TY  - JOUR
A1  - Gerecke, Christian
A1  - Schumacher, Fabian
A1  - Berndzen, Alide
A1  - Homann, Thomas
A1  - Kleuser, Burkhard
T1  - Vitamin C in combination with inhibition of mutant IDH1 synergistically activates TET enzymes and epigenetically modulates gene silencing in colon cancer cells
JF  - Epigenetics : the official journal of the DNA Methylation Society
N2  - Mutations in the enzyme isocitrate dehydrogenase 1 (IDH1) lead to metabolic alterations and a sustained formation of 2-hydroxyglutarate (2-HG). 2-HG is an oncometabolite as it inhibits the activity of alpha-ketoglutarate-dependent dioxygenases such as ten-eleven translocation (TET) enzymes. Inhibitors of mutant IDH enzymes, like ML309, are currently tested in order to lower the levels of 2-HG. Vitamin C (VC) is an inducer of TET enzymes. To test a new therapeutic avenue of synergistic effects, the anti-neoplastic activity of inhibition of mutant IDH1 via ML309 in the presence of VC was investigated in the colon cancer cell line HCT116 IDH1(R132H/+) (harbouring a mutated IDH1 allele) and the parental cells HCT116 IDH1(+/+) (wild type IDH1). Measurement of the oncometabolite indicated a 56-fold higher content of 2-HG in mutated cells compared to wild type cells. A significant reduction of 2-HG was observed in mutated cells after treatment with ML 309, whereas VC produced only minimally changes of the oncometabolite. However, combinatorial treatment with both, ML309 and VC, in mutated cells induced pronounced reduction of 2-HG leading to levels comparable to those in wild type cells. The decreased level of 2-HG in mutated cells after combinatorial treatment was accompanied by an enhanced global DNA hydroxymethylation and an increased gene expression of certain tumour suppressors. Moreover, mutated cells showed an increased percentage of apoptotic cells after treatment with non-cytotoxic concentrations of ML309 and VC. These results suggest that combinatorial therapy is of interest for further investigation to rescue TET activity and treatment of IDH1/2 mutated cancers.
KW  - Vitamin C
KW  - epigenetics
KW  - IDH1
KW  - TET
KW  - cancer cells
Y1  - 2019
U6  - https://doi.org/10.1080/15592294.2019.1666652
SN  - 1559-2294
SN  - 1559-2308
VL  - 15
IS  - 3
SP  - 307
EP  - 322
PB  - Taylor & Francis Group
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Grafen, Anika
A1  - Schumacher, Fabian
A1  - Chithelen, Janice
A1  - Kleuser, Burkhard
A1  - Beyersdorf, Niklas
A1  - Schneider-Schaulies, Jürgen
T1  - Use of Acid Ceramidase and Sphingosine Kinase Inhibitors as Antiviral Compounds Against Measles Virus Infection of Lymphocytes in vitro
JF  - Frontiers in Cell and Developmental Biology
N2  - As structural membrane components and signaling effector molecules sphingolipids influence a plethora of host cell functions, and by doing so also the replication of viruses. Investigating the effects of various inhibitors of sphingolipid metabolism in primary human peripheral blood lymphocytes (PBL) and the human B cell line BJAB we found that not only the sphingosine kinase (SphK) inhibitor SKI-II, but also the acid ceramidase inhibitor ceranib-2 efficiently inhibited measles virus (MV) replication. Virus uptake into the target cells was not grossly altered by the two inhibitors, while titers of newly synthesized MV were reduced by approximately 1 log (90%) in PBL and 70-80% in BJAB cells. Lipidomic analyses revealed that in PBL SKI-II led to increased ceramide levels, whereas in BJAB cells ceranib-2 increased ceramides. SKI-II treatment decreased sphingosine-1-phosphate (S1P) levels in PBL and BJAB cells. Furthermore, we found that MV infection of lymphocytes induced a transient (0.5-6 h) increase in S1P, which was prevented by SKI-II. Investigating the effect of the inhibitors on the metabolic (mTORC1) activity we found that ceranib-2 reduced the phosphorylation of p70 S6K in PBL, and that both inhibitors, ceranib-2 and SKI-II, reduced the phosphorylation of p70 S6K in BJAB cells. As mTORC1 activity is required for efficient MV replication, this effect of the inhibitors is one possible antiviral mechanism. In addition, reduced intracellular S1P levels affect a number of signaling pathways and functions including Hsp90 activity, which was reported to be required for MV replication. Accordingly, we found that pharmacological inhibition of Hsp90 with the inhibitor 17-AAG strongly impaired MV replication in primary PBL. Thus, our data suggest that treatment of lymphocytes with both, acid ceramidase and SphK inhibitors, impair MV replication by affecting a number of cellular activities including mTORC1 and Hsp90, which alter the metabolic state of the cells causing a hostile environment for the virus.
