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Liu Y, Weng L, Wang Y, Zhang J, Wu Q, Zhao P, Shi Y, Wang P, Fang L. Deciphering the role of CD47 in cancer immunotherapy. J Adv Res 2024; 63:129-158. [PMID: 39167629 PMCID: PMC11380025 DOI: 10.1016/j.jare.2023.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 10/05/2023] [Accepted: 10/18/2023] [Indexed: 08/23/2024] Open
Abstract
BACKGROUND Immunotherapy has emerged as a novel strategy for cancer treatment following surgery, radiotherapy, and chemotherapy. Immune checkpoint blockade and Chimeric antigen receptor (CAR)-T cell therapies have been successful in clinical trials. Cancer cells evade immune surveillance by hijacking inhibitory pathways via overexpression of checkpoint genes. The Cluster of Differentiation 47 (CD47) has emerged as a crucial checkpoint for cancer immunotherapy by working as a "don't eat me" signal and suppressing innate immune signaling. Furthermore, CD47 is highly expressed in many cancer types to protect cancer cells from phagocytosis via binding to SIRPα on phagocytes. Targeting CD47 by either interrupting the CD47-SIRPα axis or combing with other therapies has been demonstrated as an encouraging therapeutic strategy in cancer immunotherapy. Antibodies and small molecules that target CD47 have been explored in pre- and clinical trials. However, formidable challenges such as the anemia and palate aggregation cannot be avoided because of the wide presentation of CD47 on erythrocytes. AIM OF VIEW This review summarizes the current knowledge on the regulation and function of CD47, and provides a new perspective for immunotherapy targeting CD47. It also highlights the clinical progress of targeting CD47 and discusses challenges and potential strategies. KEY SCIENTIFIC CONCEPTS OF REVIEW This review provides a comprehensive understanding of targeting CD47 in cancer immunotherapy, it also augments the concept of combination immunotherapy strategies by employing both innate and adaptive immune responses.
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Affiliation(s)
- Yu'e Liu
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Linjun Weng
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Yanjin Wang
- Department of Nephrology, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, China
| | - Jin Zhang
- Department of Pharmacology and Toxicology, University of Mississippi, Medical Center, 39216 Jackson, MS, USA
| | - Qi Wu
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China
| | - Pengcheng Zhao
- School of Life Sciences and Medicine, Shandong University of Technology, No.266 Xincun West Road, Zibo 255000, Shandong Province, China
| | - Yufeng Shi
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China; Clinical Center for Brain and Spinal Cord Research, Tongji University, Shanghai 200092, China.
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China.
| | - Lan Fang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai 200092, China.
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Tabata S, Yamashita Y, Inai Y, Morita S, Kosako H, Takagi T, Shide K, Manabe S, Matsuoka TA, Shimoda K, Sonoki T, Ihara Y, Tamura S. C-Mannosyl tryptophan is a novel biomarker for thrombocytosis of myeloproliferative neoplasms. Sci Rep 2024; 14:18858. [PMID: 39143127 PMCID: PMC11324734 DOI: 10.1038/s41598-024-69496-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 08/05/2024] [Indexed: 08/16/2024] Open
Abstract
C-Mannosyl tryptophan (CMW), a unique glycosylated amino acid, is considered to be produced by degradation of C-mannosylated proteins in living organism. Although protein C-mannosylation is involved in the folding and secretion of substrate proteins, the pathophysiological function in the hematological system is still unclear. This study aimed to assess CMW in the human hematological disorders. The serum CMW levels of 94 healthy Japanese workers were quantified using hydrophilic interaction liquid chromatography. Platelet count was positively correlated with serum CMW levels. The clinical significance of CMW in thrombocytosis of myeloproliferative neoplasms (T-MPN) including essential thrombocythemia (ET) were investigated. The serum CMW levels of the 34 patients with T-MPN who presented with thrombocytosis were significantly higher than those of the 52 patients with control who had other hematological disorders. In patients with T-MPN, serum CMW levels were inversely correlated with anemia, which was related to myelofibrosis (MF). Bone marrow biopsy samples were obtained from 18 patients with ET, and serum CMW levels were simultaneously measured. Twelve patients with bone marrow fibrosis had significantly higher CMW levels than 6 patients without bone marrow fibrosis. Collectively, these results suggested that CMW could be a novel biomarker to predict MF progression in T-MPN.
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Affiliation(s)
- Shotaro Tabata
- Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Yusuke Yamashita
- Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Yoko Inai
- Department of Biochemistry, Wakayama Medical University, Wakayama, Japan
| | - Shuhei Morita
- The First Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan.
| | - Hideki Kosako
- Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Tomoyuki Takagi
- The First Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan
- Wakayama City Medical Association Seijinbyo Center, Wakayama, Japan
| | - Kotaro Shide
- Division of Hematology, Diabetes, and Endocrinology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Shino Manabe
- School of Pharmacy and Pharmaceutical Sciences, Hoshi University, Tokyo, Japan
- Research Center for Pharmaceutical Development, Graduate School of Pharmaceutical Science & Faculty of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan
| | - Taka-Aki Matsuoka
- The First Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan
| | - Kazuya Shimoda
- Division of Hematology, Diabetes, and Endocrinology, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Takashi Sonoki
- Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Yoshito Ihara
- Department of Biochemistry, Wakayama Medical University, Wakayama, Japan.
| | - Shinobu Tamura
- Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan.
- Department of Emergency and Critical Care Medicine, Wakayama Medical University, Wakayama, Japan.
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Abstract
CD36 (also known as platelet glycoprotein IV) is expressed by a variety of different cell entities, where it possesses functions as a signaling receptor, but additionally acts as a transporter for long-chain fatty acids. This dual function of CD36 has been investigated for its relevance in immune and nonimmune cells. Although CD36 was first identified on platelets, the understanding of the role of CD36 in platelet biology remained scarce for decades. In the past few years, several discoveries have shed a new light on the CD36 signaling activity in platelets. Notably, CD36 has been recognized as a sensor for oxidized low-density lipoproteins in the circulation that mitigates the threshold for platelet activation under conditions of dyslipidemia. Thus, platelet CD36 transduces atherogenic lipid stress into an increased risk for thrombosis, myocardial infarction, and stroke. The underlying pathways that are affected by CD36 are the inhibition of cyclic nucleotide signaling pathways and simultaneously the induction of activatory signaling events. Furthermore, thrombospondin-1 secreted by activated platelets binds to CD36 and furthers paracrine platelet activation. CD36 also serves as a binding hub for different coagulation factors and, thus, contributes to the plasmatic coagulation cascade. This review provides a comprehensive overview of the recent findings on platelet CD36 and presents CD36 as a relevant target for the prevention of thrombotic events for dyslipidemic individuals with an elevated risk for thrombosis.
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Affiliation(s)
- Gerd Bendas
- Department of Pharmacy, University of Bonn, Bonn, Germany
| | - Martin Schlesinger
- Department of Pharmacy, University of Bonn, Bonn, Germany
- Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany
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Qu T, Zhong T, Pang X, Huang Z, Jin C, Wang ZM, Li B, Xia Y. Ligufalimab, a novel anti-CD47 antibody with no hemagglutination demonstrates both monotherapy and combo antitumor activity. J Immunother Cancer 2022; 10:e005517. [PMID: 36450383 PMCID: PMC9717234 DOI: 10.1136/jitc-2022-005517] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2022] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND CD47 is a widely expressed transmembrane glycoprotein that delivers an antiphagocytic signal on macrophages through its interaction with SIRPα. CD47 is highly expressed in cancer cells and its overexpression is correlated with poor prognosis. CD47 blocking antibodies are actively being developed worldwide for cancer therapy, and the most challenging concern is associated with hematotoxicity. Ligufalimab (AK117) is a novel humanized IgG4 anti-CD47 antibody without hemagglutination effect. Blockade of CD47-SIRPα pathway by AK117 leads to a promising therapeutic strategy for cancer treatment with unique safety features. METHODS AK117 was discovered through a screening hierarchy excluding hemagglutination. AK117 was characterized by detecting CD47-SIRPα blocking potential. Its effect on human red blood cells was examined and the mechanism of its binding with erythrocytes was studied. The abilities of AK117 and its combination with various opsonizing antibodies to promote macrophage-dependent phagocytosis of multiple human tumor cells were determined using fluorescence microscopy and flow cytometry. In vivo, the antitumor efficacy of AK117 monotherapy and combination with AK112 (an anti-PD-1/VEGF-A bispecific antibody) was assessed in a variety of xenograft models. Toxicologic studies were evaluated in non-human primates. RESULTS AK117 bound to CD47 with high affinity and blocked the CD47-SIRPα interaction. AK117 did not induce hemagglutination and showed significantly lower degree of erythrophagocytosis compared with Hu5F9-G4, and this mechanism of hemagglutination resistance might be related to the binding conformation. AK117 enhanced macrophage-mediated phagocytosis in both hematologic cancer and solid tumor cell lines as a single agent or in combination with cetuximab and rituximab in vitro, respectively. The antitumor effects of AK117 as a single agent or in combination with AK112 were also encouraging in various xenograft models. In non-human primates, AK117 showed less hematotoxicity compared with Hu5F9-G4. CONCLUSIONS AK117 eliminated hemagglutination and also enabled to maintain full effectiveness of CD47 blockade on tumor cells, which resulted in excellent antitumor efficacy and favorable safety profile of AK117. A series of clinical trials of AK117 as a therapeutic agent in combination with various agents such as AK112 are in progress for the treatment of multiple hematologic malignancies and solid tumors.
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Affiliation(s)
- Tailong Qu
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Tingting Zhong
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Xinghua Pang
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Zhaoliang Huang
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Chunshan Jin
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Zhongmin Maxwell Wang
- Procurement and Sourcing Department and Clinical Operation Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Baiyong Li
- Research and Development Department, Akeso Biopharma Inc, Zhongshan, Guangdong, China
| | - Yu Xia
- President Office, Akeso Biopharma Inc, Zhongshan, Guangdong, China
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5
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The Role of Platelets in Diabetic Kidney Disease. Int J Mol Sci 2022; 23:ijms23158270. [PMID: 35955405 PMCID: PMC9368651 DOI: 10.3390/ijms23158270] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 01/10/2023] Open
Abstract
Diabetic kidney disease (DKD) is among the most common microvascular complications in patients with diabetes, and it currently accounts for the majority of end-stage kidney disease cases worldwide. The pathogenesis of DKD is complex and multifactorial, including systemic and intra-renal inflammatory and coagulation processes. Activated platelets play a pivotal role in inflammation, coagulation, and fibrosis. Mounting evidence shows that platelets play a role in the pathogenesis and progression of DKD. The potentially beneficial effects of antiplatelet agents in preventing progression of DKD has been studied in animal models and clinical trials. This review summarizes the current knowledge on the role of platelets in DKD, including the potential therapeutic effects of antiplatelet therapies.
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Madruga LYC, Popat KC, Balaban RC, Kipper MJ. Enhanced blood coagulation and antibacterial activities of carboxymethyl-kappa-carrageenan-containing nanofibers. Carbohydr Polym 2021; 273:118541. [PMID: 34560953 DOI: 10.1016/j.carbpol.2021.118541] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 01/10/2023]
Abstract
Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood proteins, fibrinogen and albumin, was also assessed. The adhesion and activation of platelets, and the clotting of whole blood were evaluated to characterize the ability of the nanofibers to promote hemostasis. Adhesion and morphology of both Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using fluorescence microscopy and scanning electron microscopy. CMKC-containing nanofibers demonstrated significant increases in platelet adhesion and activation, percentage of coagulation in whole blood clotting test and fibrinogen adsorption, compared to PVA nanofibers, showing blood coagulation activity. Incorporating CMKC also reduces adhesion and viability of S. aureus and P. aeruginosa bacteria after 24 h of incubation. PVA-CMKC nanofibers show potential application as dressings for wound healing applications.
