@phdthesis{Camara2014, author = {Camara, Monika}, title = {Die Rolle der CD8+ T Zellen in der Pathogenese der Experimentellen Autoimmunen Enzephalomyelitis in der Lewis Ratte}, publisher = {Journal of Neuroimmunology (2013)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-98497}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Multiple Sclerosis (MS) and its corresponding animal model Experimental Autoimmune Encephalomyelitis (EAE) are autoimmune diseases of the central nervous system (CNS). Besides CD4+ T cells specific for myelin-derived antigens CD8+ T cells additionally contribute to the pathogenesis of that disease. However, the role of CD8+ T cells during the induction phase of the disease outside the CNS has not been clarified so far. Thus the contribution of CD8+ T cells to the immunopathogenesis of EAE in the Lewis rat was investigated in this work. For that purpose active EAE was induced in normal Lewis rats and animals that were deficient for CD8+ T cells due to the application of CD8-specific monoclonal antibodies. The CD8-depleted animals showed diminished disease activity in comparison to control rats. Equally, CD8-knockout rats, characterized by the absence of functional CD8+ T cells, developed clearly reduced symptoms of the disease in comparison to wild type littermates. Reduced disease activity of the CD8-deficient animals was accompanied by reduced infiltration of T cells and macrophages into the CNS. In the draining lymph nodes activated gpMBP-specific CD4+ T cells could be detected in the absence of CD8+ T cells, but they produced less amounts of proinflammatory cytokines like interferon-gamma than CD4+ T cells of normal rats. Obviously in the active EAE, myelin-specific CD4+ T cells are not able to differentiate completely into effector cells and invade the CNS upon absence of CD8+ T cells. In contrast fully differentiated encephalitogenic CD4+ effector cells equally potently induced EAE upon transfer into either normal or CD8-deficient rats. Hence, the pathogenic potential of completely differentiated CD4+ effector cells does not depend on the presence of CD8+ T cells. With the help of a rat-IFN-gamma ELISpot interferon-gamma-producing gpMBP-specific CD8+ T cells were detected in animals immunized with gpMBP. To directly detect gpMBP-specific CD8+ T cells, RT1.Al-Ig dimeres were generated and loaded with different gpMBP-derived peptides. Indeed, CD8+ T cells specifically recognizing RT1.Al-Ig dimeres loaded with gpMBP125-133 could be detected in the draining lymph nodes of rats, immunized with gpMBP in CFA. The results of this work allow the conclusion that in the EAE of the Lewis rat interferon--producing CD8+ T cells interact with myelin-specific CD4+ T cells, thus licensing these cells to differentiate into CNS invading effector cells.}, subject = {Multiple Sklerose}, language = {de} } @article{HollmannWieseDennstaedtetal.2019, author = {Hollmann, Claudia and Wiese, Teresa and Dennst{\"a}dt, Fabio and Fink, Julian and Schneider-Schaulies, J{\"u}rgen and Beyersdorf, Niklas}, title = {Translational approaches targeting ceramide generation from sphingomyelin in T cells to modulate immunity in humans}, series = {Frontiers in Immunology}, volume = {10}, journal = {Frontiers in Immunology}, number = {2363}, issn = {1664-3224}, doi = {10.3389/fimmu.2019.02363}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198806}, year = {2019}, abstract = {In T cells, as in all other cells of the body, sphingolipids form important structural components of membranes. Due to metabolic modifications, sphingolipids additionally play an active part in the signaling of cell surface receptors of T cells like the T cell receptor or the co-stimulatory molecule CD28. Moreover, the sphingolipid composition of their membranes crucially affects the integrity and function of subcellular compartments such as the lysosome. Previously, studying sphingolipid metabolism has been severely hampered by the limited number of analytical methods/model systems available. Besides well-established high resolution mass spectrometry new tools are now available like novel minimally modified sphingolipid subspecies for click chemistry as well as recently generated mouse mutants with deficiencies/overexpression of sphingolipid-modifying enzymes. Making use of these tools we and others discovered that the sphingolipid sphingomyelin is metabolized to ceramide to different degrees in distinct T cell subpopulations of mice and humans. This knowledge has already been translated into novel immunomodulatory approaches in mice and will in the future hopefully also be applicable to humans. In this paper we are, thus, summarizing the most recent findings on the impact of sphingolipid metabolism on T cell activation, differentiation, and effector functions. Moreover, we are discussing the therapeutic concepts arising from these insights and drugs or drug candidates which are already in clinical use or could be developed for clinical use in patients with diseases as distant as major depression and chronic viral infection.}, language = {en} }