KW  - measles virus
KW  - sphingolipids
KW  - acid ceramidase
KW  - acid ceramidase inhibitor ceranib-2
KW  - sphingosine kinase
KW  - sphingosine kinase inhibitor SKI-II
Y1  - 2019
U6  - https://doi.org/10.3389/fcell.2019.00218
SN  - 2296-634X
VL  - 7
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Morris, Mackenzie C.
A1  - Kassam, Farzaan
A1  - Bercz, Aron
A1  - Beckmann, Nadine
A1  - Schumacher, Fabian
A1  - Gulbins, Erich
A1  - Makley, Amy T.
A1  - Goodman, Michael D.
T1  - The Role of Chemoprophylactic Agents in Modulating Platelet Aggregability After Traumatic Brain Injury
JF  - Journal of surgical research
N2  - Background: The pathophysiology behind the subacute but persistent hypercoagulable state after traumatic brain injury (TBI) is poorly understood but contributes to morbidity induced by venous thromboembolism. Because platelets and their microvesicles have been hypothesized to play a role in post-traumatic hypercoagulability, administration of commonly used agents may ameliorate this coagulability. We hypothesized that utilization of aspirin, ketorolac, amitriptyline, unfractionated heparin, or enoxaparin would modulate the platelet aggregation response after TBI. Methods: Concussive TBI was induced by weight drop. Mice were then randomized to receive aspirin, ketorolac, amitriptyline, heparin, enoxaparin, or saline control at 2 and 8 h after TBI. Mice were sacrificed at 6 or 24 h after injury to determine coagulability by rotational thromboelastometry (ROTEM), platelet function testing with impedance aggregometry, and microvesicle enumeration. Platelet sphingolipid metabolites were analyzed by mass spectrometry. Results: ROTEM demonstrated increased platelet contribution to maximum clot firmness at 6 h after TBI in mice that received aspirin or amitriptyline, but this did not persist at 24 h. By contrast, adenosine diphosphate- and arachidonic acid-induced platelet aggregation at 6 h was significantly lower in mice receiving ketorolac, aspirin, and amitriptyline compared with mice receiving saline at 6 h after injury and only arachidonic acid-initiated platelet aggregation was decreased by aspirin at 24 h. There were no differences in microvesicle production at either time point. Platelet sphingosine-1-phosphate levels were decreased at 6 h in the group receiving amitriptyline and increased at 24 h along with platelet ceramide levels at 24 h in the amitriptyline group. Conclusion: After TBI, amitriptyline decreased platelet aggregability and increased contribution to clot in a manner similar to aspirin. The amitriptyline effects on platelet function and sphingolipid metabolites may represent a possible role of the acid sphingomyelinase in the hypercoagulability observed after injury. In addition, inhibition of platelet reactivity may be an underappreciated benefit of low molecular weight heparins, such as enoxaparin. (C) 2019 Elsevier Inc. All rights reserved.
KW  - Trauma
KW  - Traumatic brain injury
KW  - Venous thromboembolism
KW  - Chemoprophylaxis
KW  - Sphingolipids
Y1  - 2019
U6  - https://doi.org/10.1016/j.jss.2019.06.022
SN  - 0022-4804
SN  - 1095-8673
VL  - 244
SP  - 1
EP  - 8
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Seitz, Aaron P.
A1  - Schumacher, Fabian
A1  - Baker, Jennifer
A1  - Soddemann, Matthias
A1  - Wilker, Barbara
A1  - Caldwell, Charles C.
A1  - Gobble, Ryan M.
A1  - Kamler, Markus
A1  - Becker, Katrin Anne
A1  - Beck, Sascha
A1  - Kleuser, Burkhard
A1  - Edwards, Michael J.
