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Wei JD, Kim JH. Two distinct forms of human BLT2: long-form and short-form BLT2. Front Cell Dev Biol 2023; 11:1288373. [PMID: 37954206 PMCID: PMC10637354 DOI: 10.3389/fcell.2023.1288373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 10/11/2023] [Indexed: 11/14/2023] Open
Abstract
BLT2 is a low-affinity leukotriene B4 receptor that plays an essential role in the pathogenesis of various inflammatory diseases, including asthma and cancer. BLT2 is minimally expressed in a normal internal environment but is overexpressed in a stress-induced inflammatory environment. Recent research indicated that human BLT2 has two distinct forms. Although their functions are likely to be different, very few studies investigated these differences. Therefore, this paper will discuss about the two distinct forms of human BLT2; the short-form of BLT2 and the long-form of BLT2.
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Affiliation(s)
- Jun-Dong Wei
- Department of Basic Medical Science, Medical College, Taizhou University, Taizhou, China
| | - Jae-Hong Kim
- Division of Life Sciences, College of Life Sciences, Korea University, Seoul, Republic of Korea
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2
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Blockade of the BLT1-LTB 4 axis does not affect mast cell migration towards advanced atherosclerotic lesions in LDLr -/- mice. Sci Rep 2022; 12:18362. [PMID: 36319730 PMCID: PMC9626554 DOI: 10.1038/s41598-022-23162-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 10/26/2022] [Indexed: 11/05/2022] Open
Abstract
Mast cells have been associated with the progression and destabilization of advanced atherosclerotic plaques. Reducing intraplaque mast cell accumulation upon atherosclerosis progression could be a potent therapeutic strategy to limit plaque destabilization. Leukotriene B4 (LTB4) has been reported to induce mast cell chemotaxis in vitro. Here, we examined whether antagonism of the LTB4-receptor BLT1 could inhibit mast cell accumulation in advanced atherosclerosis. Expression of genes involved in LTB4 biosynthesis was determined by single-cell RNA sequencing of human atherosclerotic plaques. Subsequently, Western-type diet fed LDLr-/- mice with pre-existing atherosclerosis were treated with the BLT1-antagonist CP105,696 or vehicle control three times per week by oral gavage. In the spleen, a significant reduction in CD11b+ myeloid cells was observed, including Ly6Clo and Ly6Chi monocytes as well as dendritic cells. However, atherosclerotic plaque size, collagen and macrophage content in the aortic root remained unaltered upon treatment. Finally, BLT1 antagonism did not affect mast cell numbers in the aortic root. Here, we show that human intraplaque leukocytes may be a source of locally produced LTB4. However, BLT1-antagonism during atherosclerosis progression does not affect either local mast cell accumulation or plaque size, suggesting that other mechanisms participate in mast cell accumulation during atherosclerosis progression.
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3
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Quast T, Zölzer K, Guu D, Alvarez L, Küsters C, Kiermaier E, Kaupp UB, Kolanus W. A Stable Chemokine Gradient Controls Directional Persistence of Migrating Dendritic Cells. Front Cell Dev Biol 2022; 10:943041. [PMID: 36016652 PMCID: PMC9395945 DOI: 10.3389/fcell.2022.943041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Navigation of dendritic cells (DCs) from the site of infection to lymphoid organs is guided by concentration gradients of CCR7 ligands. How cells interpret chemokine gradients and how they couple directional sensing to polarization and persistent chemotaxis has remained largely elusive. Previous experimental systems were limited in the ability to control fast de novo formation of the final gradient slope, long-lasting stability of the gradient and to expose cells to dynamic stimulation. Here, we used a combination of microfluidics and quantitative in vitro live cell imaging to elucidate the chemotactic sensing strategy of DCs. The microfluidic approach allows us to generate soluble gradients with high spatio-temporal precision and to analyze actin dynamics, cell polarization, and persistent directional migration in both static and dynamic environments. We demonstrate that directional persistence of DC migration requires steady-state characteristics of the soluble gradient instead of temporally rising CCL19 concentration, implying that spatial sensing mechanisms control chemotaxis of DCs. Kymograph analysis of actin dynamics revealed that the presence of the CCL19 gradient is essential to stabilize leading edge protrusions in DCs and to determine directionality, since both cytoskeletal polarization and persistent chemotaxis are abrogated in the range of seconds when steady-state gradients are perturbed. In contrast to Dictyostelium amoeba, DCs are unable to decode oscillatory stimulation of soluble chemokine traveling waves into a directional response toward the wave source. These findings are consistent with the notion that DCs do not employ adaptive temporal sensing strategies that discriminate temporally increasing and decreasing chemoattractant concentrations in our setting. Taken together, in our experimental system DCs do not depend on increasing absolute chemokine concentration over time to induce persistent migration and do not integrate oscillatory stimulation. The observed capability of DCs to migrate with high directional persistence in stable gradients but not when subjected to periodic temporal cues, identifies spatial sensing as a key requirement for persistent chemotaxis of DCs.
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Affiliation(s)
- Thomas Quast
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Karolin Zölzer
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Donald Guu
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Luis Alvarez
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Carsten Küsters
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Eva Kiermaier
- Immune and Tumor Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - U. Benjamin Kaupp
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Waldemar Kolanus
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
- *Correspondence: Waldemar Kolanus,
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4
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Eicosanoid receptors as therapeutic targets for asthma. Clin Sci (Lond) 2021; 135:1945-1980. [PMID: 34401905 DOI: 10.1042/cs20190657] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 07/23/2021] [Accepted: 08/03/2021] [Indexed: 12/16/2022]
Abstract
Eicosanoids comprise a group of oxidation products of arachidonic and 5,8,11,14,17-eicosapentaenoic acids formed by oxygenases and downstream enzymes. The two major pathways for eicosanoid formation are initiated by the actions of 5-lipoxygenase (5-LO), leading to leukotrienes (LTs) and 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), and cyclooxygenase (COX), leading to prostaglandins (PGs) and thromboxane (TX). A third group (specialized pro-resolving mediators; SPMs), including lipoxin A4 (LXA4) and resolvins (Rvs), are formed by the combined actions of different oxygenases. The actions of the above eicosanoids are mediated by approximately 20 G protein-coupled receptors, resulting in a variety of both detrimental and beneficial effects on airway smooth muscle and inflammatory cells that are strongly implicated in asthma pathophysiology. Drugs targeting proinflammatory eicosanoid receptors, including CysLT1, the receptor for LTD4 (montelukast) and TP, the receptor for TXA2 (seratrodast) are currently in use, whereas antagonists of a number of other receptors, including DP2 (PGD2), BLT1 (LTB4), and OXE (5-oxo-ETE) are under investigation. Agonists targeting anti-inflammatory/pro-resolving eicosanoid receptors such as EP2/4 (PGE2), IP (PGI2), ALX/FPR2 (LXA4), and Chemerin1 (RvE1/2) are also being examined. This review summarizes the contributions of eicosanoid receptors to the pathophysiology of asthma and the potential therapeutic benefits of drugs that target these receptors. Because of the multifactorial nature of asthma and the diverse pathways affected by eicosanoid receptors, it will be important to identify subgroups of asthmatics that are likely to respond to any given therapy.
