21 results on '"Loeser S"'
Search Results
2. The development of novel LTA4H modulators to selectively target LTB4 generation
- Author
-
Low, CM, Akthar, S, Patel, D, Loeser, S, Wong, C, Jackson, P, Blalock, JE, Hare, S, Lloyd, C, Snelgrove, RJ, Wellcome Trust, and Asthma UK
- Subjects
ENZYME ,AIRWAY INFLAMMATION ,Proline ,Neutrophils ,Amino Acid Motifs ,Anti-Inflammatory Agents ,Gene Expression ,Bone Marrow Cells ,EMPHYSEMA ,Crystallography, X-Ray ,OBSTRUCTIVE PULMONARY-DISEASE ,Leukotriene B4 ,Article ,Protein Structure, Secondary ,Substrate Specificity ,Mice ,NEUTROPHILIC INFLAMMATION ,LEUKOTRIENE A(4) HYDROLASE ,PROLINE-GLYCINE-PROLINE ,Animals ,Humans ,Protein Interaction Domains and Motifs ,Enzyme Inhibitors ,Epoxide Hydrolases ,Inflammation ,Mice, Inbred BALB C ,Science & Technology ,Binding Sites ,Hydrolysis ,AMINOPEPTIDASE ,INHIBITOR ,Recombinant Proteins ,Multidisciplinary Sciences ,Molecular Docking Simulation ,DISCOVERY ,beta-Alanine ,Science & Technology - Other Topics ,Female ,Oligopeptides ,Protein Binding - Abstract
The pro-inflammatory mediator leukotriene B4 (LTB4) is implicated in the pathologies of an array of diseases and thus represents an attractive therapeutic target. The enzyme leukotriene A4 hydrolase (LTA4H) catalyses the distal step in LTB4 synthesis and hence inhibitors of this enzyme have been actively pursued. Despite potent LTA4H inhibitors entering clinical trials all have failed to show efficacy. We recently identified a secondary anti-inflammatory role for LTA4H in degrading the neutrophil chemoattractant Pro-Gly-Pro (PGP) and rationalized that the failure of conventional LTA4H inhibitors may be that they inadvertently prevented PGP degradation. We demonstrate that these inhibitors do indeed fail to discriminate between the dual activities of LTA4H, and enable PGP accumulation in mice. Accordingly, we have developed novel compounds that potently inhibit LTB4 generation whilst leaving PGP degradation unperturbed. These novel compounds could represent a safer and superior class of LTA4H inhibitors for translation into the clinic.
- Published
- 2017
- Full Text
- View/download PDF
3. Prognostische Bedeutung der MGMT Promoter-Hypermethylierung und anderer genetischer Marker für mit Temozolomid behandelte Patienten mit malignen Gliomen
- Author
-
Sabel, M, Loeser, S, Luyken, C, Willers, R, Blaschke, B, Steiger, HJ, and Reifenberger, G
- Subjects
ddc: 610 - Published
- 2006
4. MGMT-Methylierung als möglicher prognostischer Faktor bei Patienten mit malignen Gliomen und adjuvanter Chemotherapie mit Temozolamid
- Author
-
Luyken, C, Loeser, S, Willers, R, Steiger, H, Reifenberger, G, and Sabel, M
- Subjects
ddc: 610 - Published
- 2005
5. Prognostic value of MGMT promoter hypermethylation and other genetic markers in malignant glioma patients treated with temozolomide
- Author
-
Sabel, M, Loeser, S, Luyken, C, Willers, R, Blaschke, B, Steiger, HJ, Reifenberger, G, Sabel, M, Loeser, S, Luyken, C, Willers, R, Blaschke, B, Steiger, HJ, and Reifenberger, G
- Published
- 2006
6. MGMT methylation as a potential outcome predictor in patients with malignant gliomas treated with adjuvant temozolomide chemotherapy
- Author
-
Luyken, C, Loeser, S, Willers, R, Steiger, H, Reifenberger, G, Sabel, M, Luyken, C, Loeser, S, Willers, R, Steiger, H, Reifenberger, G, and Sabel, M
- Published
- 2005
7. Identification of a 38-kDa high affinity sulfonylurea-binding peptide in insulin-secreting cells and cerebral cortex.
- Author
-
Schwanstecher, M., Löser, S., Chudziak, F., and Panten, U.
- Published
- 1994
- Full Text
- View/download PDF
8. Health economic consequences of optimal vs. observed guideline adherence of coronary angiography in patients with suspected obstructive stable coronary artery in Germany: a microsimulation model.
