@phdthesis{RomerRoche2012, author = {Romer Roche, Paula Sofia}, title = {Separation from self explains failure of circulating T-cells to respond to the CD28 superagonist TGN1412}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74933}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Stimulatory or superagonistic (SA) CD28-specific monoclonal antibodies (mAbs) are potent polyclonal activators of regulatory T cells and have proven highly effective as treatment in a wide range of rodent models for autoimmune and inflammatory diseases. In these models, a preferential activation of regulatory T cells was observed by in vivo administration of CD28SA. In stark contrast, human volunteers receiving TGN1412, a humanized CD28-specific mAb, experienced a life-threatening cytokine release syndrome during the first-in-man trial. Preclinical tests employing human peripheral blood mononuclear cells (PBMC) failed to announce the rapid cytokine release measured in the human volunteers in response to TGN1412. The aim of this thesis project was to find an explanation of why standard PBMC assays failed to predict the unexpected TGN1412-induced "cytokine storm" observed in human volunteers. CD28 superagonists can activate T cells without T cell receptor (TCR) ligation. They do depend, however, on "tonic" TCR signals received by MHC scanning, signals that they amplify. PBMC do not receive these signals in the circulation. Short-term in vitro preculture of human PBMC at a high cell density (HDC) resulted in massive cytokine release during subsequent TGN1412 stimulation. Restoration of reactivity was cell-contact dependent, associated with TCR polarization and tyrosine-phosphorylation, and blocked by HLA-specific mAb. In HDC, both CD4 T cells and monocytes functionally mature in a mutually dependent fashion. However, only CD4 memory T-cells proliferate upon TGN1412 stimulation, and were identified as the main source of pro-inflammatory cytokines. Importantly, responses to other T-cell activating agents were also enhanced if PBMC were first allowed to interact under tissue-like conditions. A new in vitro protocol is provided that returns circulating T-cells to a tissue-like status where they respond to TGN1412 stimulation, and it might represent a more reliable preclinical in vitro test for both activating and inhibitory immunomodulatory drugs. Finally, the surprising observation was made that the IgG1 "sibling" of TGN1412, which is of the poorly Fc receptor-binding IgG4 isotype, has a much lower stimulatory activity. We could exclude steric hindrance as an explanation and provide evidence for removal of TGN1112 from the T-cell surface by trans-endocytosis.}, subject = {T-Lymphozyten-Rezeptor}, language = {en} } @article{HaakeHaackSchaeferetal.2023, author = {Haake, Markus and Haack, Beatrice and Sch{\"a}fer, Tina and Harter, Patrick N. and Mattavelli, Greta and Eiring, Patrick and Vashist, Neha and Wedekink, Florian and Genssler, Sabrina and Fischer, Birgitt and Dahlhoff, Julia and Mokhtari, Fatemeh and Kuzkina, Anastasia and Welters, Marij J. P. and Benz, Tamara M. and Sorger, Lena and Thiemann, Vincent and Almanzar, Giovanni and Selle, Martina and Thein, Klara and Sp{\"a}th, Jacob and Gonzalez, Maria Cecilia and Reitinger, Carmen and Ipsen-Escobedo, Andrea and Wistuba-Hamprecht, Kilian and Eichler, Kristin and Filipski, Katharina and Zeiner, Pia S. and Beschorner, Rudi and Goedemans, Renske and Gogolla, Falk Hagen and Hackl, Hubert and Rooswinkel, Rogier W. and Thiem, Alexander and Romer Roche, Paula and Joshi, Hemant and P{\"u}hringer, Dirk and W{\"o}ckel, Achim and Diessner, Joachim E. and R{\"u}diger, Manfred and Leo, Eugen and Cheng, Phil F. and Levesque, Mitchell P. and Goebeler, Matthias and Sauer, Markus and Nimmerjahn, Falk and Schuberth-Wagner, Christine and Felten, Stefanie von and Mittelbronn, Michel and Mehling, Matthias and Beilhack, Andreas and van der Burg, Sjoerd H. and Riedel, Angela and Weide, Benjamin and Dummer, Reinhard and Wischhusen, J{\"o}rg}, title = {Tumor-derived GDF-15 blocks LFA-1 dependent T cell recruitment and suppresses responses to anti-PD-1 treatment}, series = {Nature Communications}, volume = {14}, journal = {Nature Communications}, doi = {10.1038/s41467-023-39817-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357333}, year = {2023}, abstract = {Immune checkpoint blockade therapy is beneficial and even curative for some cancer patients. However, the majority don't respond to immune therapy. Across different tumor types, pre-existing T cell infiltrates predict response to checkpoint-based immunotherapy. Based on in vitro pharmacological studies, mouse models and analyses of human melanoma patients, we show that the cytokine GDF-15 impairs LFA-1/β2-integrin-mediated adhesion of T cells to activated endothelial cells, which is a pre-requisite of T cell extravasation. In melanoma patients, GDF-15 serum levels strongly correlate with failure of PD-1-based immune checkpoint blockade therapy. Neutralization of GDF-15 improves both T cell trafficking and therapy efficiency in murine tumor models. Thus GDF-15, beside its known role in cancer-related anorexia and cachexia, emerges as a regulator of T cell extravasation into the tumor microenvironment, which provides an even stronger rationale for therapeutic anti-GDF-15 antibody development.}, language = {en} }