Dissertationen zum Thema „Checkpoint immunitaire“
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Soussan, Sarah. „B lymphocytes and autoantibodies in immune-related adverse events following immune checkpoint inhibitors in cancer patients“. Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS022.pdf.
Der volle Inhalt der QuelleImmune checkpoints inhibitors (ICI) have revolutionized the treatment of previously incurable malignancies. Unfortunately, the use of ICI also induces a bystander breakdown of peripheral tolerance leading to immune related Adverse Events (irAEs) in 30-90% of treated patients, drastically reducing quality of life and requiring therapy dose reduction or discontinuation. As ICI directly target T cells, they have been considered the main culprit for irAEs. Nevertheless, T cells cannot fully explain adverse events, and the role of B cells and their associated mechanisms have not been characterized. We therefore studied the involvement of peripheral B-cell compartment in irAEs, using both phenotypic and functional approaches, in two cohorts of solid cancer patients treated with anti-PD-1 and/or anti-CTLA-4 monoclonal antibodies. Deep phenotyping of B-cell subsets throughout the treatment and at the onset of irAEs has been performed by multi-parametric spectral flow cytometry. Subsequently, to analyze the functions of B-cell subsets, notably their ability to produce antibodies, we set-up a B-cell culture system allowing in vitro differentiation of B cells into antibody-secreting cells. This gave us the opportunity to analyze the antibody production by circulating B cells and their association with irAEs occurence. The screening of circulating B cells phenotype and function was conducted alongside the evaluation of the serum and plasma reactivity of cancer patients by complementary approaches (ELISA, Western Blot, Immunofluorescence assays). We found that, before treatment, patients that develop ICI-induced irAEs exhibit a significantly lower expression on B cell subsets of the FcγRIIB, CD85j and LAIR-1 inhibitory receptors in melanoma patients and higher expression of the CD95 and CXCR5, respectively activating and lymphoid organs re-circulatory markers in lung cancer patients. In addition, increased in baseline abundance of hyper-activated IgD- memory B cell subset or plasmablasts precursor were observed in patients that will undergo irAEs. Moreover, a part of irAEs patients exhibit baseline or ICI-induce circulating autoantibodies which could be directed against the related tissue of irAEs occurrence. Indeed, patients experiencing cardiac/muscular irAEs demonstrated autoantibodies directed against cardiac tissues and well-defined cardiac/muscle antigens. Finally, IgG derived from cardiac/muscular irAEs patients bound to human cardiomyocytes and perturbed the calcium kinetic and the contractibility of cardiac spheroids. These findings highlight a predisposition of irAEs incidence in patients with baseline highly activated and differentiated circulating B cells associated with autoantibody production. Overall, these results support the potential role of the humoral adaptative immunity in the mechanisms of ICI-induced irAEs
Dal, Cin Julian. „Analyse tissulaire des myopathies inflammatoires idiopathiques et induites par immune-checkpoint-inhibitor : apport des nouvelles approches transcriptomiques“. Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS151.pdf.
Der volle Inhalt der QuelleMyositis are a heterogeneous group of autoimmune pathologies characterized by muscle damage in patients. Myositis are separated into 5 subgroups: dermatomyositis (DM), anti-synthetase syndromes (ASyS), inclusion body myositis (IBM), autoimmune necrotizing myopathies (IMNM) and immune-checkpoint inhibitor (ICI)-induced myositis. The pathophysiological mechanisms, clinical phenotype and prognosis of each subgroup are different. Among myositis, this work focused on IMNM and ICI-induced myositis, which have the poorest prognosis. High-resolution, spatial and single-cell transcriptomic studies have made it possible to study the muscle tissue of patients with these myositis. In ICI-induced myositis, these studies have confirmed the cytotoxicity of CD8 T cells and their central role, mainly of a population of resident memory T cells identified in the muscle, as well as macrophages. We propose a pathogenic model based on the reaction of resident memory T cells to ICI treatments. In IMNM, subgroups of macrophages have been identified composed respectively of pro-inflammatory macrophages, anti-inflammatory macrophages, and macrophages close to fibro-adipogenic progenitors (FAP). We propose that necrosis can stimulate macrophages and induce their recruitment, which would allow the proliferation of FAPs at the origin of exacerbated fibrosis in patients. Understanding mechanisms among others makes it possible to consider new therapeutic targets and improve patient prognosis
Tannous, Désirée. „The combination of Gadolinium-based nanoparticles, radiotherapy and immune checkpoint inhibitors : a novel therapeutic opportunity for cancer treatment“. Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPASL082.
Der volle Inhalt der QuelleScientific discoveries linked to radiotherapy are in continuous progress and almost 60% of cancer diagnosed patients are treated with radiotherapy. However, radiation therapy still faces many limitations due to radioresistance and the side effects inflected on healthy tissues. To overcome these factors, a particular interest has been aroused on the role that nanomedicine could play in the improvement of immune-mediated anti-tumor response. In this context, we decided to assess the ability of the combination of Gadolinium nanoparticles (AGuIX) with ionizing radiation (IR) to stimulate an anti-tumor immunological response and to increase the effectiveness of radiotherapy combined to immune checkpoint blockers.AGuIX are very small nanoparticles composed of a polysiloxane matrix and gadolinium chelates. Thanks to the magnetic properties of gadolinium, these nanoparticles play the role of a contrast agent, in addition to its radiosensitizing properties, thus allowing a better targeting and an enhanced therapeutic index.Our work reveals the ability of the AGuIX+IR combination to induce genomic instability and to stimulate immunomodulatory cell signaling pathways in treated human and murine cancer cells. In parallel, we demonstrate the anti-tumor activity of this combination by assessing tumor growth and overall survival using a preclinical model of immunocompetent mice bearing tumors. Our results strongly demonstrate a synergistic effect of AGuIX + IR combination on tumor growth and overall survival by stimulating the immune system. Finally, we reveal the capacity of AGuIX + IR combination to overcome immune checkpoint blockers resistance.In conclusion, our work shows that the combination of AGuIX+IR stimulates immunomodulatory signaling pathways, induces a strong synergistic anti-tumor response and helps overcoming resistance to immunotherapies
Nougue, Manon. „Rôle immunomodulateur du système lymphatique lors du développement tumoral mammaire“. Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30261.