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5
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Fonseca MT, Moretti EH, Marques LMM, Machado BF, Brito CF, Guedes JT, Komegae EN, Vieira TS, Festuccia WT, Lopes NP, Steiner AA. A leukotriene-dependent spleen-liver axis drives TNF production in systemic inflammation. Sci Signal 2021; 14:14/679/eabb0969. [PMID: 33879603 DOI: 10.1126/scisignal.abb0969] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Production of the proinflammatory cytokine tumor necrosis factor (TNF) must be precisely regulated for effective host immunity without the induction of collateral tissue damage. Here, we showed that TNF production was driven by a spleen-liver axis in a rat model of systemic inflammation induced by bacterial lipopolysaccharide (LPS). Analysis of cytokine expression and secretion in combination with splenectomy and hepatectomy revealed that the spleen generated not only TNF but also factors that enhanced TNF production by the liver, the latter of which accounted for nearly half of the TNF secreted into the circulation. Using mass spectrometry-based lipidomics, we identified leukotriene B4 (LTB4) as a candidate blood-borne messenger in this spleen-liver axis. LTB4 was essential for spleen-liver communication in vivo, as well as for humoral signaling between splenic macrophages and Kupffer cells in vitro. LPS stimulated the splenic macrophages to secrete LTB4, which primed Kupffer cells to secrete more TNF in response to LPS in a manner dependent on LTB4 receptors. These findings provide a framework to understand how systemic inflammation can be regulated at the level of interorgan communication.
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Affiliation(s)
- Monique T Fonseca
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Eduardo H Moretti
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Lucas M M Marques
- NPPNS, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP 14040, Brazil
| | - Bianca F Machado
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Camila F Brito
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Jady T Guedes
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Evilin N Komegae
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Thayna S Vieira
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - William T Festuccia
- Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil
| | - Norberto P Lopes
- NPPNS, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP 14040, Brazil
| | - Alexandre A Steiner
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP 05508, Brazil.
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6
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van Gool MMJ, van Egmond M. IgA and FcαRI: Versatile Players in Homeostasis, Infection, and Autoimmunity. Immunotargets Ther 2021; 9:351-372. [PMID: 33447585 PMCID: PMC7801909 DOI: 10.2147/itt.s266242] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Mucosal surfaces constitute the frontiers of the body and are the biggest barriers of our body for the outside world. Immunoglobulin A (IgA) is the most abundant antibody class present at these sites. It passively contributes to mucosal homeostasis via immune exclusion maintaining a tight balance between tolerating commensals and providing protection against pathogens. Once pathogens have succeeded in invading the epithelial barriers, IgA has an active role in host-pathogen defense by activating myeloid cells through divers receptors, including its Fc receptor, FcαRI (CD89). To evade elimination, several pathogens secrete proteins that interfere with either IgA neutralization or FcαRI-mediated immune responses, emphasizing the importance of IgA-FcαRI interactions in preventing infection. Depending on the IgA form, either anti- or pro-inflammatory responses can be induced. Moreover, the presence of excessive IgA immune complexes can result in continuous FcαRI-mediated activation of myeloid cells, potentially leading to severe tissue damage. On the one hand, enhancing pathogen-specific mucosal and systemic IgA by vaccination may increase protective immunity against infectious diseases. On the other hand, interfering with the IgA-FcαRI axis by monovalent targeting or blocking FcαRI may resolve IgA-induced inflammation and tissue damage. This review describes the multifaceted role of FcαRI as immune regulator between anti- and pro-inflammatory responses of IgA, and addresses potential novel therapeutic strategies that target FcαRI in disease. ![]()
Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/xlijXy5W0xA
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Affiliation(s)
- Melissa Maria Johanna van Gool
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.,Amsterdam institute for Infection and Immunity, Amsterdam UMC, Amsterdam, Netherlands
| | - Marjolein van Egmond
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.,Amsterdam institute for Infection and Immunity, Amsterdam UMC, Amsterdam, Netherlands.,Department of Surgery, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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7
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Breedveld A, van Egmond M. IgA and FcαRI: Pathological Roles and Therapeutic Opportunities. Front Immunol 2019; 10:553. [PMID: 30984170 PMCID: PMC6448004 DOI: 10.3389/fimmu.2019.00553] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/01/2019] [Indexed: 12/12/2022] Open
Abstract
Immunoglobulin A (IgA) is the most abundant antibody class present at mucosal surfaces. The production of IgA exceeds the production of all other antibodies combined, supporting its prominent role in host-pathogen defense. IgA closely interacts with the intestinal microbiota to enhance its diversity, and IgA has a passive protective role via immune exclusion. Additionally, inhibitory ITAMi signaling via the IgA Fc receptor (FcαRI; CD89) by monomeric IgA may play a role in maintaining homeostatic conditions. By contrast, IgA immune complexes (e.g., opsonized pathogens) potently activate immune cells via cross-linking FcαRI, thereby inducing pro-inflammatory responses resulting in elimination of pathogens. The importance of IgA in removal of pathogens is emphasized by the fact that several pathogens developed mechanisms to break down IgA or evade FcαRI-mediated activation of immune cells. Augmented or aberrant presence of IgA immune complexes can result in excessive neutrophil activation, potentially leading to severe tissue damage in multiple inflammatory, or autoimmune diseases. Influencing IgA or FcαRI-mediated functions therefore provides several therapeutic possibilities. On the one hand (passive) IgA vaccination strategies can be developed for protection against infections. Furthermore, IgA monoclonal antibodies that are directed against tumor antigens may be effective as cancer treatment. On the other hand, induction of ITAMi signaling via FcαRI may reduce allergy or inflammation, whereas blocking FcαRI with monoclonal antibodies, or peptides may resolve IgA-induced tissue damage. In this review both (patho)physiological roles as well as therapeutic possibilities of the IgA-FcαRI axis are addressed.