- Author
-
Seleznova Y, Bruder O, Loeser S, Artmann J, Shukri A, Naumann M, Stock S, Wein B, and Müller D
- Subjects
- Humans, Coronary Angiography, Germany epidemiology, Guideline Adherence, Coronary Artery Disease
- Abstract
Aims: While the number of patients with stable coronary artery disease (SCAD) is similar across European countries, Germany has the highest per capita volume of coronary angiographies (CA). This study evaluated the health economic consequences of guideline-non-adherent use of CA in patients with SCAD., Methods and Results: As part of the ENLIGHT-KHK trial, a prospective observational study, this microsimulation model compared the number of major adverse cardiac events (MACE) and the costs of real-world use of CA with those of (assumed) complete guideline-adherent use (according to the German National Disease Management Guideline 2019). The model considered non-invasive testing, CA, revascularization, MACE (30 days after CA), and medical costs. Model inputs were obtained from the ENLIGHT-KHK trial (i.e. patients' records, a patient questionnaire, and claims data). Incremental cost-effectiveness ratios were calculated by comparing the differences in costs and MACE avoided from the perspective of the Statutory Health Insurance (SHI). Independent on pre-test probability (PTP) of SCAD, complete guideline adherence for usage of CA would result in a slightly lower rate of MACE (-0.0017) and less cost (€-807) per person compared with real-world guideline adherence. While cost savings were shown for moderate and low PTP (€901 and €502, respectively), for a high PTP, a guideline-adherent process results in slightly higher costs (€78) compared with real-world guideline adherence. Sensitivity analyses confirmed the results., Conclusion: Our analysis indicates that improving guideline adherence in clinical practice by reducing the amount of CAs in patients with SCAD would lead to cost savings for the German SHI., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2024
- Full Text
- View/download PDF
9. Guideline adherence in the use of coronary angiography in patients presenting at the emergency department without myocardial infarction - Results from the German ENLIGHT-KHK project.
- Author
-
Wein B, Seleznova Y, Mueller D, Naumann M, Loeser S, Steffen M, Windhoevel U, Haude M, Vom Dahl J, Schaefer U, Montenbruck M, Jegodka R, Dill T, Guelker JE, Boese D, Bogs B, Harmel E, and Bruder O
- Abstract
Background: For patients with acute myocardial infarction (AMI), direct coronary angiography (CA) is recommended, while for non-AMI patients, the diagnostic work-up depends on clinical criteria. This analysis provides initial prospective German data for the degree of guideline-adherence (GL) in the use of CA on non-AMI patients presenting at the emergency department (ED) with suspected acute coronary syndrome (ACS) according to the 2015 ESC-ACS-GL. Furthermore the implications of the application of the 2020 ESC-ACS-GL recommendations were evaluated., Methods: Patient symptoms were identified using a standardized questionnaire; medical history and diagnostic work-up were acquired from health records. In accordance with the 2015 ESC-ACS-GL, CA was considered GL-adherent if intermediate risk criteria (IRC) were present or non-invasive, image-guided testing (NIGT) was pathological., Results: Between January 2019 and August 2021, 229 patients were recruited across seven centers. Patients presented with chest pain, dyspnea, and other symptoms in 66.7%, 16.2% and 17.1%, respectively, were in mean 66.3 ± 10.5 years old, and 36.3% were female. In accordance with the 2015 ESC-ACS-GL, the use of CA was GL-adherent for 64.0% of the patients. GL-adherent compared to non-adherent use of CA resulted in revascularization more often (44.5% vs. 17.1%, p < 0.001). Applying the 2020 ESC-ACS-GL, 20.4% of CA would remain GL-adherent., Conclusions: In the majority of cases, the use of CA was adherent to the 2015 ESC-ACS-GL. With regard to the 2020 and 2023 ESC-ACS-GL, efforts to expand the utilization of NIGT are crucial, especially as GL-adherent use of CA is more likely to result in revascularization.(German Clinical Trials Register DRKS00015638; https://drks.de/search/de/trial/DRKS00015638; (registration date: 19 February 2019))., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)
- Published
- 2023
- Full Text
- View/download PDF
10. Evaluation of the guideline-adherence of coronary angiography in patients with suspected chronic coronary syndrome - Results from the German prospective multicentre ENLIGHT-KHK project.