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Affiliation(s)
- Liszt Y C Madruga
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States; Institute of Chemistry, Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Ketul C Popat
- School of Advanced Materials Discovery, Colorado State University, Fort Collins, CO, United States; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, United States; School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
| | - Rosangela C Balaban
- Institute of Chemistry, Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Matt J Kipper
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States; School of Advanced Materials Discovery, Colorado State University, Fort Collins, CO, United States; School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States.
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7
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Grenier C, Caillon A, Munier M, Grimaud L, Champin T, Toutain B, Fassot C, Blanc-Brude O, Loufrani L. Dual Role of Thrombospondin-1 in Flow-Induced Remodeling. Int J Mol Sci 2021; 22:12086. [PMID: 34769516 PMCID: PMC8584526 DOI: 10.3390/ijms222112086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/13/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
(1) Background: Chronic increases in blood flow, as in cardiovascular diseases, induce outward arterial remodeling. Thrombospondin-1 (TSP-1) is known to interact with matrix proteins and immune cell-surface receptors, but its contribution to flow-mediated remodeling in the microcirculation remains unknown. (2) Methods: Mesenteric arteries were ligated in vivo to generate high- (HF) and normal-flow (NF) arteries in wild-type (WT) and TSP-1-deleted mice (TSP-1-/-). After 7 days, arteries were isolated and studied ex vivo. (3) Results: Chronic increases in blood flow induced outward remodeling in WT mice (increasing diameter from 221 ± 10 to 280 ± 10 µm with 75 mmHg intraluminal pressure) without significant effect in TSP-1-/- (296 ± 18 to 303 ± 14 µm), neutropenic or adoptive bone marrow transfer mice. Four days after ligature, pro inflammatory gene expression levels (CD68, Cox2, Gp91phox, p47phox and p22phox) increased in WT HF arteries but not in TSP-1-/- mice. Perivascular neutrophil accumulation at day 4 was significantly lower in TSP-1-/- than in WT mice. (4) Conclusions: TSP-1 origin is important; indeed, circulating TSP-1 participates in vasodilation, whereas both circulating and tissue TSP-1 are involved in arterial wall thickness and diameter expansion.
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Affiliation(s)
- Céline Grenier
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Antoine Caillon
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Mathilde Munier
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Linda Grimaud
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Tristan Champin
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Bertrand Toutain
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | - Céline Fassot
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
| | | | - Laurent Loufrani
- UMR CNRS 6015, 49100 Angers, France; (C.G.); (A.C.); (M.M.); (L.G.); (T.C.); (B.T.); (C.F.)
- INSERM U1083, 49100 Angers, France
- MITOVASC Institute, University of Angers, 49100 Angers, France
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Kapoor S, Champion G, Basu A, Mariampillai A, Olnes MJ. Immune Therapies for Myelodysplastic Syndromes and Acute Myeloid Leukemia. Cancers (Basel) 2021; 13:5026. [PMID: 34638510 PMCID: PMC8507987 DOI: 10.3390/cancers13195026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 11/16/2022] Open
Abstract
Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are hematologic malignancies arising from the bone marrow. Despite recent advances in treating these diseases, patients with higher-risk MDS and AML continue to have a poor prognosis with limited survival. It has long been recognized that there is an immune component to the pathogenesis of MDS and AML, but until recently, immune therapies have played a limited role in treating these diseases. Immune suppressive therapy exhibits durable clinical responses in selected patients with MDS, but the question of which patients are most suitable for this treatment remains unclear. Over the past decade, there has been remarkable progress in identifying genomic features of MDS and AML, which has led to an improved discernment of the molecular pathogenesis of these diseases. An improved understanding of immune and inflammatory molecular mechanisms of MDS and AML have also recently revealed novel therapeutic targets. Emerging treatments for MDS and AML include monoclonal antibodies such as immune checkpoint inhibitors, bispecific T-cell-engaging antibodies, antibody drug conjugates, vaccine therapies, and cellular therapeutics including chimeric antigen receptor T-cells and NK cells. In this review, we provide an overview of the current understanding of immune dysregulation in MDS and AML and an update on novel immune therapies for these bone marrow malignancies.
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Affiliation(s)
- Sargam Kapoor
- Hematology and Medical Oncology, Alaska Native Tribal Health Consortium, 3900 Ambassador Dr., Anchorage, AK 99508, USA; (S.K.); (A.B.); (A.M.)
- School of Medicine, University of Washington, 1959 NE Pacific St., Seattle, WA 98195, USA;
| | - Grace Champion
- School of Medicine, University of Washington, 1959 NE Pacific St., Seattle, WA 98195, USA;
| | - Aparna Basu
- Hematology and Medical Oncology, Alaska Native Tribal Health Consortium, 3900 Ambassador Dr., Anchorage, AK 99508, USA; (S.K.); (A.B.); (A.M.)
| | - Anu Mariampillai
- Hematology and Medical Oncology, Alaska Native Tribal Health Consortium, 3900 Ambassador Dr., Anchorage, AK 99508, USA; (S.K.); (A.B.); (A.M.)
- School of Medicine, University of Washington, 1959 NE Pacific St., Seattle, WA 98195, USA;
| | - Matthew J. Olnes
- Hematology and Medical Oncology, Alaska Native Tribal Health Consortium, 3900 Ambassador Dr., Anchorage, AK 99508, USA; (S.K.); (A.B.); (A.M.)
- School of Medicine, University of Washington, 1959 NE Pacific St., Seattle, WA 98195, USA;
- WWAMI School of Medical Education, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508, USA
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9
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Jeanne A, Sarazin T, Charlé M, Kawecki C, Kauskot A, Hedtke T, Schmelzer CEH, Martiny L, Maurice P, Dedieu S. Towards the Therapeutic Use of Thrombospondin 1/CD47 Targeting TAX2 Peptide as an Antithrombotic Agent. Arterioscler Thromb Vasc Biol 2021; 41:e1-e17. [PMID: 33232198 DOI: 10.1161/atvbaha.120.314571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE TSP-1 (thrombospondin 1) is one of the most expressed proteins in platelet α-granules and plays an important role in the regulation of hemostasis and thrombosis. Interaction of released TSP-1 with CD47 membrane receptor has been shown to regulate major events leading to thrombus formation, such as, platelet adhesion to vascular endothelium, nitric oxide/cGMP (cyclic guanosine monophosphate) signaling, platelet activation as well as aggregation. Therefore, targeting TSP-1:CD47 axis may represent a promising antithrombotic strategy. Approach and Results: A CD47-derived cyclic peptide was engineered, namely TAX2, that targets TSP-1 and selectively prevents TSP-1:CD47 interaction. Here, we demonstrate for the first time that TAX2 peptide strongly decreases platelet aggregation and interaction with collagen under arterial shear conditions. TAX2 also delays time for complete thrombotic occlusion in 2 mouse models of arterial thrombosis following chemical injury, while Thbs1-/- mice recapitulate TAX2 effects. Importantly, TAX2 administration is not associated with increased bleeding risk or modification of hematologic parameters. CONCLUSIONS Overall, this study sheds light on the major contribution of TSP-1:CD47 interaction in platelet activation and thrombus formation while putting forward TAX2 as an innovative antithrombotic agent with high added-value.
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Affiliation(s)
- Albin Jeanne
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
- SATT Nord, Lille, France (A.J.)
- Apmonia Therapeutics, Reims, France (A.J., S.D.)
| | - Thomas Sarazin
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
| | - Magalie Charlé
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
| | - Charlotte Kawecki
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
| | - Alexandre Kauskot
- HITh, UMR_S 1176, INSERM Univ. Paris-Sud, Université Paris-Saclay, France (A.K.)
| | - Tobias Hedtke
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Halle (Saale), Germany (T.H., C.E.H.S.)
| | - Christian E H Schmelzer
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Halle (Saale), Germany (T.H., C.E.H.S.)
| | - Laurent Martiny
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
| | - Pascal Maurice
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
| | - Stéphane Dedieu
- UMR CNRS 7369 Matrice Extracellulaire et Dynamique Cellulaire (MEDyC), Université de Reims Champagne Ardenne (URCA), UFR Sciences Exactes et Naturelles, Reims, France (A.J., T.S., M.C., C.K., L.M., P.M., S.D.)
- Apmonia Therapeutics, Reims, France (A.J., S.D.)
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10
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Pielsticker C, Brodde MF, Raum L, Jurk K, Kehrel BE. Plasmin-Induced Activation of Human Platelets Is Modulated by Thrombospondin-1, Bona Fide Misfolded Proteins and Thiol Isomerases. Int J Mol Sci 2020; 21:ijms21228851. [PMID: 33238433 PMCID: PMC7700677 DOI: 10.3390/ijms21228851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Inflammatory processes are triggered by the fibrinolytic enzyme plasmin. Tissue-type plasminogen activator, which cleaves plasminogen to plasmin, can be activated by the cross-β-structure of misfolded proteins. Misfolded protein aggregates also represent substrates for plasmin, promoting their degradation, and are potent platelet agonists. However, the regulation of plasmin-mediated platelet activation by misfolded proteins and vice versa is incompletely understood. In this study, we hypothesize that plasmin acts as potent agonist of human platelets in vitro after short-term incubation at room temperature, and that the response to thrombospondin-1 and the bona fide misfolded proteins Eap and SCN--denatured IgG interfere with plasmin, thereby modulating platelet activation. Plasmin dose-dependently induced CD62P surface expression on, and binding of fibrinogen to, human platelets in the absence/presence of plasma and in citrated whole blood, as analyzed by flow cytometry. Thrombospondin-1 pre-incubated with plasmin enhanced these plasmin-induced platelet responses at low concentration and diminished them at higher dose. Platelet fibrinogen binding was dose-dependently induced by the C-terminal thrombospondin-1 peptide RFYVVMWK, Eap or NaSCN-treated IgG, but diminished in the presence of plasmin. Blocking enzymatically catalyzed thiol-isomerization decreased plasmin-induced platelet responses, suggesting that plasmin activates platelets in a thiol-dependent manner. Thrombospondin-1, depending on the concentration, may act as cofactor or inhibitor of plasmin-induced platelet activation, and plasmin blocks platelet activation induced by misfolded proteins and vice versa, which might be of clinical relevance.
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Affiliation(s)
- Claudia Pielsticker
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Experimental and Clinical Haemostasis, University of Muenster, 48149 Muenster, Germany; (C.P.); (L.R.)
| | | | - Lisa Raum
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Experimental and Clinical Haemostasis, University of Muenster, 48149 Muenster, Germany; (C.P.); (L.R.)
| | - Kerstin Jurk
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Experimental and Clinical Haemostasis, University of Muenster, 48149 Muenster, Germany; (C.P.); (L.R.)
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, 55131 Mainz, Germany
- Correspondence: (K.J.); (B.E.K.); Tel.: +49-6131178278 (K.J.); +49-2518356725 (B.E.K.)
| | - Beate E. Kehrel
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Experimental and Clinical Haemostasis, University of Muenster, 48149 Muenster, Germany; (C.P.); (L.R.)