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Affiliation(s)
- Annelot Breedveld
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, Netherlands
- Amsterdam Infection and Immunity Institute, Amsterdam UMC, Amsterdam, Netherlands
| | - Marjolein van Egmond
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, Netherlands
- Amsterdam Infection and Immunity Institute, Amsterdam UMC, Amsterdam, Netherlands
- Department of Surgery, Amsterdam UMC, Amsterdam, Netherlands
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8
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Inflammatory bowel disease: DCs sense LTB 4 to drive T H1 and T H17 differentiation. Cell Mol Immunol 2018; 17:307-309. [PMID: 30275533 DOI: 10.1038/s41423-018-0162-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 12/11/2022] Open
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9
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Subramanian BC, Majumdar R, Parent CA. The role of the LTB 4-BLT1 axis in chemotactic gradient sensing and directed leukocyte migration. Semin Immunol 2018; 33:16-29. [PMID: 29042024 DOI: 10.1016/j.smim.2017.07.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 06/07/2017] [Accepted: 07/13/2017] [Indexed: 12/11/2022]
Abstract
Directed leukocyte migration is a hallmark of inflammatory immune responses. Leukotrienes are derived from arachidonic acid and represent a class of potent lipid mediators of leukocyte migration. In this review, we summarize the essential steps leading to the production of LTB4 in leukocytes. We discuss the recent findings on the exosomal packaging and transport of LTB4 in the context of chemotactic gradients formation and regulation of leukocyte recruitment. We also discuss the dynamic roles of the LTB4 receptors, BLT1 and BLT2, in mediating chemotactic signaling in leukocytes and contrast them to other structurally related leukotrienes that bind to distinct GPCRs. Finally, we highlight the specific roles of the LTB4-BLT1 axis in mediating signal-relay between chemotaxing neutrophils and its potential contribution to a wide variety of inflammatory conditions including tumor progression and metastasis, where LTB4 is emerging as a key signaling component.
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Affiliation(s)
- Bhagawat C Subramanian
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States.
| | - Ritankar Majumdar
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
| | - Carole A Parent
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, United States; Department of Pharmacology, University of Michigan School of Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States.
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10
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Sharma P, Sharma A, Srivastava M. In vivo neutralization of α4 and β7 integrins inhibits eosinophil trafficking and prevents lung injury during tropical pulmonary eosinophilia in mice. Eur J Immunol 2017; 47:1501-1512. [PMID: 28736941 DOI: 10.1002/eji.201747086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 05/27/2017] [Accepted: 07/20/2017] [Indexed: 01/21/2023]
Abstract
Integrins regulate leukocyte trafficking during homeostasis and inflammatory conditions. However, the role of α4 and β7 integrins in guiding eosinophil transmigration into the lungs during filarial manifestation of Tropical Pulmonary Eosinophilia (TPE) has not been explored. In this study, mice exhibiting TPE manifestations were administered with in vivo neutralizing antibodies against integrins α4 and β7 or their combination and immuno-pathological parameters were evaluated. Results show an intact lung barrier, significantly lower lung inflammation and reduced eosinophil counts in the Bronchoalveolar lavage fluid and lungs of mice receiving anti-α4+ β7 treatment. Reduced eosinophil peroxidase and β-hexosaminidase activity, downregulation of inflammatory genes, lower production of inflammatory lipid intermediates like prostaglandins E2 and D2, leukotriene B4 and cysteinyl leukotrienes were also noted in anti-α4+ β7 treated mice. Reduced accumulation of central memory, effector memory, regulatory T cells and lower production of IL-4, IL-5, and TGF-β were other cardinal features of anti-α4+ β7 treated mice lungs. Flow cytometry-sorted lung eosinophils from anti-α4+ β7 treated mice showed higher apoptotic potential, downregulated anti-apoptotic gene Bcl-2, and exhibited reduced F-actin polymerization and calcium influx as compared to IgG controls. In summary, neutralization of α4+ β7 integrins impairs the transmigration, activation and survival of eosinophils and reduces TPE induced pathology in mice lungs.
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Affiliation(s)
- Pankaj Sharma
- Parasitology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Aditi Sharma
- Parasitology Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Mrigank Srivastava
- Parasitology Division, CSIR-Central Drug Research Institute, Lucknow, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
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11
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Thermodynamic properties of leukotriene A 4 hydrolase inhibitors. Bioorg Med Chem 2016; 24:5243-5248. [DOI: 10.1016/j.bmc.2016.08.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/20/2016] [Accepted: 08/25/2016] [Indexed: 02/03/2023]
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12
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Differential Contribution of BLT1 and BLT2 to Leukotriene B4-Induced Human NK Cell Cytotoxicity and Migration. Mediators Inflamm 2015; 2015:389849. [PMID: 26696753 PMCID: PMC4678237 DOI: 10.1155/2015/389849] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/03/2015] [Indexed: 12/16/2022] Open
Abstract
Accumulating evidence indicates that leukotriene B4 (LTB4) via its receptors BLT1 and/or BLT2 (BLTRs) could have an important role in regulating infection, tumour progression, inflammation, and autoimmune diseases. In the present study, we showed that LTB4 not only augments cytotoxicity by NK cells but also induces their migration. We found that approximately 30% of fresh NK cells express BLT1, 36% express BLT2, and 15% coexpress both receptors. The use of selective BLTR antagonists indicated that BLT1 was involved in both LTB4-induced migration and cytotoxicity, whereas BLT2 was involved exclusively in NK cell migration, but only in response to higher concentrations of LTB4. BLT1 and BLT2 expression increased after activation of NK cells with IL-2 and IL-15. These changes of BLTR expression by cytokines were reflected in enhanced NK cell responses to LTB4. Our findings suggest that BLT1 and BLT2 play differential roles in LTB4-induced modulation of NK cell activity.
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13
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Leukotriene B4 Enhances NOD2-Dependent Innate Response against Influenza Virus Infection. PLoS One 2015; 10:e0139856. [PMID: 26444420 PMCID: PMC4596707 DOI: 10.1371/journal.pone.0139856] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/16/2015] [Indexed: 12/13/2022] Open
Abstract
Leukotriene B4 (LTB4), a central mediator of inflammation, is well known for its chemoattractant properties on effectors cells of the immune system. LTB4 also has the ability to control microbial infection by improving host innate defenses through the release of antimicrobial peptides and modulation of intracellular Toll-like receptors (TLRs) expression in response to agonist challenge. In this report, we provide evidences that LTB4 acts on nucleotide-binging oligomerization domain 2 (NOD2) pathway to enhance immune response against influenza A infection. Infected mice receiving LTB4 show improved survival, lung architecture and reduced lung viral loads as compared to placebo-treated animals. NOD2 and its downstream adaptor protein IPS-1 have been found to be essential for LTB4-mediated effects against IAV infection, as absence of NOD2 or IPS-1 diminished its capacity to control viral infection. Treatment of IAV-infected mice with LTB4 induces an increased activation of IPS-1-IRF3 axis leading to an enhanced production of IFNβ in lungs of infected mice. LTB4 also has the ability to act on the RICK-NF-κB axis since administration of LTB4 to mice challenged with MDP markedly increases the secretion of IL-6 and TNFα in lungs of mice. TAK1 appears to be essential to the action of LTB4 on NOD2 pathway since pretreatment of MEFs with TAK1 inhibitor prior stimulation with IAV or MDP strongly abrogated the potentiating effects of LTB4 on both IFNβ and cytokine secretion. Together, our results demonstrate that LTB4, through its ability to activate TAK1, potentiates both IPS-1 and RICK axis of the NOD2 pathway to improve host innate responses.