- Author
-
Wein B, Seleznova Y, Mueller D, Naumann M, Loeser S, Artmann J, Fritz T, Steffen M, Windhoevel U, Haude M, Vom Dahl J, Schaefer U, Montenbruck M, Zarse M, Jegodka R, Dill T, Guelker JE, Boese D, and Bruder O
- Abstract
Background: With 900'000 coronary angiographies (CA) per year, Germany has the highest annual per capita volume in Europe. Until now there are no prospective clinical data on the degree of guideline-adherence in the use of CA in patients with suspected chronic coronary syndrome (CCS) in Germany., Methods: Between January 2019 and August 2021, 458 patients with suspected CCS were recruited in nine German centres. Guideline-adherence was evaluated according to the current European Society of Cardiology and German guidelines. Pre-test probability (PTP) for CAD was determined using age, gender, and a standardized patient questionnaire to identify symptoms. Data on the diagnostic work-up were obtained from health records., Results: Patients were in mean 66.6 years old, male in 57.3 %, had known CAD in 48.4 % and presented with typical, atypical, non-anginal chest pain or dyspnoea in 35.7 %, 41.3 %, 23.0 % and 25.4 %, respectively. PTP according to the European guidelines was in mean 24.2 % (11.9 %-36.5 % 95 % CI). 20.9 % of the patients received guideline-recommended preceding non-invasive image guided testing. The use of CA was adherent to the European and German guideline recommendations in 20.4 % and 25.4 %, respectively. In multivariate-analysis, arterial hypertension and prior revascularization were predictors of guideline non-adherence., Conclusion: These are the first prospective clinical data which demonstrated an overall low degree of guideline-adherence in the use of CA in patients with suspected CCS in the German health care setting. To improve adherence rates, the availability of and access to non-invasive image guided testing needs to be strengthened. (German Clinical Trials Registry DRKS00015638 - Registration Date: 19.02.2019)., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
11. Evaluation of Guideline Adherence for Cardiac Catheterization in Patients With Presumed Obstructive Coronary Artery Disease in Germany (ENLIGHT-KHK) - A Multicentre, Prospective, Observational Study.
- Author
-
Seleznova Y, Wein B, Müller D, Naumann M, Bruder O, Steffen M, Windhövel U, Loeser S, Artmann J, Fritz T, Eckardt M, Stock S, and Naber CK
- Subjects
- Germany, Guideline Adherence, Humans, Prospective Studies, Cardiac Catheterization, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease therapy
- Abstract
Introduction: The diagnosis or exclusion of obstructive stable coronary artery disease (SCAD) in clinical practice is challenging and therefore clinical guidelines provide recommendations on the use of non-invasive and invasive testing. For Germany, data obtained from the OECD and health insurances indicate a potential non-adherence to guideline-recommended diagnostic pathways. However, there is a lack of prospective and reliable evidence for appropriate use of invasive coronary angiography (CA) in Germany., Objective: To provide evidence on the nature and extent of guideline non-adherence in patients undergoing CA with presumed obstructive SCAD in Germany and, to evaluate the clinical and economic consequences of potential deviations in guideline adherence., Methods: ENLIGHT-KHK is a multicentre, prospective observational study recruiting 1500 patients being admitted for CA with presumed obstructive SCAD and exclusion of acute myocardial infarction (DRKS00015638). The primary outcome measure is the adherence to clinical guidelines in the decision-making process for use of CA. Therefore, the patients' diagnostic pathways and adherence to German and European guidelines will be assessed using clinical data, health-claims data, and a patient questionnaire. The primary safety outcome is a composite of myocardial infarction, stroke and all-cause death. Secondary outcome measures are periprocedural complications and costs. Using a decision-analytic model, the clinical and economic impact of observed guideline adherence in clinical practice will be assessed. Potential barriers and facilitators of guideline-adherent decision-making will be evaluated via semi-structured interviews., Conclusions: ENLIGHT-KHK will give insights into the appropriateness of invasive CA in Germany and enable the development of concepts to improve guideline-adherence in the German health-care setting., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper!, (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
