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- Magalhaes, Isabelle
(author)
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CD8alpha/alpha+ T-cells and immune memory
- 2009
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Doctoral thesis (other academic/artistic)abstract
- A better understanding of T-cell memory formation is crucial for rationale vaccine design and the identification of correlates of immune protection. The CD8αα homodimer expressed on CD8+ T-cells is not anymore considered to represent a TCR co-receptor, it may rather represent a mechanism to modulate T-cell avidity and identify a subset of memory T-cells. The aim of the work presented in this thesis was to characterize the CD8αα+ T-cell compartment in the context of vaccination, where T-cell memory plays a pivotal role. We analyzed in Paper I the phenotype of CD8αα+ T-cells in healthy donors and in rhesus macaque monkeys (Macaca mulatta) which represent a very valuable animal model for preclinical vaccine trials. CD8αα+ T-cells were present in healthy donors and in a higher frequency in rhesus monkeys. In both species, the CD8αα+ T-cell compartment was enriched in differentiated (effector and memory) T-cells, as compared to the CD4+ and CD8αβ+ T-cell compartments, and displayed a polyfunctional capacity. We developed assays allowing to study the T-cell compartment in rhesus monkeys, and showed that CD8αα+ T-cells can be studied in rhesus monkeys. In Paper II, we assessed longitudinally the presence of CD8αα+ T- cells in patients with melanoma who underwent peptide-based vaccination and showed a partial or complete tumor regression. CD8αα+ T-cells represented a stable population with an effector or terminally differentiated phenotype, and Melan-A/MART-1-specific CD8αα+ T-cells were detected in one patient up to five years after vaccination. The oligoclonal TCR repertoire of CD8αα+ T-cells and the similar TCR repertoire of Melan-A/MART-1 of CD8αα+ and CD8αβ+ T-cells, supported our hypothesis that CD8αα+ T-cells arise from CD8αβ+ T-cells which downregulated CD8β chain expression upon Ag stimulation. We identified, in Paper III, an increase of Mtb-specific CD8αα+ T-cells in rhesus monkeys after TB vaccination. The characterization of CD8αα+ T-cells phenotype in rhesus monkeys after TB vaccination and after Mtb infection was further analyzed in Paper IV. CD8αα+ T-cells underwent similar phenotypical changes as observed in the CD4+ and CD8αβ+ T-cell compartments, in vaccinated but not in non-vaccinated animals: loss of IL-7Rα after the first Ad boost, and transient decrease of precursor T-cells (defined by CD45RA/CCR7 expression) after Mtb challenge. These results suggest that CD8αα+ T-cells contribute to the formation of immunological memory and participate in the formation of the cellular immune response. We hypothesize that the expression of CD8αα enables to modulate the avidity of CD8+ T-cells with high affinity TCRs. Yet, the mechanisms of CD8αα+ T-cells formation need to be further elucidated. Altogether, our data underscores the role of CD8αα+ T-cells in the establishment of immune memory in humans and rhesus monkeys. The detection and characterization of Ag-specific CD8αα+ T-cells may represent a relevant marker in the context of vaccine trials and to custom-tailor immune therapeutic strategies with the aim to establish long-lived and Ag-specific immune responses.
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- Magalhaes, Isabelle, et al.
(author)
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Facing the future : challenges and opportunities in adoptive T cell therapy in cancer
- 2019
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In: Expert Opinion on Biological Therapy. - : Taylor & Francis Group. - 1471-2598 .- 1744-7682. ; 19:8, s. 811-827
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Journal article (peer-reviewed)abstract
- INTRODUCTION: In recent years, immunotherapy for the treatment of solid cancer has emerged as a promising therapeutic alternative. Adoptive cell therapy (ACT), especially T cell-based, has been found to cause tumor regression and even cure in a percentage of treated patients. Checkpoint inhibitors further underscore the potential of the T cell compartment in the treatment of cancer. Not all patients respond to these treatments; however, many challenges remain.AREAS COVERED: This review covers the challenges and progress in tumor antigen target identification and selection, and cell product manufacturing for T cell ACT. Tumor immune escape mechanisms and strategies to overcome those in the context of T cell ACT are also discussed.EXPERT OPINION: The immunotherapy toolbox is rapidly expanding and improving, and the future promises further breakthroughs in the T cell ACT field. The heterogeneity of the tumor microenvironment and the multiplicity of tumor immune escape mechanisms pose formidable challenges to successful T cell immunotherapy in solid tumors, however. Individualized approaches and strategies combining treatments targeting different immunotherapeutic aspects will be needed in order to expand the applicability and improve the response rates in future.