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14
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Jana B, Czarzasta J, Jaroszewski J. Synthesis of leukotrienes in porcine uteri with endometritis induced by infection with Escherichia coli. Reprod Fertil Dev 2015; 26:1007-16. [PMID: 23924575 DOI: 10.1071/rd13191] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 06/29/2013] [Indexed: 12/27/2022] Open
Abstract
Leukotrienes (LTs) are lipid mediators that play a significant role in the inflammatory process. Their production in inflamed uteri is not fully understood. The present experiment aimed to determine LTB4 and LTC4 amounts, 5-lipooxygenase (5-LO), LTA4 hydrolase (LTAH) and LTC4 synthase (LTCS) mRNA levels and protein expression in inflamed porcine uteri. On Day 3 of the oestrous cycle (Day 0 of the study), either Escherichia coli suspension or saline were infused into uterine horns. Collection of uterine tissues and washings took place eight or sixteen days later. In gilts suffering from endometritis increased LTB4 and LTC4 levels in the endometrium and washings and 5-LO mRNA levels in the myometrium on Days 8 and 16, 5-LO protein levels in the endometrium and myometrium on Day 8, LTAH mRNA and protein levels in the endometrium and myometrium on Days 8 and 16, respectively. Although LTCS mRNA and protein expression in the myometrium and LTCS protein expression in the endometrium were enhanced on Day 16 after Escherichia coli inoculation, LTCS mRNA levels decreased on Day 8 in both tissues. Our study shows the upregulation of LT production in inflamed porcine uteri, which suggests the importance of these factors to the process of uterine inflammation.
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Affiliation(s)
- Barbara Jana
- Division of Reproductive Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland
| | - Joanna Czarzasta
- Division of Reproductive Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland
| | - Jerzy Jaroszewski
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719 Olsztyn, Poland
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15
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Dawson DR, Branch-Mays G, Gonzalez OA, Ebersole JL. Dietary modulation of the inflammatory cascade. Periodontol 2000 2013; 64:161-97. [DOI: 10.1111/j.1600-0757.2012.00458.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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16
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Le Bel M, Brunet A, Gosselin J. Leukotriene B4, an endogenous stimulator of the innate immune response against pathogens. J Innate Immun 2013; 6:159-68. [PMID: 23988515 DOI: 10.1159/000353694] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 06/13/2013] [Indexed: 12/22/2022] Open
Abstract
Leukotriene B4 (LTB4) is an endogenous lipid mediator of inflammation derived from arachidonic acid by the sequential action of cytosolic phospholipase A2 and 5-lipoxygenase. This mediator was initially recognized for its involvement in the recruitment of neutrophils. However, in the last decade, LTB4 has been clearly demonstrated to play a significant role in the control of microbial infections through its ability to activate host innate defenses. In this review, we will focus on the modulator effects of LTB4 on the innate defenses and discuss its therapeutic potential against viral pathogens.
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Affiliation(s)
- Manon Le Bel
- Laboratory of Innate Immunology, Centre Hospitalier Universitaire de Québec, and Department of Molecular Medicine, Laval University, Quebec City, Que., Canada
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Henderson WR, Ye X, Lai Y, Ni Z, Bollinger JG, Tien YT, Chi EY, Gelb MH. Key role of group v secreted phospholipase A2 in Th2 cytokine and dendritic cell-driven airway hyperresponsiveness and remodeling. PLoS One 2013; 8:e56172. [PMID: 23451035 PMCID: PMC3581544 DOI: 10.1371/journal.pone.0056172] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/07/2013] [Indexed: 11/23/2022] Open
Abstract
Background Previous work has shown that disruption of the gene for group X secreted phospholipase A2 (sPLA2-X) markedly diminishes airway hyperresponsiveness and remodeling in a mouse asthma model. With the large number of additional sPLA2s in the mammalian genome, the involvement of other sPLA2s in the asthma model is possible – in particular, the group V sPLA2 (sPLA2-V) that like sPLA2-X is highly active at hydrolyzing membranes of mammalian cells. Methodology and Principal Findings The allergen-driven asthma phenotype was significantly reduced in sPLA2-V-deficient mice but to a lesser extent than observed previously in sPLA2-X-deficient mice. The most striking difference observed between the sPLA2-V and sPLA2-X knockouts was the significant impairment of the primary immune response to the allergen ovalbumin (OVA) in the sPLA2-V−/− mice. The impairment in eicosanoid generation and dendritic cell activation in sPLA2-V−/− mice diminishes Th2 cytokine responses in the airways. Conclusions This paper illustrates the diverse roles of sPLA2s in the immunopathogenesis of the asthma phenotype and directs attention to developing specific inhibitors of sPLA2-V as a potential new therapy to treat asthma and other allergic disorders.
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Affiliation(s)
- William R Henderson
- Center for Allergy and Inflammation, UW Medicine at South Lake Union, Department of Medicine, University of Washington, Seattle, Washington, United States of America.
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Inada T, Ueshima H, Shingu K. Intravenous anesthetic propofol suppresses leukotriene production in murine dendritic cells. J Immunotoxicol 2012; 10:262-9. [PMID: 22953970 DOI: 10.3109/1547691x.2012.712066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Leukotrienes, divided into cysteinyl leukotrienes (CysLTs), which are important mediators of asthmatic responses, and leukotriene B4 (LTB4), a chemotactic and chemokinetic agent for leukocytes, are potent lipid mediators generated from arachidonic acid by 5-lipoxygenase (5-LO). Leukotrienes are also considered to have immunoregulatory and pro-inflammatory actions. Propofol is an intravenous anesthetic widely used for anesthesia and sedation that is alleged to possess anti-inflammatory properties. The present study examined the effect of propofol on leukotriene production by dendritic cells (DC). In murine bone marrow-derived DC, propofol significantly suppressed CysLT and LTB4 production after short-term stimulation with zymosan. The protein levels of cytosolic phospholipase A2 and 5-LO, or arachidonic acid release from plasma membranes, were not affected by the presence of propofol. Although zymosan treatment induced or enhanced the phosphorylation of ERK1/2, p-38 MAPK, and JNK, which presumably up-regulates the activity of 5-LO, the presence of propofol had no additional effect on the phosphorylation status of any of these MAPKs. Similarly, zymosan significantly increased the concentration of intracellular calcium, which is the most crucial activator of 5-LO, but no additional concentration changes were observed with the addition of propofol. Lastly, in an in-vitro cell-free ferrous oxidation-xylenol orange assay, propofol significantly inhibited the 5-LO activity of purified human recombinant 5-LO enzyme with an IC50 of ~7.5 µM. Thus, propofol's inhibition of 5-LO is not likely restricted to the circumstances surrounding the production of leukotrienes from DC, but applicable to other types of immune and non-immune cells that produce leukotrienes. The 5-LO-inhibiting activity of propofol may, at least in part, contribute to the well-known anti-inflammatory activity of propofol.
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Affiliation(s)
- Takefumi Inada
- Department of Anesthesiology, Kansai Medical University, Osaka, Japan.
