its ability to support significant macrophage adhesion, development, and fusion leading to FBGC formation. Vitronectin supported high degrees of FBGC formation at an absorption concentration between 5 and 25 microg/mL. These findings suggest that adsorbed vitronectin is critical in the collective events that support and promote FBGC formation on biomedical polymers, and that the propensity for vitronectin adsorption may underlie the material surface chemistry dependency of FBGC formation.
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Affiliation(s)
- Amy K McNally
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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Petzinger J, Saltel F, Hersemeyer K, Daniel JM, Preissner KT, Wehrle-Haller B, Kanse SM. Urokinase receptor (CD87) clustering in detergent-insoluble adhesion patches leads to cell adhesion independently of integrins. ACTA ACUST UNITED AC 2007; 14:137-55. [PMID: 17957530 DOI: 10.1080/15419060701557487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The urokinase-type plasminogen activator receptor (uPAR) is a glycosylphosphatidyl inositol-anchored protein that mediates cell adhesion to the extracellular matrix protein vitronectin (VN). We demonstrate here that this cell adhesion process is accompanied by the formation of an adhesion patch characterized by an accumulation of uPAR into areas of direct contact between the cell and the matrix. The adhesion patch requires the glycolipid anchor and develops only on a VN-coated substrate, but not on fibronectin. It consists of detergent-insoluble microdomains that accumulate F-actin and tyrosine-phosphorylated proteins, but not beta(1) integrins. Lack of inhibition of adhesion in the presence of integrin-blocking reagents and adhesion on a VN fragment without the RGD sequence indicated that the adhesion of uPAR-bearing cells on VN could occur independently of integrins. Hence, uPAR-mediated cell adhesion on VN relies on the formation of a unique cellular structure that we have termed "detergent-insoluble adhesion patch" (DIAP).
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Affiliation(s)
- Jutta Petzinger
- Institute for Biochemistry, Justus-Liebig University, Giessen, Germany
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35
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Tsuruta Y, Park YJ, Siegal GP, Liu G, Abraham E. Involvement of Vitronectin in Lipopolysaccaride-Induced Acute Lung Injury. THE JOURNAL OF IMMUNOLOGY 2007; 179:7079-86. [DOI: 10.4049/jimmunol.179.10.7079] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Park EJ, Mora JR, Carman CV, Chen J, Sasaki Y, Cheng G, von Andrian UH, Shimaoka M. Aberrant activation of integrin alpha4beta7 suppresses lymphocyte migration to the gut. J Clin Invest 2007; 117:2526-38. [PMID: 17786243 PMCID: PMC1952632 DOI: 10.1172/jci31570] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 06/26/2007] [Indexed: 11/17/2022] Open
Abstract
Integrin adhesion molecules mediate lymphocyte migration and homing to normal and inflamed tissues. While the ligand-binding activity of integrins is known to be modulated by conformational changes, little is known about how the appropriate balance of integrin adhesiveness is maintained in order to optimize the migratory capacity of lymphocytes in vivo. In this study we examined the regulation of the gut homing receptor alpha4beta7 integrin by manipulating at the germline level an integrin regulatory domain known as adjacent to metal ion-dependent adhesion site (ADMIDAS). ADMIDAS normally serves to raise the activation threshold of alpha4beta7, thereby stabilizing it in the default nonadhesive state. Lymphocytes from knockin beta7 (D146A) mice, which harbor a disrupted ADMIDAS, not only expressed an alpha4beta7 integrin that persistently adhered to mucosal addressin cell adhesion molecule-1 (MAdCAM-1), but also exhibited perturbed cell migration along MAdCAM-1 substrates resulting from improper de-adhesion of the lymphocyte trailing edge. In vivo, aberrantly activated alpha4beta7 enhanced adhesion to Peyer's patch venules, but suppressed lymphocyte homing to the gut, diminishing the capacity of T cells to induce colitis. Our results underscore the importance of a proper balance in the adhesion and de-adhesion of the alpha4beta7 integrin, both for lymphocyte trafficking to the gut and for colitis progression.
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Affiliation(s)
- Eun Jeong Park
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - J. Rodrigo Mora
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Christopher V. Carman
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - JianFeng Chen
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Yoshiteru Sasaki
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Guiying Cheng
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Ulrich H. von Andrian
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Motomu Shimaoka
- CBR Institute for Biomedical Research, Boston, Massachusetts, USA.