A1  - Gulbins, Erich
T1  - Sphingosine-coating of plastic surfaces prevents ventilator-associated pneumonia
JF  - Journal of molecular medicine
N2  - Ventilator-associated pneumonia (VAP) is a major cause of morbidity and mortality in critically ill patients. Here, we employed the broad antibacterial effects of sphingosine to prevent VAP by developing a novel method of coating surfaces of endotracheal tubes with sphingosine and sphingosine analogs. Sphingosine and phytosphingosine coatings of endotracheal tubes prevent adherence and mediate killing of Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus, even in biofilms. Most importantly, sphingosine-coating of endotracheal tubes also prevented P. aeruginosa and S. aureus pneumonia in vivo. Coating of the tubes with sphingosine was stable, without obvious side effects on tracheal epithelial cells and did not induce inflammation. In summary, we describe a novel method to coat plastic surfaces and provide evidence for the application of sphingosine and phytosphingosine as novel antimicrobial coatings to prevent bacterial adherence and induce killing of pathogens on the surface of endotracheal tubes with potential to prevent biofilm formation and VAP.Key messagesNovel dip-coating method to coat plastic surfaces with lipids.Sphingosine and phytosphingosine as novel antimicrobial coatings on plastic surface.Sphingosine coatings of endotracheal tubes prevent bacterial adherence and biofilms.Sphingosine coatings of endotracheal tubes induce killing of pathogens.Sphingosine coatings of endotracheal tubes ventilator-associated pneumonia.
KW  - Coating
KW  - Plastic surfaces
KW  - Sphingosine
KW  - Ventilation
KW  - Acinetobacter baumannii
KW  - Pseudomonas aeruginosa
KW  - Staphylococcus aureus
Y1  - 2019
U6  - https://doi.org/10.1007/s00109-019-01800-1
SN  - 0946-2716
SN  - 1432-1440
VL  - 97
IS  - 8
SP  - 1195
EP  - 1211
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Börtlein, Charlene
A1  - Schumacher, Fabian
A1  - Kleuser, Burkhard
A1  - Dölken, Lars
A1  - Avota, Elita
T1  - Role of Neutral Sphingomyelinase-2 (NSM 2) in the Control of T Cell Plasma Membrane Lipid Composition and Cholesterol Homeostasis
JF  - Frontiers in cell and developmental biology
N2  - The activity of neutral sphingomyelinase-2 (NSM2) to catalyze the conversion of sphingomyelin (SM) to ceramide and phosphocholine at the cytosolic leaflet of plasma membrane (PM) is important in T cell receptor (TCR) signaling. We recently identified PKC zeta as a major NSM2 downstream effector which regulates microtubular polarization. It remained, however, unclear to what extent NSM2 activity affected overall composition of PM lipids and downstream effector lipids in antigen stimulated T cells. Here, we provide a detailed lipidomics analyses on PM fractions isolated from TCR stimulated wild type and NSM2 deficient (Delta NSM) Jurkat T cells. This revealed that in addition to that of sphingolipids, NSM2 depletion also affected concentrations of many other lipids. In particular, NSM2 ablation resulted in increase of lyso-phosphatidylcholine (LPC) and lyso-phosphatidylethanolamine (LPE) which both govern PM biophysical properties. Crucially, TCR dependent upregulation of the important T cell signaling lipid diacylglycerol (DAG), which is fundamental for activation of conventional and novel PKCs, was abolished in Delta NSM cells. Moreover, NSM2 activity was found to play an important role in PM cholesterol transport to the endoplasmic reticulum (ER) and production of cholesteryl esters (CE) there. Most importantly, CE accumulation was essential to sustain human T cell proliferation. Accordingly, inhibition of CE generating enzymes, the cholesterol acetyltransferases ACAT1/SOAT1 and ACAT2/SOAT2, impaired TCR driven expansion of both CD4(+) and CD8(+) T cells. In summary, our study reveals an important role of NSM2 in regulating T cell functions by its multiple effects on PM lipids and cholesterol homeostasis.
KW  - neutral sphingomyelinase-2
KW  - T cell receptor
KW  - plasma membrane
KW  - lyso-phospholipids
KW  - diacylglycerol
KW  - cholesteryl ester
Y1  - 2019
U6  - https://doi.org/10.3389/fcell.2019.00226
SN  - 2296-634X
VL  - 7
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Wanjiku, Barbara
A1  - Yamamoto, Kenji
A1  - Klossek, Andre
A1  - Schumacher, Fabian
A1  - Pischon, Hannah
A1  - Mundhenk, Lars
A1  - Rancan, Fiorenza
A1  - Judd, Martyna M.