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19
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Shutt JD, Boger P, Neale JR, Patel P, Sampson AP. Activity of the leukotriene pathway in Barrett's metaplasia and oesophageal adenocarcinoma. Inflamm Res 2012; 61:1379-84. [PMID: 22851204 DOI: 10.1007/s00011-012-0539-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 07/17/2012] [Accepted: 07/19/2012] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Leukotriene (LT) B(4) is a lipid inflammatory mediator implicated in tumorigenesis in animal models of Barrett's oesophagitis, but little is known about the cysteinyl-leukotrienes (LTC(4), LTD(4), LTE(4)), which have distinct inflammatory and tumorigenic actions in other tissues. We recently showed that the terminal enzymes for the synthesis of both LT families are highly expressed in human oesophageal adenocarcinoma (OA) tissues. This study therefore examined the capacity of Barrett's metaplasia (BM) and OA tissues to synthesise LTs in vitro. SUBJECTS AND METHODS Oesophageal biopsies from patients with BM (n = 14), high-grade dysplasia (n = 2), OA (n = 11), and squamous control tissues (n = 11) were cultured with calcium ionophore A32187 (2 μM) for 60 min. LTB(4) and cysteinyl-leukotrienes were extracted and measured by specific enzyme immunoassays. RESULTS Levels of LTB(4) and cysteinyl-leukotrienes were 8.6-fold (P < 0.01) and 2.4-fold (P < 0.02) higher, respectively, in OA tissues than in squamous control tissues, but levels in BM tissues (n = 14) were not altered. Production of the two LT families correlated across all tissue types (r = 0.62, p < 0.00005). CONCLUSIONS Increased synthesis of LTB(4) and cysteinyl-leukotrienes has not previously been shown in human OA tissue and our results may indicate a role of these lipids in Barrett's disease progression.
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Affiliation(s)
- James David Shutt
- Department of Luminal Gastroenterology, University Hospitals Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, UK
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20
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McCarthy MK, Weinberg JB. Eicosanoids and respiratory viral infection: coordinators of inflammation and potential therapeutic targets. Mediators Inflamm 2012; 2012:236345. [PMID: 22665949 PMCID: PMC3362132 DOI: 10.1155/2012/236345] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 03/12/2012] [Indexed: 12/20/2022] Open
Abstract
Viruses are frequent causes of respiratory infection, and viral respiratory infections are significant causes of hospitalization, morbidity, and sometimes mortality in a variety of patient populations. Lung inflammation induced by infection with common respiratory pathogens such as influenza and respiratory syncytial virus is accompanied by increased lung production of prostaglandins and leukotrienes, lipid mediators with a wide range of effects on host immune function. Deficiency or pharmacologic inhibition of prostaglandin and leukotriene production often results in a dampened inflammatory response to acute infection with a respiratory virus. These mediators may, therefore, serve as appealing therapeutic targets for disease caused by respiratory viral infection.
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Affiliation(s)
- Mary K. McCarthy
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jason B. Weinberg
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI 48109, USA
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21
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Leukotriene C4 induces migration of human monocyte-derived dendritic cells without loss of immunostimulatory function. Blood 2012; 119:3113-22. [PMID: 22323449 DOI: 10.1182/blood-2011-10-385930] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Generation of human monocyte-derived dendritic cells (DCs) for cancer vaccination involves ex vivo maturation in the presence of proinflammatory cytokines and prostaglandin E(2) (PGE(2)). Although the inclusion of PGE(2) during maturation is imperative for the induction of DC migration, PGE(2) has unfavorable effects on the immunostimulatory capacity of these cells. Like PGE(2), leukotrienes (LTs) are potent mediators of DC migration. We therefore sought to characterize the migratory and immunologic properties of DCs that matured in the presence of LTB(4), LTC(4), LTD(4), and PGE(2). Here, we demonstrate that DCs matured in the presence of LTC(4), but not LTB(4) or LTD(4), are superior to PGE(2)-matured DCs in stimulating CD4(+) T-cell responses and in inducing antigen-specific cytotoxic T lymphocytes (CTLs) in vitro without concomitant induction or recruitment of regulatory T cells (Tregs). LTC(4)-matured DCs migrate efficiently through layers of extracellular matrix and secrete higher levels of immunostimulatory IL-12p70 while producing reduced levels of immune-inhibitory IL-10, IL12p40, indoleamine-2,3-dioxidase, and TIMP-1 (tissue inhibitor of matrix metalloproteinases). Intracellular calcium mobilization and receptor antagonist studies reveal that, in contrast to LTD(4), LTC(4) did not signal through CysLTR(1) in DCs. Collectively, our data suggest that LTC(4) represents a promising candidate to replace PGE(2) in DC maturation protocols for cancer vaccination.
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Wei JD, Kim JY, Kim JH. BLT2 phosphorylation at Thr355
by Akt is necessary for BLT2-mediated chemotaxis. FEBS Lett 2011; 585:3501-6. [DOI: 10.1016/j.febslet.2011.10.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 10/12/2011] [Accepted: 10/19/2011] [Indexed: 11/29/2022]
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De Oliveira EO, Wang K, Kong HS, Kim S, Miessau M, Snelgrove RJ, Shim YM, Paige M. Effect of the leukotriene A4 hydrolase aminopeptidase augmentor 4-methoxydiphenylmethane in a pre-clinical model of pulmonary emphysema. Bioorg Med Chem Lett 2011; 21:6746-50. [PMID: 21983441 DOI: 10.1016/j.bmcl.2011.09.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 09/12/2011] [Accepted: 09/14/2011] [Indexed: 01/27/2023]
Abstract
The leukotriene A(4) hydrolase enzyme is a dual functioning enzyme with the following two catalytic activities: an epoxide hydrolase function that transforms the lipid metabolite leukotriene A(4) to leukotriene B(4) and an aminopeptidase function that hydrolyzes short peptides. To date, all drug discovery efforts have focused on the epoxide hydrolase activity of the enzyme, because of extensive biological characterization of the pro-inflammatory properties of its metabolite, leukotriene B(4). Herein, we have designed a small molecule, 4-methoxydiphenylmethane, as a pharmacological agent that is bioavailable and augments the aminopeptidase activity of the leukotriene A(4) hydrolase enzyme. Pre-clinical evaluation of our drug showed protection against intranasal elastase-induced pulmonary emphysema in murine models.
