@article{BoertleinSchumacherKleuseretal.2019,
  author    = {B{\"o}rtlein, Charlene and Schumacher, Fabian and Kleuser, Burkhard and D{\"o}lken, Lars and Avota, Elita},
  title     = {Role of neutral sphingomyelinase-2 (NSM 2) in the control of T cell plasma membrane lipid composition and cholesterol homeostasis},
  series = {Frontiers in Cell and Developmental Biology},
  volume    = {7},
  journal   = {Frontiers in Cell and Developmental Biology},
  number    = {226},
  issn      = {2296-634X},
  doi       = {10.3389/fcell.2019.00226},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190596},
  year      = {2019},
  abstract  = {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 PKCζ 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 (ΔNSM) 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 ΔNSM 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.},
  language  = {en}
}
@article{DerakhshaniKurzJaptoketal.2019,
  author    = {Derakhshani, Shaghayegh and Kurz, Andreas and Japtok, Lukasz and Schumacher, Fabian and Pilgram, Lisa and Steinke, Maria and Kleuser, Burkhard and Sauer, Markus and Schneider-Schaulies, Sibylle and Avota, Elita},
  title     = {Measles virus infection fosters dendritic cell motility in a 3D environment to enhance transmission to target cells in the respiratory epithelium},
  series = {Frontiers in Immunology},
  volume    = {10},
  journal   = {Frontiers in Immunology},
  number    = {1294},
  doi       = {10.3389/fimmu.2019.01294},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201818},
  year      = {2019},
  abstract  = {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.},
  language  = {en}
}