- OxProtect GmbH, 48149 Muenster, Germany;
- Correspondence: (K.J.); (B.E.K.); Tel.: +49-6131178278 (K.J.); +49-2518356725 (B.E.K.)
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Immune checkpoint inhibition in myeloid malignancies: Moving beyond the PD-1/PD-L1 and CTLA-4 pathways. Blood Rev 2020; 45:100709. [PMID: 32487480 DOI: 10.1016/j.blre.2020.100709] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/26/2020] [Accepted: 05/13/2020] [Indexed: 12/12/2022]
Abstract
Immune checkpoint inhibitors (ICI) have yielded mixed but largely underwhelming results in clinical trials in patients with acute myeloid leukemia and myelodysplastic syndromes to date. However, increasing understanding of the immunologic landscape, potential biomarkers for benefits, and mechanisms of resistance, as well as the use of rational combinations, and identification of novel targets leaves plenty of room for optimism. Herein, we review recent advances in the preclinical and clinical development of ICI therapy in patients with myeloid malignancies and explore some of the important challenges facing the field such as the absence of validated biomarkers, the development of synergistic and safe combination therapies, and efforts to determine the best setting of ICI along the disease course. We finally foresee the future of the field and propose solutions to some of the major beforementioned obstacles.
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Ma L, Zhu M, Gai J, Li G, Chang Q, Qiao P, Cao L, Chen W, Zhang S, Wan Y. Preclinical development of a novel CD47 nanobody with less toxicity and enhanced anti-cancer therapeutic potential. J Nanobiotechnology 2020; 18:12. [PMID: 31931812 PMCID: PMC6956557 DOI: 10.1186/s12951-020-0571-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND CD47, the integrin-related protein, plays an important role in immune resistance and escape of tumor cells. Antibodies blocking the CD47/SIRPα signal pathway can effectively stimulate macrophage-mediated phagocytosis of tumor cells, which becomes a promising approach for tumor immunotherapy. Nanobodies (Nbs) derived from camelid animals are emerging as a new force in antibody therapy. RESULTS HuNb1-IgG4, an innovative anti-CD47 nanobody, was developed with high affinity and specificity. It effectively enhanced macrophage-mediated phagocytosis of tumor cells in vitro and showed potent anti-ovarian and anti-lymphoma activity in vivo. Importantly, HuNb1-IgG4 did not induce the agglutination of human red blood cells (RBCs) in vitro and exhibited high safety for hematopoietic system in cynomolgus monkey. In addition, HuNb1-IgG4 could be produced on a large scale in CHO-S cells with high activity and good stability. Also, we established anti-CD47/CD20 bispecific antibody (BsAb) consisted of HuNb1 and Rituximab, showing more preference binding to tumor cells and more potent anti-lymphoma activity compared to HuNb1-IgG4. CONCLUSIONS Both of HuNb1-IgG4 and anti-CD47/CD20 BsAb are potent antagonists of CD47/SIRPα pathway and promising candidates for clinical trials.
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Affiliation(s)
- Linlin Ma
- Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Min Zhu
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Junwei Gai
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Guanghui Li
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Qing Chang
- Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Peng Qiao
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Longlong Cao
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Wanqing Chen
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China
| | - Siyuan Zhang
- XPCC Tenth Division Beitun Hospital, Beitun, Xinjiang, China
| | - Yakun Wan
- Shanghai Novamab Biopharmaceuticals Co., Ltd, Shanghai, China.
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Philipp Bewersdorf J, Stahl M, Zeidan AM. Immune checkpoint-based therapy in myeloid malignancies: a promise yet to be fulfilled. Expert Rev Anticancer Ther 2019; 19:393-404. [PMID: 30887841 PMCID: PMC6527485 DOI: 10.1080/14737140.2019.1589374] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 02/27/2019] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Immune system evasion is essential for tumor cell survival and is mediated by the immunosuppressive tumor microenvironment and the activation of inhibitory immune checkpoints. While immune checkpoint-based therapy yielded impressive results in several advanced solid malignancies such as melanoma and non-small cell lung cancer, its role in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) is still evolving. Areas covered: Here we review the immunology in the tumor microenvironment in the bone marrow and discuss the current preclinical and clinical data for immune checkpoint-based therapy in myeloid neoplasms. Expert commentary: Clinical trials of immune checkpoint inhibitors (ICI) in AML and MDS are still in early stages and reported results so far have been modest especially for monotherapy use in the refractory settings. However, there are preliminary data for synergistic effects for combination of multiple ICI with hypomethylating agents and conventional chemotherapy. ICI might also be effective in eradicating minimal residual disease and to prevent relapse following induction chemotherapy or hematopoietic stem cell transplant. Additional trials to provide insight into the efficacy and safety profile of immune checkpoint-based therapy, its optimal timing and potential combination with other types of therapy as well as identification of predictive biomarkers are needed.
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Affiliation(s)
- Jan Philipp Bewersdorf
- Department of Internal Medicine, Section of Hematology, Yale University School of Medicine, New Haven, CT
| | - Maximilian Stahl
- Department of Medicine, Section of Hematologic Oncology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Amer M Zeidan
- Department of Internal Medicine, Section of Hematology, Yale University School of Medicine, New Haven, CT
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Liu Y, Bewersdorf JP, Stahl M, Zeidan AM. Immunotherapy in acute myeloid leukemia and myelodysplastic syndromes: The dawn of a new era? Blood Rev 2018; 34:67-83. [PMID: 30553527 DOI: 10.1016/j.blre.2018.12.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 12/02/2018] [Accepted: 12/04/2018] [Indexed: 12/27/2022]
Abstract
Immunotherapy has revolutionized therapy in both solid and liquid malignancies. The ability to cure acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) with an allogeneic hematopoietic stem cell transplant (HSCT) is proof of concept for the application of immunotherapy in AML and MDS. However, outside of HSCT, only the anti-CD33 antibody drug conjugate gemtuzumab ozogamicin is currently approved as an antibody-targeted therapy for AML. Several avenues of immunotherapeutic drugs are currently in different stages of clinical development. Here, we review recent advances in antibody-based therapy, immune checkpoint inhibitors, vaccines and adoptive cell-based therapy for patients with AML and MDS. First, we discuss different antibody constructs. Immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein-1 (PD-1) and CD47 as well as peptide, dendritic cell and dendritic/AML cell-based vaccines are reviewed next. Lastly, adoptive cell-based therapy including chimeric antigen receptor (CAR)-T cell and NK cell therapy is discussed.
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Affiliation(s)
- Yuxin Liu
- Department of Internal Medicine, Section of Hematology, Yale University School of Medicine, New Haven, CT, USA
| | - Jan Philipp Bewersdorf
- Department of Internal Medicine, Section of Hematology, Yale University School of Medicine, New Haven, CT, USA
| | - Maximilian Stahl
- Department of Medicine, Section of Hematologic Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Amer M Zeidan
- Department of Internal Medicine, Section of Hematology, Yale University School of Medicine, New Haven, CT, USA.
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Seif K, Alidzanovic L, Tischler B, Ibrahim N, Zagrapan B, Rauscher S, Salzmann M, Hell L, Mauracher LM, Budde U, Schmid JA, Jilma B, Pabinger I, Assinger A, Starlinger P, Brostjan C. Neutrophil-Mediated Proteolysis of Thrombospondin-1 Promotes Platelet Adhesion and String Formation. Thromb Haemost 2018; 118:2074-2085. [PMID: 30419595 PMCID: PMC6298231 DOI: 10.1055/s-0038-1675229] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thrombospondin-1 (TSP-1) is primarily expressed by platelets and endothelial cells (ECs) and rapidly released upon their activation. It functions in haemostasis as a bridging molecule in platelet aggregation, by promoting platelet adhesion to collagen and by protecting von Willebrand factor strings from degradation. In blood of patients undergoing surgery and in co-cultures of neutrophils with platelets or ECs, we observed proteolysis of the 185 kDa full-length TSP-1 to a 160-kDa isoform. We hypothesized that TSP-1 processing may alter its haemostatic properties. Selective enzyme inhibitors in co-cultures revealed that neutrophil proteases elastase and cathepsin G mediate TSP-1 processing. The cut site of cathepsin G was mapped to TSP-1 amino acids R237/T238 by Edman sequencing. Formation of neutrophil extracellular traps protected TSP-1 from complete degradation and promoted controlled processing to the 160-kDa isoform. Haemostatic properties were tested by platelet aggregation, adhesion, coagulation and string formation under flow. Platelets from TSP-1 deficient mice did not differ from wild-type in platelet aggregation but showed severe impairment of platelet adhesion to collagen and string formation under flow. Reconstitution experiments revealed that the 160-kDa TSP-1 isoform was markedly more potent than the 185-kDa full-length molecule in restoring function. Thus, TSP-1 processing by neutrophil proteases yields a 160-kDa isoform which shows enhanced potency to promote platelet adhesion and string formation. This finding reveals a novel mechanism of neutrophil-mediated thrombus formation and provides first evidence for the impact of TSP-1 proteolysis on its haemostatic properties.
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Affiliation(s)
- Katharina Seif
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Lejla Alidzanovic
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Barbara Tischler
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Nahla Ibrahim
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Branislav Zagrapan
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Sabine Rauscher
- Core Facility Imaging, Medical University of Vienna, Vienna, Austria
| | - Manuel Salzmann
- Centre for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Lena Hell
- Clinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Lisa-Marie Mauracher
- Clinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | | | - Johannes A Schmid
- Centre for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Bernd Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Ingrid Pabinger
- Clinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Alice Assinger
- Centre for Physiology and Pharmacology, Institute of Physiology, Medical University of Vienna, Vienna, Austria
| | - Patrick Starlinger
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Christine Brostjan
- Department of Surgery, Surgical Research Laboratory, Medical University of Vienna, Vienna, Austria
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Roberts DD, Kaur S, Isenberg JS. Regulation of Cellular Redox Signaling by Matricellular Proteins in Vascular Biology, Immunology, and Cancer. Antioxid Redox Signal 2017; 27:874-911. [PMID: 28712304 PMCID: PMC5653149 DOI: 10.1089/ars.2017.7140] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/11/2017] [Accepted: 07/13/2017] [Indexed: 12/15/2022]
Abstract
SIGNIFICANCE In contrast to structural elements of the extracellular matrix, matricellular proteins appear transiently during development and injury responses, but their sustained expression can contribute to chronic disease. Through interactions with other matrix components and specific cell surface receptors, matricellular proteins regulate multiple signaling pathways, including those mediated by reactive oxygen and nitrogen species and H2S. Dysregulation of matricellular proteins contributes to the pathogenesis of vascular diseases and cancer. Defining the molecular mechanisms and receptors involved is revealing new therapeutic opportunities. Recent Advances: Thrombospondin-1 (TSP1) regulates NO, H2S, and superoxide production and signaling in several cell types. The TSP1 receptor CD47 plays a central role in inhibition of NO signaling, but other TSP1 receptors also modulate redox signaling. The matricellular protein CCN1 engages some of the same receptors to regulate redox signaling, and ADAMTS1 regulates NO signaling in Marfan syndrome. In addition to mediating matricellular protein signaling, redox signaling is emerging as an important pathway that controls the expression of several matricellular proteins. CRITICAL ISSUES Redox signaling remains unexplored for many matricellular proteins. Their interactions with multiple cellular receptors remains an obstacle to defining signaling mechanisms, but improved transgenic models could overcome this barrier. FUTURE DIRECTIONS Therapeutics targeting the TSP1 receptor CD47 may have beneficial effects for treating cardiovascular disease and cancer and have recently entered clinical trials. Biomarkers are needed to assess their effects on redox signaling in patients and to evaluate how these contribute to their therapeutic efficacy and potential side effects. Antioxid. Redox Signal. 27, 874-911.