Der volle Inhalt der QuelleThe lymphatic system is a unidirectional vascular network transporting lymph, enabling drainage of interstitial fluids, transport of intestinal lipids, and also immune monitoring and tolerance. Nevertheless, the lymphatic system is involved in many pathologies, and particularly in tumor progression. Indeed, the lymphatic system promotes the metastatic spread, carried by lymphatic vessels to distant organs. More recently, the lymphatic system has been identified as a key regulator of immune responses during tumor development. The immune system is essential for tumor detection and establishment of anti-tumor lymphocyte responses. However, at advanced stages of tumor development, immune escape mechanisms are established in favor of tumor growth. These mechanisms are mediated not only by tumors themselves, but also by various players in the tumor environment. The lymphatic system is one of these players, particularly found in breast tumor environment. Advanced-stage breast adenocarcinomas respond to immunotherapies that target immune checkpoints responsible for immune escape. Indeed, the lymphatic system potentiates tumor response to these immunotherapies, playing a dual role in immunomodulation in the tumor context. Lymphatic vessels are able to recruit T cells to the tumor site to stimulate anti-tumor immune surveillance, but are also able to generate T cell immunosuppressive mechanisms through the expression of immune checkpoints. During my thesis, I therefore studied immunomodulatory mechanisms of the lymphatic system during mammary tumor development. I observed that the lymphatic system controls a switch from immune surveillance to immunosuppression, particularly induced by ligands of TIGIT immune checkpoint. I have shown that activation of tumor lymphatic vessels leads to overexpression of Nectin-2, which inhibits T cells overexpressing TIGIT. This in turn reduces cytotoxic CD8+ T cell responses to promote tumor growth
Miloro, Giorgia. „Déterminer le rôle du récepteur de mort Fas/CD95 dans la co-stimulation des cellules T“. Electronic Thesis or Diss., Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ6036.
Der volle Inhalt der QuelleFas (CD95/TNFRSF6), a type-I transmembrane receptor of the tumor necrosis factor receptor (TNFR) superfamily, is a well-known cell death activator. However, it has been also implicated in non-cell death processes including cell survival, differentiation, migration. Whereas the molecular cascade that initiates apoptosis upon Fas engagement with its ligand FasL is particularly well described, the informations concerning the molecular mechanisms underlying the Fas mediated non-apoptotic pathways are sparse.As indicated by the induction of autoimmunity and lymphoproliferation in ALPS patients harboringmutations in either the receptor or its ligand, the Fas/FasL system plays a major role in T cell immune homeostasis and thus, in the control of autoimmunity and cancer. On one side, the Fas mediated death has been described critical for (i) the deletion of autoreactive lymphocytes, and thus in the maintenance of peripheral tolerance; (ii) the control of the number of lymphocytes activated by weak antigens during pathogen infections.On the other side, and beyond cell death induction, some Fas non-death pathways have been described in T cells, among which the role of Fas as co-regulatory receptor for the TCR during its activation. Despite the potential importance of this role in immunotherapeutic strategies, only few and controversial studies related to this involvement were done. Indeed, whereas several studies have described Fas as a TCR co-stimulatory receptor, others defined an inhibition of T cell activation by Fas-TCR concomitant stimulation. In this context, the aim of my PhD project consisted into molecularly dissect the Fas-TCR co-signaling.By using both primary T cells and cell lines bearing a specific transgenic TCR, we could define Fas as a costimulatory receptor. By exploiting biochemical approaches as well as flow cytometry and microscopy we could decipher the Fas-TCR crosstalk both at functional and molecular level. First, we show that Fas-TCR costimulation occurs in both naïve and in memory T cells as well as in both CD4+ and CD8+ T cell subpopulations.Molecularly, we could describe that Fas enhances the TCR signaling at membrane proximal level, since the phosphorylation of the first proteins involved in TCR activation is increased. Furthermore, both membrane-bound and soluble FasL are capable to initiate Fas co-stimulatory signal. Lastly, we could exclude the involvement of FADD and Caspase-8, first actors of Fas signaling, in the co-activation, and even more importantly, the involvement of the death domain of Fas cytoplasmic tail, unveiling the implication of another Fas receptor domain. To describe the molecular mechanisms and the context where Fas-TCR co-stimulation occurs might be of an outstanding importance in the comprehension of Fas physiopathology in T cells and for future studies that might involve its potential for immunotherapeutic strategies
Dupaty, Léa. „Evaluation in vivo de protéines immunorégulatrices dérivées de CTLA-4 et de PD-L1 pour leur capacité à inhiber les réponses immunitaires dans le contexte de la thérapie génique musculaire par AAV“. Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR133/document.
Der volle Inhalt der QuelleGene therapy consist into introducing genetic material into cells to treat genetic disorders. Most gene therapies use viral vectors to carry the gene within target cells. In case of monogenic disorders, adeno-associated viruses (AAV) has become a vector of choice because of its lack of pathogenicity, its large tropism and its capacity to transduce quiescent cells. The use of AAV is approved in Europe to treat a rare lysosomal storage disease and has recently been approved by the FDA to treat a genetic cause of blindness. However, most clinical trials face immune responses directed against AAV components which may be highly immunogenic. This deleterious immunogenicity often lead to the trial failure. In addition, transgenic protein can also be immunogenic, aimaing to the destruction of transduced cells and ultimatly to gene therapy failure. In clinic, immunosuppressive drug remain the only option to counteract unwanted immune responses. These drugs possess infectious and tumorigenic side effects, therefore strategies aiming to rather capable to induce tolerance toward the transgenic protein are being developped and needed. The objectif of this work was to implement a new strategy aiming to study the immunoregulatory and tolerogenic effect of fusion proteins derived from CTLA-4 and PD-L1. We used a murin model recapitulating the immunes responses induced by an AAV coding for an immunogenic model protein, ovalbumin (Ova) presented in previous studies by our group and others. Then, we synthesized AAV coding for our newly designed immunoregulatory protein and injected them into mice along with AAV-Ova. This strategy of vectorized immunoregulation (VIR) allowed to evaluate the intrinsic capacity of each individual proteins to modulate immune responses against Ova directly in vivo. Eventually, this work allow to 1) assess the benefits and limits of the VIR strategy, 2) the deletrious long-term effects of CTLA-4/Fc on central and peripheral Tregs in mice, 3) to demonstrate the interest of new molecules specifically derived from PD-L1/Fc over the immune tolerance through the long-term persistance of Ova transgene
Delage, Laure. „Des déficiences génétiques comme modèles naturels pour l'étude de la régulation des checkpoints immunitaires et la caractérisation des réponses auto-immunes“. Electronic Thesis or Diss., Université Paris Cité, 2021. http://www.theses.fr/2021UNIP5190.