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- Magalhaes, Isabelle, et al.
(author)
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Mesothelin Expression in Patients with High-Grade Serous Ovarian Cancer Does Not Predict Clinical Outcome But Correlates with CD11c+ Expression in Tumor
- 2020
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In: Advances in Therapy. - : Springer. - 0741-238X .- 1865-8652. ; 37:12, s. 5023-5031
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Journal article (peer-reviewed)abstract
- Introduction: Mesothelin (MSLN) is overexpressed in several tumors including ovarian cancer and is the target of current trials. There is limited and conflicting data on MSLN prognostic impact in ovarian cancer.Methods: We performed a retrospective study on patients with high-grade serous ovarian cancer, analyzing MSLN expression by immunohistochemistry and examining the correlation of its expression to overall and progression-free survival. Correlations of expression of MSLN, CD8, and macrophage markers in different tumor compartments were also investigated.Results: Positive MSLN expression was detected in 55.1% of primary tumors and 51.5% of the metastases. MSLN expression was not correlated with survival. We observed a significant positive correlation (r = 0.34, p = 0.01) between MSLN expression in the metastatic site and CD11c expression in total tumor area and perivascular area in the primary tumor.Conclusion: Our results show that MSLN expression does not correlate with clinical outcome. The impact of the correlation between MSLN and CD11c+ cells on immunotherapy outcome should be further explored.
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- Radestad, Emelie, et al.
(author)
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Immune profiling and identification of prognostic immune-related risk factors in human ovarian cancer
- 2019
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In: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 8:2
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Journal article (peer-reviewed)abstract
- Suppression of immune reactivity by increased expression of co-inhibitory receptors has been discussed as a major reason as to why the immune system fails to control tumor development. Elucidating the co-inhibitory expression pattern of tumor-infiltrating lymphocytes in different cancer types will help to develop future treatment strategies. We characterized markers reflecting and affecting T-cell functionality by flow cytometry on lymphocytes isolated from blood, ascites and tumor from advanced ovarian cancer patients (n = 35). Significantly higher proportions of CD4+ and CD8+ T-cells expressed coinhibitory receptors LAG-3, PD-1 and TIM-3 in tumor and ascites compared to blood. Co-expression was predominantly observed among intratumoral CD8+ T-cells and the most common combination was PD-1 and TIM-3. Analysis of 26 soluble factors revealed highest concentrations of IP-10 and MCP-1 in both ascites and tumor. Correlating these results with clinical outcome revealed the proportion of CD8+ T-cells without expression of LAG-3, PD-1 and TIM-3 to be beneficial for overall survival. In total we identified eight immune-related risk factors associated with reduced survival. Ex vivo activation showed tumor-derived CD4+ and CD8+ T-cells to be functionally active, assessed by the production of IFN-gamma, IL-2, TNF-alpha, IL-17 and CD107a. Blocking the PD-1 receptor resulted in significantly increased release of IFN-. suggesting potential reinvigoration. The ovarian tumor environment exhibits an inflammatory milieu with abundant presence of infiltrating immune cells expressing inhibitory checkpoints. Importantly, we found subsets of CD8+ T-cells with double and triple expression of co-inhibitory receptors, supporting the need for multiple checkpoint-targeting agents to overcome T-cell dysfunction in ovarian cancer.
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- Schoutrop, Esther, et al.
