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Tian XQ, Wu Y, Cai Z, Qian W. BDSF Is a Degradation-Prone Quorum-Sensing Signal Detected by the Histidine Kinase RpfC of Xanthomonas campestris pv. campestris. Appl Environ Microbiol 2022;:e0003122. [PMID: 35369702 DOI: 10.1128/aem.00031-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Diffusible signal factors (DSFs) are medium-chain fatty acids that induce bacterial quorum sensing. Among these compounds, BDSF is a structural analog of DSF that is commonly detected in bacterial species, and it is the predominant in planta quorum-sensing signal in Xanthomonas campestris. How BDSF is sensed in Xanthomonas spp. and the functional diversity between BDSF and DSF remain unclear. In this study, we generated genetic and biochemical evidence that BDSF is a low-active regulator of X. campestris pv. campestris quorum sensing, whereas trans-BDSF does not seem to be a signaling compound. BDSF is detected by the sensor histidine kinase RpfC. Although BDSF has relatively low physiological activities, it binds to the RpfC sensor with a high affinity and activates RpfC autophosphorylation to a level that is similar to that induced by DSF in vitro. The inconsistency in the physiological and biochemical activities of BDSF is not due to RpfC-RpfG phosphorylation or RpfG hydrolase. Neither BDSF nor DSF controls the phosphotransferase and phosphatase activities of RpfC or the ability of RpfG hydrolase activity to degrade the bacterial second messenger cyclic di-GMP. We demonstrated that BDSF is prone to degradation by RpfB, a critical fatty acyl coenzyme A ligase involved in the turnover of DSF-family signals. rpfB mutations lead to substantial increases in BDSF-induced quorum sensing. Although DSF and BDSF are similarly detected by RpfC, our data suggest that their differential degradation in cells is the major factor responsible for the diversity in their physiological effects. IMPORTANCE The diffusible signal factor (DSF) family consists of quorum-sensing signals employed by Gram-negative bacteria. These signals are a group of cis-2-unsaturated fatty acids, such as DSF, BDSF, IDSF, CDSF, and SDSF. However, the functional divergence of various DSF signals remains unclear. The present study demonstrates that though BDSF is a low active quorum-sensing signal, it binds histidine kinase RpfC with a higher affinity and activates RpfC autophosphorylation to the similar level as DSF. Rather than regulation of enzymatic activities of RpfC and its cognate response regulator RpfG encoding a c-di-GMP hydrolase, BDSF is prone to degradation in bacterial cells by RpfB, which effectively avoided the inhibition of bacterial growth by accumulating high concentrations of BDSF. Therefore, our study sheds new light on the functional differences of quorum-sensing signals and shows that bacteria balance quorum sensing and growth by fine-tuning concentrations of signaling chemicals.
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Pathan-Chhatbar S, Drechsler C, Richter K, Morath A, Wu W, OuYang B, Xu C, Schamel WW. Direct Regulation of the T Cell Antigen Receptor's Activity by Cholesterol. Front Cell Dev Biol 2021; 8:615996. [PMID: 33490080 PMCID: PMC7820176 DOI: 10.3389/fcell.2020.615996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/09/2020] [Indexed: 11/14/2022] Open
Abstract
Biological membranes consist of hundreds of different lipids that together with the embedded transmembrane (TM) proteins organize themselves into small nanodomains. In addition to this function of lipids, TM regions of proteins bind to lipids in a very specific manner, but the function of these TM region-lipid interactions is mostly unknown. In this review, we focus on the role of plasma membrane cholesterol, which directly binds to the αβ T cell antigen receptor (TCR), and has at least two opposing functions in αβ TCR activation. On the one hand, cholesterol binding to the TM domain of the TCRβ subunit keeps the TCR in an inactive, non-signaling conformation by stabilizing this conformation. This assures that the αβ T cell remains quiescent in the absence of antigenic peptide-MHC (the TCR's ligand) and decreases the sensitivity of the T cell toward stimulation. On the other hand, cholesterol binding to TCRβ leads to an increased formation of TCR nanoclusters, increasing the avidity of the TCRs toward the antigen, thus increasing the sensitivity of the αβ T cell. In mouse models, pharmacological increase of the cholesterol concentration in T cells caused an increase in TCR clustering, and thereby enhanced anti-tumor responses. In contrast, the γδ TCR does not bind to cholesterol and might be regulated in a different manner. The goal of this review is to put these seemingly controversial findings on the impact of cholesterol on the αβ TCR into perspective.