Der volle Inhalt der QuelleRecessive NBEAL2 mutations have been reported in patients with Gray Platelet Syndrome (GPS). This syndrome is characterized by a macro-thrombocytopenia, with platelets lacking alpha-granules, leading to bleeding disorders, often associated with splenomegaly. Thus, NBEAL2 plays a crucial role in the trafficking of alpha-granules in platelets. Moreover, our lab has also described NBEAL2 deficiencies in patients presenting clinical features of the autoimmune lymphoproliferative syndrome, suggesting a role of NBEAL2 in immune homeostasis and tolerance. A broader international cohort of GPS patients has been described, revealing immune system abnormalities (autoimmune diseases, autoantibodies, lymphopenia). If the role of NBEAL2 in the traffic of granules is often investigated, the exact mechanism leading to the development of autoimmune manifestations in GPS patients remains unknown. NBEAL2 belongs to a protein family involved in vesicular trafficking, all of which possess a conserved BEACH domain. Within this BEACH-domain containing proteins family, one of the closest members to NBEAL2 is LRBA. LRBA is involved in the recycling of CTLA-4, an inhibitory immune checkpoint. CTLA-4 plays a crucial role in the regulation of immune responses and tolerance. Recessive mutations of LRBA lead to similar clinical features as partial CTLA-4 deficiency: autoimmunity, lymphocytic infiltrations, and progressive B lymphopenia. Physiologically, LRBA prevents the lysosomal degradation of CTLA-4 and allows its recycling to the membrane. By analogy with LRBA, we investigated the importance of NBEAL2 in immune checkpoints intracellular trafficking and we brought new insights on its role in lymphocytes. Thus, NBEAL2 is a scaffold protein, binding LRBA, and involved in CTLA-4 trafficking as well as in vesicular trafficking in general. This work brings new knowledge to the regulation of CTLA-4 in activated T lymphocytes, a list of new partners for NBEAL2 protein and a new model of vesicular trafficking in which NBEAL2 is involved. Finally, a better understanding of the mechanisms leading to autoimmunity in patients with gray platelets syndrome could lead to better diagnosis and treatment management
Bendavid-Anquetil, Céline. „Rôle des anticorps monoclonaux au cours des myopathies auto-immunes : de l’étude des auto-anticorps spécifiques des myopathies nécrosantes auto-immunes à la description physiopathologique des myosites induites par l’immunothérapie anti-tumorale“. Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS257.
Der volle Inhalt der QuelleMyositis is a rare autoimmune disease that may occur spontaneously, idiopathic inflammatory myopathies, or be induced by treatments such as immune checkpoint inhibitors (ICI). Among myositis, this work focused on the study of two entities: immune-mediated necrotizing myopathy (IMNM), and ICI-induced myositis. Inflammatory myopathies are separated into homogeneous subgroups in terms of clinical, biological, and histological phenotype thanks to the identification of myositis-specific autoantibodies. Each of these entities is associated with antibodies that play a role in the occurrence of the disease by different mechanisms. In IMNM, anti-SRP (signal recognition particle) autoantibodies appear to play a direct pathogenic role via activation of the classical complement pathway. Thirteen anti-SRP autoantibodies from patient samples were produced, including five autoantibodies specifically recognizing SRP by two different techniques. These human anti-SRP autoantibodies will be used to develop models of IMNM and to understand their mechanisms of action as well as to define their antigenic targets. Regarding ICI-induced myositis, therapeutic monoclonal antibodies directed against inhibitory co-stimulatory molecules induce a break of immune tolerance within the muscle tissue. The description of a series of patients from pharmacovigilance database allowed us to characterize a specific clinical phenotype associated with a poor prognosis, particularly in the case of associated myocarditis. The study of the systemic immune response and of the muscle transcriptomic profile has highlighted a central role of cytotoxic T lymphocytes and macrophages in the pathophysiology of the disease.Eventually, the description of pathophysiological mechanisms is mandatory to identify new therapeutic targets and then improve myositis treatment strategy
Anna, François. „Développement d'une immunothérapie anti-tumorale basée sur un récepteur antigénique chimérique (CAR) ciblant le point de contrôle immunitaire HLA-G : implications pour les tumeurs et leur microenvironnement“. Thesis, Université de Paris (2019-....), 2019. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=4021&f=26655.
Der volle Inhalt der QuelleOver the last decade, anti-tumor immunotherapies have been a breakthrough in the oncology field following the clinical successes obtained with immune checkpoint inhibitors (ICPs) or chimeric antigenic receptors (CAR) based therapies. However, they are less effective against solid tumors, especially because of the lack of tumor specific antigen and of a tumor microenvironment capable of inhibiting the immune response favoring the tumor expansion. The HLA-G molecule is an immunosuppressive protein originally exclusively demonstrated to be involved in maternal-fetal tolerance but whose function has been hijacked by tumors to inhibit and escape from immune responses. HLA-G is now identified as an exquisite tumor associated antigen and its inhibition is crucial to restore the anti-tumor immune responses. Yet, no immunotherapy directed against HLA-G has been developed to date.The lack of effective treatment against or targeting HLA-G is related to the inefficiency to induce antibodies against this complex protein since HLA-G could be expressed through several isoforms that are immunosuppressives. In the first part of this study, thanks to an original immunization method based on the use of lentiviral vectors, we demonstrate the possibility to generate antibodies which are capable to recognize the HLA-G interaction domain with its receptors and are expected to inhibit the ICP function of HLA-G. The second part describes a CAR-T cell immunotherapy targeting HLA-G for its TAA properties. We first focused on the regulation and on the expression of the CAR chain at the transcriptional level. This approach was meant to limit the side effects caused by CAR therapies such as continuous activation of the CAR-T cells or elimination of healthy cells expressing the targeted antigen. We then generated two new 3rd generation CARs demonstrated to specifically recognize major HLA-G isoforms expressed by tumor cells and to eradicate HLA-G expressing tumor cells in vitro and in vivo. Several optimizations were carried out on the CAR chain structure to increase CAR-T cells cytotoxic function and to control their persistence through the insertion of the iC9 suicide gene. Given the results presented here, we provide the first vitro and vivo proofs of concept that a CAR therapy directly targeting HLA-G, and more generally an ICP is strikingly efficient.Finally, we discussed the potential for both anti-HLA-G blocking monoclonal antibodies and CAR-T cells immunotherapies against solid tumors and its implication against the tumor microenvironment and possible combinations with other immunotherapies
Wierz, Marina. „Characterization of the Tumor Microenvironment in Chronic Lymphocytic Leukemia by Mass Cytometry : Implications for Immunotherapy Dual PD1/LAG3 Immune Checkpoint Blockade Limits Tumor Development in a Murine Model of Chronic Lymphocytic Leukemia High-dimensional Mass Cytometry Analysis Revealed Microenvironment Complexity in Chronic Lymphocytic Leukemia“. Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL020.