Department of Anesthesia,
Department of Pathology,
Gastrointestinal Unit, Massachusetts General Hospital, and
Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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37
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Zirlik A, Maier C, Gerdes N, MacFarlane L, Soosairajah J, Bavendiek U, Ahrens I, Ernst S, Bassler N, Missiou A, Patko Z, Aikawa M, Schönbeck U, Bode C, Libby P, Peter K. CD40 ligand mediates inflammation independently of CD40 by interaction with Mac-1. Circulation 2007; 115:1571-80. [PMID: 17372166 DOI: 10.1161/circulationaha.106.683201] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Strong evidence supports a role for CD40 ligand (CD40L) as marker and mediator of inflammatory diseases such as atherosclerosis. Despite extensive characterization of CD40, the classic receptor of CD40L, its role in immune defense against inflammatory diseases remains uncertain. The present study aimed to characterize the contribution of CD40 signaling to atherogenesis. METHODS AND RESULTS Surprisingly, mice deficient in both CD40 and the low-density lipoprotein receptor did not develop smaller lesions in the aortic arch, root, and thoracoabdominal aorta compared with mice deficient only in the low-density lipoprotein receptor that consumed an atherogenic diet for 8 and 16 weeks. By flow cytometry, radioactive binding assays, and immunoprecipitation, we demonstrate that CD40L interacts with the integrin Mac-1, which results in Mac-1-dependent adhesion and migration of inflammatory cells as well as myeloperoxidase release in vitro. Furthermore, mice deficient in CD40L show significantly reduced thioglycolate-elicited invasion of inflammatory cells into the peritoneal cavity compared with mice deficient in CD40 and wild-type controls. Inhibition of Mac-1 in low-density lipoprotein receptor-deficient mice attenuates lesion development and reduces lesional macrophage accumulation. CONCLUSIONS These observations identify the interaction of CD40L and Mac-1 as an alternative pathway for CD40L-mediated inflammation. This novel mechanism expands understanding of inflammatory signaling during atherogenesis.
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MESH Headings
- Animals
- Aorta, Thoracic/chemistry
- Aorta, Thoracic/pathology
- Aortic Diseases/etiology
- Aortic Diseases/pathology
- Atherosclerosis/etiology
- Atherosclerosis/genetics
- Atherosclerosis/physiopathology
- Atherosclerosis/prevention & control
- CD40 Ligand/deficiency
- CD40 Ligand/physiology
- CHO Cells
- Chemotaxis, Leukocyte/physiology
- Cholesterol, Dietary/toxicity
- Cricetinae
- Cricetulus
- Crosses, Genetic
- Diet, Atherogenic
- Foam Cells/pathology
- Genetic Predisposition to Disease
- Humans
- Inflammation/etiology
- Inflammation/genetics
- Inflammation/physiopathology
- Lipids/analysis
- Macrophage-1 Antigen/physiology
- Macrophages/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Models, Biological
- Monocytes/drug effects
- Monocytes/enzymology
- Peritonitis/chemically induced
- Peritonitis/metabolism
- Peritonitis/pathology
- Peroxidase/metabolism
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Rheology
- Tetradecanoylphorbol Acetate/pharmacology
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Affiliation(s)
- Andreas Zirlik
- Donald W. Reynolds Center, Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
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38
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Chen J, Seviour R. Medicinal importance of fungal beta-(1-->3), (1-->6)-glucans. ACTA ACUST UNITED AC 2007; 111:635-52. [PMID: 17590323 DOI: 10.1016/j.mycres.2007.02.011] [Citation(s) in RCA: 347] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 01/25/2007] [Accepted: 02/19/2007] [Indexed: 11/21/2022]
Abstract
Non-cellulosic beta-glucans are now recognized as potent immunological activators, and some are used clinically in China and Japan. These beta-glucans consist of a backbone of glucose residues linked by beta-(1-->3)-glycosidic bonds, often with attached side-chain glucose residues joined by beta-(1-->6) linkages. The frequency of branching varies. The literature suggests beta-glucans are effective in treating diseases like cancer, a range of microbial infections, hypercholesterolaemia, and diabetes. Their mechanisms of action involve them being recognized as non-self molecules, so the immune system is stimulated by their presence. Several receptors have been identified, which include: dectin-1, located on macrophages, which mediates beta-glucan activation of phagocytosis and production of cytokines, a response co-ordinated by the toll-like receptor-2. Activated complement receptors on natural killer cells, neutrophils, and lymphocytes, may also be associated with tumour cytotoxicity. Two other receptors, scavenger and lactosylceramide, bind beta-glucans and mediate a series of signal pathways leading to immunological activation. Structurally different beta-glucans appear to have different affinities toward these receptors and thus generate markedly different host responses. However, the published data are not always easy to interpret as many of the earlier studies used crude beta-glucan preparations with, for the most part, unknown chemical structures. Careful choice of beta-glucan products is essential if their benefits are to be optimized, and a better understanding of how beta-glucans bind to receptors should enable more efficient use of their biological activities.