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Affiliation(s)
- David D. Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Sukhbir Kaur
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Jeffrey S. Isenberg
- Division of Pulmonary, Allergy and Critical Care, Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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18
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Anti-leukemic activity and tolerability of anti-human CD47 monoclonal antibodies. Blood Cancer J 2017; 7:e536. [PMID: 28234345 PMCID: PMC5386341 DOI: 10.1038/bcj.2017.7] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/05/2017] [Indexed: 01/04/2023] Open
Abstract
CD47, a broadly expressed cell surface protein, inhibits cell phagocytosis via interaction with phagocyte-expressed SIRPα. A variety of hematological malignancies demonstrate elevated CD47 expression, suggesting that CD47 may mediate immune escape. We discovered three unique CD47-SIRPα blocking anti-CD47 monoclonal antibodies (mAbs) with low nano-molar affinity to human and cynomolgus monkey CD47, and no hemagglutination and platelet aggregation activity. To characterize the anti-cancer activity elicited by blocking CD47, the mAbs were cloned into effector function silent and competent Fc backbones. Effector function competent mAbs demonstrated potent activity in vitro and in vivo, while effector function silent mAbs demonstrated minimal activity, indicating that blocking CD47 only leads to a therapeutic effect in the presence of Fc effector function. A non-human primate study revealed that the effector function competent mAb IgG1 C47B222-(CHO) decreased red blood cells (RBC), hematocrit and hemoglobin by >40% at 1 mg/kg, whereas the effector function silent mAb IgG2σ C47B222-(CHO) had minimal impact on RBC indices at 1 and 10 mg/kg. Taken together, our findings suggest that targeting CD47 is an attractive therapeutic anti-cancer approach. However, the anti-cancer activity observed with anti-CD47 mAbs is Fc effector dependent as are the side effects observed on RBC indices.
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Cointe S, Rhéaume É, Martel C, Blanc-Brude O, Dubé E, Sabatier F, Dignat-George F, Tardif JC, Bonnefoy A. Thrombospondin-1-Derived Peptide RFYVVMWK Improves the Adhesive Phenotype of CD34 + Cells From Atherosclerotic Patients With Type 2 Diabetes. Cell Transplant 2016; 26:327-337. [PMID: 27938493 DOI: 10.3727/096368916x693329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
CD34+ progenitor cells are growing in use for vascular repair. However, in diabetic individuals with cardiovascular diseases, these cells have dysfunctional engraftment capabilities, which compromise their use for autologous cell therapy. The thrombospondin-1-derived peptide RFYVVMWK has previously been reported to stimulate cell adhesiveness through CD47 and integrin activation pathways. Our aim was to test whether RFYVVMWK preconditioning could modulate CD34+ cell phenotype and enhance its proadhesive properties in diabetic patients. Peripheral blood mononuclear CD34+ cells isolated from 40 atherosclerotic patients with type 2 diabetes (T2D; n = 20) or without (non-T2D; n = 20) were preconditioned with 30 μM RFYVVMWK or truncated peptide RFYVVM. CD34+ cell adhesion was assessed on a vitronectin-collagen matrix and on TNF-α or IL-1β-stimulated HUVEC monolayers. Adhesion receptors, platelet/CD34+ cell conjugates, and cell viability were analyzed by flow cytometry and confocal microscopy. RFYVVMWK increased the adhesion of T2D CD34+ cells by eightfold to the vitronectin-collagen matrix (p < 0.001) corresponding to a threefold increase compared to unstimulated non-T2D CD34+ cells. The peptide induced the formation of platelet/CD34+ conjugates and increased the expression of TSP-1, CD29, CD51/CD61, and CD62P in both T2D and non-T2D cells. However, RFYVVMWK treatment did not affect the viability/apoptosis of CD34+ progenitor cells. In conclusion, priming CD34+ cells with RFYVVMWK may enhance their vascular engraftment during autologous proangiogenic cell therapy.
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20
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Soto-Pantoja DR, Kaur S, Roberts DD. CD47 signaling pathways controlling cellular differentiation and responses to stress. Crit Rev Biochem Mol Biol 2015; 50:212-30. [PMID: 25708195 DOI: 10.3109/10409238.2015.1014024] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CD47 is a widely expressed integral membrane protein that serves as the counter-receptor for the inhibitory phagocyte receptor signal-regulatory protein-α (SIRPα) and as a signaling receptor for the secreted matricellular protein thrombospondin-1. Recent studies employing mice and somatic cells lacking CD47 have revealed important pathophysiological functions of CD47 in cardiovascular homeostasis, immune regulation, resistance of cells and tissues to stress and chronic diseases of aging including cancer. With the emergence of experimental therapeutics targeting CD47, a more thorough understanding of CD47 signal transduction is essential. CD47 lacks a substantial cytoplasmic signaling domain, but several cytoplasmic binding partners have been identified, and lateral interactions of CD47 with other membrane receptors play important roles in mediating signaling resulting from the binding of thrombospondin-1. This review addresses recent advances in identifying the lateral binding partners, signal transduction pathways and downstream transcription networks regulated through CD47 in specific cell lineages. Major pathways regulated by CD47 signaling include calcium homeostasis, cyclic nucleotide signaling, nitric oxide and hydrogen sulfide biosynthesis and signaling and stem cell transcription factors. These pathways and other undefined proximal mediators of CD47 signaling regulate cell death and protective autophagy responses, mitochondrial biogenesis, cell adhesion and motility and stem cell self-renewal. Although thrombospondin-1 is the best characterized agonist of CD47, the potential roles of other members of the thrombospondin family, SIRPα and SIRPγ binding and homotypic CD47 interactions as agonists or antagonists of signaling through CD47 should also be considered.
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Affiliation(s)
- David R Soto-Pantoja
- a Laboratory of Pathology , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
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Frazão JB, Errante PR, Condino-Neto A. Toll-like receptors' pathway disturbances are associated with increased susceptibility to infections in humans. Arch Immunol Ther Exp (Warsz) 2013; 61:427-43. [PMID: 24057516 DOI: 10.1007/s00005-013-0243-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 08/04/2013] [Indexed: 01/03/2023]
Abstract
Toll-like receptors (TLRs) sense microbial products and play an important role in innate immunity. Currently, 11 members of TLRs have been identified in humans, with important function in host defense in early steps of the inflammatory response. TLRs are present in the plasma membrane (TLR1, TLR2, TLR4, TLR5, TLR6) and endosome (TLR3, TLR7, TLR8, TLR9) of leukocytes. TLRs and IL-1R are a family of receptors related to the innate immune response that contain an intracellular domain known as the Toll-IL-1R (TIR) domain that recruits the TIR-containing cytosolic adapters MyD88, TRIF, TIRAP and TRAM. The classical pathway results in the activation of both nuclear factor κB and MAPKs via the IRAK complex, with two active kinases (IRAK-1 and IRAK-4) and two non-catalytic subunits (IRAK-2 and IRAK-3/M). The classical pro-inflammatory TLR signaling pathway leads to the synthesis of inflammatory cytokines and chemokines, such as IL-1β, IL-6, IL-8, IL-12 and TNF-α. In humans, genetic defects have been identified that impair signaling of the TLR pathway and this may result in recurrent pyogenic infections, as well as virus and fungi infections. In this review, we discuss the main mechanisms of microbial recognition and the defects involving TLRs.
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Affiliation(s)
- Josias Brito Frazão
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, 1730, Lineu Prestes Avenue, São Paulo, SP, 05508-000, Brazil,
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Paul DS, Albers CA, Rendon A, Voss K, Stephens J, van der Harst P, Chambers JC, Soranzo N, Ouwehand WH, Deloukas P. Maps of open chromatin highlight cell type-restricted patterns of regulatory sequence variation at hematological trait loci. Genome Res 2013; 23:1130-41. [PMID: 23570689 PMCID: PMC3698506 DOI: 10.1101/gr.155127.113] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nearly three-quarters of the 143 genetic signals associated with platelet and erythrocyte phenotypes identified by meta-analyses of genome-wide association (GWA) studies are located at non-protein-coding regions. Here, we assessed the role of candidate regulatory variants associated with cell type–restricted, closely related hematological quantitative traits in biologically relevant hematopoietic cell types. We used formaldehyde-assisted isolation of regulatory elements followed by next-generation sequencing (FAIRE-seq) to map regions of open chromatin in three primary human blood cells of the myeloid lineage. In the precursors of platelets and erythrocytes, as well as in monocytes, we found that open chromatin signatures reflect the corresponding hematopoietic lineages of the studied cell types and associate with the cell type–specific gene expression patterns. Dependent on their signal strength, open chromatin regions showed correlation with promoter and enhancer histone marks, distance to the transcription start site, and ontology classes of nearby genes. Cell type–restricted regions of open chromatin were enriched in sequence variants associated with hematological indices. The majority (63.6%) of such candidate functional variants at platelet quantitative trait loci (QTLs) coincided with binding sites of five transcription factors key in regulating megakaryopoiesis. We experimentally tested 13 candidate regulatory variants at 10 platelet QTLs and found that 10 (76.9%) affected protein binding, suggesting that this is a frequent mechanism by which regulatory variants influence quantitative trait levels. Our findings demonstrate that combining large-scale GWA data with open chromatin profiles of relevant cell types can be a powerful means of dissecting the genetic architecture of closely related quantitative traits.
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Affiliation(s)
- Dirk S Paul
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom.
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Sick E, Boukhari A, Deramaudt T, Rondé P, Bucher B, André P, Gies JP, Takeda K. Activation of CD47 receptors causes proliferation of human astrocytoma but not normal astrocytes via an Akt-dependent pathway. Glia 2011; 59:308-19. [PMID: 21125662 DOI: 10.1002/glia.21102] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CD47 is a membrane receptor that plays pivotal roles in many pathophysiological processes, including infection, inflammation, cell spreading, proliferation, and apoptosis. We show that activation of CD47 increases proliferation of human U87 and U373 astrocytoma cells but not normal astrocytes. CD47 function-blocking antibodies inhibit proliferation of untreated U87 and U373 cells but not normal astrocytes, suggesting that CD47 may be constitutively activated in astrocytoma. CD47 expression levels were similar in our three cell types. CD47 couples to G-proteins in astrocytes and astrocytoma and especially to the Gβγ dimer. Downstream signaling following CD47 activation involves Gβγ dimer-dependent activation of the PI3K/Akt pathway in astrocytoma cells but not in normal astrocytes. This pathway is known to be deregulated in astrocytoma, leading to cell proliferation and enhanced survival signals. Putative PLIC-1 interaction with CD47 in astrocytoma cells but not astrocytes may contribute to the proliferative effect observed upon activation of CD47. Our data indicate that CD47 receptors have a stimulatory role in cell proliferation and demonstrate for the first time that CD47 signals via the PI3K/Akt pathway in cancerous cells but not normal cells.
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Affiliation(s)
- Emilie Sick
- Université de Strasbourg, CNRS UMR 7213-Pharmacologie, Faculté de Pharmacie, 74 rte du Rhin, Illkirch, France.