Der volle Inhalt der QuelleChronic lymphocytic leukemia (CLL), the most frequent leukemia in adults, is characterized by the accumulation of mature B lymphocytes in peripheral blood and lymphoid tissues. The progression of CLL is highly dependent on complex interactions within the tumor microenvironment (TME) and despite recent advances in CLL treatment targeting the TME, CLL remains an incurable disease. Therefore, we wanted to deeply characterize the immune landscape in the TME in murine and human CLL to identify novel potential targets for an immunotherapeutic approach. For this purpose, we performed a comprehensive and extensive characterization by high-dimensional mass cytometry to establish an extensive cartography of immune cell subsets. We demonstrated that relevant changes in the immune cell composition, especially the expansion of specific lymphoid and myeloid immune cell subsets, are associated with strong immune suppression thereby contributing to an escape phenotype in CLL. These CLL-associated changes can be restored in preclinical models by a dual PD1/LAG3 immune checkpoint blockade. Moreover, we demonstrated a high T cell heterogeneity between patients that can be stratified according to their T cell profile, and the correlation of specific T cell subsets with time to initial treatment, highlighting their potential prognostic value. In conclusion, with this first CyTOF study in CLL, we expanded the current knowledge of the phenotypic complexity of the TME. We demonstrated that dual targeting of immune checkpoints efficiently controlled CLL development in preclinical models and therefore could have potential benefits in CLL to restore a functional anti-tumor immunity
Balança, Camille-Charlotte. „Contribution des réponses immunitaires adaptatives spécifiques des antigènes tumoraux à l'efficacité clinique de l'immunothérapie par inhibition de l'axe PD-1/PD-L1“. Thesis, Toulouse 3, 2021. http://www.theses.fr/2021TOU30007.
Der volle Inhalt der QuelleExhausted tumor-infiltrating lymphocytes (TILs) are characterized by immune checkpoint (IC) expression, for instance PD-1. One of the major immunotherapy approaches, based on IC inhibition, has proved efficient in the control of tumor progression in many cancers. Despite this progress, only a proportion of patients experience clinical benefit. To improve responses to IC inhibitors, understanding mechanisms involved in TIL exhaustion and investigating which T cells are able to respond to immunotherapy are required. We investigated both CD8 and CD4 T-cell exhaustion and its relation to tumor antigen (Ag) specificity and to responsiveness to IC inhibition in cancer patients. We demonstrated that CD8 T-cell exhaustion at the tumor site was only attained by tumor Ag-specific cells that were characterized by the sequential acquisition of ICs and by CD28 loss. Their circulating counterparts expressed less ICs and at lower levels and were CD28+. Specific CD8 TILs were dysfunctional, nonetheless, they maintained high cytotoxic potential and expressed tissue residency markers. We showed that PD-1 inhibition has a dual effect on specific CD8 T cells. It rescued their effector functions at the tumor site and enhanced their proliferation in the periphery. Importantly, the quantity of exhausted and specific TILs was predictive of response to therapy and of survival in patients treated with PD-1-targeting immunotherapy. Assessment of CD4 TIL exhaustion underscored similarities with the CD8 exhaustion program, in particular their specificity for tumor Ag and sequential acquisition of ICs although ICs characterizing terminally exhausted CD4 TILs were different than those found in CD8 TILs. Importantly, PD-1 blockade on CD4 TILs restored their helper functions, leading to dendritic cell maturation and, consequently, increased tumor-specific CD8 T-cell proliferation. Our data imply that under anti-PD-1/PD-L1, effector functions of terminally exhausted CD8 TILs is rescued and the tumor site is replenished by memory CD8 T cells which proliferate following direct blockade of PD-1 and through reinvigoration of the helper activity of tumor Ag-specific CD4 T cells. Our results position tumor Ag-specific T cells as major players of responsiveness to PD-1-blocking immunotherapy and identify predictive biomarkers of response to immunotherapy
Liu, Peng. „Mort cellulaire immunogène induite par le crizotinib dans le cancer poumon non à petites cellules“. Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS148.
Der volle Inhalt der QuelleAccumulating evidence suggests that certain conventional chemotherapies, radiotherapies, as well as targeted therapies mediate their long-term therapeutic success by inducing immunogenic cell death (ICD), which stimulate the release or exposure of danger-associated molecular patterns from or on cancer cells, causing their recognition by the immune system, thus reinstating immunosurveillance. An unbiased screen identified crizotinib as a tyrosine kinase inhibitor that is potent in provoking hallmarks of ICD. In subsequent low-throughput validation experiments, crizotinib promoted Calreticulin exposure, ATP secretion, HMGB1 release, as well as ER stress in both human and murine cancer cells, especially if it is combined with normally non-ICD inducing chemotherapeutics such as cisplatin. ICD induced by the combination of chemotherapy and crizotinib was also observed in non-small cell lung carcinoma (NSCLC) cells lacking activating mutations of the crizotinib targets ALK and ROS1, suggesting an off-target-mediated mode of action. Comparative studies indicated that exclusively the clinically used (R) isoform of crizotinib was efficient in inducing cell death and stimulating ICD hallmarks whereas the (S) enantiomer lacked those characteristics. When combined with cisplatin, crizotinib-killed fibrosarcoma MCA205 cells as well as lung cancer TC-1 cells efficiently vaccinated syngeneic immunocompetent mice against a re-challenge with live cancer cells of the same types. Crizotinib improved the efficacy of chemotherapy with non-ICD inducers (such as cisplatin and mitomycin C) on three distinct (transplantable, carcinogen- or oncogene induced) orthotopic NSCLC models, none of which relied on the activation of ALK or ROS1. Of note these anticancer effects were completely lost if any of the ICD signals was blocked. These anticancer efficacies in different models were linked to an increased T lymphocyte infiltration as a sign of an immune response and were lost if such tumors grew on immunodeficient (nu/nu) mice that are athymic and hence lack thymus-dependent T lymphocytes, or on immunocompetent mice with a neutralization of interferon-. The combination of cisplatin and crizotinib led to an increase in the expression of CTLA-4, PD-1 and PD-L1 in tumors, coupled to a strong sensitization of NSCLC to immunotherapy with antibodies blocking CTLA-4 and PD-1. Hence, a combination of crizotinib, conventional chemotherapy and immune checkpoint blockade may be active against NSCLC, and these data might facilitate the design of clinical trials to evaluated novel combination regiments for the treatment of NSCLC
GUIDA, ANNALISA. „Decifrare la risposta immunitaria ai checkpoint inibitori e ricerca di nuovi biomarcatori nel carcinoma renale metastatico“. Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2020. http://hdl.handle.net/11380/1201007.