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Affiliation(s)
- Jiezhong Chen
- Cancer Biology Program, Diamantia Institute for Cancer, Immunology and Metabolic Medicine, University of Queensland, Brisbane, Queensland 4102, Australia.
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39
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Eisenhardt SU, Schwarz M, Schallner N, Soosairajah J, Bassler N, Huang D, Bode C, Peter K. Generation of activation-specific human anti-alphaMbeta2 single-chain antibodies as potential diagnostic tools and therapeutic agents. Blood 2006; 109:3521-8. [PMID: 17164347 DOI: 10.1182/blood-2006-03-007179] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The leukocyte integrin Mac-1 (alpha(M)beta(2)) plays a pivotal role in inflammation and host defense. Upon leukocyte activation, Mac-1 undergoes a conformational change exposing interaction sites for multiple ligands. We aimed to generate single-chain antibodies (scFv's) directed against activation-specific Mac-1 ligand-binding sites. Using human scFv phage libraries, we developed subtractive strategies with depletion of phages binding to nonactivated Mac-1 and selection of phages binding to activated Mac-1, using monocytes as well as CHO cells transfected with native or mutated, activated Mac-1. Three scFv clones demonstrated exclusive binding to activated Mac-1. Mac-1 binding of the ligands fibrinogen, heparin, and ICAM-1, but not C3bi, was inhibited. Using alanine substitutions, the paratope was identified within the heavy chain HCDR3s of the scFv's. The epitope was localized to Lys(245)-Arg(261) of the alpha(M) I-domain. In a pilot study with septicemic patients, we provide initial support for the use of these scFv's as markers of monocyte activation and as potential diagnostic tools. Potential therapeutic use was tested in adhesion assays under static and flow conditions demonstrating the selective blockade of activated monocytes only. Furthermore, scFv HCDR3-derived peptides retain selectivity for the activated integrin, providing a unique template for the potential development of inhibitors that are specific for the activated Mac-1.
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40
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von Zur Muhlen C, von Elverfeldt D, Bassler N, Neudorfer I, Steitz B, Petri-Fink A, Hofmann H, Bode C, Peter K. Superparamagnetic iron oxide binding and uptake as imaged by magnetic resonance is mediated by the integrin receptor Mac-1 (CD11b/CD18): implications on imaging of atherosclerotic plaques. Atherosclerosis 2006; 193:102-11. [PMID: 16997307 DOI: 10.1016/j.atherosclerosis.2006.08.048] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 07/23/2006] [Accepted: 08/23/2006] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Superparamagnetic iron oxide nanoparticles (SPIONs) have been successfully used for magnetic resonance imaging (MRI) of atherosclerotic plaques. Endocytosis into monocytes/macrophages has been proposed as the mechanism for SPION uptake, but a specific receptor has not been identified yet. A potential candidate is the versatile integrin Mac-1 (CD11b/CD18, alphaMbeta2), which is involved in leukocyte adhesion, complement activation and phagocytosis. METHODS AND RESULTS Intracellular SPION-accumulation was confirmed in cultured human monocytes using immunohistochemistry and iron staining. Recombinant cells expressing Mac-1 in different activation states as well as human monocytes with or without PMA stimulation were incubated either with an unspecific IgG or a CD11b-blocking antibody. Thereafter, cells were incubated with FITC-labeled amino-covered SPIONs or ferumoxtran-10 SPIONs and signal intensity was quantified by flow cytometry. Depending on the activation status of Mac-1, a significant increase in SPION binding/uptake was observed, independent on surface coating. Furthermore, SPION binding/uptake was significantly reduced after CD11b blockade. Results were confirmed in recombinant cells incubated with amino-PVA SPIONs and ferumoxtran-10, using T2(*)-weighted 3T MRI. CONCLUSION The integrin Mac-1 is directly involved in SPION binding/uptake. Thus, monocytes abundantly expressing Mac-1 and especially activated monocytes expressing activated Mac-1 may be useful vehicles for high resolution MRI labeling of atherosclerotic plaques.