12. The E3 ligase Cbl-b and TAM receptors regulate cancer metastasis via natural killer cells.
- Author
-
Paolino M, Choidas A, Wallner S, Pranjic B, Uribesalgo I, Loeser S, Jamieson AM, Langdon WY, Ikeda F, Fededa JP, Cronin SJ, Nitsch R, Schultz-Fademrecht C, Eickhoff J, Menninger S, Unger A, Torka R, Gruber T, Hinterleitner R, Baier G, Wolf D, Ullrich A, Klebl BM, and Penninger JM
- Subjects
- Adaptor Proteins, Signal Transducing deficiency, Adaptor Proteins, Signal Transducing genetics, Animals, Anticoagulants pharmacology, Anticoagulants therapeutic use, Female, Killer Cells, Natural drug effects, Killer Cells, Natural metabolism, Male, Mammary Neoplasms, Experimental drug therapy, Mammary Neoplasms, Experimental genetics, Mammary Neoplasms, Experimental immunology, Melanoma, Experimental drug therapy, Melanoma, Experimental genetics, Melanoma, Experimental immunology, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Neoplasm Metastasis drug therapy, Neoplasm Metastasis prevention & control, Proto-Oncogene Proteins antagonists & inhibitors, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-cbl deficiency, Proto-Oncogene Proteins c-cbl genetics, Receptor Protein-Tyrosine Kinases antagonists & inhibitors, Ubiquitin-Protein Ligases deficiency, Ubiquitin-Protein Ligases genetics, Ubiquitination, Warfarin pharmacology, Warfarin therapeutic use, c-Mer Tyrosine Kinase, Axl Receptor Tyrosine Kinase, Adaptor Proteins, Signal Transducing metabolism, Killer Cells, Natural immunology, Mammary Neoplasms, Experimental pathology, Melanoma, Experimental pathology, Neoplasm Metastasis immunology, Proto-Oncogene Proteins c-cbl metabolism, Receptor Protein-Tyrosine Kinases metabolism, Ubiquitin-Protein Ligases metabolism
- Abstract
Tumour metastasis is the primary cause of mortality in cancer patients and remains the key challenge for cancer therapy. New therapeutic approaches to block inhibitory pathways of the immune system have renewed hopes for the utility of such therapies. Here we show that genetic deletion of the E3 ubiquitin ligase Cbl-b (casitas B-lineage lymphoma-b) or targeted inactivation of its E3 ligase activity licenses natural killer (NK) cells to spontaneously reject metastatic tumours. The TAM tyrosine kinase receptors Tyro3, Axl and Mer (also known as Mertk) were identified as ubiquitylation substrates for Cbl-b. Treatment of wild-type NK cells with a newly developed small molecule TAM kinase inhibitor conferred therapeutic potential, efficiently enhancing anti-metastatic NK cell activity in vivo. Oral or intraperitoneal administration using this TAM inhibitor markedly reduced murine mammary cancer and melanoma metastases dependent on NK cells. We further report that the anticoagulant warfarin exerts anti-metastatic activity in mice via Cbl-b/TAM receptors in NK cells, providing a molecular explanation for a 50-year-old puzzle in cancer biology. This novel TAM/Cbl-b inhibitory pathway shows that it might be possible to develop a 'pill' that awakens the innate immune system to kill cancer metastases.
- Published
- 2014
- Full Text
- View/download PDF
13. ISCOMATRIX vaccines mediate CD8+ T-cell cross-priming by a MyD88-dependent signaling pathway.
- Author
-
Wilson NS, Yang B, Morelli AB, Koernig S, Yang A, Loeser S, Airey D, Provan L, Hass P, Braley H, Couto S, Drane D, Boyle J, Belz GT, Ashkenazi A, and Maraskovsky E
- Subjects
- Animals, Antibodies, Monoclonal administration & dosage, Antigens, Neoplasm immunology, CD40 Antigens immunology, CD8-Positive T-Lymphocytes drug effects, Cancer Vaccines administration & dosage, Cholesterol administration & dosage, Cross-Priming drug effects, Dendritic Cells drug effects, Dendritic Cells immunology, Drug Combinations, Humans, Killer Cells, Natural drug effects, Killer Cells, Natural immunology, Melanoma, Experimental immunology, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Myeloid Differentiation Factor 88 immunology, Myeloid Differentiation Factor 88 metabolism, Ovalbumin immunology, Phospholipids administration & dosage, Receptor Cross-Talk drug effects, Saponins administration & dosage, Signal Transduction drug effects, CD8-Positive T-Lymphocytes immunology, Cancer Vaccines immunology, Cholesterol immunology, Phospholipids immunology, Saponins immunology
- Abstract
Generating a cytotoxic CD8(+) T-cell response that can eradicate malignant cells is the primary objective of cancer vaccine strategies. In this study we have characterized the innate and adaptive immune response to the ISCOMATRIX adjuvant, and the ability of vaccine antigens formulated with this adjuvant to promote antitumor immunity. ISCOMATRIX adjuvant led to a rapid innate immune cell response at the injection site, followed by the activation of natural killer and dendritic cells (DC) in regional draining lymph nodes. Strikingly, major histocompatibility complex (MHC) class I cross-presentation by CD8α(+) and CD8α(-) DCs was enhanced by up to 100-fold when antigen was formulated with ISCOMATRIX adjuvant. These coordinated features enabled efficient CD8(+) T-cell cross-priming, which exhibited prophylactic and therapeutic tumoricidal activity. The therapeutic efficacy of an ISCOMATRIX vaccine was further improved when co-administered with an anti-CD40 agonist antibody, suggesting that ISCOMATRIX-based vaccines may combine favorably with other immune modifiers in clinical development to treat cancer. Finally, we identified a requirement for the myeloid differentiation primary response gene 88 (MyD88) adapter protein for both innate and adaptive immune responses to ISCOMATRIX vaccines in vivo. Taken together, our findings support the utility of the ISCOMATRIX adjuvant for use in the development of novel vaccines, particularly those requiring strong CD8(+) T-cell immune responses, such as therapeutic cancer vaccines.