Der volle Inhalt der QuelleNivolumab represents the new second-line treatment for metastatic renal cell carcinoma (mRCC). This drug is a fully human IgG4 against PD-1 and his role is to inhibits programmed death-1 (PD-1)/PD-1 ligand 1 (PD-L1) immune checkpoint. In the majority of patients, this drug is able to restore the patient’s tumour-specific T-cell-mediated response thus improving both overall survival and objective response rate. However, a lack of clinical response occurs in a number of patients, raising questions about how to predict and increase the number of patients who receive long-term clinical benefit from immune checkpoint therapy. The requirement for the immune system as a mediator of the drug's activity suggests that the balance of positive and negative regulators of the immune response at the time of therapy may be critical for therapy efficacy. Of particular interest are soluble factors involved in the recruitment and regulation of effector T cells, the frequency of different subsets of regulatory T cells and the ratio between effector T cells and regulatory T cells. The main aim of this project is to identify immune and serum biomarkers that are modulated in patients with metastatic renal cell carcinoma during and treated with immune checkpoint inhibitors and that can discriminate patients who most likely benefit from such therapy. This is a prospective, longitudinal, study on patients with mRCC who will receive Nivolumab in standard clinical practice. The project investigates changes in main immune parameters in patients with mRCC treated with nivolumab by analysing blood samples at baseline and after 1, 2, 3, 6 and eventually 12 months. Thirty mL of blood were collected and peripheral blood mononuclear cells (PBMC) were isolated according to standard procedures. PBMC were stored in liquid nitrogen. Then, PBMC were thawed according to standard procedures and stained with a viability probe and the following antibodies recognizing: CD3, CD4, CD8, CD25, CD127, FoxP3, ICOS, CXCXR6, CXCR3, CD95, CD45RA, CCR7, CD95, HLA-DR, CD38, CD28, CD27, CD71, CD87, CD39, TIM3, TIGIT, CCR4, Glycoforin, PD-1/IgG4, CD57, KI-67. This 28-color multicolour flow cytometry panel was set up in collaboration with Dr. Lugli (Humanitas, Milan). Samples were acquired by using a BD Symphony flow cytometer. Compensation was set using single stained controls and gating strategy was checked by using FMO. Data analysis was performed using FlowJo 9.6 under Mac OSX. From January 2016 until October 2018 we enrolled 21 patients. The median age was 60 years (33-79). The majority of patients had clear cell histology (90%). Nivolumab was given as second-line therapy in 57% of patients, as third line therapy in 29% of cases. According with International Metastatic Renal Cell Carcinoma Database Consortium Score (IMDC score) 72% of patients were in the intermediate prognostic risk group and 14% in poor risk. With a median follow-up of 14 months (min: 2 max: 31), 6-months and 12-months survival rate were 74% (95%CI 48-88) and 47% (95%CI 22-68), respectively. Median progression-free survival (PFS) was 4.2 months (95% 3-10). Disease control was achieved in 8 patients (40%), defined responder (R). At time of analysis treatment was ongoing in 4 patients. Preliminary data on PBMC show that Ki-67, a marker of cell proliferation, is increased after 15 days of therapy in some patients. Accordingly, the expression of HLA-DR and CD38 are increased. Reactivation of the immune system is one of the main goals of nivolumab. We expect to identify easily measurable immune biomarkers that predict the responsiveness to nivolumab. Finding novel biomarkers that predict the response to therapy with nivolumab and monitor its efficacy can be of great benefit for the success of treatment. Longer follow up is required to assess preliminary immunological data.
Cohen, Romain. „Caractérisation phénotypique et clinique des cancers colorectaux métastatiques avec instabilité des microsatellites Clinical and molecular characterization of hereditary and sporadic metastatic colorectal cancer harbouring microsatellite instability/DNA mismatch repair deficiency Association of primary resistance to immune checkpoint inhibitors in metastatic colorectal cancer with misdiagnosis of microsatellite instability or mismatch repair deficiency status“. Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS313.
Der volle Inhalt der QuelleMicrosatellite instability (MSI) is a tumor phenotype linked to somatic or germline inactivating alterations of DNA mismatch repair (MMR) genes. MSI is observed in approximately 5% of metastatic colorectal cancers (mCRC) and has recently emerged as a major positive predictive biomarker for the efficacy of immune checkpoint inhibitors (ICKi) amongst mCRC patients. The objectives of my work was to clinically and molecularly characterize MSI mCRC, to evaluate the accuracy of MSI screening methods and the response to immunotherapy in the context of ICKi clinical trials. Fist, I show that sporadic and inherited MSI mCRC display distinct natural history (Cohen et al., Eur J Cancer 2017). In a second work, I show that MSI testing in routine practice is associated with almost 10% of false positives due to misinterpration of IHC and PCR assays. Moreover, these false-positives are the main cause of mCRC primary resistance to ICKi observed in clinical trials (Cohen*, Hain* et al., JAMA Oncol. 2018). After summarizing the literature concerning MSI, its consequences on CRC and immunotherapy, I present the results of the nosologic and diagnostic works developed during this doctoral thesis. Then I will go on perspectives in the context of MSI cancer
LO, TARTARO DOMENICO. „Melanoma metastatico e carcinoma renale: focus sul ruolo delle cellule T CD8+ nelle risposte agli inibitori dei checkpoint immunitari“. Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2022. http://hdl.handle.net/11380/1278345.
Der volle Inhalt der QuelleCD8 T lymphocytes play a central role in immunity to cancer through their capacity to kill malignant cells. However, prolonged exposure to cognate antigens in tumor microenvironment contribute to induce severe CD8 T cell exhaustion (Tex). During the last decade cancer treatment has been revolutionized by immune check point inhibitors (ICIs) that block the activity of inhibitor receptors, such as PD-1 present on the surface of Tex cells, reinvigorating them. Despite observations of durable responses to ICI therapy, not all patients respond to the treatment. Therefore, we focused our attention on identifying alterations that occur in circulating CD8 T lymphocytes of metastatic melanoma (mM) and metastatic renal-cell carcinoma (mRCC) patients during treatment with anti-PD1, in order to understand how and why some patients respond or not to ICI therapy. The first cohort comprised 28 patients with mM, 17 of whom were defined responders (R) whereas 11 non-responders (NR). Cryopreserved PBMC, obtained prior to initiating therapy (T0) after the first (T1) and second therapy cycles (T2), was studied by 30 parameter high-dimensional flow cytometry in combination with single cell RNA-sequencing (scRNAsq). The second cohort comprised 19 patients with mRCC, 5 of which were defined responders (R) whereas 14 non-responders (NR). Cryopreserved PBMC, obtained prior to initiating therapy (T0) after the first (T1), second (T2) and third therapy cycle (T3), was studied by 28 flow cytometry and analyzed using FAUST, a novel non-parametric method for unsupervised discovery of cell population. In R patients we found an increase of proliferating effector memory (EM) cells expressing high level of Ki67, ICOS, CD95, HLA-DR, CD71, CD98, CXCR6, granulysin and CD38, both before and after first and second cycle of ICI therapy. scRNA-seq revealed the presence of activated mucosal associated invariant T (MAIT) cells expressing CD69 and CXCR4, and their increase in R compared to NR, before and after ICI therapy. Along with increased percentage of peripheral MAIT cells we also observed greater ability to produce IFN-g and GRZM-B in R patients, before starting therapy but not after. In silico analysis of public datasets revealed the presence of MAIT cells within primary and metastatic lesions and their increased level within lesions regressing after ICI. Finally, to associate our finding with clinical outcomes, we correlated the median level (1.7% of CD8 T cells) of circulating MAIT cells with the response to therapy. Using this value as a threshold, patients who exhibited MAIT frequency above the threshold showed a better response to therapy. Flow cytometry reveals that CD8 T cells from mRCC patients could be classified in 61 cell clusters. Due to the relatively low number of patients responding to therapy, we found similar percentages of clusters in R and NR at all timepoints. However, considering all patients treated with anti-PD1 (n=19), therapy induced a redistribution of different subpopulations of CD8 T cells. In particular, T stem cell memory (TSCM) decreased after the third cycle of therapy. On the contrary, the EM compartments increased after therapy. In terms of functionality, we observed that, if compared with EM, after therapy TSCM lost proliferative potential but retained more polyfunctionality, producing simultaneously TNF and IFN-g. In conclusion, we provide evidence that mM and mRCC patients differently respond to anti-PD1 therapy, the formers are characterized by more activated MAIT in R patients, while the latter are characterized by a pool of circulating likely-exhausted TSCM.