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Affiliation(s)
- Eliseu O De Oliveira
- Georgetown University Medical Center, Lombardi Comprehensive Cancer Center, Washington, DC 20057, USA
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24
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Pal I, Ramsey JD. The role of the lymphatic system in vaccine trafficking and immune response. Adv Drug Deliv Rev 2011; 63:909-22. [PMID: 21683103 DOI: 10.1016/j.addr.2011.05.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 01/26/2011] [Indexed: 01/13/2023]
Abstract
The development and improvement of vaccines has been a significant endeavor on the part of the medical community for more than the last two centuries, and the success of these efforts is obvious when one considers the millions of lives that have been saved. Recent work in the field of vaccines, however, indicates that vaccines may be developed for even more challenging diseases than those previously addressed. It will be important in achieving this feat to account for the physical and chemical processes related to vaccine trafficking, rather than solely relying on our knowledge of the pathogen and our empirical experience. A thorough understanding of the lymphatic system is essential considering the role it plays in antigen trafficking and all immunological activity. This review describes the results of recent work that provides insight into the physiological processes of the lymphatic system and its various components with an emphasis on vaccine antigen trafficking from the administration site to secondary lymphoid tissues and the ensuing immune response. The review also discusses current challenges in designing vaccines and presents modern strategies for designing vaccines to better interface with the lymphatic system.
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Bäck M, Dahlén SE, Drazen JM, Evans JF, Serhan CN, Shimizu T, Yokomizo T, Rovati GE. International Union of Basic and Clinical Pharmacology. LXXXIV: Leukotriene Receptor Nomenclature, Distribution, and Pathophysiological Functions. Pharmacol Rev 2011; 63:539-84. [DOI: 10.1124/pr.110.004184] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Selective inhibition of leukotriene receptor BLT-2 reduces vascular oxidative stress and improves endothelial function in ApoE−/− mice. Mol Cell Biochem 2011; 359:25-31. [DOI: 10.1007/s11010-011-0995-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 07/06/2011] [Indexed: 01/06/2023]
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Eicosanoid regulation of hematopoiesis and hematopoietic stem and progenitor trafficking. Leukemia 2010; 24:1993-2002. [PMID: 20882043 DOI: 10.1038/leu.2010.216] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hematopoietic stem cell (HSC) transplantation is a potentially curative treatment for numerous hematological malignancies. The transplant procedure as performed today takes advantage of HSC trafficking; either egress of HSC from the bone marrow to the peripheral blood, that is, mobilization, for acquisition of the hematopoietic graft, and/or trafficking of HSC from the peripheral blood to bone marrow niches in the recipient patient, that is HSC homing. Numerous studies, many of which are reviewed herein, have defined hematopoietic regulatory mechanisms mediated by the 20-carbon lipid family of eicosanoids, and recent evidence strongly supports a role for eicosanoids in regulation of hematopoietic trafficking, adding a new role whereby eicosanoids regulate hematopoiesis. Short-term exposure of HSC to the eicosanoid prostaglandin E(2) increases CXCR4 receptor expression, migration and in vivo homing of HSC. In contrast, cannabinoids reduce hematopoietic progenitor cell (HPC) CXCR4 expression and induce HPC mobilization when administered in vivo. Leukotrienes have been shown to alter CD34(+) cell adhesion, migration and regulate HSC proliferation, suggesting that eicosanoids have both opposing and complimentary roles in the regulation of hematopoiesis. As numerous FDA approved compounds regulate eicosanoid signaling or biosynthesis, the utility of eicosanoid-based therapeutic strategies to improve hematopoietic transplantation can be rapidly evaluated.
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Kim JY, Lee WK, Yu YG, Kim JH. Blockade of LTB4-induced chemotaxis by bioactive molecules interfering with the BLT2-Galphai interaction. Biochem Pharmacol 2010; 79:1506-15. [PMID: 20097180 DOI: 10.1016/j.bcp.2010.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/12/2010] [Accepted: 01/13/2010] [Indexed: 01/30/2023]
Abstract
BLT2, a low-affinity leukotriene B4 (LTB4) receptor, is a member of the G-protein coupled receptor (GPCR) family and is involved in the pathogenesis of inflammatory diseases such as asthma. Despite its clinical implications, however, no pharmacological inhibitors are available. In the present study, we screened for small molecules that interfere with the interaction between the third intracellular loop region of BLT2 (BLT2iL3) and the Galphai3 protein subunit (Galphai3), using a high-throughput screening (HTS) assay with a library of 1040 FDA-approved drugs and bioactive compounds. We identified two small molecules-purpurin [1,2,4-trihydroxy-9,10-anthraquinone; IC50 = 1.6 microM for BLT2] and chloranil [tetrachloro-1,4-benzoquinone; IC50 = 0.42 microM for BLT2]-as specific BLT2-blocking agents. We found that blockade of the BLT2iL3-Galphai3 interaction by these small molecules inhibited the BLT2-downstream signaling cascade. For example, BLT2-signaling to phosphoinositide-3 kinase (PI3K)/Akt phosphorylation was completely abolished by these molecules. Furthermore, we observed that these small molecules blocked LTB4-induced chemotaxis by inhibiting the BLT2-PI3K/Akt-downstream, Rac1-reactive oxygen species-dependent pathway. Taken together, our results show that purpurin and chloranil interfere with the interaction between BLT2iL3 and Galphai3 and thus block the biological functions of BLT2 (e.g., chemotaxis). The present findings suggest a potential application of purpurin and chloranil as pharmacological therapeutic agents against BLT2-associated inflammatory human diseases.
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Toxins-useful biochemical tools for leukocyte research. Toxins (Basel) 2010; 2:428-52. [PMID: 22069594 PMCID: PMC3153219 DOI: 10.3390/toxins2040428] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 03/24/2010] [Indexed: 12/28/2022] Open
Abstract
Leukocytes are a heterogeneous group of cells that display differences in anatomic localization, cell surface phenotype, and function. The different subtypes include e.g., granulocytes, monocytes, dendritic cells, T cells, B cells and NK cells. These different cell types represent the cellular component of innate and adaptive immunity. Using certain toxins such as pertussis toxin, cholera toxin or clostridium difficile toxin, the regulatory functions of Gαi, Gαs and small GTPases of the Rho family in leukocytes have been reported. A summary of these reports is discussed in this review.
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Abstract
Eicosanoids, including prostaglandins and leukotrienes, are biologically active lipids that have been implicated in various pathological processes, such as inflammation and cancer. This Review highlights our understanding of the intricate roles of eicosanoids in epithelial-derived tumours and their microenvironment. The knowledge of how these lipids orchestrate the complex interactions between transformed epithelial cells and the surrounding stromal cells is crucial for understanding tumour evolution, progression and metastasis. Understanding the molecular mechanisms underlying the role of prostaglandins and other eicosanoids in cancer progression will help to develop more effective cancer chemopreventive and/or therapeutic agents.