A1  - Ahmed, Muniruddin
A1  - Zoschke, Christian
A1  - Kleuser, Burkhard
A1  - Rühl, Eckart
A1  - Schäfer-Korting, Monika
T1  - Qualifying X-ray and Stimulated Raman Spectromicroscopy for Mapping Cutaneous Drug Penetration
JF  - Analytical chemistry
N2  - Research on topical drug delivery relies on reconstructed human skin (RHS) in addition to ex vivo human and animal skin, each with specific physiological features. Here, we compared the penetration of dexamethasone from an ethanolic hydroxyethyl cellulose gel into ex vivo human skin, murine skin, and RHS. For comprehensive insights into skin morphology and penetration enhancing mechanisms, scanning transmission X-ray microscopy (STXM), liquid chromatography tandem mass spectrometry (LC-MS/MS), and stimulated Raman spectromicroscopy (SRS) were combined. STXM offers high spatial resolution with label-free drug detection and is therefore sensitive to tissue damage. Despite differences in sample preparation and data analysis, the amounts of dexamethasone in RHS, detected and quantified by STXM and LC-MS/MS, were very similar and increased during the first 100 min of exposure. SRS revealed interactions between the gel and the stratum corneum or, more specifically, its protein and lipid structures. Similar to both types of ex vivo skin, higher protein-to-lipid ratios within the stratum corneum of RHS indicated reduced lipid amounts after 30 min of ethanol exposure. Extended ethanol exposure led to a continued reduction of lipids in the ex vivo matrixes, while protein integrity appeared to be compromised in RHS, which led to declining protein signals. In conclusion, LC-MS/MS proved the predictive capability of STXM for label-free drug detection. Combining STXM with SRS precisely dissected the penetration enhancing effects of ethanol. Further studies on topical drug delivery should consider the potential of these complementary techniques.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.analchem.9b00519
SN  - 0003-2700
SN  - 1520-6882
VL  - 91
IS  - 11
SP  - 7208
EP  - 7214
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Wigger, Dominik
A1  - Gulbins, Erich
A1  - Kleuser, Burkhard
A1  - Schumacher, Fabian
T1  - Monitoring the Sphingolipid de novo Synthesis by Stable-Isotope Labeling and Liquid Chromatography-Mass Spectrometry
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Sphingolipids are a class of lipids that share a sphingoid base backbone. They exert various effects in eukaryotes, ranging from structural roles in plasma membranes to cellular signaling. De novo sphingolipid synthesis takes place in the endoplasmic reticulum (ER), where the condensation of the activated C₁₆ fatty acid palmitoyl-CoA and the amino acid L-serine is catalyzed by serine palmitoyltransferase (SPT). The product, 3-ketosphinganine, is then converted into more complex sphingolipids by additional ER-bound enzymes, resulting in the formation of ceramides. Since sphingolipid homeostasis is crucial to numerous cellular functions, improved assessment of sphingolipid metabolism will be key to better understanding several human diseases. To date, no assay exists capable of monitoring de novo synthesis sphingolipid in its entirety. Here, we have established a cell-free assay utilizing rat liver microsomes containing all the enzymes necessary for bottom-up synthesis of ceramides. Following lipid extraction, we were able to track the different intermediates of the sphingolipid metabolism pathway, namely 3-ketosphinganine, sphinganine, dihydroceramide, and ceramide. This was achieved by chromatographic separation of sphingolipid metabolites followed by detection of their accurate mass and characteristic fragmentations through high-resolution mass spectrometry and tandem-mass spectrometry. We were able to distinguish, unequivocally, between de novo synthesized sphingolipids and intrinsic species, inevitably present in the microsome preparations, through the addition of stable isotope-labeled palmitate-d₃ and L-serine-d₃. To the best of our knowledge, this is the first demonstration of a method monitoring the entirety of ER-associated sphingolipid biosynthesis. Proof-of-concept data was provided by modulating the levels of supplied cofactors (e.g., NADPH) or the addition of specific enzyme inhibitors (e.g., fumonisin B₁). The presented microsomal assay may serve as a useful tool for monitoring alterations in sphingolipid de novo synthesis in cells or tissues. Additionally, our methodology may be used for metabolism studies of atypical substrates – naturally occurring or chemically tailored – as well as novel inhibitors of enzymes involved in sphingolipid de novo synthesis.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 800 