Micelli, Lupinacci Renato. „Caractérisation anatomo-clinique et phénotypique des adénocarcinomes canalaires du pancréas avec instabilité des microsatellites“. Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066311/document.
Der volle Inhalt der QuellePancreatic ductal adenocarcinoma (PDAC) is a major health problem in France and around the world. PDAC is developed mainly from two precursor lesions: pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm (IPMN). There are several molecular mechanisms underlying pancreatic oncogenesis. Particularly, we were interested in the MSI (MicroSatellite Instability) which is due to a defective DNA Mismatch Repair (MMR) system, which normally functions to recognize and repair erroneous insertions, deletions, and mis-incorporation of bases that can arise during DNA replication and recombination. The MSI phenotype was first described in the familial cancer condition known as Lynch syndrome (LS), where the MMR genes MLH1, MSH2, MSH6 or PMS2 harbor germline mutations. Interest in MSI tumors has recently increased after studies have highlighted the concomitant expression of multiple active immune checkpoint (ICK) markers including PD-1 and PD-L1 and the role of the MSI status to predict clinical benefit from immune checkpoint blockade. A Our results indicate that the MSI phenotype occurs in PDAC with a frequency of 1-2%. Our data showed that IHC using antibodies against the four MMR proteins was more sensitive for the assessment of MSI status than PCR-based methods. In addition, we demonstrate for the first time a statistically significant positive association between MSI and IPMNs in PDAC. MSI PDAC, including IPMN, are unlikely to be sporadic since they display molecular features that are usually observed in LS-related neoplasms. Also, our results highlight that an MSI-driven immunogenic pathway to cancer is active in MSI PDACs but suggest that MSI-driven somatic events may be tissue-specific. We observed a stronger lymphocytic tumor infiltration by activated TCD8 cells in MSI PDAC compared to MSS PDAC and found a positive association between PD-L1 expression and MSI status, suggesting that MSI PDAC could be responsive to ICK blockade therapy
Cohen, Charlotte. „La Fractalkine (FKN) comme traitement des métastases osseuses de CNPC au sein d’une stratégie multimodale : une étude préclinique sur un modèle murin“. Electronic Thesis or Diss., Université Côte d'Azur, 2020. http://www.theses.fr/2020COAZ6030.
Der volle Inhalt der QuelleIn France, about 50 000 new cases of lung cancer are diagnosed every year. Sixty percent of them are already metastatic. Bone localizations are described in 20 to 40% of cases and they are associated with poor survival (5 to 10 % at 5 years) and impaired quality of life. New therapeutic options are mandatory to improve survival and functional prognosis.A chemokine, the fractalkine (FKN), represents a promising one. It is known for its capacity of leukocytes recruitment and its impact on the bone metabolism. It could be able to restore anti-tumor immunity and to act on osteolysis, when delivered locally. The impact on tumor development is highly complex and depends on the expression of its receptor by tumor cells, its molecular form, the location of the lesion, and the tumor type.We first planned to determine the impact of the FKN on the tumor development within a syngeneic murine model of bone metastasis of lung cancer, using either LL2 lung cancer cell line expressing a low (LL2-FKNlo) or a high level of FKN (LL2-FKNhi).FKN had an anti-tumoral effect, able to reduce the tumor-weight by 73% in the LL2-FKNhi groups, compared to LL2-FKNlo one, at day 14. High level of expression of FKN was associated with an increase in the recruitment of inflammatory monocytes, natural killer cells, and more specifically B lymphocytes (LB). Together, they formed an immunopermissive tumoral microenvironment. We also noted significant modification of expression level of genes involved in osteoformation and regulation of immunity.The FKN anti-tumor effect tended to decrease after day 14. At the same time, we quoted a high level of infiltration of LL2-FKNhi tumors by T regulatory lymphocytes (LTreg). We suspected their implication in this loss of effect.We tried therapeutic associations, able to stimulate anti-tumor immunity through immune checkpoint blockade (monoclonal antibody against CTLA4, PD1, PDL1, or TIM3) or to block LTreg (cyclophosphamide, anti-GITR antibody) in association with high FKN expression. The goal was to prolong and/or to reinforce its anti-tumoral effect.To date, the used administration protocols weren’t able to induce such an effect. Other protocols need to be tested.This work highlighted an anti-tumoral effect of FKN in this murine model of bone metastasis of lung cancer and identified the underlying mechanisms. It pointed out new therapeutics associations options based on the anti-tumoral implication of LB, and pro-tumoral action of LTreg
Casadei, Beatrice <1986>. „Ruolo del Microbiota Intestinale Nella Risposta al Trattamento con Anticorpi anti Checkpoints Immunitari in Pazienti Affetti da Linfoma“. Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9789/1/Casadei%20B.%20PhD%20Def.pdf.
Der volle Inhalt der QuelleSingle-agent monoclonal antibodies targeting the immune checkpoint PD-1 (programmed death 1) are an efficient and safe therapeutic option in patients with relapsed/refractory B-cell lymphoma. However, many patients progress or lose response to anti-PD1. Recent studies have highlighted the role of the gut microbiota (GM) in influencing the response to chemo-immunotherapeutic agents. Here, we hypothesize that the longitudinal characterization (pre, during, and post-therapy) of GM of lymphoma patients treated with checkpoint inhibitors and its correlation with treatment response and development of adverse events may have a role in outlining the outcome of such patients and in identifying new risk stratification criteria.
Zielonka, Elisabeth Maria. „The function of p53 homologs in oocyte meiotic checkpoints and the innate airway immune system“. Strasbourg, 2011. http://www.theses.fr/2011STRA6041.
