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Abstract
Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ signaling pathway that is evolutionarily conserved across eukaryotes. SOCE is triggered physiologically when the endoplasmic reticulum (ER) Ca2+ stores are emptied through activation of inositol 1,4,5-trisphosphate receptors. SOCE is mediated by the Ca2+ release-activated Ca2+ (CRAC) channels, which are highly Ca2+ selective. Upon store depletion, the ER Ca2+-sensing STIM proteins aggregate and gain extended conformations spanning the ER-plasma membrane junctional space to bind and activate Orai, the pore-forming proteins of hexameric CRAC channels. In recent years, studies on STIM and Orai tissue-specific knockout mice and gain- and loss-of-function mutations in humans have shed light on the physiological functions of SOCE in various tissues. Here, we describe recent findings on the composition of native CRAC channels and their physiological functions in immune, muscle, secretory, and neuronal systems to draw lessons from transgenic mice and human diseases caused by altered CRAC channel activity.
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Affiliation(s)
- Scott M Emrich
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA;
| | - Ryan E Yoast
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA;
| | - Mohamed Trebak
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA;
- Department of Pharmacology and Chemical Biology and Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Bailey CP, Figueroa M, Gangadharan A, Lee DA, Chandra J. Scaffolding LSD1 Inhibitors Impair NK Cell Metabolism and Cytotoxic Function Through Depletion of Glutathione. Front Immunol 2020; 11:2196. [PMID: 33042135 PMCID: PMC7527493 DOI: 10.3389/fimmu.2020.02196] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/11/2020] [Indexed: 12/17/2022] Open
Abstract
Cell therapies such as chimeric-antigen receptor (CAR) T-cells and NK cells are cutting-edge methods for treating cancer and other diseases. There is high interest in optimizing drug treatment regimens to best work together with emerging cell therapies, such as targeting epigenetic enzymes to stimulate recognition of tumor cells by immune cells. Herein, we uncover new mechanisms of the histone demethylase LSD1, and various inhibitors targeting unique domains of LSD1, in the function of NK cells grown for cell therapy. Catalytic inhibitors (tranylcypromine and the structural derivatives GSK LSD1 and RN-1) can irreversibly block the demethylase activity of LSD1, while scaffolding inhibitors (SP-2509 and clinical successor SP-2577, also known as seclidemstat) disrupt epigenetic complexes that include LSD1. Relevant combinations of LSD1 inhibitors with cell therapy infusions and immune checkpoint blockade have shown efficacy in pre-clinical solid tumor models, reinforcing a need to understand how these drugs would impact T- and NK cells. We find that scaffolding LSD1 inhibitors potently reduce oxidative phosphorylation and glycolysis of NK cells, and higher doses induce mitochondrial reactive oxygen species and depletion of the antioxidant glutathione. These effects are unique to scaffolding inhibitors compared to catalytic, to NK cells compared to T-cells, and importantly, can fully ablate the lytic capacity of NK cells. Supplementation with biologically achievable levels of glutathione rescues NK cell cytolytic function but not NK cell metabolism. Our results suggest glutathione supplementation may reverse NK cell activity suppression in patients treated with seclidemstat.
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Affiliation(s)
- Cavan P Bailey
- Department of Pediatrics-Research, MD Anderson Cancer Center, Houston, TX, United States.,Department of Epigenetics and Molecular Carcinogenesis, MD Anderson Cancer Center, Houston, TX, United States.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
| | - Mary Figueroa
- Department of Pediatrics-Research, MD Anderson Cancer Center, Houston, TX, United States.,Department of Epigenetics and Molecular Carcinogenesis, MD Anderson Cancer Center, Houston, TX, United States.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
| | - Achintyan Gangadharan
- Department of Pediatrics-Research, MD Anderson Cancer Center, Houston, TX, United States
| | - Dean A Lee
- Department of Pediatrics, Nationwide Children's and the Ohio State Comprehensive Cancer Center, Columbus, OH, United States
| | - Joya Chandra
- Department of Pediatrics-Research, MD Anderson Cancer Center, Houston, TX, United States.,Department of Epigenetics and Molecular Carcinogenesis, MD Anderson Cancer Center, Houston, TX, United States.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
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Vaeth M, Kahlfuss S, Feske S. CRAC Channels and Calcium Signaling in T Cell-Mediated Immunity. Trends Immunol 2020; 41:878-901. [PMID: 32711944 DOI: 10.1016/j.it.2020.06.012] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/22/2022]
Abstract
Calcium (Ca2+) signals play fundamental roles in immune cell function. The main sources of Ca2+ influx in mammalian lymphocytes following antigen receptor stimulation are Ca2+ release-activated Ca2+ (CRAC) channels. These are formed by ORAI proteins in the plasma membrane and are activated by stromal interaction molecules (STIM) located in the endoplasmic reticulum (ER). Human loss-of-function (LOF) mutations in ORAI1 and STIM1 that abolish Ca2+ influx cause a unique disease syndrome called CRAC channelopathy that is characterized by immunodeficiency autoimmunity and non-immunological symptoms. Studies in mice lacking Stim and Orai genes have illuminated many cellular and molecular mechanisms by which these molecules control lymphocyte function. CRAC channels are required for the differentiation and function of several T lymphocyte subsets that provide immunity to infection, mediate inflammation and prevent autoimmunity. This review examines new insights into how CRAC channels control T cell-mediated immunity.
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Affiliation(s)
- Martin Vaeth
- Institute of Systems Immunology, Julius-Maximilians University of Würzburg, Würzburg, Germany; Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Sascha Kahlfuss
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology, and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany; Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY, USA.