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Affiliation(s)
- Salma Pathan-Chhatbar
- Centre for Biological Signalling Studies and Centre for Integrative Biological Signalling Studies, University Freiburg, Freiburg, Germany.,Department of Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
| | - Carina Drechsler
- Centre for Biological Signalling Studies and Centre for Integrative Biological Signalling Studies, University Freiburg, Freiburg, Germany.,Department of Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
| | - Kirsten Richter
- Immunology, Infectious Diseases and Ophthalmology Disease Translational Area, Roche Innovation Center Basel, Basel, Switzerland
| | - Anna Morath
- Centre for Biological Signalling Studies and Centre for Integrative Biological Signalling Studies, University Freiburg, Freiburg, Germany.,Department of Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
| | - Wei Wu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Bo OuYang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Chenqi Xu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Wolfgang W Schamel
- Centre for Biological Signalling Studies and Centre for Integrative Biological Signalling Studies, University Freiburg, Freiburg, Germany.,Department of Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
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Li TM, Coan JP, Krajewski K, Zhang L, Elias JE, Strahl BD, Gozani O, Chua KF. Binding to medium and long chain fatty acyls is a common property of HEAT and ARM repeat modules. Sci Rep 2019; 9:14226. [PMID: 31578417 PMCID: PMC6775327 DOI: 10.1038/s41598-019-50817-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/13/2019] [Indexed: 02/01/2023] Open
Abstract
Covalent post-translational modification (PTM) of proteins with acyl groups of various carbon chain-lengths regulates diverse biological processes ranging from chromatin dynamics to subcellular localization. While the YEATS domain has been found to be a prominent reader of acetylation and other short acyl modifications, whether additional acyl-lysine reader domains exist, particularly for longer carbon chains, is unclear. Here, we employed a quantitative proteomic approach using various modified peptide baits to identify reader proteins of various acyl modifications. We discovered that proteins harboring HEAT and ARM repeats bind to lysine myristoylated peptides. Recombinant HEAT and ARM repeats bind to myristoylated peptides independent of the peptide sequence or the position of the myristoyl group. Indeed, HEAT and ARM repeats bind directly to medium- and long-chain free fatty acids (MCFA and LCFA). Lipidomic experiments suggest that MCFAs and LCFAs interact with HEAT and ARM repeat proteins in mammalian cells. Finally, treatment of cells with exogenous MCFAs and inhibitors of MCFA-CoA synthases increase the transactivation activity of the ARM repeat protein β-catenin. Taken together, our results suggest an unappreciated role for fatty acids in the regulation of proteins harboring HEAT or ARM repeats.
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Affiliation(s)
- Tie-Mei Li
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - John P Coan
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Program in Cancer Biology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA
| | - Krzysztof Krajewski
- Department of Biochemistry & Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Lichao Zhang
- Chan Zuckenberg Biohub, Stanford, CA, 94305, USA
| | | | - Brian D Strahl
- Department of Biochemistry & Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Or Gozani
- Department of Biology, Stanford University, Stanford, CA, 94305, USA. .,Program in Cancer Biology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Katrin F Chua
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA. .,Program in Cancer Biology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA. .,Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, 94304, USA.
