@phdthesis{Wiese2022, author = {Wiese, Teresa}, title = {Pharmacological targeting of acid sphingomyelinase increases CD4\(^+\) Foxp3\(^+\) regulatory T cell subsets in patients with major depression}, doi = {10.25972/OPUS-23347}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233471}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Lack of acid sphingomyelinase (ASM) activity, either through genetic deficiency or through pharmacological inhibition, is linked with increased activity and frequency of Foxp3+ regulatory T cells (Treg) among cluster of differentiation (CD) 4+ T cells in mice in vivo and in vitro1. Thus, pharmacological blockade of ASM activity, which catalyzes the cleavage of sphingomyelin to ceramide and phosphocholine, might be used as a new therapeutic mechanism to correct numeric and/ or functional Treg de-ficiencies in diseases like multiple sclerosis or major depression. In the present study, the effect of pharmacological inhibition of ASM in humans, in vitro and in vivo, was analyzed. In the in vitro experiments, peripheral blood mono-nuclear cells (PBMC) of healthy human blood donors were treated with two widely prescribed antidepressants with high (sertraline, Ser) or low (citalopram, Cit) capaci-ty to inhibit ASM activity. Similar to the findings in mice an increase in the frequency of Treg among human CD4+ T cells upon inhibition of ASM activity was observed. For the analysis in vivo, a prospective study of the composition of the CD4+ T cell com-partment of patients treated for major depression was done. The data show that pharmacological inhibition of ASM activity was superior to antidepressants with little or no ASM-inhibitory activity in increasing CD45RA- CD25high effector Treg (efTreg) frequencies among CD4+ T cells to normal levels. Independently of ASM inhibition, correlating the data with the clinical response, i.e. improvement of the Hamilton rat-ing scale for depression (HAMD) by at least 50 per cent (\%) after four weeks of treatment, it was found that an increase in efTreg frequencies among CD4+ cells dur-ing the first week of treatment identified patients with a clinical response. Regarding the underlying mechanism, it could be found that the positive effect of ASM inhibition on Treg required CD28 co-stimulation suggesting that enhanced CD28 co-stimulation was the driver of the observed increase in the frequency of Treg among human CD4+ T cells. Inhibition of ASM activity was further associated with changes in the expression and shuttling of CTLA-4, a key inhibitory molecule ex-pressed by Treg, between cellular compartments but the suppressive activity of CTLA-4 through its transendocytosis activity was unaffected by the inhibition of ASM activity. In summary, the frequency of (effector) Treg among CD4+ T cells in mice and in hu-mans is increased after inhibition of ASM activity suggesting that ASM blockade might beneficially modulate autoimmune diseases and depression-promoting in-flammation.}, subject = {Treg}, language = {en} } @phdthesis{Lin2004, author = {Lin, Chia-Huey}, title = {Functional characterization of rat CTLA-4 and CD25+CD4+ regulatory T cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-8521}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2004}, abstract = {Summary: In the present work, two important negative regulators of T cell responses in rats were examined. At the molecular level, rat CTLA-4, a receptor important for deactivating T cell responses, was examined for the expression pattern and in vitro functions. For this purpose, anti-rat CTLA-4 mAbs were generated. Consistent with the studies in mice and humans, rat CTLA-4 was detectable only in CD25+CD4+ regulatory T cells in unstimulated rats, and was upregulated in all activated T cells. Cross-linking rat CTLA-4 led to the deactivation of anti-TCR- and anti-CD28 stimulated (costimulation) T cell responses such as reduction in activation marker expression, proliferation, and cytokine IL-2 production. Although T cells stimulated with the superagonistic anti-CD28 antibody alone without TCR engagement also increased their CTLA-4 expression, a delayed kinetics of CTLA-4 upregulation was found in cells stimulated in this way. The physiological relevance of this finding needs further investigation. At the cellular level, rat CD25+CD4+ regulatory T cells were examined here in detail. Using rat anti-CTLA-4 mAbs, the phenotype of CD25+CD4+ regulatory T cells was investigated. Identical to the mouse and human Treg phenotype, rat CD25+CD4+ T cells constitutively expressed CTLA-4, were predominantly CD45RC low, and expressed high level of CD62L (L-selectin). CD25+CD4+ cells proliferated poorly and were unable to produce IL-2 upon engagement of the TCR and CD28. Furthermore, rat CD25+CD4+ cells produced high amounts of anti-inflammatory cytokine IL-10 upon stimulation. Importantly, freshly isolated CD25+CD4+ T cells from na{\"i}ve rats exhibited suppressor activities in the in vitro suppressor assays. In vitro, CD25+CD4+ regulatory T cells proliferated vigorously upon superagonistic anti-CD28 stimulation and became very potent suppressor cells. In vivo, a single injection of CD28 superagonist into rats induced transient accumulation and activation of CD25+CD4+ regulatory T cells. These findings suggest firstly that efficient expansion of CD25+CD4+ cells without losing their suppressive effects (even enhance their suppressive activities) can be achieved with the superagonistic anti- CD28 antibody in vitro. Secondly, the induction of disproportional expansion of CD25+CD4+ cells by a single injection of superagonistic anti-CD28 antibody in vivo implies that superagonistic anti-CD28 antibody may be a promising candidate in treating autoimmune diseases by causing a transient increase of activated CD25+CD4+ T cells and thus tipping ongoing autoimmune responses toward selftolerance.