KW  - sphingolipid de novo synthesis
KW  - serine palmitoyltransferase
KW  - mass spectrometry
KW  - stable-isotope labeling
KW  - ceramides
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441158
SN  - 1866-8372
IS  - 800
ER  - 
TY  - JOUR
A1  - Wigger, Dominik
A1  - Gulbins, Erich
A1  - Kleuser, Burkhard
A1  - Schumacher, Fabian
T1  - Monitoring the Sphingolipid de novo Synthesis by Stable-Isotope Labeling and Liquid Chromatography-Mass Spectrometry
JF  - Frontiers in Cell and Developmental Biology
N2  - Sphingolipids are a class of lipids that share a sphingoid base backbone. They exert various effects in eukaryotes, ranging from structural roles in plasma membranes to cellular signaling. De novo sphingolipid synthesis takes place in the endoplasmic reticulum (ER), where the condensation of the activated C₁₆ fatty acid palmitoyl-CoA and the amino acid L-serine is catalyzed by serine palmitoyltransferase (SPT). The product, 3-ketosphinganine, is then converted into more complex sphingolipids by additional ER-bound enzymes, resulting in the formation of ceramides. Since sphingolipid homeostasis is crucial to numerous cellular functions, improved assessment of sphingolipid metabolism will be key to better understanding several human diseases. To date, no assay exists capable of monitoring de novo synthesis sphingolipid in its entirety. Here, we have established a cell-free assay utilizing rat liver microsomes containing all the enzymes necessary for bottom-up synthesis of ceramides. Following lipid extraction, we were able to track the different intermediates of the sphingolipid metabolism pathway, namely 3-ketosphinganine, sphinganine, dihydroceramide, and ceramide. This was achieved by chromatographic separation of sphingolipid metabolites followed by detection of their accurate mass and characteristic fragmentations through high-resolution mass spectrometry and tandem-mass spectrometry. We were able to distinguish, unequivocally, between de novo synthesized sphingolipids and intrinsic species, inevitably present in the microsome preparations, through the addition of stable isotope-labeled palmitate-d₃ and L-serine-d₃. To the best of our knowledge, this is the first demonstration of a method monitoring the entirety of ER-associated sphingolipid biosynthesis. Proof-of-concept data was provided by modulating the levels of supplied cofactors (e.g., NADPH) or the addition of specific enzyme inhibitors (e.g., fumonisin B₁). The presented microsomal assay may serve as a useful tool for monitoring alterations in sphingolipid de novo synthesis in cells or tissues. Additionally, our methodology may be used for metabolism studies of atypical substrates – naturally occurring or chemically tailored – as well as novel inhibitors of enzymes involved in sphingolipid de novo synthesis.
KW  - sphingolipid de novo synthesis
KW  - serine palmitoyltransferase
KW  - mass spectrometry
KW  - stable-isotope labeling
KW  - ceramides
Y1  - 2019
U6  - https://doi.org/10.3389/fcell.2019.00210
SN  - 2296-634X
VL  - 7
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Castaño Martínez, María Teresa
A1  - Schumacher, Fabian
A1  - Schumacher, Silke
A1  - Kochlik, Bastian Max
A1  - Weber, Daniela
A1  - Grune, Tilman
A1  - Biemann, Ronald
A1  - McCann, Adrian
A1  - Abraham, Klaus
A1  - Weikert, Cornelia
A1  - Kleuse, Burkhard
A1  - Schürmann, Annette
A1  - Laeger, Thomas
T1  - Methionine restriction prevents onset of type 2 diabetes in NZO mice
JF  - The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology
N2  - Dietary methionine restriction (MR) is well known to reduce body weight by increasing energy expenditure (EE) and insulin sensitivity. An elevated concentration of circulating fibroblast growth factor 21 (FGF21) has been implicated as a potential underlying mechanism. The aims of our study were to test whether dietary MR in the context of a high-fat regimen protects against type 2 diabetes in mice and to investigate whether vegan and vegetarian diets, which have naturally low methionine levels, modulate circulating FGF21 in humans. New Zealand obese (NZO) mice, a model for polygenic obesity and type 2 diabetes, were placed on isocaloric high-fat diets (protein, 16 kcal%; carbohydrate, 52 kcal%; fat, 32 kcal%) that provided methionine at control (Con; 0.86% methionine) or low levels (0.17%) for 9 wk. Markers of glucose homeostasis and insulin sensitivity were analyzed. Among humans, low methionine intake and circulating FGF21 levels were investigated by comparing a vegan and a vegetarian diet to an omnivore diet and evaluating the effect of a short-term vegetarian diet on FGF21 induction. In comparison with the Con group, MR led to elevated plasma FGF21 levels and prevented the onset of hyperglycemia in NZO mice. MR-fed mice exhibited increased insulin sensitivity, higher plasma adiponectin levels, increased EE, and up-regulated expression of thermogenic genes in subcutaneous white adipose tissue. Food intake and fat mass did not change. Plasma FGF21 levels were markedly higher in vegan humans compared with omnivores, and circulating FGF21 levels increased significantly in omnivores after 4 d on a vegetarian diet. These data suggest that MR induces FGF21 and protects NZO mice from high-fat diet-induced glucose intolerance and type 2 diabetes. The normoglycemic phenotype in vegans and vegetarians may be caused by induced FGF21. MR akin to vegan and vegetarian diets in humans may offer metabolic benefits via increased circulating levels of FGF21 and merits further investigation.-Castano-Martinez, T., Schumacher, F., Schumacher, S., Kochlik, B., Weber, D., Grune, T., Biemann, R., McCann, A., Abraham, K., Weikert, C., Kleuser, B., Schurmann, A., Laeger, T. Methionine restriction prevents onset of type 2 diabetes in NZO mice.
KW  - energy expenditure
KW  - hyperglycemia
KW  - obesity
KW  - vegan
KW  - vegetarian
Y1  - 2019
U6  - https://doi.org/10.1096/fj.201900150R
SN  - 0892-6638
SN  - 1530-6860
VL  - 33
IS  - 6
SP  - 7092
EP  - 7102
PB  - Federation of American Societies for Experimental Biology
CY  - Bethesda
ER  - 
TY  - JOUR
A1  - Derakhshani, Shaghayegh
A1  - Kurz, Andreas
A1  - Japtok, Lukasz
A1  - Schumacher, Fabian
A1  - Pilgram, Lisa
A1  - Steinke, Maria
A1  - Kleuser, Burkhard
A1  - Sauer, Markus
A1  - Schneider-Schaulies, Sibylle
A1  - Avota, Elita
T1  - Measles Virus Infection Fosters Dendritic Cell Motility in a 3D Environment to Enhance Transmission to Target Cells in the Respiratory Epithelium
JF  - Frontiers in immunology
N2  - Transmission of measles virus (MV) from dendritic to airway epithelial cells is considered as crucial to viral spread late in infection. Therefore, pathways and effectors governing this process are promising targets for intervention. To identify these, we established a 3D respiratory tract model where MV transmission by infected dendritic cells (DCs) relied on the presence of nectin-4 on H358 lung epithelial cells. Access to recipient cells is an important prerequisite for transmission, and we therefore analyzed migration of MV-exposed DC cultures within the model. Surprisingly, enhanced motility toward the epithelial layer was observed for MV-infected DCs as compared to their uninfected siblings. This occurred independently of factors released from H358 cells indicating that MV infection triggered cytoskeletal remodeling associated with DC polarization enforced velocity. Accordingly, the latter was also observed for MV-infected DCs in collagen matrices and was particularly sensitive to ROCK inhibition indicating infected DCs preferentially employed the amoeboid migration mode. This was also implicated by loss of podosomes and reduced filopodial activity both of which were retained in MV-exposed uninfected DCs. Evidently, sphingosine kinase (SphK) and sphingosine-1-phosphate (S1P) as produced in response to virus-infection in DCs contributed to enhanced velocity because this was abrogated upon inhibition of sphingosine kinase activity. These findings indicate that MV infection promotes a push-and-squeeze fast amoeboid migration mode via the SphK/S1P system characterized by loss of filopodia and podosome dissolution. Consequently, this enables rapid trafficking of virus toward epithelial cells during viral exit.
KW  - dendritic cell
KW  - cell migration
KW  - measles virus
KW  - 3D tissue model
KW  - sphingosine-1-phosphate
Y1  - 2019
U6  - https://doi.org/10.3389/fimmu.2019.01294
SN  - 1664-3224
VL  - 10
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  -