0000000000654657

AUTHOR

Philipp Osterloh

showing 5 related works from this author

Proteasomes shape the repertoire of T cells participating in antigen-specific immune responses

2006

Differences in the cleavage specificities of constitutive proteasomes and immunoproteasomes significantly affect the generation of MHC class I ligands and therefore the activation of CD8-positive T cells. Based on these findings, we investigated whether proteasomal specificity also influences CD8-positive T cells during thymic selection by peptides derived from self proteins. We find that one of the self peptides responsible for positive selection of ovalbumin-specific OT-1 T cells, which is derived from the f-actin capping protein (Cpalpha1), is efficiently generated only by immunoproteasomes. Furthermore, OT-1 mice backcrossed onto low molecular mass protein 7 (LMP7)-deficient mice show a…

Proteasome Endopeptidase ComplexOvalbuminActin Capping ProteinsT-LymphocytesMolecular Sequence DataReceptors Antigen B-CellThymus GlandBiologyEpitopeInterleukin 21MiceImmune systemAntigenMultienzyme ComplexesMHC class ICytotoxic T cellT cell repertoire; selectionAnimalsIL-2 receptorAmino Acid SequenceAntigensSelection GeneticBone Marrow TransplantationMice KnockoutMultidisciplinaryBiological SciencesMolecular biologyPeptide FragmentsMice Inbred C57BLCTL*biology.proteinLymph Nodes
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Transcutaneous immunization with imiquimod is amplified by CD40 ligation and results in sustained cytotoxic T-lymphocyte activation and tumor protect…

1999

Transcutaneous immunization (TCI) using ligands of Toll-like receptors (TLRs) and cytotoxic T-lymphocyte (CTL) epitopes lead to the induction of potent T-cell responses. To characterize the efficacy of TCI-mediated CTL activation, we monitored the frequency and functional activity of specific CTL induced with TCI using the ovalbumin-derived epitope SIINFEKL composed in creme containing the synthetic TLR7 ligand R-837. We found that the frequency and activity decayed rapidly 10 d post-TCI. Consistently, no significant memory T-cell formation was detectable. In a prophylactic vaccination setting, TCI was protective against a lethal challenge with ovalbumin expressing EG.7 thymoma cells when t…

Time Factorsmedicine.drug_classT cellmedicine.medical_treatmentBiologyMonoclonal antibodyAdministration CutaneousLymphocyte ActivationEpitopeMiceAntigenCell Line TumorNeoplasmsmedicineImmunology and AllergyCytotoxic T cellAnimalsCD40 AntigensImiquimodGeneral MedicineImmunotherapyMice Inbred C57BLSurvival RateCTL*medicine.anatomical_structureImmunizationImmunologyAminoquinolinesImmunizationImmunotherapyImmunologic MemoryNeoplasm TransplantationT-Lymphocytes CytotoxicClinical reviews in allergyimmunology
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Cutting edge: priming of CTL by transcutaneous peptide immunization with imiquimod.

2005

Abstract CTL are important in combating cancer and viruses. Therefore, triggering the complete potential of CTL effector functions by new vaccination strategies will not only improve prophylaxis of tumor or virus-related diseases, but also open opportunities for effective therapeutic immunizations. Using transcutaneous immunization, we show that epicutaneous (e.c.)4 application of an ointment containing a CTL epitope and the TLR7 ligand imiquimod is highly effective in activating T cells in mice using TCR-transgenic CTL or in wild-type mice. Transcutaneous immunization-activated CTL mount a full-blown immune response against the target epitope characterized by proliferation, cytolytic activ…

Cytotoxicity ImmunologicAdoptive cell transferImmunologyReceptors Antigen T-CellPriming (immunology)Epitopes T-Lymphocytechemical and pharmacologic phenomenaImiquimodMice TransgenicAdministration CutaneousLymphocyte ActivationResting Phase Cell CycleEpitopeMiceImmune systemmedicineImmunology and AllergyAnimalsCells CulturedMice KnockoutImiquimodbusiness.industryTLR7VirologyAdoptive TransferVaccinationMice Inbred C57BLCTL*Protein TransportImmunologyVaccines SubunitAminoquinolinesLymph NodesbusinessSpleenmedicine.drugT-Lymphocytes CytotoxicJournal of immunology (Baltimore, Md. : 1950)
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Dendritic cell aggresome-like-induced structure formation and delayed antigen presentation coincide in influenza virus-infected dendritic cells.

2005

Abstract Influenza virus infection induces maturation of murine dendritic cells (DCs), which is most important for the initiation of an immune response. However, in contrast to EL-4 and MC57 cells, DCs present viral CTL epitopes with a delay of up to 10 h. This delay in Ag presentation coincides with the up-regulation of MHC class I molecules as well as costimulatory molecules on the cell surface and the accumulation of newly synthesized ubiquitinated proteins in large cytosolic structures, called DC aggresome-like-induced structures (DALIS). These structures were observed previously after LPS-induced maturation of DCs, and it was speculated that they play a role in the regulation of MHC cl…

Time FactorsImmunologyAntigen presentationCellAntigen-Presenting CellsEpitopes T-Lymphocytechemical and pharmacologic phenomenaBone Marrow CellsVirusCell LineMiceImmune systemCell Line TumorMHC class ImedicineImmunology and AllergyAnimalsHumansReceptors ImmunologicCells CulturedAntigen PresentationMice Inbred C3HbiologyUbiquitinViral Core ProteinsRNA-Binding ProteinsCell DifferentiationDendritic cellDendritic CellsNucleocapsid ProteinsVirologyToll-Like Receptor 2Cell biologyNucleoproteinMice Inbred C57BLToll-Like Receptor 4Aggresomemedicine.anatomical_structureNucleoproteinsInfluenza A virusbiology.proteinCytoplasmic StructuresT-Lymphocytes CytotoxicJournal of immunology (Baltimore, Md. : 1950)
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Synergistic activation of dendritic cells by combined Toll-like receptor ligation induces superior CTL responses in vivo.

2006

Toll-like receptors (TLRs) are able to interact with pathogen-derived products and their signals induce the coordinated activation of innate and adaptive immune mechanisms. Dendritic cells (DCs) play a central role in these events. As the different TLRs are able to trigger MyD88/TRIF-dependent and -independent signaling pathways, we wondered if the simultaneous activation of these signaling cascades would synergize with respect to DC activation and induce superior cytotoxic T-lymphocyte (CTL) activity in vivo. We observed that indeed the combined activation of MyD88-dependent and -independent signaling induced by TLR7 and TLR3 ligands provoked a more rapid and more sustained bone marrow–der…

T-LymphocytesImmunologyBone Marrow CellsBiologyLigandsBiochemistryT-Lymphocytes RegulatoryMiceCytotoxic T cellAnimalsAntigen-presenting cellAdaptor Proteins Signal TransducingCD86Toll-like receptorCD40Membrane GlycoproteinsToll-Like ReceptorsImmunityhemic and immune systemsCell BiologyHematologyDendritic cellDendritic CellsAcquired immune systemCell biologyToll-Like Receptor 3Mice Inbred C57BLCTL*Toll-Like Receptor 7ImmunologyMyeloid Differentiation Factor 88biology.proteinSignal TransductionT-Lymphocytes CytotoxicBlood
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