Der volle Inhalt der QuelleP53 is a major tumor suppressor gene, which is mutated in over 70% of cancer cases. Its two mammalian paralogs, p63 and p73, differ structurally from p53. Females only possess a limited pool of gametes, which all enter dictyate arrest around the time of birth. During this phase, oocytes are extremely sensitive to DNA damage, which causes apoptosis and reduces fertility. TAp63α is a key player in maintaining the genomic integrity in oocytes. The exact mechanism so far remains unknown. It is clear that DNA DSB caused by irradiation activate TAp63α through phosphorylation. We were able to show that, unlike p53 TAp63α in arrested oocytes is kept in an inactive imeric state. In the case of DNA damage, the inactive dimeric TAp63α gets hosphorylated, and thus activated. This leads to a formation together with a econd dimer of a tetrameric TAp63α. In this tetrameric state TAp63α has a igher DNA binding affinity, leading to the induction of apoptosis related enes, as identified by gene expression profiling. He second part pertains to the role of p73 in the innate immune system of he airway. The overall aim is to better understand chronic and acute airway nflammation. Previous work showed that p73 knockdown in mice results in hronic airway inflammation. We developed an in vitro model by differentiating uman upper airway stem cells in an air-liquid interface culture system, which ave rise to both ciliated cells expressing TAp73 and secretory cells. Ogether, the engineering of a conditional TAp73 in vivo model and the in itro airway model permit a molecular analysis of the innate immune response f ciliated cells and the pathway involving p73
CORTELLINI, ALESSIO. „Studio sul ruolo della storia familiare di neoplasie come fattore predittivo surrogato per l'immunoterapia con inibitori dei checkpoint immunitari PD-1/PD-L1“. Doctoral thesis, Università degli Studi dell'Aquila, 2022. http://hdl.handle.net/11697/191960.
Der volle Inhalt der QuelleUllah, Matti. „Immune Checkpoints in Peritoneal Carcinomatosis : HLA-G, PD-L1 & the Impact of Cancer Therapies“. Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS288.
Der volle Inhalt der QuellePeritoneal carcinomatosis (PC) is a term used for widespread metastatic dissemination of cancer to the peritoneal cavity. It is characterized by the accumulation of fluid called “ascites” and is considered a terminal stage of cancer, as it is hard to treat. The overall survival rate for untreated patients is six-months. However, owing to modern techniques like HIPEC, the survival rate can be increased up to five years. The ascites accumulated in PC, consists of tumor cells, cytokines and immune cells. Cancer cells express specific proteins to suppress immune cells activity and their attack, known as immune checkpoints. PD-1/PD-L1 and CTLA-4 are well established immune checkpoint pathways adapted by cancer in evading immunity. Recently, HLA-G has been recognized as an immune checkpoint and has been found to decrease overall survival in several types of solid cancers. We evaluated the expression of HLA-G in ascites from ovarian carcinomatosis. We found that HLA-G is expressed by cancer cells in ascites from all of the patients(n=16) with ovarian carcinomatosis. Moreover, increased levels of sHLA-G1 and HLA-G5 were found in ascites. This presence of sHLA-G isoforms was found to be positively correlated with Tregs and negatively correlated with cytotoxic T-cells (CD8) and NK-cells suggesting the role of HLA-G in immune suppression. Further, we found that ascites can induce the expression of HLA-G in “Hospicells” via inflammatory cytokines. Among the inflammatory cytokines, TGF-β and IL-1β are of crucial importance in HLA-G induction with IL-1β being more potent compared to TGF-β. Further, we found that IL-1β induces HLA-G expression through NF-κB pathway.In a separate cohort of peritoneal carcinomatosis(n=27), consisting of patients with cancer from a different origin, we found that cancer cell cluster in ascites (n=23) had a heterogeneous gene expression of PD-L1, CTLA-4 and HLA-G. Further, we found that all of the patients presented soluble levels of HLA-G in their ascites. However, one patient was negative for soluble PD-L1 and only 5 patients presented soluble CTLA-4 levels in their ascites. This heterogeneity explains why some of the patients respond to immune therapy while others don’t. This also suggests the need for prescreening patients before immune therapy. Moreover, we found a very strong positive correlation (rs=0.793) between gene level of PD-L1 and CTLA-4, while no correlation was found for HLA-G with PD-L1 and CTLA-4 suggesting that HLA-G acts independently of both the immune checkpoints. Also, we evaluated the expression of these immune checkpoints by cells in peritoneal tissue (n=20). We found low expression of HLA-G and PD-L1, but the majority of the samples were found strongly positive for sHLA-G presence. This sHLA-G can provide an immune-suppressive environment for the attachment of the cancer cell clusters to the peritoneal membrane to form cancer nodule. Additionally, we developed an in-vitro cytotoxicity assay to show that the ascites can provide the immune-suppressive action by interfering with immune cell interaction and delaying the lysis of cancer cells by the immune cells.In parallel, we found that the differentiation of the cancer cells results in increased expression of immune checkpoints like HLA-G or PD-L1. This may render these cells more immune resistant and can protect against immune attack. However, in-vivo mice model is needed to study the oncogenic potential of these differentiated cells. Further, we report that the expression of HLA-G and PD-L1 is dependent on the cell cycle phase. The cancer cells, if blocked in mitotic phase express high levels of HLA-G and PD-L1, while lowest expression was observed in G1-phase. Therefore, we suggest avoiding the use of mitotic inhibitors as it may increase the immune suppression of cancer. Moreover, as Ki-67 is directly related to the mitotic index, we suggest developing a Ki-67 scale to evaluate the immune-suppressive profile of cancer patients
Mestrallet, Guillaume. „Propriétés immunitaires des kératinocytes humains et de leurs précurseurs Human Keratinocytes Inhibit CD4+T-Cell Proliferation Through TGFB1 Secretion and Surface Expression of HLA-G1 and PD-L1 Immune Checkpoints“. Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASL052.
Der volle Inhalt der QuelleHuman skin protects the body from infection and injury. It involves immune cells and epithelial cells, but their interactions remain to be explored. Here, we address this point showing that keratinocytes inhibit CD4+ T cell proliferation even under inflammatory conditions. This is done through secretion of soluble factors such as TGF-β as well as cell-surface expression of immune checkpoints such as HLA-G and PD-L1. In this regard, we describe for the first time the expression of HLA-G in healthy human skin and its role in tissue keratinocyte-driven immunomodulation. Overexpression of HLA-G with an inducible vector increases the immunomosupressive properties of keratinocytes, opening perspectives for their use in cell therapy in allogeneic settings.Stem cells are essential for the maintenance and renewal of tissues, but their ability to be protected from immune reactions remains unclear. Here, we show that keratinocyte precursors of the interfollicular epidermis are able to inhibit CD4+ T cell proliferation. The immune escape of keratinocyte precursors may be explained by an overexpression of HLA-G and PD-L1 immune checkpoints. These results indicate prospects for investigating immune escape in skin cancer and autoimmune pathologies
Giraldo-Castillo, Nicolas. „The Immune Microenvironment in Clear Cell Renal Cell Carcinoma : The heterogeneous immune contextures accompanying CD8+ T cell infiltration in clear cell Renal Cell Carcinoma“. Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066321/document.