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25
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Glucose regulation of thrombospondin and its role in the modulation of smooth muscle cell proliferation. EXPERIMENTAL DIABETES RESEARCH 2010; 2010. [PMID: 20689700 PMCID: PMC2905704 DOI: 10.1155/2010/617052] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/05/2010] [Accepted: 04/16/2010] [Indexed: 11/17/2022]
Abstract
Smooth muscle cells (SMC) maintained in high glucose are more responsive to IGF-I than those in normal glucose. There is significantly more thrombospondin-1 (TSP-1) in extracellular matrix surrounding SMC grown in 25 mM glucose. In this study we investigated 1) the mechanism by which glucose regulates TSP-1 levels and 2) the mechanism by which TS-1 enhances IGF-I signaling. The addition of TSP-1 to primary SMC was sufficient to enhance IGF-I responsiveness in normal glucose. Reducing TSP-1 protein levels inhibited IGF-I signaling in SMC maintained in high glucose. We determined that TSP-1 protected IAP/CD47 from cleavage and thereby facilitated its association with SHP substrate-1 (SHPS-1). We have shown previously that the hyperglycemia induced protection of IAP from cleavage is an important component of the ability of hyperglycemia to enhance IGF-I signaling. Furthermore we determined that TSP-1 also enhanced phosphorylation of the beta3 subunit of the alphaVbeta3 integrin, another molecular event that we have shown are critical for SMC response to IGF-I in high glucose. Our studies also revealed that the difference in the amount of TSP-1 in the two different glucose conditions was due, at least in part, to a difference in the cellular uptake and degradation of TSP-1.
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26
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Chin AC, Fournier B, Peatman EJ, Reaves TA, Lee WY, Parkos CA. CD47 and TLR-2 cross-talk regulates neutrophil transmigration. THE JOURNAL OF IMMUNOLOGY 2009; 183:5957-63. [PMID: 19812191 DOI: 10.4049/jimmunol.0900789] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neutrophil (PMN) infiltration into tissues is a hallmark of acute inflammation and is crucial for the rapid removal of microbial pathogens. Previous studies have shown that PMN transmigration is regulated by the cell surface protein CD47. However this phenomenon in the context of microbial invasion and subsequent TLR signaling is poorly understood. In this study, we assessed the role of TLR2 and CD47 costimulation in regulating PMN transmigration. Human PMN transmigration across acellular collagen-coated filters toward the bacterial chemoattractant fMLP was more significantly inhibited by MALP-2 (TLR2/6 agonist) than Pam(3)CSK(4) (TLR2/1 agonist). Subsequent experiments demonstrated that treatment with MALP-2 or anti-human CD47 mAbs delayed human PMN transfilter migration, while combined treatment led to further delayed inhibition. Interestingly, stimulation of PMNs with MALP-2 resulted in an increase in surface expression of CD11b, but not CD47. In experiments addressing the role of TLR agonists in regulating CD47-mediated PMN transmigration, incubation with MALP-2 or with anti-mouse CD47 mAbs did not inhibit transfilter migration of TLR2(-/-) or MyD88(-/-)-deficient murine bone marrow-derived PMNs. Similarly, inhibition of MyD88 homodimerization reversed the attenuation of human PMN transmigration induced by MALP-2 or anti-human CD47 mAbs. Separate experiments demonstrated that CD47(-/-) murine bone marrow-derived PMNs exhibited 4-fold decreased sensitivity toward MALP-2. Collectively, these findings suggest that activation of CD47 signaling enhances PMN sensitivity toward TLR2 activation which, in turn, signals their arrival at a site of invasion and may facilitate antimicrobial function.
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Affiliation(s)
- Alex C Chin
- Epithelial Pathobiology Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA.
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27
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Jin G, Tsuji K, Xing C, Yang YG, Wang X, Lo EH. CD47 gene knockout protects against transient focal cerebral ischemia in mice. Exp Neurol 2009; 217:165-70. [PMID: 19233173 DOI: 10.1016/j.expneurol.2009.02.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 01/16/2009] [Accepted: 02/04/2009] [Indexed: 11/29/2022]
Abstract
CD47 is a cell surface glycoprotein that helps mediate neutrophil transmigration across blood vessels. The present study was performed to determine whether absence of the CD47 gene decreases focal ischemic brain damage. Mice were subjected to 90 min middle cerebral artery occlusion. CD47 knockout mice were compared against matching wildtype mice. CD47 expression was checked by Western blotting. Infarct volume and ischemic brain swelling were quantified with cresyl violet-stained brain sections at 24 and 72 h after ischemia. The tight junction protein claudin-5 was detected by imunohistochemistry. Two surrogate markers of neuroinflammation, brain levels of matrix metalloproteinase-9 (MMP-9) and infiltration of neutrophils, were assessed by immunohistochemistry. Western blots confirmed that CD47 was absent in knockout brains. Ischemia did not appear to upregulate total brain levels of CD47 in WT mice. In CD47 knockout mice, infarct volumes were reduced at 24 and 72 h after ischemia, and hemispheric swelling was decreased at 72 h. Loss of claudin-5 was observed in ischemic WT brain. This effect was ameliorated in CD47 knockout brains. Extravasation of neutrophils into the brain parenchyma was significantly reduced in CD47 knockout mice compared to wildtype mice. MMP-9 appeared to be upregulated in microvessels within ischemic brain. MMP-9 levels were markedly lower in CD47 knockout brains compared to wildtype brains. We conclude that CD47 is broadly involved in neuroinflammation, and this integrin-associated-protein plays a role in promoting MMP-9 upregulaton, neutrophil extravasation, brain swelling and progression of acute ischemic brain injury.
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Affiliation(s)
- Guang Jin
- Department of Radiology and Neurology, Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Massachusetts 02129, USA
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28
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Isenberg JS, Frazier WA, Roberts DD. Thrombospondin-1: a physiological regulator of nitric oxide signaling. Cell Mol Life Sci 2008; 65:728-42. [PMID: 18193160 PMCID: PMC2562780 DOI: 10.1007/s00018-007-7488-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Thrombospondin-1 is a secreted protein that modulates vascular cell behavior via several cell surface receptors. In vitro, nanomolar concentrations of thrombospondin-1 are required to alter endothelial and vascular smooth muscle cell adhesion, proliferation, motility, and survival. Yet, much lower levels of thrombospondin-1 are clearly functional in vivo. This discrepancy was explained with the discovery that the potency of thrombospondin-1 increases more than 100-fold in the presence of physiological levels of nitric oxide (NO). Thrombospondin-1 binding to CD47 inhibits NO signaling by preventing cGMP synthesis and activation of its target cGMP-dependent protein kinase. This potent antagonism of NO signaling allows thrombospondin-1 to acutely constrict blood vessels, accelerate platelet aggregation, and if sustained, inhibit angiogenic responses. Acute antagonism of NO signaling by thrombospondin-1 is important for hemostasis but becomes detrimental for tissue survival of ischemic injuries. New therapeutic approaches targeting thrombospondin-1 or CD47 can improve recovery from ischemic injuries and overcome a deficit in NO-responsiveness in aging. (Part of a Multi-author Review).
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Affiliation(s)
- J. S. Isenberg
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10, Room 2A33, 10 Center Dr MSC1500, Bethesda, Maryland 20892 USA
| | - W. A. Frazier
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110 USA
| | - D. D. Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10, Room 2A33, 10 Center Dr MSC1500, Bethesda, Maryland 20892 USA
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29
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Isenberg JS, Romeo MJ, Yu C, Yu CK, Nghiem K, Monsale J, Rick ME, Wink DA, Frazier WA, Roberts DD. Thrombospondin-1 stimulates platelet aggregation by blocking the antithrombotic activity of nitric oxide/cGMP signaling. Blood 2007; 111:613-23. [PMID: 17890448 PMCID: PMC2200855 DOI: 10.1182/blood-2007-06-098392] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Platelet alpha-granules constitute the major rapidly releasable reservoir of thrombospondin-1 in higher animals. Although some fragments and peptides derived from thrombospondin-1 stimulate or inhibit platelet aggregation, its physiologic function in platelets has remained elusive. We now show that endogenous thrombospondin-1 is necessary for platelet aggregation in vitro in the presence of physiologic levels of nitric oxide (NO). Exogenous NO or elevation of cGMP delays thrombin-induced platelet aggregation under high shear and static conditions, and exogenous thrombospondin-1 reverses this delay. Thrombospondin-1-null murine platelets fail to aggregate in response to thrombin in the presence of exogenous NO or 8Br-cGMP. At physiologic concentrations of the NO synthase substrate arginine, thrombospondin-1-null platelets have elevated basal cGMP. Ligation of CD36 or CD47 is sufficient to block NO-induced cGMP accumulation and mimic the effect of thrombospondin-1 on aggregation. Exogenous thrombospondin-1 also reverses the suppression by NO of alphaIIb/beta3 integrin-mediated platelet adhesion on immobilized fibrinogen, mediated in part by increased GTP loading of Rap1. Thrombospondin-1 also inhibits cGMP-mediated activation of cGMP-dependent protein kinase and thereby prevents phosphorylation of VASP. Thus, release of thrombospondin-1 from alpha-granules during activation provides positive feedback to promote efficient platelet aggregation and adhesion by overcoming the antithrombotic activity of physiologic NO.
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Affiliation(s)
- Jeff S Isenberg
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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30
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31
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Kato H, Honda S, Yoshida H, Kashiwagi H, Shiraga M, Honma N, Kurata Y, Tomiyama Y. SHPS-1 negatively regulates integrin alphaIIbbeta3 function through CD47 without disturbing FAK phosphorylation. J Thromb Haemost 2005; 3:763-74. [PMID: 15842360 DOI: 10.1111/j.1538-7836.2005.01235.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
CD47 (integrin-associated protein) serves as a receptor for thrombospondin-1 (TSP-1) and Src homology 2 domain-containing protein tyrosine phosphatase substrate-1 (SHPS-1), and the TSP-1/CD47 interaction has been believed to augment integrin-mediated platelet function. Here, employing SHPS-1-immunoglobulin (Ig) as a ligand, we have newly demonstrated that CD47 acts as an inhibitory receptor for platelet function. The binding of SHPS-1-Ig was solely mediated by CD47, because CD47-deficient platelets failed to bind murine SHPS-1-Ig. The human SHPS-1/CD47 interaction inhibited the platelet aggregation induced by several kinds of agonists at a low concentration. Moreover, human SHPS-1 expressed on the cell surface as well as soluble SHPS-1-Ig markedly inhibited the platelet spreading on, but not initial adhesion to, immobilized fibrinogen. Again, neither murine SHPS-1 expressed on the cell surface nor murine SHPS-1-Ig inhibited the spreading of CD47-deficient platelets. We further investigated the tyrosine phosphorylation of signaling proteins during platelet spreading on immobilized fibrinogen. Unexpectedly, SHPS-1 inhibited alpha(IIb)beta(3)-mediated platelet spreading without disturbing focal adhesion kinase (FAK) tyrosine phosphorylation. Further examination revealed that SHPS-1 inhibited the tyrosine phosphorylation of alpha-actinin, a downstream effector of FAK, but not of cortactin. Thus, it is likely that the SHPS-1/CD47 interaction inhibits alpha(IIb)beta(3)-mediated outside-in signaling by interfering with the downstream pathway of FAK. Taken together, our data suggest that SHPS-1 negatively regulates platelet function via CD47, especially alpha(IIb)beta(3)-mediated outside-in signaling.
