Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-16574 Wissenschaftlicher Artikel Grimmig, Tanja; Moench, Romana; Kreckel, Jennifer; Haack, Stephanie; Rueckert, Felix; Rehder, Roberta; Tripathi, Sudipta; Ribas, Carmen; Chandraker, Anil; Germer, Christoph T.; Gasser, Martin; Waaga-Gasser, Ana Maria Toll Like Receptor 2, 4, and 9 Signaling Promotes Autoregulative Tumor Cell Growth and VEGF/PDGF Expression in Human Pancreatic Cancer Toll like receptor (TLR) signaling has been suggested to play an important role in the inflammatory microenvironment of solid tumors and through this inflammation-mediated tumor growth. Here, we studied the role of tumor cells in their process of self-maintaining TLR expression independent of inflammatory cells and cytokine milieu for autoregulative tumor growth signaling in pancreatic cancer. We analyzed the expression of TLR2, -4, and -9 in primary human cancers and their impact on tumor growth via induced activation in several established pancreatic cancers. TLR-stimulated pancreatic cancer cells were specifically investigated for activated signaling pathways of VEGF/PDGF and anti-apoptotic Bcl-xL expression as well as tumor cell growth. The primary pancreatic cancers and cell lines expressed TLR2, -4, and -9. TLR-specific stimulation resulted in activated MAP-kinase signaling, most likely via autoregulative stimulation of demonstrated TLR-induced VEGF and PDGF expression. Moreover, TLR activation prompted the expression of Bcl-xL and has been demonstrated for the first time to induce tumor cell proliferation in pancreatic cancer. These findings strongly suggest that pancreatic cancer cells use specific Toll like receptor signaling to promote tumor cell proliferation and emphasize the particular role of TLR2, -4, and -9 in this autoregulative process of tumor cell activation and proliferation in pancreatic cancer. 2016 2060 International Journal of Molecular Sciences 17 12 urn:nbn:de:bvb:20-opus-165743 10.3390/ijms17122060 Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) OPUS4-23902 Wissenschaftlicher Artikel Haack, Stephanie; Baiker, Sarah; Schlegel, Jan; Sauer, Markus; Sparwasser, Tim; Langenhorst, Daniela; Beyersdorf, Niklas Superagonistic CD28 stimulation induces IFN-γ release from mouse T helper 1 cells in vitro and in vivo 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. 2021 3 European Journal of Immunology 51 3 738 741 urn:nbn:de:bvb:20-opus-239028 10.1002/eji.202048803 Institut für Virologie und Immunbiologie OPUS4-17672 Wissenschaftlicher Artikel Langenhorst, Daniela; Haack, Stephanie; Göb, Selina; Uri, Anna; Lühder, Fred; Vanhove, Bernhard; Hünig, Thomas; Beyersdorf, Niklas CD28 costimulation of T helper 1 cells enhances cytokine release in vivo Compared to naive T cells, differentiated T cells are thought to be less dependent on CD28 costimulation for full activation. To revisit the role of CD28 costimulation in mouse T cell recall responses, we adoptively transferred in vitro generated OT-II T helper (Th) 1 cells into C57BL/6 mice (Thy1.2\(^{+}\)) and then either blocked CD28-ligand interactions with Fab fragments of the anti-CD28 monoclonal antibody (mAb) E18 or deleted CD28 expression using inducible CD28 knock-out OT-II mice as T cell donors. After injection of ovalbumin protein in adjuvant into the recipient mice we observed that systemic interferon (IFN)γ release strongly depended on CD28 costimulation of the Th1 cells, while secondary clonal expansion was not reduced in the absence of CD28 costimulation. For human memory CD4\(^{+}\) T cell responses we also noted that cytokine release was reduced upon inhibition of CD28 costimulation. Together, our data highlight the so far underestimated role of CD28 costimulation for the reactivation of fully differentiated CD4\(^{+}\) T cells. 