0000000000757085

AUTHOR

Bettina Kalt

showing 5 related works from this author

Variant toxin B and a functional toxin A produced by Clostridium difficile C34.

2001

A particular property of Clostridium difficile strain C34 is an insertion of approximately 2 kb in the tcdA-C34 gene that does not hinder expression of a fully active TcdA-C34 molecule. Intoxication with TcdA-C34 induced an arborized appearance in eukaryotic cells (D-type cytopathic effect); intoxication with TcdB-C34 induced a spindle-like appearance of cells (S-type cytopathic effect). Inactivation of GTPases with purified toxins revealed that Rho, Rac, Cdc42, and Rap are substrates of TcdA-C34. The variant cytotoxin TcdB-C34 inactivated Rho, Rac, Cdc42, Rap, Ral, and R-Ras. Hence, this is the first ‘S-type’ cytotoxin which inactivates both Rho and R-Ras, and is coexpressed with a ‘D-type…

MaleCell SurvivalBacterial ToxinsClostridium difficile toxin AClostridium difficile toxin BGTPaseEnterotoxinCHO CellsBiologymedicine.disease_causeMicrobiologyMicrobiologyEnterotoxinsBacterial ProteinsCricetinaeGeneticsmedicineAnimalsHumansMolecular BiologyCells CulturedCytopathic effectSkinToxinClostridioides difficileCytotoxinsGenetic VariationClostridium difficileMolecular biologyCdc42 GTP-Binding ProteinDNA Transposable ElementsMicroscopy Electron ScanningFEMS microbiology letters
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HMG-CoA reductase promotes protein prenylation and therefore is indispensible for T-cell survival.

2017

AbstractStatins are a well-established family of drugs that lower cholesterol levels via the competitive inhibition of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). In addition, the pleiotropic anti-inflammatory effects of statins on T cells make them attractive as therapeutic drugs in T-cell-driven autoimmune disorders. Since statins do not exclusively target HMGCR and thus might have varying effects on different cell types, we generated a new mouse strain allowing for the tissue-specific deletion of HMGCR. Deletion of HMGCR expression in T cells led to a severe decrease in their numbers with the remaining cells displaying an activated phenotype, with an increased pro…

0301 basic medicineCancer ResearchGeranylgeranyl pyrophosphateCell SurvivalT cellT-LymphocytesImmunologyProtein PrenylationMevalonic AcidCell CountMevalonic acidLymphocyte ActivationT-Lymphocytes Regulatory03 medical and health sciencesCellular and Molecular Neurosciencechemistry.chemical_compound0302 clinical medicinePolyisoprenyl PhosphatesmedicineAnimalsbiologyCell DeathIntegrasesCholesterolCell BiologyHydroxymethylglutaryl-CoA reductaseCell biologyMice Inbred C57BL030104 developmental biologymedicine.anatomical_structurePhenotypeBiochemistrychemistryHMG-CoA reductasebiology.proteinProtein prenylationlipids (amino acids peptides and proteins)Hydroxymethylglutaryl CoA ReductasesOriginal ArticleMevalonate pathway030217 neurology & neurosurgeryGene DeletionCell deathdisease
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A chimeric ribozyme in Clostridium difficile combines features of group I introns and insertion elements

2002

CdlSt1, a DNA insertion of 1975 bp, was identified within tcdA-C34, the enterotoxin gene of the Clostridium difficile isolate C34. Located in the catalytic domain A1-C34, Cd/St1 combines features of two genetic elements. Within the first 434 nt structures characteristic for group I introns were found; encoding the two transposase-like proteins tlpA and tlpB nucleotides 435-1975 represent the remainder of a IS605-like insertion element. We show that the entire CdlSt1 is accurately spliced from tcdA-C34 primary transcripts and that purified TcdA-C34 toxin is of regular size and catalytic activity. A search for CdlSt1-related sequences demonstrates that the element is widespread in toxinogenic…

GeneticsOpen reading framebiologyRNA splicingIntronRibozymebiology.proteinInterrupted geneGroup I catalytic intronGroup II intronORFSMolecular BiologyMicrobiologyMolecular Microbiology
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EBI2 Is Highly Expressed in Multiple Sclerosis Lesions and Promotes Early CNS Migration of Encephalitogenic CD4 T Cells

2017

Arrival of encephalitogenic T cells at inflammatory foci represents a critical step in development of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. EBI2 and its ligand, 7{alpha},25-OHC, direct immune cell localization in secondary lymphoid organs. CH25H and CYP7B1 hydroxylate cholesterol to 7{alpha},25-OHC. During EAE, we found increased expression of CH25H by microglia and CYP7B1 by CNS-infiltrating immune cells elevating the ligand concentration in the CNS. Two critical pro-inflammatory cytokines, interleukin-23 (IL-23) and interleukin-1 beta (IL-1{beta}), maintained expression of EBI2 in differentiating Th17 cells. In line with this, EBI2 enhan…

0301 basic medicineCD4-Positive T-LymphocytesCentral Nervous SystemMaleGPR183Cancer ResearchEncephalomyelitis Autoimmune ExperimentalOxysterolCentral nervous systemInterleukin-1betaCytochrome P450 Family 7CH25HmicrogliaAutoimmunityBiologymedicine.disease_causemultiple sclerosisInterleukin-23General Biochemistry Genetics and Molecular BiologyAutoimmunityReceptors G-Protein-Coupled03 medical and health sciencesMiceImmune systemCell MovementmedicineAnimalsEBI2lcsh:QH301-705.5MicrogliaEAEMultiple sclerosisExperimental autoimmune encephalomyelitisGPR1837α25-OHCmedicine.diseaseMice Inbred C57BLDisease Models Animal030104 developmental biologymedicine.anatomical_structurelcsh:Biology (General)ImmunologySteroid HydroxylasesTh17 CellsFemaleTh17CNSoxysterolCell Reports
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The tumor suppressor CYLD controls the function of murine regulatory T cells.

2012

Abstract CYLD was originally identified as a tumor suppressor gene mutated in familial cylindromatosis, an autosomal dominant predisposition to multiple benign neoplasms of the skin known as cylindromas. The CYLD protein is a deubiquitinating enzyme that acts as a negative regulator of NF-κB and JNK signaling through its interaction with NEMO and TNFR-associated factor 2. We have previously described a novel mouse strain that expresses solely and excessively a naturally occurring splice variant of CYLD (CYLDex7/8). In this study, we demonstrate that CYLD plays a critical role in Treg development and function. T cells of CYLDex7/8 mice had a hyperactive phenotype manifested by increased prod…

Tumor suppressor geneT cellImmunologyBiologyT-Lymphocytes RegulatoryDeubiquitinating Enzyme CYLDlaw.inventionProinflammatory cytokineMicelawmedicineImmunology and AllergyAnimalsCTLA-4 AntigenIL-2 receptorTumor Suppressor ProteinsInterleukin-2 Receptor alpha SubunitIntracellular Signaling Peptides and ProteinsNF-kappa BFOXP3PhenotypeMice Mutant StrainsCell biologyDeubiquitinating Enzyme CYLDCysteine Endopeptidasesmedicine.anatomical_structureGene Expression RegulationImmunologySuppressorJournal of immunology (Baltimore, Md. : 1950)
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