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Aguilar-toalá J, Estrada-montoya M, Liceaga A, Garcia H, González-aguilar G, Vallejo-cordoba B, González-córdova A, Hernández-mendoza A. An insight on antioxidant properties of the intracellular content of Lactobacillus casei CRL-431. Lebensm Wiss Technol 2019; 102:58-63. [DOI: 10.1016/j.lwt.2018.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Abhay Kumar N, Prasada Rao UJS, Jeyarani T, Indrani D. Effect of ingredients on rheological, physico-sensory, and nutritional characteristics of omega-3-fatty acid enriched eggless cake. J Texture Stud 2017; 48:439-449. [PMID: 28967226 DOI: 10.1111/jtxs.12247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 12/07/2016] [Accepted: 12/27/2016] [Indexed: 11/30/2022]
Abstract
The effect of defatted soya flour (DS), flax seed powder (FS) in combination (DSFS) with emulsifiers such as glycerol monostearate, GMS (DSFSG) and sodium stearoyl-2-lactylate, SSL (DSFSS) on the rheological, physico-sensory, protein subunit composition by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), fatty acid profile, and nutritional characteristics of eggless cake was studied. Use of DSFS, DSFSG, and DSFSS increased the amylograph peak viscosity, hot and cold paste viscosities similar to the egg. Addition of DSFS, DSFSG, and DSFSS increased viscosity of eggless cake batter; cake volume and the overall quality score (OQS) of eggless cake. Among these, highest improvement in OQS was brought about by DSFSG. According to SDS-PAGE results, the improvement by DSFSG is due to crosslinking of wheat-soya-flax proteins similar to wheat-egg proteins crosslinking. The eggless cake with DSFSG was found to be rich in omega-3-fatty acid as it contained 0.6% of linolenic acid compared to 0.1% each of cake with egg and eggless cake. PRACTICAL APPLICATIONS As eggs are significant source of cholesterol, there has been an increased interest in search of ingredients that can replace egg in cakes. Hence, recent trend in the baking industry is to produce eggless cake using a combination of different ingredients and additives. However, there is no scientific information on the interaction of non-egg protein with wheat protein in building up the structure and also to improve the nutritional quality with respect to protein and fatty acids profiles of eggless cake. The information generated on the use of combination of defatted soya flour and flax seed along with emulsifiers will be helpful for the commercial manufacture of omega-3-fatty acid rich eggless cake with desired quality attributes.
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Affiliation(s)
- N Abhay Kumar
- Flour Milling, Baking and Confectionery Technology Department, CSIR - Central Food Technological Research Institute, Mysore, Karnataka, 570020, India
| | - U J S Prasada Rao
- Department of Biochemistry, CSIR - Central Food Technological Research Institute, Mysore, Karnataka, 570020, India
| | - T Jeyarani
- Traditional Food and Sensory Science, CSIR - Central Food Technological Research Institute, Mysore, Karnataka, 570020, India
| | - D Indrani
- Flour Milling, Baking and Confectionery Technology Department, CSIR - Central Food Technological Research Institute, Mysore, Karnataka, 570020, India
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Swamy M, Beck-Garcia K, Beck-Garcia E, Hartl FA, Morath A, Yousefi OS, Dopfer EP, Molnár E, Schulze AK, Blanco R, Borroto A, Martín-Blanco N, Alarcon B, Höfer T, Minguet S, Schamel WW. A Cholesterol-Based Allostery Model of T Cell Receptor Phosphorylation. Immunity 2016; 44:1091-101. [PMID: 27192576 DOI: 10.1016/j.immuni.2016.04.011] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 11/17/2015] [Accepted: 04/11/2016] [Indexed: 12/20/2022]
Abstract
Signaling through the T cell receptor (TCR) controls adaptive immune responses. Antigen binding to TCRαβ transmits signals through the plasma membrane to induce phosphorylation of the CD3 cytoplasmic tails by incompletely understood mechanisms. Here we show that cholesterol bound to the TCRβ transmembrane region keeps the TCR in a resting, inactive conformation that cannot be phosphorylated by active kinases. Only TCRs that spontaneously detached from cholesterol could switch to the active conformation (termed primed TCRs) and then be phosphorylated. Indeed, by modulating cholesterol binding genetically or enzymatically, we could switch the TCR between the resting and primed states. The active conformation was stabilized by binding to peptide-MHC, which thus controlled TCR signaling. These data are explained by a model of reciprocal allosteric regulation of TCR phosphorylation by cholesterol and ligand binding. Our results provide both a molecular mechanism and a conceptual framework for how lipid-receptor interactions regulate signal transduction.
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Wang F, Beck-García K, Zorzin C, Schamel WWA, Davis MM. Inhibition of T cell receptor signaling by cholesterol sulfate, a naturally occurring derivative of membrane cholesterol. Nat Immunol 2016; 17:844-50. [PMID: 27213689 PMCID: PMC4916016 DOI: 10.1038/ni.3462] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/08/2016] [Indexed: 12/13/2022]
Abstract
Most adaptive immune responses require the activation of specific T cells through the T cell antigen receptor (TCR)-CD3 complex. Here we show that cholesterol sulfate (CS), a naturally occurring analog of cholesterol, inhibits CD3 ITAM phosphorylation, a crucial first step in T cell activation. In biochemical studies, CS disrupted TCR multimers, apparently by displacing cholesterol, which is known to bind TCRβ. Moreover, CS-deficient mice showed heightened sensitivity to a self-antigen, whereas increasing CS content by intrathymic injection inhibited thymic selection, indicating that this molecule is an intrinsic regulator of thymocyte development. These results reveal a regulatory role for CS in TCR signaling and thymic selection, highlighting the importance of the membrane microenvironment in modulating cell surface receptor activation.
