@phdthesis{Tischner2007, author = {Tischner, Denise}, title = {Mechanistische Untersuchungen zur Therapie von Multipler Sklerose am Beispiel der Experimentellen Autoimmunen Encephalomyelitis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-25258}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2007}, abstract = {No abstract available}, subject = {Autoimmunit{\"a}t}, language = {de} } @phdthesis{Thumbs2000, author = {Thumbs, Alexander}, title = {Modulation der Immunglobulinproduktion bei Ratten mit CD28-spezifischen monoklonalen Antik{\"o}rpern}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-1180774}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2000}, abstract = {Einer der wichigsten co-stimulatorischen Rezeptoren auf T-Zellen ist CD28. In Abh{\"a}ngigkeit vom TZR-Signal nimmt CD28 Einfluss auf die Th1/Th2-Differenzierung der Immunantwort. Die rattenspezifischen mAk JJ316 und JJ319 binden an das CD28-Molek{\"u}l und haben beide ein gleich starkes co-stimulatorisches Potential. Gabe des mitogenen CD28-spezifischen mAkJJ316 - und nicht des konventionellen mAk JJ319 - f{\"u}hrt auch ohne TZR-Signal in vitro zu Produktion und Proliferation der Zellen (Direkte Stimulation). In vivo f{\"u}hrt Gabe von JJ316 zu einer Erh{\"o}hung der Zellzahl in Milz und Lymphknoten mit einem Maximum nach drei Tagen. In vitro f{\"u}hrte Behandlung mi mAk JJ316 zu einem Anstieg Th2-spezifischer Immunglobuline. In dieser Arbeit konnte gezeigt werden, dass die Gabes des mitogenen CD28-spezifischen mAk JJ316 im Vergleich mit dem konventionellen CD28-spezifischen mAk JJ319 auch in vivo zu einer Erh{\"o}hung der Th2-spezifischen Immunglobuline (IgG1, IgG2a, IgE) bei Brown-Norway- und Lewis-Ratten f{\"u}hrt.}, subject = {Maus}, language = {de} } @article{UriWernerLuehderetal.2017, author = {Uri, Anna and Werner, Sandra and L{\"u}hder, Fred and H{\"u}nig, Thomas and Kerkau, Thomas and Beyersdorf, Niklas}, title = {Protection of mice from acute graft-versus-host disease requires CD28 co-stimulation on donor CD4\(^{+}\) Foxp3\(^{+}\) regulatory T Cells}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {721}, doi = {10.3389/fimmu.2017.00721}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158469}, year = {2017}, abstract = {Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell plus T cell transplantation (allo-HSCT). In this study, we investigated the requirement for CD28 co-stimulation of donor CD4\(^{+}\) conventional (CD4\(^{+}\)CD25\(^{-}\)Foxp3\(^{-}\), Tconv) and regulatory (CD4\(^{+}\)CD25\(^{+}\)Foxp3\(^{+}\), Treg) T cells in aGvHD using tamoxifen-inducible CD28 knockout (iCD28KO) or wild-type (wt) littermates as donors of CD4\(^{+}\) Tconv and Treg. In the highly inflammatory C57BL/6 into BALB/c allo-HSCT transplantation model, CD28 depletion on donor CD4\(^{+}\) Tconv reduced clinical signs of aGvHD, but did not significantly prolong survival of the recipient mice. Selective depletion of CD28 on donor Treg did not abrogate protection of recipient mice from aGvHD until about day 20 after allo-HSCT. Later, however, the pool of CD28-depleted Treg drastically declined as compared to wt Treg. Consequently, only wt, but not CD28-deficient, Treg were able to continuously suppress aGvHD and induce long-term survival of the recipient mice. To our knowledge, this is the first study that specifically evaluates the impact of CD28 expression on donor Treg in aGvHD. Moreover, the delayed kinetics of aGvHD lethality after transplantation of iCD28KO Treg provides a novel animal model for similar disease courses found in patients after allo-HSCT.