- Published
- 2012
- Full Text
- View/download PDF
14. An Fcγ receptor-dependent mechanism drives antibody-mediated target-receptor signaling in cancer cells.
- Author
-
Wilson NS, Yang B, Yang A, Loeser S, Marsters S, Lawrence D, Li Y, Pitti R, Totpal K, Yee S, Ross S, Vernes JM, Lu Y, Adams C, Offringa R, Kelley B, Hymowitz S, Daniel D, Meng G, and Ashkenazi A
- Subjects
- Animals, Antibodies, Monoclonal genetics, Antibodies, Monoclonal immunology, Antibodies, Monoclonal pharmacology, Antibodies, Monoclonal therapeutic use, Antibodies, Monoclonal, Humanized, Apoptosis immunology, B-Lymphocytes drug effects, B-Lymphocytes metabolism, CD40 Antigens agonists, CD40 Antigens immunology, Cell Line, Tumor, Female, HCT116 Cells, Humans, Immunoglobulin Fc Fragments genetics, Immunoglobulin G genetics, Immunoglobulin G immunology, Immunoglobulin G pharmacology, Killer Cells, Natural immunology, Leukocytes immunology, Leukocytes metabolism, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Knockout, Mutation genetics, Mutation immunology, Myeloid Cells immunology, NF-kappa B metabolism, Neoplasms drug therapy, Neoplasms pathology, Polymorphism, Single Nucleotide genetics, Polymorphism, Single Nucleotide immunology, Protein Binding genetics, Protein Binding immunology, Receptor Aggregation immunology, Receptors, IgG genetics, Receptors, TNF-Related Apoptosis-Inducing Ligand agonists, Receptors, TNF-Related Apoptosis-Inducing Ligand immunology, Xenograft Model Antitumor Assays, Antibodies, Monoclonal metabolism, Neoplasms metabolism, Receptors, IgG metabolism, Receptors, TNF-Related Apoptosis-Inducing Ligand metabolism, Signal Transduction immunology
- Abstract
Antibodies to cell-surface antigens trigger activatory Fcγ receptor (FcγR)-mediated retrograde signals in leukocytes to control immune effector functions. Here, we uncover an FcγR mechanism that drives antibody-dependent forward signaling in target cells. Agonistic antibodies to death receptor 5 (DR5) induce cancer-cell apoptosis and are in clinical trials; however, their mechanism of action in vivo is not fully defined. Interaction of the DR5-agonistic antibody drozitumab with leukocyte FcγRs promoted DR5-mediated tumor-cell apoptosis. Whereas the anti-CD20 antibody rituximab required activatory FcγRs for tumoricidal function, drozitumab was effective in the context of either activatory or inhibitory FcγRs. A CD40-agonistic antibody required similar FcγR interactions to stimulate nuclear factor-κB activity in B cells. Thus, FcγRs can drive antibody-mediated receptor signaling in target cells., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