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Affiliation(s)
- Hisashi Kato
- Department of Internal Medicine and Molecular Science, Graduate School of Medicine B5, Osaka University, Osaka, Japan
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32
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Numakawa T, Ishimoto T, Suzuki S, Numakawa Y, Adachi N, Matsumoto T, Yokomaku D, Koshimizu H, Fujimori KE, Hashimoto R, Taguchi T, Kunugi H. Neuronal roles of the integrin-associated protein (IAP/CD47) in developing cortical neurons. J Biol Chem 2004; 279:43245-53. [PMID: 15297459 DOI: 10.1074/jbc.m406733200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Little is known about the role of the integrin-associated protein (IAP, or CD47) in neuronal development and its function in the central nervous system. We investigated neuronal responses in IAP-overexpressing cortical neurons using a virus-gene transfer system. We found that dendritic outgrowth was significantly enhanced in IAP (form 4)-transfected neurons. Furthermore, synaptic proteins including synaptotagmin, syntaxin, synapsin I, and SNAP25 (25-kDa synaptosomal associated protein) were up-regulated. In accordance with this finding, the release of the excitatory transmitter glutamate and the frequencies of Ca2+ oscillations (glutamate-mediated synaptic transmission) were increased. Interestingly, the overexpression of IAP activated mitogen-activated protein kinase (MAPK), and this activation was required for the IAP-dependent biological effects. After down-regulation of the endogenous IAP by small interfering RNA, MAPK activity, synaptic protein levels, and glutamate release decreased. These observations suggest that the IAP plays important roles in dendritic outgrowth and synaptic transmission in developing cortical neurons through the activation of MAPK.
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Affiliation(s)
- Tadahiro Numakawa
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry of Japan, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
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33
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Miyashita M, Ohnishi H, Okazawa H, Tomonaga H, Hayashi A, Fujimoto TT, Furuya N, Matozaki T. Promotion of neurite and filopodium formation by CD47: roles of integrins, Rac, and Cdc42. Mol Biol Cell 2004; 15:3950-63. [PMID: 15215311 PMCID: PMC491849 DOI: 10.1091/mbc.e04-01-0019] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Axon extension during development is guided by many factors, but the signaling mechanisms responsible for its regulation remain largely unknown. We have now investigated the role of the transmembrane protein CD47 in this process in N1E-115 neuroblastoma cells. Forced expression of CD47 induced the formation of neurites and filopodia. Furthermore, an Fc fusion protein containing the extracellular region of the CD47 ligand SHPS-1 induced filopodium formation, and this effect was enhanced by CD47 overexpression. SHPS-1-Fc also promoted neurite and filopodium formation triggered by serum deprivation. Inhibition of Rac or Cdc42 preferentially blocked CD47-induced formation of neurites and filopodia, respectively. Overexpression of CD47 resulted in the activation of both Rac and Cdc42. The extracellular region of CD47 was sufficient for the induction of neurite formation by forced expression, but the entire structure of CD47 was required for enhancement of filopodium formation by SHPS-1-Fc. Neurite formation induced by CD47 was also inhibited by a mAb to the integrin beta3 subunit. These results indicate that the interaction of SHPS-1 with CD47 promotes neurite and filopodium formation through the activation of Rac and Cdc42, and that integrins containing the beta3 subunit participate in the effect of CD47 on neurite formation.
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MESH Headings
- Androstadienes/pharmacology
- Animals
- Antibodies, Monoclonal/immunology
- Antigens, CD/analysis
- Antigens, CD/genetics
- Antigens, CD/physiology
- Antigens, Differentiation/genetics
- Antigens, Differentiation/pharmacology
- Antigens, Differentiation/physiology
- CD47 Antigen
- Cells, Cultured
- Immunoglobulin Fc Fragments/genetics
- Immunoglobulin Fc Fragments/pharmacology
- Integrin beta3/immunology
- Integrin beta3/physiology
- Intercellular Signaling Peptides and Proteins
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/pharmacology
- Membrane Glycoproteins/physiology
- Mice
- Mutation/genetics
- Neural Cell Adhesion Molecule L1/genetics
- Neural Cell Adhesion Molecule L1/pharmacology
- Neural Cell Adhesion Molecule L1/physiology
- Neurites/chemistry
- Neurites/metabolism
- Neurites/ultrastructure
- Neurons/drug effects
- Neurons/metabolism
- Peptides/pharmacology
- Pseudopodia/ultrastructure
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Wortmannin
- cdc42 GTP-Binding Protein/antagonists & inhibitors
- cdc42 GTP-Binding Protein/physiology
- rac GTP-Binding Proteins/physiology
- rho GTP-Binding Proteins/physiology
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Affiliation(s)
- Motoaki Miyashita
- Biosignal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
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34
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Fujimoto TT, Katsutani S, Shimomura T, Fujimura K. Thrombospondin-bound integrin-associated protein (CD47) physically and functionally modifies integrin alphaIIbbeta3 by its extracellular domain. J Biol Chem 2003; 278:26655-65. [PMID: 12736272 DOI: 10.1074/jbc.m302194200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrin-associated protein (IAP/CD47) is a receptor for the C-terminal cell binding domain of thrombospondin (TS). A peptide from the C-terminal cell binding domain, KRFYVVMWKK (4N1K) binds to IAP and stimulates the integrin-dependent cell functions, including platelet aggregation. We investigated the mechanism by which TS-bound IAP modulates the affinity of platelet integrin, alphaIIbbeta3. Platelet aggregation induced by 4N1K was not completely inhibited by energy depletion with sodium azide and 2-deoxy-d-glucose, although ADP or collagen-induced platelet response was completely inhibited. The binding of ligand-mimetic antibody PAC1 to alphaIIbbeta3 was also induced in the energy-depleted platelets. In the transfected Namalwa cells, 4N1K induced activation of the alphaIIbbeta3 with mutated beta3 (Ser-752 to Pro), which is a non-responsive form to inside-out signaling, as well as wild type alphaIIbbeta3. The truncated form of IAP with only the extracellular immunoglobulin-like (Ig) domain was sufficient for the activation of alphaIIbbeta3 in Chinese hamster ovary cells, although the IAP-mediated intracellular signaling was abolished, which was monitored by the absence of down-regulation of mitogen-activated protein kinase phosphorylation. Furthermore, the soluble recombinant Ig domain of IAP induced PAC1 binding to alphaIIbbeta3 on Chinese hamster ovary cells when added with 4N1K. Physical association between the soluble recombinant Ig domain of IAP and purified alphaIIbbeta3 was detected in the presence of 4N1K. These data indicate that the extracellular Ig domain of IAP, when bound to TS, interacts with alphaIIbbeta3 and can change alphaIIbbeta3 in a high affinity state without the requirement of intracellular signaling. This extracellular event would be a novel mechanism of affinity modulation of integrin.
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Affiliation(s)
- Tetsuro-Takahiro Fujimoto
- Department of Hematology and Oncology, Division of Clinical Pharmacotherapeutics, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
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35
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Lagadec P, Dejoux O, Ticchioni M, Cottrez F, Johansen M, Brown EJ, Bernard A. Involvement of a CD47-dependent pathway in platelet adhesion on inflamed vascular endothelium under flow. Blood 2003; 101:4836-43. [PMID: 12609828 DOI: 10.1182/blood-2002-11-3483] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Resting platelet adhesion to inflammatory vascular endothelium is thought to play a causal role in secondary thrombus formation or microcirculatory disturbance after vessel occlusion. However, though adhesion receptors involved in platelet-matrix interactions have been extensively studied, the molecular mechanisms involved in platelet-endothelium interactions are incompletely characterized and have been mainly studied under static conditions. Using human platelets or platelets from wild-type and CD47-/- mice in whole blood, we demonstrated that at low shear rate, CD47 expressed on human and mouse platelets significantly contributes to platelet adhesion on tumor necrosis factor-alpha (TNF-alpha)-stimulated vascular endothelial cells. Using the CD47 agonist peptide 4N1K and blocking monoclonal antibodies (mAbs), we showed that CD47 binds the cell-binding domain (CBD) of endothelial thrombospondin-1 (TSP-1), inducing activation of the platelet alphaIIbbeta3 integrin that in turn becomes able to link the endothelial receptors intercellular adhesion molecule 1 (ICAM-1) and alphavbeta3. Platelet CD36 and GPIbalpha are also involved because platelet incubation with blocking mAbs directed against each of these 2 receptors significantly decreased platelet arrest. Given that anti-CD47 treatment of platelets did not further decrease the adhesion of anti-CD36-treated platelets and CD36 is a TSP-1 receptor, it appears that CD36/TSP-1 interaction could trigger the CD47-dependent pathway. Overall, CD47 antagonists may be potentially useful to inhibit platelet adhesion on inflamed endothelium.
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Affiliation(s)
- Patricia Lagadec
- Unité Institut National de la Santé et de la Recherche Médicale (INSERM) U343 et Laboratoire d'Immunologie, Nice, France
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36
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Voit S, Udelhoven M, Lill G, Aktas B, Nieswandt B, Schrör K, Weber AA. The C-terminal peptide of thrombospondin-1 stimulates distinct signaling pathways but induces an activation-independent agglutination of platelets and other cells. FEBS Lett 2003; 544:240-5. [PMID: 12782324 DOI: 10.1016/s0014-5793(03)00472-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A peptide from the C-terminal domain of thrombospondin-1 (4N1-1) has been proposed to stimulate platelet aggregation by a novel mechanism involving both an activation-independent agglutination and an activation-dependent, glycoprotein (GP) IIb/IIIa-mediated aggregation which involves GPVI signaling but does not involve CD47. The present study demonstrates that 4N1-1 stimulated a different pattern of signal transduction pathways than the GPVI agonist convulxin. Furthermore, 4N1-1-induced platelet aggregation was activation-independent and not dependent on GPVI or GPIIb/IIIa. Interestingly, 4N1-1 also stimulated activation-independent agglutination of different megakaryocytic and non-megakaryocytic cells. 4N1-1-induced cell agglutination but not platelet signaling was inhibited by anti-CD47 antibodies.
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Affiliation(s)
- Simone Voit
- Institut für Pharmakologie und Klinische Pharmakologie, Universitätsklinikum Düsseldorf, Moorenstr. 5, Germany
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37
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Trumel C, Plantavid M, Lévy-Tolédano S, Ragab A, Caen JP, Aguado E, Malissen B, Payrastre B. Platelet aggregation induced by the C-terminal peptide of thrombospondin-1 requires the docking protein LAT but is largely independent of alphaIIb/beta3. J Thromb Haemost 2003; 1:320-9. [PMID: 12871507 DOI: 10.1046/j.1538-7836.2003.00068.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Thrombospondin-1 (TSP1) is abundantly secreted during platelet activation and plays a role in irreversible platelet aggregation. A peptide derived from the C-terminal domain of TSP1, RFYVVMWK (RFY) can activate human platelets at least in part via its binding to integrin-associated protein. Although integrin-associated protein is known to physically interact with alphaIIb/beta3, we found that this major platelet integrin had only a partial implication in RFY-mediated platelet aggregation. Accordingly, RFY induced a significant Glanzmann type I thrombasthenic platelet aggregation. The alphaIIb/beta3-dependent part of platelet aggregation induced by RFY was mainly due to secreted ADP and thromboxane A2. In the absence of alphaIIb/beta3 and fibrinogen, RFY stimulated a rapid tyrosine phosphorylation of a set of proteins, including Syk, linker for activation of T cells (LAT) and phospholipase Cgamma2. This signaling pathway was critical for RFY-mediated platelet activation as revealed by the use of pharmacological inhibitors as well as LAT-deficient mouse platelets. Phosphoinositide 3-kinase activation was also required for RFY-mediated platelet aggregation. Our results unravel a new alphaIIb/beta3 and fibrinogen-independent mechanism for platelet aggregation in response to the active peptide from the C-terminal domain of TSP1.