}, subject = {Ratte}, language = {en} } @article{KochPetzoldWesselyetal.2022, author = {Koch, Elias A. T. and Petzold, Anne and Wessely, Anja and Dippel, Edgar and Gesierich, Anja and Gutzmer, Ralf and Hassel, Jessica C. and Haferkamp, Sebastian and K{\"a}hler, Katharina C. and Knorr, Harald and Kreuzberg, Nicole and Leiter, Ulrike and Loquai, Carmen and Meier, Friedegund and Meissner, Markus and Mohr, Peter and Pf{\"o}hler, Claudia and Rahimi, Farnaz and Schadendorf, Dirk and Schell, Beatrice and Schlaak, Max and Terheyden, Patrick and Thoms, Kai-Martin and Schuler-Thurner, Beatrice and Ugurel, Selma and Ulrich, Jens and Utikal, Jochen and Weichenthal, Michael and Ziller, Fabian and Berking, Carola and Heppt, Markus V.}, title = {Immune checkpoint blockade for metastatic uveal melanoma: re-induction following resistance or toxicity}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {3}, issn = {2072-6694}, doi = {10.3390/cancers14030518}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254814}, year = {2022}, abstract = {Re-induction with immune checkpoint blockade (ICB) needs to be considered in many patients with uveal melanoma (UM) due to limited systemic treatment options. Here, we provide hitherto the first analysis of ICB re-induction in UM. A total of 177 patients with metastatic UM treated with ICB were included from German skin cancer centers and the German national skin cancer registry (ADOReg). To investigate the impact of ICB re-induction, two cohorts were compared: patients who received at least one ICB re-induction (cohort A, n = 52) versus those who received only one treatment line of ICB (cohort B, n = 125). In cohort A, a transient benefit of overall survival (OS) was observed at 6 and 12 months after the treatment start of ICB. There was no significant difference in OS between both groups (p = 0.1) with a median OS of 16.2 months (cohort A, 95\% CI: 11.1-23.8) versus 9.4 months (cohort B, 95\% CI: 6.1-14.9). Patients receiving re-induction of ICB (cohort A) had similar response rates compared to those receiving ICB once. Re-induction of ICB may yield a clinical benefit for a small subgroup of patients even after resistance or development of toxicities.}, language = {en} } @article{KochPetzoldWesselyetal.2021, author = {Koch, Elias A. T. and Petzold, Anne and Wessely, Anja and Dippel, Edgar and Gesierich, Anja and Gutzmer, Ralf and Hassel, Jessica C. and Haferkamp, Sebastian and Hohberger, Bettina and K{\"a}hler, Katharina C. and Knorr, Harald and Kreuzberg, Nicole and Leiter, Ulrike and Loquai, Carmen and Meier, Friedegund and Meissner, Markus and Mohr, Peter and Pf{\"o}hler, Claudia and Rahimi, Farnaz and Schadendorf, Dirk and Schell, Beatrice and Schlaak, Max and Terheyden, Patrick and Thoms, Kai-Martin and Schuler-Thurner, Beatrice and Ugurel, Selma and Ulrich, Jens and Utikal, Jochen and Weichenthal, Michael and Ziller, Fabian and Berking, Carola and Heppt, Markus}, title = {Immune checkpoint blockade for metastatic uveal melanoma: patterns of response and survival according to the presence of hepatic and extrahepatic metastasis}, series = {Cancers}, volume = {13}, journal = {Cancers}, number = {13}, issn = {2072-6694}, doi = {10.3390/cancers13133359}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242603}, year = {2021}, abstract = {Background: Since there is no standardized and effective treatment for advanced uveal melanoma (UM), the prognosis is dismal once metastases develop. Due to the availability of immune checkpoint blockade (ICB) in the real-world setting, the prognosis of metastatic UM has improved. However, it is unclear how the presence of hepatic and extrahepatic metastasis impacts the response and survival after ICB. Methods: A total of 178 patients with metastatic UM treated with ICB were included in this analysis. Patients were recruited from German skin cancer centers and the German national skin cancer registry (ADOReg). To investigate the impact of hepatic metastasis, two cohorts were compared: patients with liver metastasis only (cohort A, n = 55) versus those with both liver and extra-hepatic metastasis (cohort B, n = 123). Data were analyzed in both cohorts for response to treatment, progression-free survival (PFS), and overall survival (OS). The survival and progression probabilities were calculated with the Kaplan-Meier method. Log-rank tests, χ\(^2\) tests, and t-tests were performed to detect significant differences between both cohorts. Results: The median OS of the overall population was 16 months (95\% CI 13.4-23.7) and the median PFS, 2.8 months (95\% CI 2.5-3.0). The median OS was longer in cohort B than in cohort A (18.2 vs. 6.1 months; p = 0.071). The best objective response rate to dual ICB was 13.8\% and to anti-PD-1 monotherapy 8.9\% in the entire population. Patients with liver metastases only had a lower response to dual ICB, yet without significance (cohort A 8.7\% vs. cohort B 16.7\%; p = 0.45). Adverse events (AE) occurred in 41.6\%. Severe AE were observed in 26.3\% and evenly distributed between both cohorts. Conclusion: The survival of this large cohort of patients with advanced UM was more favorable than reported in previous benchmark studies. Patients with both hepatic and extrahepatic metastasis showed more favorable survival and higher response to dual ICB than those with hepatic metastasis only.}, language = {en} }