15. Prognostic significance of molecular markers and extent of resection in primary glioblastoma patients.
- Author
-
Felsberg J, Rapp M, Loeser S, Fimmers R, Stummer W, Goeppert M, Steiger HJ, Friedensdorf B, Reifenberger G, and Sabel MC
- Subjects
- Adult, Aged, Aged, 80 and over, Brain Neoplasms surgery, Brain Neoplasms therapy, Chromosomes, Human, Pair 1, Chromosomes, Human, Pair 10, Chromosomes, Human, Pair 19, Combined Modality Therapy, DNA Methylation, DNA Modification Methylases genetics, DNA Repair Enzymes genetics, Female, Glioblastoma surgery, Humans, Loss of Heterozygosity, Male, Middle Aged, Mutation, Polymorphism, Single Nucleotide, Prognosis, Promoter Regions, Genetic, RNA, Messenger metabolism, Survival Analysis, Tumor Suppressor Proteins genetics, Biomarkers, Tumor analysis, Brain Neoplasms genetics, DNA Modification Methylases analysis, DNA Repair Enzymes analysis, Glioblastoma genetics, Glioblastoma therapy, Tumor Suppressor Proteins analysis
- Abstract
Purpose: Despite multimodal aggressive treatment glioblastoma patients still face a rather poor prognosis. Recent data indicate that certain molecular markers, in particular MGMT promoter hypermethylation, are associated with response to alkylating chemotherapy and longer survival. The clinical significance of other glioblastoma-associated molecular aberrations and their relationship to MGMT promoter hypermethylation is still poorly understood., Experimental Design: We conducted a translational study involving 67 newly diagnosed glioblastoma patients treated at our institution from 1998 to 2004. All patients were treated by open resection, followed by radiotherapy and adjuvant temozolomide chemotherapy. The tumors were investigated for MGMT promoter methylation, mRNA and protein expression, as well as presence of MGMT sequence polymorphisms. In addition, we screened for genetic aberrations of the EGFR, TP53, CDK4, MDM2, and PDGFRA genes as well as allelic losses on chromosomal arms 1p, 10q, and 19q., Results: Correlation of molecular findings with clinical data revealed significantly longer time to progression after onset of chemotherapy and longer overall survival of patients with MGMT-hypermethylated tumors. In contrast, MGMT protein expression, MGMT polymorphisms, and aberrations in any of the other genes and chromosomes were not significantly linked to patient outcome. Multivariate analysis identified MGMT promoter hypermethylation and near-complete tumor resection as the most important parameters associated with better prognosis., Conclusion: Our study provides novel insights into the significance of molecular and clinical markers in predicting the prognosis of glioblastoma patients, which may improve stratification of patients into distinct prognostic subgroups.
- Published
- 2009
- Full Text
- View/download PDF
16. The ubiquitin E3 ligase Cbl-b in T cells tolerance and tumor immunity.
- Author
-
Loeser S and Penninger JM
- Subjects
- Animals, Humans, Neoplasms genetics, Protein Binding, Proto-Oncogene Proteins c-cbl deficiency, Proto-Oncogene Proteins c-cbl genetics, Signal Transduction immunology, Immune Tolerance immunology, Neoplasms enzymology, Neoplasms immunology, Proto-Oncogene Proteins c-cbl metabolism, T-Lymphocytes enzymology, T-Lymphocytes immunology
- Abstract
The implication of the immune system in tumor surveillance is proven and widely accepted. However, anti-cancer immunotherapy is still difficult due to insufficient activation, immune suppression and tolerance induction. The ubiquitin E3 ligase Cbl-b, is a member of the Cbl (casitas B-lineage lymphoma) protein family and was identified as a key dominant "tolerogenic" factor in T cells that directly regulates T-cell activation by controlling activation thresholds and the requirement for co-stimulation. Intriguingly, Cbl-b deficient mice spontaneously reject a variety of cancers including spontaneous solid tumors and hematopoietic malignancies. Mechanistically, modulation of Cbl-b in T cells controls activation of tumor-reactive cytotoxic T cells in vivo and might circumvent several limitations of T cell immunotherapy. Therefore manipulation of Cbl-b might provide us with a unique opportunity for future immune treatment of human disorders such as autoimmunity, chronic viral infections, or cancer.
- Published
- 2007
- Full Text
- View/download PDF
17. Regulation of peripheral T cell tolerance by the E3 ubiquitin ligase Cbl-b.
- Author
-
Loeser S and Penninger JM
- Subjects
- Adaptor Proteins, Signal Transducing immunology, Adaptor Proteins, Signal Transducing metabolism, Clonal Anergy physiology, Humans, Proto-Oncogene Proteins c-cbl immunology, Proto-Oncogene Proteins c-cbl metabolism, Clonal Anergy immunology, Self Tolerance immunology, T-Lymphocytes immunology, Ubiquitin-Protein Ligases physiology
- Abstract
The family of the Casitas B-lineage Lymphoma (Cbl) proteins, c-Cbl, Cbl-b, and Cbl-3, function as E3 ubiquitin ligases and molecular adaptors. In particular, Cbl-b acts as a gatekeeper in T cell activation that controls activation thresholds and the requirement for co-stimulation. Loss of Cbl-b expression renders animals susceptible to antigen-triggered autoimmunity suggesting that Cbl-b is a key autoimmunity gene. In addition, Cbl-b plays a critical role in T cell anergy and escape from regulatory T cells (Treg) suppression. Modulation of Cbl-b might provide us with a unique opportunity for future immune treatment of human disorders such as autoimmunity, immunodeficiency, or cancer.