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Affiliation(s)
- C Trumel
- INSERM, Unité 563, Centre de Physiopathologie Toulouse Purpan, Department of Oncogenesis and Cell Signaling in Hematopoetic Cells, Hôpital Purpan, Toulouse, France
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38
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Lymn JS, Patel MK, Clunn GF, Rao SJ, Gallagher KL, Hughes AD. Thrombospondin-1 differentially induces chemotaxis and DNA synthesis of human venous smooth muscle cells at the receptor-binding level. J Cell Sci 2002; 115:4353-60. [PMID: 12376566 DOI: 10.1242/jcs.00119] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thrombospondin-1 is a large matricellular protein that acts as a pleiotropic growth factor for human vascular smooth muscle cells, and may play a role in the progression of vascular disease. Although we have previously demonstrated the dependence of both thrombospondin-1-stimulated cell chemotaxis and proliferation on tyrosine kinases, the receptor mechanisms involved remain obscure. This investigation aims to determine the nature of the receptor(s) involved in the cellular responses to thrombospondin-1. Cellular signals were identified by western blotting following cell stimulation, while cellular responses were assessed by measuring DNA synthesis and chemotaxis. These data demonstrate that thrombospondin-1-induced cell chemotaxis can be inhibited by a peptide containing the Arg-Gly-Asp motif, a function-blocking alpha(v)beta(3) antibody, a function-blocking integrin-associated protein (IAP) antibody and pertussis toxin, while thrombospondin-1-stimulated DNA synthesis is inhibited by a function-blocking alpha(3)beta(1) antibody. Similarly the Arg-Gly-Asp-containing peptide inhibits tyrosine phosphorylation of focal adhesion kinase and the p85 regulatory subunit of phosphatidylinositol 3-kinase, but does not significantly affect tyrosine phosphorylation, or activation, of extracellular-regulated kinase. These data suggest that soluble thrombospondin-1 interacts with human vascular smooth muscle cells via two independent and separable receptor-binding sites, to differentially stimulate cell chemotaxis and DNA synthesis.
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Affiliation(s)
- Joanne S Lymn
- Clinical Pharmacology, National Heart and Lung Institute, Imperial College of Science, Technology & Medicine, QEQM Wing, St Mary's Hospital, Paddington, London W2 1NY, UK.
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39
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Saumet A, de Jesus N, Legrand C, Dubernard V. Association of thrombospondin-1 with the actin cytoskeleton of human thrombin-activated platelets through an alphaIIbbeta3- or CD36-independent mechanism. Biochem J 2002; 363:473-82. [PMID: 11964147 PMCID: PMC1222499 DOI: 10.1042/0264-6021:3630473] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Thrombospondin-1 (TSP-1) is an adhesive glycoprotein which, when secreted from alpha-granules of activated platelets, can bind to the cell surface and participate in platelet aggregate formation. In this study, we show that thrombin activation leads to the rapid and specific association of a large amount of secreted alpha-granular TSP-1 with the actin cytoskeleton. This cytoskeletal association of TSP-1 was correlated with platelet secretion, but not aggregation, and was inhibited by cytochalasin D, an inhibitor of actin polymerization. Association of TSP-1 with the actin cytoskeleton was mediated by membrane receptors, as shown by using MAII, a TSP-1-specific monoclonal antibody that inhibited both TSP-1 surface binding to activated platelets and cytoskeletal association. TSP-1 and its potential membrane receptors, e.g. alphaIIbbeta3 integrin, CD36 and CD47, concomitantly associated with the actin cytoskeleton. However, studies on platelets from a patient with type I Glanzmann's thrombasthenia lacking alphaIIbbeta3 and another with barely detectable CD36 showed normal TSP-1 surface expression and association with the actin cytoskeleton. Likewise, no involvement of CD47 in TSP-1 association with the actin cytoskeleton could be inferred from experiments with control platelets using the function-blocking anti-CD47 antibody B6H12. Finally, assembly of signalling complexes, as observed through translocation of tyrosine-phosphorylated proteins and kinases to the actin cytoskeleton, was found to occur in concert with cytoskeletal association of TSP-1, in control platelets as well as in thrombasthenic and CD36-deficient platelets. Our results imply a role for the actin cytoskeleton in the membrane-surface expression process of TSP-1 molecules and suggest a possible coupling of TSP-1 receptors to signalling events occurring independently of alphaIIbbeta3 or CD36. These results provide new insights into the link between surface-bound TSP-1 and the contractile actin microfilament system which may promote platelet aggregate cohesion.
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Affiliation(s)
- Anne Saumet
- INSERM Unité 553, Institut d'Hématologie Université Paris 7, Hôpital Saint-Louis, 75010 Paris, France
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Tulasne D, Judd BA, Johansen M, Asazuma N, Best D, Brown EJ, Kahn M, Koretzky GA, Watson SP. C-terminal peptide of thrombospondin-1 induces platelet aggregation through the Fc receptor gamma-chain-associated signaling pathway and by agglutination. Blood 2001; 98:3346-52. [PMID: 11719373 DOI: 10.1182/blood.v98.12.3346] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A peptide from the C-terminal domain of thrombospondin-1 (Arg-Phe-Tyr-Val-Val-Met-Trp-Lys; known as 4N1-1) has been reported to induce platelet aggregation and to bind to the integrin-associated protein (IAP), which is also known as CD47. In this study, it was discovered that 4N1-1 or its derivative peptide, 4N1K, induces rapid phosphorylation of the Fc receptor (FcR) gamma chain, Syk, SLP-76, and phospholipase C gamma2 in human platelets. A specific inhibitor of Src family kinases, 4-amino-4-(4-methylphenyl)-7-(t-butyl) pyrazola[3,4-d]pyrimidine, prevented phosphorylation of these proteins, abolished platelet secretion, and reduced aggregation by approximately 50%. A similar inhibition of aggregation to 4N1-1 was obtained in the presence of Arg-Gly-Asp-Ser in mouse platelets deficient in FcR gamma chain or SLP-76 and in patients with type I Glanzmann thrombasthenia. These results show that 4N1-1 signals through a pathway similar to that used by the collagen receptor glycoprotein (GP) VI. The alphaIIbbeta3-independent aggregation induced by 4N1-1 was also observed in fixed platelets and platelets from patients with Bernard-Soulier syndrome, which are deficient in GPIbalpha. Surprisingly, the ability of 4N1-1 to stimulate aggregation and tyrosine phosphorylation was not altered in platelets pretreated with anti-IAP antibodies and in IAP-deficient mice. These results show that the C-terminal peptide of thrombospondin induces platelet aggregation through the FcR gamma-chain signaling pathway and through agglutination. The latter pathway is independent of signaling events and does not use GPIbalpha or alphaIIbbeta3. Neither of these pathways is mediated by IAP.
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Affiliation(s)
- D Tulasne
- Department of Pharmacology, University of Oxford, United Kingdom.
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41
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Sajid M, Hu Z, Guo H, Li H, Stouffer GA. Vascular expression of integrin-associated protein and thrombospondin increase after mechanical injury. J Investig Med 2001; 49:398-406. [PMID: 11523695 DOI: 10.2310/6650.2001.33784] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Integrin-associated protein (IAP) is a thrombospondin (TSP)-binding, Gi protein-coupled cell surface receptor. The vascular function of IAP has not been defined, and it is not known whether TSP and IAP are expressed at the same time in injured arteries. METHODS Left brachial arteries of baboons were injured using balloon withdrawal technique. Arteries were harvested 1 week after injury, and immunohistochemistry and in situ hybridization were performed using standard techniques. Uninjured right brachial arteries served as a control. Proliferation studies were performed using cultured human aortic smooth muscle cells (SMC). RESULTS We found significant IAP expression in the media and neointima 7 days after injury using BRIC-126, an immunoglobulin (Ig) G2b monoclonal antibody that recognizes IAP with high specificity. In contrast, IAP staining in the uninjured vessel was only observed in the endothelium. Concurrent with IAP expression, TSP mRNA and protein expression in the neointima and media was enhanced 1 week after injury. In cultured SMC, activation of IAP was sufficient to elicit a proliferative response. TSP-induced proliferation was inhibited by antibodies that block TSP binding to IAP and mimicked by 4N1K, a 10-amino acid peptide derived from the IAP binding site within the carboxyl terminus of TSP. CONCLUSIONS Vascular expression of IAP and TSP increased after mechanical injury and activation of IAP elicited a proliferative response in cultured SMC. These findings support the hypothesis that IAP participates in vascular healing responses.
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Affiliation(s)
- M Sajid
- Thrombosis Research Section, Baylor College of Medicine, Houston, Tex, USA
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Onitsuka I, Jung SM, Ikeda H, Imaizumi T, Moroi M. Real-time analysis of the interaction of platelets with immobilized thrombospondin under flow conditions. Thromb Res 2001; 101:455-65. [PMID: 11323003 DOI: 10.1016/s0049-3848(01)00208-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The platelet granule protein (TS) is extracellularly secreted upon platelet activation and then binds to the platelet surface where it can interact with various adhesive proteins. Here, we have analyzed platelet interactions with a TS-coated surface under flow conditions, a model for platelet adhesion onto surface-bound TS under physiological conditions. Platelets exhibited temporary, very short-time adhesion on the TS surface, but no firm adhesion. This adhesion was inhibited by NNKY5-5 (anti-glycoprotein (GP) Ib antibody) and AJvW-2 (anti-von Willebrand factor (vWF)), indicating that both platelet GP Ib and plasma vWF contribute to this interaction. Antibodies against platelet collagen receptor integrin alpha(2)beta(1) had no significant effect. These results suggested that binding of vWF to TS is the first step in platelet interaction with the TS surface. By surface plasmon resonance spectroscopy, a dissociation constant (K(d)) of 3.97x10(-7) M was obtained for the binding reaction between immobilized TS and vWF. These results suggest the following model for platelet interaction with the TS surface under flow: plasma vWF first binds to the immobilized TS and then platelets interact with the TS-bound vWF. A low density of bound vWF would account for the observed weak interaction between TS and platelets under flow.
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Affiliation(s)
- I Onitsuka
- Department of Protein Biochemistry, Institute of Life Science, Kurume University, 2432-3 Aikawa-machi, Kurume, 839-0861, Fukuoka, Japan
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Nesselroth SM, Willis AI, Fuse S, Olson ET, Lawler J, Sumpio BE, Gahtan V. The C-terminal domain of thrombospondin-1 induces vascular smooth muscle cell chemotaxis. J Vasc Surg 2001; 33:595-600. [PMID: 11241132 DOI: 10.1067/mva.2001.112318] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Thrombospondin-1 (TSP-1), an acute-phase reactant implicated in vascular disease, is a 420-kd multifunctional glycoprotein chemotactic for vascular smooth muscle cells (VSMCs). TSP-1 has six domains of repeating homologous amino acid sequences: N-terminal, procollagen homology, type 1 repeat, type 2 repeat, type 3 repeat/RGD (T3), and C-terminal (COOH). The purpose of this experiment was to determine which domains of TSP-1 induce VSMC chemotaxis. METHODS A modified Boyden Chamber chemotaxis assay was used to assess VSMC migration. Serum-free medium, TSP-1, or each of the fusion proteins (10 and 20 microg/mL) synthesized for the different domains were placed in the bottom wells. Quiescent bovine aortic VSMCs (50,000) were placed in the top wells. After 4 hours at 37 degrees C, migrated VSMCs were recorded as cells per five fields (400x) and analyzed with the paired t test. To verify the fusion protein data, we performed chemotaxis assays with antibodies to each of the domains (25 microg/mL) combined with TSP-1 (20 microg/mL) in the bottom wells and VSMCs in the top wells. RESULTS The COOH domain significantly stimulated VSMC chemotaxis (P = <.001). To a lesser extent, the N-terminal and T3 domains also induced chemotaxis (P <.05). However, only the anti-COOH antibody (C6.7) and the anti-integrin-associated protein portion of COOH antibody (D4.6) significantly inhibited TSP-1-induced VSMC chemotaxis (by 85% and 92%, respectively). CONCLUSIONS These results implicate the COOH domain as the portion of the TSP-1 molecule primarily responsible for VSMC chemotaxis. This experiment suggests that future strategies in the prevention of VSMC migration, an initial step in the development of vascular lesions, may involve selective inhibition of the COOH domain of TSP-1.