}, language = {en} } @article{HaackBaikerSchlegeletal.2021, author = {Haack, Stephanie and Baiker, Sarah and Schlegel, Jan and Sauer, Markus and Sparwasser, Tim and Langenhorst, Daniela and Beyersdorf, Niklas}, title = {Superagonistic CD28 stimulation induces IFN-γ release from mouse T helper 1 cells in vitro and in vivo}, series = {European Journal of Immunology}, volume = {51}, journal = {European Journal of Immunology}, number = {3}, doi = {10.1002/eji.202048803}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239028}, pages = {738 -- 741}, year = {2021}, abstract = {Like human Th1 cells, mouse Th1 cells also secrete IFN-γ upon stimulation with a superagonistic anti-CD28 monoclonal antibody (CD28-SA). Crosslinking of the CD28-SA via FcR and CD40-CD40L interactions greatly increased IFN-γ release. Our data stress the utility of the mouse as a model organism for immune responses in humans.}, language = {en} } @phdthesis{Haack2021, author = {Haack, Stephanie}, title = {A novel mouse model for systemic cytokine release upon treatment with a superagonistic anti-CD28 antibody}, doi = {10.25972/OPUS-23775}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The adaptive immune system is known to provide highly specific and effective immunity against a broad variety of pathogens due to different effector cells. The most prominent are CD4+ T-cells which differentiate after activation into distinct subsets of effector and memory cells, amongst others T helper 1 (Th1) cells. We have recently shown that mouse as well as human Th1 cells depend on T cell receptor (TCR) signals concomitant with CD28 costimulation in order to secrete interferon  (IFN) which is considered as their main effector function. Moreover, there is a class of anti-CD28 monoclonal antibodies that is able to induce T cell (re-)activation without concomitant TCR ligation. These so-called CD28-superagonists (CD28-SA) have been shown to preferentially activate and expand CD4+ Foxp3+ regulatory T (Treg) cells and thereby efficaciously conferring protection e.g. against autoimmune responses in rodents and non-human primates. Considering this beneficial effect, CD28-SA were thought to be of great impact for immunotherapeutic approaches and a humanized CD28-SA was subjected to clinical testing starting with a first-in-man trial in London in 2006. Unexpectedly, the volunteers experienced life-threatening side effects due to a cytokine release syndrome (CRS) that was unpredicted by the preclinical studies prior to the trial. Retrospectively, CD4+ memory T cells within the tissues were identified as source of pro-inflammatory cytokines released upon CD28-SA administration. This was not predicted by the preclinical testing indicating a need for more reliable and predictive animal models. Whether mouse CD4+ T cells are generally irresponsive to CD28-SA stimulation or rather the lack of a bona fide memory T cell compartment in cleanly housed specific-pathogen-free (SPF) mice is the reason why the rodent models failed to predict the risk for a CRS remained unclear. To provide SPF mice with a true pool of memory/effector T cells, we transferred in vitro differentiated TCR-transgenic OT-II Th1 cells into untreated recipient mice. Given that Treg cells suppress T cell activation after CD28- SA injection in vivo, recipients were either Treg-competent or Treg-deficient, wild type or DEREG mice, respectively. Subsequent CD28-SA administration resulted in induction of systemic pro-inflammatory cytokine release, dominated by IFN, that was observed to be much more pronounced and robust in Treg-deficient recipients. Employing a newly established in vitro system mirroring the in vivo responses to CD28-SA stimulation of Th1 cells revealed that antigen-presenting cells (APCs) amplify CD28-SAinduced IFN release by Th1 cells due to CD40/CD40L-interactions. Thus, these data are the first to show that mouse Th1 cells are indeed sensitive to CD28-SA stimulation in vivo and in vitro responding with strong IFN release accompanied by secretion of further pro-inflammatory cytokines, which is compatible with a CRS. In conclusion, this study will facilitate preclinical testing of immunomodulatory agents providing a mouse model constituting more "human-like" conditions allowing a higher degree of reliability and translationability.}, subject = {CD28}, language = {en} }