2018 Frontiers in Immunology 9 1060 urn:nbn:de:bvb:20-opus-176726 10.3389/fimmu.2018.01060 Institut für Virologie und Immunbiologie OPUS4-27743 Wissenschaftlicher Artikel Vargas, Juan Gamboa; Wagner, Jennifer; Shaikh, Haroon; Lang, Isabell; Medler, Juliane; Anany, Mohamed; Steinfatt, Tim; Mosca, Josefina Peña; Haack, Stephanie; Dahlhoff, Julia; Büttner-Herold, Maike; Graf, Carolin; Viera, Estibaliz Arellano; Einsele, Hermann; Wajant, Harald; Beilhack, Andreas A TNFR2-Specific TNF fusion protein with improved in vivo activity Tumor necrosis factor (TNF) receptor-2 (TNFR2) has attracted considerable interest as a target for immunotherapy. Indeed, using oligomeric fusion proteins of single chain-encoded TNFR2-specific TNF mutants (scTNF80), expansion of regulatory T cells and therapeutic activity could be demonstrated in various autoinflammatory diseases, including graft-versus-host disease (GvHD), experimental autoimmune encephalomyelitis (EAE) and collagen-induced arthritis (CIA). With the aim to improve the in vivo availability of TNFR2-specific TNF fusion proteins, we used here the neonatal Fc receptor (FcRn)-interacting IgG1 molecule as an oligomerizing building block and generated a new TNFR2 agonist with improved serum retention and superior in vivo activity. Methods Single-chain encoded murine TNF80 trimers (sc(mu)TNF80) were fused to the C-terminus of an in mice irrelevant IgG1 molecule carrying the N297A mutation which avoids/minimizes interaction with Fcγ-receptors (FcγRs). The fusion protein obtained (irrIgG1(N297A)-sc(mu)TNF80), termed NewSTAR2 (New selective TNF-based agonist of TNF receptor 2), was analyzed with respect to activity, productivity, serum retention and in vitro and in vivo activity. STAR2 (TNC-sc(mu)TNF80 or selective TNF-based agonist of TNF receptor 2), a well-established highly active nonameric TNFR2-specific variant, served as benchmark. NewSTAR2 was assessed in various in vitro and in vivo systems. Results STAR2 (TNC-sc(mu)TNF80) and NewSTAR2 (irrIgG1(N297A)-sc(mu)TNF80) revealed comparable in vitro activity. The novel domain architecture of NewSTAR2 significantly improved serum retention compared to STAR2, which correlated with efficient binding to FcRn. A single injection of NewSTAR2 enhanced regulatory T cell (Treg) suppressive activity and increased Treg numbers by > 300% in vivo 5 days after treatment. Treg numbers remained as high as 200% for about 10 days. Furthermore, a single in vivo treatment with NewSTAR2 upregulated the adenosine-regulating ectoenzyme CD39 and other activation markers on Tregs. TNFR2-stimulated Tregs proved to be more suppressive than unstimulated Tregs, reducing conventional T cell (Tcon) proliferation and expression of activation markers in vitro. Finally, singular preemptive NewSTAR2 administration five days before allogeneic hematopoietic cell transplantation (allo-HCT) protected mice from acute GvHD. Conclusions NewSTAR2 represents a next generation ligand-based TNFR2 agonist, which is efficiently produced, exhibits improved pharmacokinetic properties and high serum retention with superior in vivo activity exerting powerful protective effects against acute GvHD. 2022 Frontiers in Immunology 13 urn:nbn:de:bvb:20-opus-277436 10.3389/fimmu.2022.888274 Graduate School of Life Sciences OPUS4-23775 Dissertation Haack, Stephanie A novel mouse model for systemic cytokine release upon treatment with a superagonistic anti-CD28 antibody 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. 2021 urn:nbn:de:bvb:20-opus-237757 10.25972/OPUS-23775 Graduate School of Life Sciences