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Affiliation(s)
- S M Nesselroth
- Yale University School of Medicine, Section of Vascular Surgery and the Harvard Medical School, New Haven, CT 06520, USA
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Thorne RF, Marshall JF, Shafren DR, Gibson PG, Hart IR, Burns GF. The integrins alpha3beta1 and alpha6beta1 physically and functionally associate with CD36 in human melanoma cells. Requirement for the extracellular domain OF CD36. J Biol Chem 2000; 275:35264-75. [PMID: 10956645 DOI: 10.1074/jbc.m003969200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lateral association between different transmembrane glycoproteins can serve to modulate integrin function. Here we characterize a physical association between the integrins alpha(3)beta(1) and alpha(6)beta(1) and CD36 on the surface of melanoma cells and show that ectopic expression of CD36 by CD36-negative MV3 melanoma cells increases their haptotactic migration on extracellular matrix components. The association was demonstrated by co-immunoprecipitation, reimmunoprecipitation, and immunoblotting of surface-labeled cells lysed in Brij 96 detergent. Confocal microscopy illustrated the co-association of alpha(3) and CD36 in cell membrane projections and ruffles. A requirement for the extracellular domain of CD36 in this association was shown by co-immunoprecipitation experiments using surface-labeled MV3 melanoma or COS-7 cells that had been transiently transfected with chimeric constructs between CD36 and intercellular adhesion molecule 1 (ICAM-1) or with a truncation mutant of CD36. CD36 is known to engage in signal transduction and to localize to membrane microdomains or rafts in several cell types. Toward a mechanistic explanation for the functional effects of CD36 expression, we demonstrate that in fractionated Triton X-100 lysates of the MV3 cells stably transfected with CD36, CD36 was greatly enriched with the detergent-insoluble fractions that represent plasma membrane rafts. Significantly, when these fractionated lysates were reprobed for endogenous beta(1) integrin, it was found that a 4-fold increase in the proportion of the mature protein was contained within the detergent-insoluble fractions when extracted from the CD36-transfected cells compared with MV3 cells transfected with vector only. These results suggest that in melanoma cells CD36 expression may induce the sequestration of certain integrins into membrane microdomains and promote cell migration.
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Affiliation(s)
- R F Thorne
- Cancer Research Unit and Department of Microbiology, Faculty of Medicine and Health Sciences, University of Newcastle, New South Wales 2308, Australia.
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Abstract
Cell migration requires a dynamic interaction between the cell, its substrate, and the cytoskeleton-associated motile apparatus. Integrin-associated protein (IAP)/CD47 is a 50-kd cell surface protein that is physically associated with β3 integrins and that modulates the functions of β3 integrins in various cells. However, in B-lymphocytes that express β1 integrins but few β3 integrins, the roles of IAP/CD47 remain to be determined. Cross-linking of IAP/CD47 by the immobilized anti-IAP/CD47 monoclonal antibody (mAb) B6H12, but not 2D3, produced signals to promote polarization with lamellipodia, a characteristic morphology during leukocyte migration, in pre-B and mature B-cell lines (BALL, Nalm6, ONHL-1, Daudi), but not in myeloma cell lines (RPMI8226, OPM-2). In the presence of the immobilized fibronectin (FN), soluble B6H12 could increase the rate of the polarization and activate migratory activity of BALL cells to FN in a transwell filter assay. Furthermore, the dominant-negative form of CDC42 completely blocked B6H12-induced morphologic and functional changes without inhibiting phorbol 12-myristate 13-acetate–induced spreading on FN in BALL cells, whereas the dominant-negative form of Rac1 inhibited all these changes. These findings demonstrate that in B-lymphocytes, IAP/CD47 may transduce the signals to activate the migratory activity, in which CDC42 may be specifically involved, and that IAP/CD47 shows synergistic effect with 4β1 on B-cell migration. These findings would provide new insight into the role of IAP/CD47 on B-cell function.
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Abstract
AbstractCell migration requires a dynamic interaction between the cell, its substrate, and the cytoskeleton-associated motile apparatus. Integrin-associated protein (IAP)/CD47 is a 50-kd cell surface protein that is physically associated with β3 integrins and that modulates the functions of β3 integrins in various cells. However, in B-lymphocytes that express β1 integrins but few β3 integrins, the roles of IAP/CD47 remain to be determined. Cross-linking of IAP/CD47 by the immobilized anti-IAP/CD47 monoclonal antibody (mAb) B6H12, but not 2D3, produced signals to promote polarization with lamellipodia, a characteristic morphology during leukocyte migration, in pre-B and mature B-cell lines (BALL, Nalm6, ONHL-1, Daudi), but not in myeloma cell lines (RPMI8226, OPM-2). In the presence of the immobilized fibronectin (FN), soluble B6H12 could increase the rate of the polarization and activate migratory activity of BALL cells to FN in a transwell filter assay. Furthermore, the dominant-negative form of CDC42 completely blocked B6H12-induced morphologic and functional changes without inhibiting phorbol 12-myristate 13-acetate–induced spreading on FN in BALL cells, whereas the dominant-negative form of Rac1 inhibited all these changes. These findings demonstrate that in B-lymphocytes, IAP/CD47 may transduce the signals to activate the migratory activity, in which CDC42 may be specifically involved, and that IAP/CD47 shows synergistic effect with 4β1 on B-cell migration. These findings would provide new insight into the role of IAP/CD47 on B-cell function.
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47
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Paul BZ, Jin J, Kunapuli SP. Molecular mechanism of thromboxane A(2)-induced platelet aggregation. Essential role for p2t(ac) and alpha(2a) receptors. J Biol Chem 1999; 274:29108-14. [PMID: 10506165 DOI: 10.1074/jbc.274.41.29108] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thromboxane A(2) is a positive feedback lipid mediator produced following platelet activation. The G(q)-coupled thromboxane A(2) receptor subtype, TPalpha, and G(i)-coupled TPbeta subtype have been shown in human platelets. ADP-induced platelet aggregation requires concomitant signaling from two P2 receptor subtypes, P2Y1 and P2T(AC), coupled to G(q) and G(i), respectively. We investigated whether the stable thromboxane A(2) mimetic, (15S)-hydroxy-9, 11-epoxymethanoprosta-5Z,13E-dienoic acid (U46619), also causes platelet aggregation by concomitant signaling through G(q) and G(i), through co-activation of TPalpha and TPbeta receptor subtypes. Here we report that secretion blockade with Ro 31-8220, a protein kinase C inhibitor, completely inhibited U46619-induced, but not ADP- or thrombin-induced, platelet aggregation. Ro 31-8220 had no effect on U46619-induced intracellular calcium mobilization or platelet shape change. Furthermore, U46619-induced intracellular calcium mobilization and shape change were unaffected by A3P5P, a P2Y1 receptor-selective antagonist, and/or cyproheptadine, a 5-hydroxytryptamine subtype 2A receptor antagonist. Either Ro 31-8220 or AR-C66096, a P2T(AC) receptor selective antagonist, abolished U46619-induced inhibition of adenylyl cyclase. In addition, AR-C66096 drastically inhibited U46619-mediated platelet aggregation, which was further inhibited by yohimbine, an alpha(2A)-adrenergic receptor antagonist. Furthermore, inhibition of U46619-induced platelet aggregation by Ro 31-8220 was relieved by activation of the G(i) pathway by selective activation of either the P2T(AC) receptor or the alpha(2A)-adrenergic receptor. We conclude that whereas thromboxane A(2) causes intracellular calcium mobilization and shape change independently, thromboxane A(2)-induced inhibition of adenylyl cyclase and platelet aggregation depends exclusively upon secretion of other agonists that stimulate G(i)-coupled receptors.
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Affiliation(s)
- B Z Paul
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Abstract
Intracellular signals are received and generated by the alpha(IIb)beta(3) integrin on platelets. Recent advances have been made in the areas of agonist receptors that initiate platelet activation, downstream signaling molecules (e.g. small G-proteins and kinases) and changes in ligand-occupied alpha(IIb)beta(3) that cause further signaling and clot retraction.
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Affiliation(s)
- L V Parise
- Department of Pharmacology Center for Thrombosis and Hemostasis Lineberger Comprehensive Cancer Center CB# 7365, The University of North Carolina at Chapel Hill Chapel Hill, NC, USA. parise@med. unc.edu
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Wu AL, Wang J, Zheleznyak A, Brown EJ. Ubiquitin-related proteins regulate interaction of vimentin intermediate filaments with the plasma membrane. Mol Cell 1999; 4:619-25. [PMID: 10549293 DOI: 10.1016/s1097-2765(00)80212-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Integrin-associated protein (IAP, CD47) is a plasma membrane receptor for thrombospondins and signal regulatory proteins (SIRPs) that has an essential role in host defense through its association with integrins. The IAP gene encodes alternatively spliced carboxyterminal cytoplasmic tails that have no previously described function. IAP cytoplasmic tails can bind two related proteins that mediate interaction between IAP and vimentin-containing intermediate filaments, named proteins linking IAP with cytoskeleton (PLICs). Integrins interact with PLICs indirectly, through IAP. Transfection of PLICs induces redistribution of vimentin and cell spreading in IAP-expressing cells. This novel connection between plasma membrane and cytoskeleton is likely to be significant in many adhesion-dependent cell functions.
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Affiliation(s)
- A L Wu
- Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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50
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Abstract
Integrin-associated protein (IAP; or CD47) is a receptor for the cell binding domain (CBD) of thrombospondin-1 (TS1). In platelets, IAP associates with and regulates the function of IIbβ3 integrin (Chung et al, J Biol Chem 272:14740, 1997). We test here the possibility that CD47 may also modulate the function of platelet integrin 2β1, a collagen receptor. The CD47 agonist peptide, 4N1K (KRFYVVMWKK), derived from the CBD, synergizes with soluble collagen in aggregating platelet-rich plasma. 4N1K and intact TS1 also induce the aggregation of washed, unstirred platelets on immobilized collagen with a rapid increase in tyrosine phosphorylation. The effects of TS1 and 4N1K on platelet aggregation are absolutely dependent on IAP, as shown by the use of platelets from IAP−/− mice. Prostaglandin E1 (PGE1) prevents 4N1K-dependent aggregation on immobilized collagen but does not inhibit the 4N1K peptide stimulation of 2β1-dependent platelet spreading. Finally, a detergent-stable, physical association of IAP and 2β1 integrin is detected by coimmunoprecipitation. These results imply a role for IAP and TS1 in the early activation of platelets upon adhesion to collagen.
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