(author)
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Mesothelin-Specific CAR T Cells Target Ovarian Cancer
- 2021
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In: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 81:11, s. 3022-3035
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Journal article (peer-reviewed)abstract
- New therapeutic options for patients with ovarian cancer are urgently needed. Therefore, we evaluated the efficacy of two second-generation mesothelin (MSLN)-directed CAR T cells in orthotopic mouse models of ovarian cancer. Treatment with CAR T cells expressing an MSLN CAR construct including the CD28 domain (M28z) significantly prolonged survival, but no persistent tumor control was observed. Despite lower response rates, MSLN-4-1BB (MBBz) CAR T cells induced long-term remission in some SKOV3-bearing mice. Tumor-infiltrating M28z and MBBz CAR T cells upregulated PD-1 and LAG3 in an antigen-dependent manner while MSLN+ tumor cells expressed the corresponding ligands (PD-L1 and HLA-DR), demonstrating that coin-hibitory pathways impede CAR T-cell persistence in the ovarian tumor microenvironment. Furthermore, profiling plasma soluble factors identified a cluster of M28z- and MBBz-treated mice characterized by elevated T-cell secreted factors that had increased survival, higher CD8(+) T-cell tumor infiltration, less exhausted CAR T-cell phenotypes, and increased HLA-DR expression by tumor cells. Altogether, our study demonstrates the therapeutic potential of MSLN-CAR T cells to treat ovarian cancer. Significance: These findings demonstrate that MSLN-directed CAR T cells can provide antitumor immunity against ovarian cancer.
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| 7. |
- Schoutrop, Esther, et al.
(author)
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Tuned activation of MSLN-CAR T cells induces superior antitumor responses in ovarian cancer models
- 2023
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In: Journal for ImmunoTherapy of Cancer. - : BMJ Publishing Group Ltd. - 2051-1426. ; 11:2
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Journal article (peer-reviewed)abstract
- BACKGROUND: Limited persistence of functional CAR T cells in the immunosuppressive solid tumor microenvironment remains a major hurdle in the successful translation of CAR T cell therapy to treat solid tumors. Fine-tuning of CAR T cell activation by mutating CD3ζ chain immunoreceptor tyrosine-based activation motifs (ITAMs) in CD19-CAR T cells (containing the CD28 costimulatory domain) has proven to extend functional CAR T cell persistence in preclinical models of B cell malignancies.METHODS: In this study, two conventional second-generation MSLN-CAR T cell constructs encoding for either a CD28 co-stimulatory (M28z) or 4-1BB costimulatory (MBBz) domain and a novel mesothelin (MSLN)-directed CAR T cell construct encoding for the CD28 costimulatory domain and CD3ζ chain containing a single ITAM (M1xx) were evaluated using in vitro and in vivo preclinical models of ovarian cancer. Two ovarian cancer cell lines and two orthotopic models of ovarian cancer in NSG mice were used: SKOV-3 cells inoculated through microsurgery in the ovary and to mimic a disseminated model of advanced ovarian cancer, OVCAR-4 cells injected intraperitoneally. MSLN-CAR T cell treatment efficacy was evaluated by survival analysis and the characterization and quantification of the different MSLN-CAR T cells were performed by flow cytometry, quantitative PCR and gene expression analysis.RESULTS: M1xx CAR T cells elicited superior antitumor potency and persistence, as compared with the conventional second generation M28z and MBBz CAR T cells. Ex vivo M28z and MBBz CAR T cells displayed a more exhausted phenotype than M1xx CAR T cells as determined by co-expression of PD-1, LAG-3 and TIM-3. Furthermore, M1xx CAR T cells showed superior ex vivo IFNy, TNF and GzB production and were characterized by a self-renewal gene signature.CONCLUSIONS: Altogether, our study demonstrates the enhanced therapeutic potential of MSLN-CAR T cells expressing a mutated CD3ζ chain containing a single ITAM for the treatment of ovarian cancer. CAR T cells armored with calibrated activation potential may improve the clinical responses in solid tumors.
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