- Published
- 2007
- Full Text
- View/download PDF
18. Spontaneous tumor rejection by cbl-b-deficient CD8+ T cells.
- Author
-
Loeser S, Loser K, Bijker MS, Rangachari M, van der Burg SH, Wada T, Beissert S, Melief CJ, and Penninger JM
- Subjects
- Adaptor Proteins, Signal Transducing genetics, Adaptor Proteins, Signal Transducing immunology, Animals, CD4-Positive T-Lymphocytes immunology, CD4-Positive T-Lymphocytes metabolism, CD8-Positive T-Lymphocytes immunology, Female, Immunologic Memory, Interleukin-2 Receptor alpha Subunit metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Mutation genetics, Neoplasms genetics, Neoplasms pathology, Proto-Oncogene Proteins c-cbl genetics, Proto-Oncogene Proteins c-cbl immunology, Survival Rate, Ultraviolet Rays adverse effects, Adaptor Proteins, Signal Transducing deficiency, Adaptor Proteins, Signal Transducing metabolism, CD8-Positive T-Lymphocytes metabolism, Neoplasms immunology, Proto-Oncogene Proteins c-cbl deficiency, Proto-Oncogene Proteins c-cbl metabolism
- Abstract
The concept of tumor surveillance implies that specific and nonspecific components of the immune system eliminate tumors in the early phase of malignancy. Understanding the biochemical mechanisms of tumor immunosurveillance is of paramount significance because it might allow one to specifically modulate spontaneous antitumor activity. We report that inactivation of the E3 ligase Casitas B cell lymphoma-b (Cbl-b) confers spontaneous in vivo rejection of tumor cells that express human papilloma virus antigens. Moreover, cbl-b(-/-) mice develop significantly fewer ultraviolet B (UVB)-induced skin malignancies and reject UVB-induced skin tumors. CD8(+) T cells were identified as key players in the spontaneous tumor rejection response. Loss of Cbl-b not only enhances antitumor reactivity of CD8(+) T cells but also occurs in the absence of CD4(+) T cells. Mechanistically, cbl-b(-/-) CD8(+) T cells are resistant to T regulatory cell-mediated suppression and exhibit enhanced activation and rapid tumor infiltration. Importantly, therapeutic transfer of naive cbl-b(-/-) CD8(+) T cells is sufficient to mediate rejection of established tumors. Even up to 1 yr after the first encounter with the tumor cells, cbl-b(-/-) mice carry an "anticancer memory." These data identify Cbl-b as a key signaling molecule that controls spontaneous antitumor activity of cytotoxic T cells in different cancer models. Inhibition of Cbl-b is a novel approach to stimulate long-lasting immunity against cancer.
- Published
- 2007
- Full Text
- View/download PDF
19. Distinct genetic signatures among pilocytic astrocytomas relate to their brain region origin.
- Author
-
Sharma MK, Mansur DB, Reifenberger G, Perry A, Leonard JR, Aldape KD, Albin MG, Emnett RJ, Loeser S, Watson MA, Nagarajan R, and Gutmann DH
- Subjects
- Adolescent, Adult, Algorithms, Astrocytoma metabolism, Astrocytoma pathology, Child, Child, Preschool, Cluster Analysis, Female, Gene Expression Profiling, Humans, Infratentorial Neoplasms metabolism, Infratentorial Neoplasms pathology, Male, Middle Aged, Neurofibromatosis 1 genetics, Neurofibromatosis 1 metabolism, Neurofibromatosis 1 pathology, Oligonucleotide Array Sequence Analysis, Supratentorial Neoplasms metabolism, Supratentorial Neoplasms pathology, Astrocytoma genetics, Infratentorial Neoplasms genetics, Supratentorial Neoplasms genetics
- Abstract
Pilocytic astrocytomas (PAs) are the most common glioma in children. Whereas many PAs are slow-growing or clinically indolent, others exhibit more aggressive features with tumor recurrence and death. To identify genetic signatures that might predict PA clinical behavior, we did gene expression profiling on 41 primary PAs arising sporadically and in patients with neurofibromatosis type 1 (NF1). Whereas no expression signature was found that could discriminate clinically aggressive or recurrent tumors from more indolent cases, PAs arising in patients with NF1 did exhibit a unique gene expression pattern. In addition, we identified a gene expression signature that stratified PAs by location (supratentorial versus infratentorial). Lastly, we also identified a gene expression pattern common to PAs and normal mouse astrocytes and neural stem cells from these distinct brain regions as well as a gene expression pattern shared between PAs and another human glial tumor (ependymoma) arising supratentorially compared with those originating in the posterior fossa. These results suggest that glial tumors share an intrinsic, lineage-specific molecular signature that reflects the brain region in which their nonmalignant predecessors originated.