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Affiliation(s)
- C von Zur Muhlen
- Department of Cardiology & Angiology, University Hospital of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
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41
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Pendu R, Terraube V, Christophe OD, Gahmberg CG, de Groot PG, Lenting PJ, Denis CV. P-selectin glycoprotein ligand 1 and beta2-integrins cooperate in the adhesion of leukocytes to von Willebrand factor. Blood 2006; 108:3746-52. [PMID: 16926295 DOI: 10.1182/blood-2006-03-010322] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Von Willebrand factor (VWF) is an essential component of hemostasis. However, animal studies using VWF-deficient mice suggest that VWF may also contribute to inflammation. In the present study, we demonstrate that VWF was able to interact with polymorphonuclear leukocytes (PMNs) and monocytes under static and flow conditions. Adhesion under flow was dominated by short-lasting contact with resting PMNs, whereas adhesion of phorbol-12-myristate-13-acetate (PMA)-stimulated PMNs was characterized by firm adhesion. Transient binding of PMNs to VWF appeared to be mediated by P-selectin glycoprotein ligand-1 (PSGL-1). Moreover, recombinant PSGL-1 protein and cell surface-expressed PSGL-1 directly interacted with VWF. As for stable adhesion by PMA-stimulated PMNs, we observed that static adhesion and adhesion under flow were strongly inhibited (greater than 75%) by neutrophil-inhibitory factor, an inhibitor of beta2-integrin function. In addition, the isolated I-domain of alphaMbeta2 bound to VWF, and cell lines expressing alphaLbeta2 or alphaXbeta2 adhered efficiently to VWF. Taken together, our data showed that VWF can function as an adhesive surface for various leukocyte subsets (monocytes, PMNs). Analogous to VWF-platelet interaction, VWF provided binding sites for leukocyte receptors involved in rolling (PSGL-1) and stable (beta2-integrins) adhesion. VWF is unique in its intrinsic capacity to combine the rolling and the stable adhesion step in the interaction with leukocytes.
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Affiliation(s)
- Ronan Pendu
- INSERM U. 770, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cedex, France
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42
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Barthel SR, Jarjour NN, Mosher DF, Johansson MW. Dissection of the hyperadhesive phenotype of airway eosinophils in asthma. Am J Respir Cell Mol Biol 2006; 35:378-86. [PMID: 16601240 PMCID: PMC1550734 DOI: 10.1165/rcmb.2006-0027oc] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Asthma is characterized by appearance of eosinophils in the airway. Eosinophils purified from the airway 48 h after segmental antigen challenge are described as exhibiting greater adhesion to albumin-coated surfaces via an unidentified beta2 integrin and increased expression of alphaMbeta2 (CD11b/18) compared with purified blood eosinophils. We have investigated the determinants of this hyperadhesive phenotype. Airway eosinophils exhibited increased reactivity with the CBRM1/5 anti-alphaM activation-sensitive antibody as well as enhanced adhesion to VCAM-1 (CD106) and diverse ligands, including albumin, ICAM-1 (CD54), fibrinogen, and vitronectin. Purified blood eosinophils did not adhere to the latter diverse ligands. Enhanced adhesion of airway eosinophils was blocked by anti-alphaMbeta2. Podosomes, structures implicated in cell movement and proteolysis of matrix proteins, were larger and more common on airway eosinophils adherent to VCAM-1 when compared with blood eosinophils. Incubation of blood eosinophils with IL-5 replicated the phenotype of airway eosinophils. That is, IL-5 enhanced recognition of alphaM by CBRM1/5; stimulated alphaMbeta2-mediated adhesion to VCAM-1, albumin, ICAM-1, fibrinogen, and vitronectin; and increased podosome formation on VCAM-1. Thus, the hyperadhesion of airway eosinophils after antigen challenge is mediated by upregulated and activated alphaMbeta2.