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Affiliation(s)
- Dingzhi Wang
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA
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31
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Kim EY, Seo JM, Cho KJ, Kim JH. Ras-induced invasion and metastasis are regulated by a leukotriene B4 receptor BLT2-linked pathway. Oncogene 2009; 29:1167-78. [DOI: 10.1038/onc.2009.412] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Choi JA, Lee JW, Kim H, Kim EY, Seo JM, Ko J, Kim JH. Pro-survival of estrogen receptor-negative breast cancer cells is regulated by a BLT2–reactive oxygen species-linked signaling pathway. Carcinogenesis 2009; 31:543-51. [DOI: 10.1093/carcin/bgp203] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gaudreault E, Gosselin J. Leukotriene B4 potentiates CpG signaling for enhanced cytokine secretion by human leukocytes. THE JOURNAL OF IMMUNOLOGY 2009; 183:2650-8. [PMID: 19620296 DOI: 10.4049/jimmunol.0804135] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TLRs are known to be important in innate host defense against a variety of microbial infections. In particular, TLR9 has been associated with immune defense against different foreign organisms by recognition of unmethylated DNA sequences. In this report, we provide evidence that leukotriene B(4) (LTB(4)) has the capacity to modulate TLR9 expression on human neutrophils. The effect of LTB(4) was found to be specific, because related leukotrienes such as LTC(4) and LTD(4) or neutrophil agonists IL-8 and C5a failed to modulate TLR9 expression in neutrophils. Using fluorochrome-tagged CpG DNA, we observed that LTB(4) treatment also increased TLR9 ligand binding in neutrophils. Moreover, LTB(4) stimulation potentiates CpG-mediated signaling via an endosome-independent mechanism in human neutrophils, leading to enhanced secretion of proinflammatory cytokines. The increase in cytokine secretion by LTB(4) following CpG stimulation of neutrophils was associated with the activation of TGF-beta-activated kinase (TAK-1) as well as p38 and c-Jun (JNK) kinases. In contrast, in PBMC LTB(4) leads to an increase in cytokine secretion following CpG stimulation but via a MyD88- and endosome-dependent mechanism. As observed in neutrophils, PBMC stimulation with LTB(4) in the presence of CpG also results in enhanced TAK-1, p38, and JNK phosphorylation/activation. These data provide new evidence underlying the immunomodulatory properties of LTB(4) leading to antimicrobial defense.
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Affiliation(s)
- Eric Gaudreault
- Laboratory of Innate Immunology, Centre Hospitalier Universitaire de Quebec Research Center, Laval University, Quebec, Canada
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Kim GY, Lee JW, Cho SH, Seo JM, Kim JH. Role of the low-affinity leukotriene B4 receptor BLT2 in VEGF-induced angiogenesis. Arterioscler Thromb Vasc Biol 2009; 29:915-20. [PMID: 19286633 DOI: 10.1161/atvbaha.109.185793] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The leukotriene B(4) (LTB(4)) receptor BLT2 is expressed in endothelium, but no clear physiological function for it has yet been identified, especially in vascular angiogenesis. The purpose of this study is to characterize the potential function of BLT2 in vascular endothelial growth factor (VEGF)-induced angiogenesis. METHODS AND RESULTS VEGF significantly upregulates BLT2 expression in human umbilical vein endothelial cells (HUVECs), and BLT2 knockdown by siRNA or inhibition of BLT2 by a specific BLT2 antagonist LY255283 attenuates VEGF-induced angiogenesis, which was determined by its effect on the formation of tube-like structures and on transmigration. The role of BLT2 in VEGF-induced angiogenesis was more evident in vivo, where BLT2 inhibition by LY255283 almost completely blocked VEGF-induced vessel formation in Matrigel-plug assays. In addition, we found that VEGF upregulates synthesis of the BLT2 ligand, 12(S)-hydroxyeicosatetraenoic acid (HETE). siRNA knockdown of 12-lipoxygenase (12-LO) expression attenuates VEGF-induced angiogenesis in HUVECs, and the addition of 12(S)-HETE to the 12-LO knockdown-HUVECs restores VEGF-induced angiogenesis. The activation of BLT2 itself by either 12(S)-HETE or LTB(4) evoked significant angiogenic phenotypes, both in vitro and in vivo. CONCLUSIONS Our findings indicate that BLT2 plays an essential role in mediating VEGF-induced angiogenesis.
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Affiliation(s)
- Geun-Young Kim
- College of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul, 136-701, Korea
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BLT2 is expressed in PanINs, IPMNs, pancreatic cancer and stimulates tumour cell proliferation. Br J Cancer 2008; 99:1064-73. [PMID: 18781173 PMCID: PMC2567081 DOI: 10.1038/sj.bjc.6604655] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer has an abysmal prognosis. Targets for early detection, prevention and therapy are desperately needed. Inflammatory pathways have an important impact on tumour growth and progression. Expression of BLT2 (the second leukotriene B(4) receptor) was investigated by real-time RT-PCR and immunohistochemistry. Cell proliferation was studied after stable transfection with BLT2, after treatment with siRNA and Compound A as an agonist. BLT2 is expressed in all pancreatic cancer cell lines. Results from real-time RT-PCR revealed significant overexpression of BLT2 in malignant intraductal papillary mucinous neoplasias (IPMNs) and pancreatic adenocarcinoma. Intense staining was evident in IPMNs, infiltrating tumour cells and advanced pancreatic intraepithelial neoplasias (PanINs) but not in normal ductal cells. Overexpression of BLT2 as well as stimulation of Colo357, Panc-1 and AsPC1 cells with Compound A caused a significant increase in tumour cell proliferation, an effect reversed after siRNA treatment. This study demonstrates for the first time the expression of BLT2 in the pancreas and overexpression in pancreatic cancers and malignant IPMNs in particular. Upregulation of BLT2 is already evident in precursor lesions (PanINs, IPMNs). Overexpression of this receptor leads to significant growth stimulation. Therefore, we suggest BLT2 as a new target for chemoprevention and therapy for pancreatic cancer.
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Randolph GJ, Ochando J, Partida-Sánchez S. Migration of dendritic cell subsets and their precursors. Annu Rev Immunol 2008; 26:293-316. [PMID: 18045026 DOI: 10.1146/annurev.immunol.26.021607.090254] [Citation(s) in RCA: 344] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The ability of dendritic cells (DCs) to initiate and orchestrate immune responses is a consequence of their localization within tissues and their specialized capacity for mobilization. The migration of a given DC subset is typified by a restricted capacity for recirculation, contrasting markedly with T cells. Routes of DC migration into lymph nodes differ notably for distinct DC subsets. Here, we compare the distinct migratory patterns of plasmacytoid DCs (pDCs), CD8alpha(+) DCs, Langerhans cells, and conventional myeloid DCs and discuss how the highly regulated patterns of DC migration in vivo may affect their roles in immunity. Finally, to gain a more molecular appreciation of the specialized migratory properties of DCs, we review the signaling cascades that govern the process of DC migration.
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Affiliation(s)
- Gwendalyn J Randolph
- Department of Gene and Cell Medicine, Immunology Institute, Mount Sinai School of Medicine, New York, New York 10029, USA.