- Published
- 2007
- Full Text
- View/download PDF
20. Epidermal RANKL controls regulatory T-cell numbers via activation of dendritic cells.
- Author
-
Loser K, Mehling A, Loeser S, Apelt J, Kuhn A, Grabbe S, Schwarz T, Penninger JM, and Beissert S
- Subjects
- Animals, Autoimmunity, Cell Count, Epidermal Cells, Epidermis metabolism, Immune Tolerance radiation effects, Mice, Mice, Inbred C3H, Mice, Inbred C57BL, Mice, Transgenic, RANK Ligand genetics, RANK Ligand metabolism, Ultraviolet Rays, Dendritic Cells physiology, Epidermis physiology, RANK Ligand physiology, T-Lymphocytes, Regulatory cytology
- Abstract
Regulatory CD4(+)CD25(+) T cells are important in suppressing immune responses. The requirements for the maintenance of peripheral CD4(+)CD25(+) T cells remain incompletely understood. Receptor activator of NF-kappaB (RANK) and its ligand (RANKL; also known as CD254, OPGL and TRANCE) are key regulators of bone remodeling, mammary gland formation, lymph node development and T-cell/dendritic cell communication. Here we report that RANKL is expressed in keratinocytes of the inflamed skin. RANKL overexpression in keratinocytes resulted in functional alterations of epidermal dendritic cells and systemic increases of regulatory CD4(+)CD25(+) T cells. Thus, epidermal RANKL expression can change dendritic cell functions to maintain the number of peripheral CD4(+)CD25(+) regulatory T cells. Epidermal RANKL mediated ultraviolet-induced immunosuppression and overexpression of epidermal RANKL suppressed allergic contact hypersensitivity responses and the development of systemic autoimmunity. Therefore, environmental stimuli at the skin can rewire the local and systemic immune system by means of RANKL.
- Published
- 2006
- Full Text
- View/download PDF
21. Phase II trial of lomustine plus temozolomide chemotherapy in addition to radiotherapy in newly diagnosed glioblastoma: UKT-03.
- Author
-
Herrlinger U, Rieger J, Koch D, Loeser S, Blaschke B, Kortmann RD, Steinbach JP, Hundsberger T, Wick W, Meyermann R, Tan TC, Sommer C, Bamberg M, Reifenberger G, and Weller M
- Subjects
- Administration, Oral, Adult, Aged, Antineoplastic Combined Chemotherapy Protocols adverse effects, Brain Neoplasms drug therapy, Brain Neoplasms radiotherapy, Chemotherapy, Adjuvant, Dacarbazine administration & dosage, Dacarbazine adverse effects, Dacarbazine analogs & derivatives, Disease-Free Survival, Drug Administration Schedule, Female, Glioblastoma genetics, Humans, Lomustine administration & dosage, Lomustine adverse effects, Male, Middle Aged, Predictive Value of Tests, Prognosis, Promoter Regions, Genetic, Radiotherapy, Adjuvant, Survival Analysis, Temozolomide, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, DNA Methylation, Glioblastoma drug therapy, Glioblastoma radiotherapy, O(6)-Methylguanine-DNA Methyltransferase genetics
- Abstract
Purpose: To evaluate toxicity and efficacy of the combination of lomustine, temozolomide (TMZ) and involved-field radiotherapy in patients with newly diagnosed glioblastoma (GBM)., Patients and Methods: Thirty-one adult patients (median Karnofsky performance score 90; median age, 51 years) accrued in two centers received involved-field radiotherapy (60 Gy in 2-Gy fractions) and chemotherapy with lomustine 100 mg/m2 (day 1) and TMZ 100 mg/m2/d (days 2 to 6) with individual dose adjustments according to hematologic toxicity., Results: A median of five courses (range, one to six courses) were delivered. WHO grade 4 hematotoxicity was observed in five patients (16%) and one of these patients died as a result of septicemia. Nonhematologic toxicity included one patient with WHO grade 4 drug-induced hepatitis (leading to discontinuation of lomustine and TMZ) and one patient with WHO grade 2 lung fibrosis (leading to discontinuation of lomustine). The progression-free survival (PFS) rate at 6 months was 61.3%. The median PFS was 9 months (95% CI, 5.3 to 11.7 months), the median overall survival time (MST) was 22.6 months (95% CI, 12.5 to not assessable), the 2-year survival rate was 44.7%. O6-methylguanine-DNA methyltransferase (MGMT) gene-promoter methylation in the tumor tissue was associated with longer PFS (P = .014, log-rank test) and MST (P = .037)., Conclusion: The combination of lomustine, TMZ, and radiotherapy had acceptable toxicity and yielded promising survival data in patients with newly diagnosed GBM. MGMT gene-promoter methylation was a strong predictor of survival.
- Published
- 2006
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.