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Affiliation(s)
- Steven R Barthel
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, 4285A Medical Sciences Center, 1300 University Avenue, Madison, Wisconsin 53706-1532, USA
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43
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Ahrens IG, Moran N, Aylward K, Meade G, Moser M, Assefa D, Fitzgerald DJ, Bode C, Peter K. Evidence for a differential functional regulation of the two beta(3)-integrins alpha(V)beta(3) and alpha(IIb)beta(3). Exp Cell Res 2006; 312:925-37. [PMID: 16434034 DOI: 10.1016/j.yexcr.2005.11.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2004] [Revised: 11/28/2005] [Accepted: 11/30/2005] [Indexed: 11/22/2022]
Abstract
The functional regulation of integrins is a major determinant of cell adhesion, migration and tissue maintenance. The binding of cytoskeletal proteins to various sites of integrin cytoplasmic domains is a key mechanism of this functional regulation. Expression of recombinant integrin alpha(IIb)beta(3) and alpha(M)beta(2) lacking the GFFKR-region in CHO cells results in constitutively activated integrins. In contrast, CHO cells stably expressing either a GFFKR-deleted alpha(V(del))beta(3) or a FF to AA-substituted alpha(V(AA))beta(3) do not reveal a constitutively activated integrin. Adhesion to immobilized fibrinogen is strongly impaired in alpha(V(del))beta(3) or alpha(V(AA))beta(3)-expressing cells, whereas it is not impaired in alpha(IIb)beta(3) and alpha(M)beta(2), both lacking the GFFKR-region. In a parallel plate flow chamber assay, alpha(V)beta(3)-expressing cells adhere firmly to fibrinogen and spread even at shear rates of 15 to 20 dyn/cm(2), whereas alpha(V(del))beta(3) or alpha(V(AA))beta(3) cells are detached at 15 dyn/cm(2). Actin stress fiber formation and focal adhesion plaques containing alpha(V)beta(3) are observed in alpha(V)beta(3) cells but not in alpha(V(del))beta(3) or alpha(V(AA))beta(3)-expressing cells. As an additional manifestation of impaired outside-in signaling, phosphorylation of pp125(FAK) was reduced in these cells. In summary, we report that the GFFKR-region of the alpha(V)-cytoplasmic domain and in particular two phenylalanines are essential for integrin alpha(V)beta(3) function, especially for outside-in signaling. Our results suggest that the two beta(3)-integrins alpha(IIb)beta(3) and alpha(V)beta(3) are differentially regulated via their GFFKR-region.
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Affiliation(s)
- I G Ahrens
- Department of Cardiology and Angiology, Internal Medicine III, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
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44
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Van de Walle GR, Vanhoorelbeke K, Majer Z, Illyés E, Baert J, Pareyn I, Deckmyn H. Two Functional Active Conformations of the Integrin α2β1, Depending on Activation Condition and Cell Type. J Biol Chem 2005; 280:36873-82. [PMID: 16103112 DOI: 10.1074/jbc.m508148200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
For several integrins, the existence of multiple conformational states has been studied intensively. For the integrin alpha2beta1, a major collagen receptor on platelets and other cell types, however, no such experimental data were available thus far. Recently, our group has developed a monoclonal antibody IAC-1 sensitive to the molecular conformation of alpha2beta1 because it only binds to the activated state of alpha2beta1 on platelets, induced upon inside-out signaling. By investigating IAC-1 binding in combination with collagen binding after inside-out stimulation and outside manipulation, we demonstrated the existence of three different conformations of alpha2beta1 on platelets and Chinese hamster ovary cells as follows: (i) a nonactivated, resting state with no collagen nor IAC-1 binding; (ii) an intermediate state, induced by outside manipulation, with collagen but no IAC-1 binding; and (iii) a fully activated state, induced after inside-out stimulation, with both collagen and IAC-1 binding. Moreover, these different conformational states of alpha2beta1 are dependent on the cell type where alpha2beta1 is expressed, as IAC-1 binding to peripheral blood mononuclear cells and Jurkat cells could also be induced by outside manipulation, in contrast to platelets and alpha2beta1-expressing Chinese hamster ovary cells. Finally, we revealed a functional relevance for these different conformational states because the conformation of alpha2beta1, induced after outside manipulation, resulted in significantly more cell spreading on coated collagen compared with nonactivated or inside-out stimulated cells.
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Affiliation(s)
- Gerlinde R Van de Walle
- Laboratories for Thrombosis Research, Interdisciplinary Research Centre, Katholieke Universiteit Leuven, Campus Kortrijk, 8500 Kortrijk, Belgium
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