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Affiliation(s)
- Feng Wang
- The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Katharina Beck-García
- Center for Biological Signaling Studies (BIOSS) and Faculty of Biology, University of Freiburg, Freiburg, Germany
- Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Carina Zorzin
- Center for Biological Signaling Studies (BIOSS) and Faculty of Biology, University of Freiburg, Freiburg, Germany
- Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
| | - Wolfgang W A Schamel
- Center for Biological Signaling Studies (BIOSS) and Faculty of Biology, University of Freiburg, Freiburg, Germany
- Centre for Chronic Immunodeficiency (CCI), University of Freiburg, Freiburg, Germany
| | - Mark M Davis
- The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, California, USA
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Frenzel E, Wrenger S, Brügger B, Salipalli S, Immenschuh S, Aggarwal N, Lichtinghagen R, Mahadeva R, Marcondes AMQ, Dinarello CA, Welte T, Janciauskiene S. α1-Antitrypsin Combines with Plasma Fatty Acids and Induces Angiopoietin-like Protein 4 Expression. J Immunol 2015; 195:3605-16. [PMID: 26363050 DOI: 10.4049/jimmunol.1500740] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/06/2015] [Indexed: 11/19/2022]
Abstract
α1-Antitrypsin (A1AT) purified from human plasma upregulates expression and release of angiopoietin-like protein 4 (Angptl4) in adherent human blood monocytes and in human lung microvascular endothelial cells, providing a mechanism for the broad immune-regulatory properties of A1AT independent of its antiprotease activity. In this study, we demonstrate that A1AT (Prolastin), a potent inducer of Angptl4, contains significant quantities of the fatty acids (FA) linoleic acid (C18:2) and oleic acid (C18:1). However, only trace amounts of FAs were present in preparations that failed to increase Angplt4 expression, for example, A1AT (Zemaira) or M-type A1AT purified by affinity chromatography. FA pull-down assays with Western blot analysis revealed a FA-binding ability of A1AT. In human blood-adherent monocytes, A1AT-FA conjugates upregulated expression of Angptl4 (54.9-fold, p < 0.001), FA-binding protein 4 (FABP4) (11.4-fold, p < 0.001), and, to a lesser degree, FA translocase (CD36) (3.1-fold, p < 0.001) relative to A1AT devoid of FA (A1AT-0). These latter effects of A1AT-FA were blocked by inhibitors of peroxisome proliferator-activated receptor (PPAR) β/δ (ST247) and PPARγ (GW9662). When compared with controls, cell pretreatment with ST247 diminished the effect of A1AT-LA on Angptl4 mRNA (11.6- versus 4.1-fold, p < 0.001) and FABP4 mRNA (5.4- versus 2.8-fold, p < 0.001). Similarly, preincubation of cells with GW9662 inhibited inducing effect of A1AT-LA on Angptl4 mRNA (by 2-fold, p < 0.001) and FABP4 mRNA (by 3-fold, p < 0.001). Thus, A1AT binds to FA, and it is this form of A1AT that induces Angptl4 and FABP4 expression via a PPAR-dependent pathway. These findings provide a mechanism for the unexplored area of A1AT biology independent of its antiprotease properties.
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Affiliation(s)
- Eileen Frenzel
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany
| | - Sabine Wrenger
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany
| | - Britta Brügger
- Biochemistry Center, Heidelberg University, 69120 Heidelberg, Germany
| | - Sandeep Salipalli
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany
| | - Stephan Immenschuh
- Institute for Transfusion Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Nupur Aggarwal
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany
| | - Ralf Lichtinghagen
- Institute of Clinical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Ravi Mahadeva
- Department of Respiratory Medicine, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - A Mario Q Marcondes
- Department of Medicine, University of Washington, Seattle, WA 98195; Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Charles A Dinarello
- Department of Medicine, University of Colorado Denver, Aurora, CO 80045; and Department of Medicine, Radboud University Medical Centre, Nijmegen 30625, the Netherlands
| | - Tobias Welte
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany
| | - Sabina Janciauskiene
- Department of Respiratory Medicine, Hannover Medical School, 30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover, Member of the German Center for Lung Research, 30626 Hannover, Germany;
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