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Sayed BA, Christy A, Quirion MR, Brown MA. The master switch: the role of mast cells in autoimmunity and tolerance. Annu Rev Immunol 2008; 26:705-39. [PMID: 18370925 DOI: 10.1146/annurev.immunol.26.021607.090320] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There are many parallels between allergic and autoimmune responses. Both are considered hypersensitivity responses: pathologies that are elicited by an exuberant reaction to antigens that do not pose any inherent danger to the organism. Although mast cells have long been recognized as central players in allergy, only recently has their role in autoimmunity become apparent. Because of the commonalities of these responses, much of what we have learned about the underlying mast cell-dependent mechanisms of inflammatory damage in allergy and asthma can be used to understand autoimmunity. Here we review mast cell biology in the context of autoimmune disease. We discuss the huge diversity in mast cell responses that can exert either proinflammatory or antiinflammatory activity. We also consider the myriad factors that cause one response to predominate over another in a particular immune setting.
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Affiliation(s)
- Blayne A Sayed
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
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Hicks A, Monkarsh SP, Hoffman AF, Goodnow R. Leukotriene B4 receptor antagonists as therapeutics for inflammatory disease: preclinical and clinical developments. Expert Opin Investig Drugs 2008; 16:1909-20. [PMID: 18042000 DOI: 10.1517/13543784.16.12.1909] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Leukotriene B(4) (LTB(4)) is a lipid inflammatory mediator derived from membrane phospholipids by the sequential actions of cytosolic phospholipase A2 (PLA2), 5-lipoxygenase (5-LO) and leukotriene A(4) (LTA(4)) hydrolase. Several inflammatory diseases, including asthma, chronic obstructive pulmonary disease, arthritis and inflammatory bowel disease, have been associated with elevated levels of LTB(4). As a result, pharmacological strategies to modulate the synthesis of LTB(4) (inhibition of PLA2, 5-LO or LTA(4) hydrolase) or the effects of LTB(4) itself (antagonism of LTB(4) receptors) are being developed by several companies. Two G-protein-coupled receptors mediate the effects of LTB(4), namely BLT1 and BLT2. The pharmacology, expression and function of these two receptors were last reviewed by Tager and Luster in 2004. Since then, there has been an increased understanding of the function of these receptors, in particular for the lesser understood of the two receptors, BLT2. Furthermore, since last reviewed in 1996, there have been several clinical developments in the use of BLT receptor antagonists for inflammatory diseases. This review summarizes the latest preclinical and clinical developments in BLT antagonism for inflammatory diseases and discusses potential future developments.
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Affiliation(s)
- Alexandra Hicks
- Department of Inflammation Discovery, 340 Kingsland Street, Nutley, New Jersey, NJ 07110, USA.
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Whittle BJR, Varga C, Berko A, Horvath K, Posa A, Riley JP, Lundeen KA, Fourie AM, Dunford PJ. Attenuation of inflammation and cytokine production in rat colitis by a novel selective inhibitor of leukotriene A4 hydrolase. Br J Pharmacol 2007; 153:983-91. [PMID: 18157165 DOI: 10.1038/sj.bjp.0707645] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Leukotriene B(4) (LTB(4)), formed by the sequential actions of the 5-lipoxygenase (5-LO) and leukotriene A(4) hydrolase (LTA(4)H), is a pro-inflammatory mediator implicated in the pathogenesis of inflammatory bowel disease. However, inhibitors of 5-LO have not proved to be consistent in their therapeutic efficacy in colitis. Another approach to inhibiting LTB(4) synthesis is through the use of inhibitors of LTA(4)H, such as the novel, potent and selective compound, JNJ 26993135. EXPERIMENTAL APPROACH The effect of oral administration of JNJ 26993135 has been evaluated in a rat model of colitis provoked by colonic instillation of trinitrobenzenesulphonic acid (TNBS). The extent and severity of the macroscopic inflammatory response, the colonic levels of myeloperoxidase (MPO) and LTB(4) and of the pro-inflammatory cytokines, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured. KEY RESULTS Oral administration of JNJ 26993135 (5, 15 and 30 mg kg(-1), twice a day) dose-dependently reduced both the extent and intensity of the colonic inflammatory damage observed 3 days after TNBS challenge. JNJ 26993135 also dose-dependently reduced the elevated colonic levels of LTB(4), as well as the inflammatory biomarkers, MPO, IL-6 and TNF-alpha. This dosing regimen was supported by the pharmacokinetic profile of JNJ 26993135, along with the demonstration of the inhibition of ex vivo production of LTB(4) in whole blood following oral administration. CONCLUSIONS AND IMPLICATIONS These results with JNJ 26993135 in the rat TNBS model support the role of LTB(4) in colitis and the potential value of targeting LTA(4)H for the treatment of inflammatory bowel diseases.
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Affiliation(s)
- B J R Whittle
- William Harvey Research Institute, Barts and the London, Queen Mary's School of Medicine, Charterhouse Square, London, UK.
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Rao NL, Dunford PJ, Xue X, Jiang X, Lundeen KA, Coles F, Riley JP, Williams KN, Grice CA, Edwards JP, Karlsson L, Fourie AM. Anti-inflammatory activity of a potent, selective leukotriene A4 hydrolase inhibitor in comparison with the 5-lipoxygenase inhibitor zileuton. J Pharmacol Exp Ther 2007; 321:1154-60. [PMID: 17371808 DOI: 10.1124/jpet.106.115436] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Leukotriene A(4) hydrolase (LTA(4)H) catalyzes production of the proinflammatory lipid mediator, leukotriene (LT) B(4), which is implicated in a number of inflammatory diseases. We have identified a potent and selective inhibitor of both the epoxide hydrolase and aminopeptidase activities of recombinant human LTA(4)H (IC(50), approximately 10 nM). In a murine model of arachidonic acid-induced ear inflammation, the LTA(4)H inhibitor, JNJ-26993135 (1-[4-(benzothiazol-2-yloxy)-benzyl]-piperidine-4-carboxylic acid), dose-dependently inhibited ex vivo LTB(4) production in blood, in parallel with dose-dependent inhibition of neutrophil influx (ED(50), 1-3 mg/kg) and ear edema. In murine whole blood and in zymosan-induced peritonitis, JNJ-26993135 selectively inhibited LTB(4) production, without affecting cysteinyl leukotriene production, while maintaining or increasing production of the anti-inflammatory mediator, lipoxin (LX) A(4). The 5-lipoxygenase (5-LO) inhibitor zileuton showed inhibition of LTB(4), LTC(4), and LXA(4) production. Although zileuton inhibited LTB(4) production in the peritonitis model more effectively than the LTA(4)H inhibitor, the influx of neutrophils into the peritoneum after 1 and 2 h was significantly higher in zileuton- versus JNJ-26993135-treated animals. This difference may have been mediated by the increased LXA(4) levels in the presence of the LTA(4)H inhibitor. The selective inhibition of LTB(4) production by JNJ-26993135, while increasing levels of the anti-inflammatory mediator, LXA(4), may translate to superior therapeutic efficacy versus 5-LO or 5-LO-activating protein inhibitors in LTB(4)-mediated inflammatory diseases.
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Affiliation(s)
- Navin L Rao
- Johnson and Johnson Pharmaceutical Research and Development LLC, 3210 Merryfield Row, San Diego, CA 92121, USA
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