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Phatarpekar PV, Billadeau DD. Molecular regulation of the plasma membrane-proximal cellular steps involved in NK cell cytolytic function. J Cell Sci 2020; 133:133/5/jcs240424. [PMID: 32086255 DOI: 10.1242/jcs.240424] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Natural killer (NK) cells, cytolytic lymphocytes of the innate immune system, play a crucial role in the immune response against infection and cancer. NK cells kill target cells through exocytosis of lytic granules that contain cytotoxic proteins, such as perforin and granzymes. Formation of a functional immune synapse, i.e. the interface between the NK cell and its target cell enhances lysis through accumulation of polymerized F-actin at the NK cell synapse, leading to convergence of lytic granules to the microtubule organizing center (MTOC) and its subsequent polarization along microtubules to deliver the lytic granules to the synapse. In this review, we focus on the molecular mechanisms regulating the cellular processes that occur after the lytic granules are delivered to the cytotoxic synapse. We outline how - once near the synapse - the granules traverse the clearings created by F-actin remodeling to dock, tether and fuse with the plasma membrane in order to secrete their lytic content into the synaptic cleft through exocytosis. Further emphasis is given to the role of Ca2+ mobilization during degranulation and, whenever applicable, we compare these mechanisms in NK cells and cytotoxic T lymphocytes (CTLs) as adaptive immune system effectors.
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Affiliation(s)
- Prasad V Phatarpekar
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Daniel D Billadeau
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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Zhou X, Friedmann KS, Lyrmann H, Zhou Y, Schoppmeyer R, Knörck A, Mang S, Hoxha C, Angenendt A, Backes CS, Mangerich C, Zhao R, Cappello S, Schwär G, Hässig C, Neef M, Bufe B, Zufall F, Kruse K, Niemeyer BA, Lis A, Qu B, Kummerow C, Schwarz EC, Hoth M. A calcium optimum for cytotoxic T lymphocyte and natural killer cell cytotoxicity. J Physiol 2018; 596:2681-2698. [PMID: 29368348 DOI: 10.1113/jp274964] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/04/2018] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells are required to eliminate cancer cells. We analysed the Ca2+ dependence of CTL and NK cell cytotoxicity and found that in particular CTLs have a very low optimum of [Ca2+ ]i (between 122 and 334 nm) and [Ca2+ ]o (between 23 and 625 μm) for efficient cancer cell elimination, well below blood plasma Ca2+ levels. As predicted from these results, partial down-regulation of the Ca2+ channel Orai1 in CTLs paradoxically increases perforin-dependent cancer cell killing. Lytic granule release at the immune synapse between CTLs and cancer cells has a Ca2+ optimum compatible with this low Ca2+ optimum for efficient cancer cell killing, whereas the Ca2+ optimum for CTL migration is slightly higher and proliferation increases monotonously with increasing [Ca2+ ]o . We propose that a partial inhibition of Ca2+ signals by specific Orai1 blockers at submaximal concentrations could contribute to tumour elimination. ABSTRACT Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells are required to protect the human body against cancer. Ca2+ is a key metabolic factor for lymphocyte function and cancer homeostasis. We analysed the Ca2+ dependence of CTL and NK cell cytotoxicity against cancer cells and found that CTLs have a bell-shaped Ca2+ dependence with an optimum for cancer cell elimination at rather low [Ca2+ ]o (23-625 μm) and [Ca2+ ]i (122-334 nm). This finding predicts that a partial inhibition of Orai1 should increase (rather than decrease) cytotoxicity of CTLs at [Ca2+ ]o higher than 625 μm. We tested this hypothesis in CTLs and indeed found that partial down-regulation of Orai1 by siRNA increases the efficiency of cancer cell killing. We found two mechanisms that may account for the Ca2+ optimum of cancer cell killing: (1) migration velocity and persistence have a moderate optimum between 500 and 1000 μm [Ca2+ ]o in CTLs, and (2) lytic granule release at the immune synapse between CTLs and cancer cells is increased at 146 μm compared to 3 or 800 μm, compatible with the Ca2+ optimum for cancer cell killing. It has been demonstrated in many cancer cell types that Orai1-dependent Ca2+ signals enhance proliferation. We propose that a decrease of [Ca2+ ]o or partial inhibition of Orai1 activity by selective blockers in the tumour microenvironment could efficiently reduce cancer growth by simultaneously increasing CTL and NK cell cytotoxicity and decreasing cancer cell proliferation.
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Affiliation(s)
- Xiao Zhou
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Kim S Friedmann
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Hélène Lyrmann
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Yan Zhou
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Rouven Schoppmeyer
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Arne Knörck
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Sebastian Mang
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Cora Hoxha
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Adrian Angenendt
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Christian S Backes
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Carmen Mangerich
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Renping Zhao
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Sabrina Cappello
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany.,Cardiovascular Physiology, University Medical Center, University of Göttingen, Göttingen, 37073, Germany
| | - Gertrud Schwär
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Carmen Hässig
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Marc Neef
- Department of Theoretical Physics, Saarland University, Saarbrücken, 66041, Germany
| | - Bernd Bufe
- Physiology, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Frank Zufall
- Physiology, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Karsten Kruse
- Department of Theoretical Physics, Saarland University, Saarbrücken, 66041, Germany.,Department of Biochemistry and Theoretical Physics, University of Geneva, Geneva, 1211, Switzerland
| | - Barbara A Niemeyer
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Annette Lis
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Bin Qu
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Carsten Kummerow
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Eva C Schwarz
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
| | - Markus Hoth
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421, Germany
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