Der volle Inhalt der QuelleTo decipher the potential mechanisms linking increased CD8+ T cell infiltration with an adverse clinical outcome in ccRCC, in this study we determined: 1) the prognosis associated with the expression of immune checkpoints and its coordination with dendritic cell (DC) and CD8+ cell infiltration, and 2) the phenotypic traits of CD8+ tumor infiltrating lymphocytes. The prognosis associated with CD8+ and DC infiltrations, in addition to the expression of immune checkpoints were investigated in a cohort of 135 ccRCC by quantitative immunohistochemistry. We found that the densities of CD8+, PD-1+ and LAG-3+ cells were closely correlated, and independently associated with decreased PFS and OS. In addition, patients whose tumors presented both high densities of PD-1+ cells and PD-L1+ and/or L2+ tumor cells, displayed the worst clinical outcome. High densities of immature DC isolated in the tumour stroma were associated with high expression of immune checkpoints and patients’ poor clinical outcome. In contrast, the presence of mature DC within Tertiary Lymphoid Structures identified, among the tumours with high CD8+-TIL densities, those with low expression of immune checkpoints and prolonged survival. We also investigated the phenotype of freshly isolated CD8+TIL in 21 ccRCC by flow cytometry. We found a group tumors (8/21) characterised by the over-expression of inhibitory (PD-1 and TIM-3) and activation markers (CD69 and CD38), the expansion of the effector memory cell subpopulation (CCR7-CD45RA-), and a trend toward more aggressive features. In summary, we demonstrated that the infiltration with CD8+ TIL in ccRCC is accompanied by the enhanced expression of immune checkpoints and a poorly coordinated immune response in a subgroup of aggressive tumors
Arakelian, Tsolère. „Impact of Targeting the Autophagy Related Gene Beclin 1 on the Immune Landscape of Melanoma“. Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS193.
Der volle Inhalt der QuelleImmune Checkpoint Blockades (ICBs)-based immunotherapy has emerged as a promising treatment for melanoma patients; however only a small subset of patients reaps a long term benefit. One of the major challenges to enhance the efficacy and extend the benefit of ICBs to non-responder patients is to design innovative approaches allowing the switch of “immune desert cold tumors” to “immune infiltrated hot tumors" which are eligible for ICB-based therapies. Here, we investigated the impact of targeting the early autophagy gene Beclin1 on the immune landscape of B16-F10 melanoma tumors. We found that targeting Beclin1 (Becn1-) significantly inhibited B16-F10 tumor growth and increased the infiltration of CD45+ leukocytes into the tumor bed. Immune phenotyping revealed an increased infiltration of active Natural Killer (NK) cells, inflammatory and resident type 1 macrophages, dendritic cells, and active CD8+ T lymphocytes. The inhibition of Becn1- tumor growth was no longer observed by depleting host CD8+ T cells, thus highlighting their major role in the control of Becn1- B16-F10 tumor development. We showed that Beclin1-dependent regulation of the immune landscape was associated with profound modulation of the cytokine/chemokine network in the tumor microenvironment (TME). Importantly, we revealed that Becn1- tumors displayed an inflammatory cytokine signature (comprised, but not restricted to, CCL5, CXCL10 and IFNg) that could be responsible for the switch from cold non T-inflamed to hot T-inflamed tumors. Mechanistically, we reported that the overexpression of IFNg in Becn1- TME was responsible for the induction of Programed Death ligand-1 (PD-L1) on tumor cells through the activation of JAK/STATs pathway. Overall, this study highlights Beclin1 as a valuable target, able to drive immune effectors cells into the melanoma tumors by inducing an inflammatory signature. This study provides the proof of concept for combining drugs inhibiting early autophagy process along with ICBs as a cutting-edge approach to improve their efficacy
Xie, Wei. „Transcription Inhibitor Lurbinectedin and Oncolytic Peptide LTX-401 trigger Immunogenic Cell Death and Synergize With Immune Checkpoint Blockade Lurbinectedin Synergizes With Immune Checkpoint Blockade To Generate Anticancer Immunity Tumor Lysis With LTX-401 Creates Anticancer Immunity Autophagy Induction by Thiostrepton Improves the Efficacy of Immunogenic Chemotherapy Oncolysis With DTT-205 and DTT-304 Generates Immunological Memory in Cured Animals“. Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL072.
Der volle Inhalt der QuelleCancer is the second leading cause of death worldwide, despite the existence of standard treatment, innovative therapeutic strategies and drugs are still in urgent demand. The combination of immunogenic cell death (ICD) inducing drugs and immune checkpoint blockade (ICB) seems to be a promising modality. In this thesis, we demonstrated Lurbinectedin, a transcription inhibitor newly approved for relapsed lung cancer treatment, triggers hallmarks of ICD in four different human and murine cell lines in vitro. Vaccinated with Lurbinectedin-treated fibrosarcoma cell protects immunocompetent mice from rechallenge with syngeneic tumours. Lurbinectedin restrains transplanted fibrosarcoma growth in an immune dependent manner. Both transplanted MCA205 cancer and hormone/carcinogen induced breast cancer were sensitized by Lurbinectedin to PD-1 and CTLA-4 double ICBs. Of note, long-term immunological memory was generated in cured mice. Further, we evaluated the anticancer capacity of LTX-401, an oncolytic peptide designed for local immunotherapy. Sequential intratumoral injections of LTX-401 dramatically retards subcutaneous MCA205 and TC-1 tumour growth in immunocompetent host, yet shows limited therapeutic effect of anti-CTLA-4 or anti-PD-1/anti-CTLA-4 ICBs. Moreover, sequential LTX-401 treatment with double ICBs exhibits systemic antitumor immunity to both treated and abscopal tumour. In conclusion, lurbinectedin and LTX-401 induce cancer cell immunogenic cell death and enhance the anticancer effects of immune chekcpoint blockade. These results lay the experimental foundation of combination regiments and may facilitate the clinical trial design
Girard, Pauline. „Pathophysiologie des pDCs et des Lymphocytes Tγδ en contexte de mélanome, et potentiel de leur interaction pour le développement de nouvelles thérapies The features of circulating and tumor-infiltrating gdT cells in melanoma patients display critical perturbations with prognostic impact on clinical outcome Potent Bidirectional Cross-Talk Between Plasmacytoid Dendritic Cells and γδT Cells Through BTN3A, Type I/II IFNs and Immune Checkpoints“. Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALV042.
Der volle Inhalt der QuelleBoth pDCs and γδT cells harbor critical roles in immune responses induction and orientation. Their unique features, high functional plasticity and ability to interact with many immune cell types allow them to bridge innate and adaptive immunity. They actively contribute to protective and pathogenic immune responses, which render them very attractive both as targets and vectors for cancer immunotherapy. Yet, γδT cells have not been extensively explored in melanoma, and despite strategic and closed missions, cross-talks between pDCs and γδT cells have not been deciphered yet, neither in healthy context nor in cancers, especially in melanoma where the long-term control of the tumor still remains a challenge. We provided here a detailed investigation of the phenotypic and functional properties of circulating and tumor-infiltrating γδT cells in melanoma patients, as well as their impact on clinical evolution. We also characterized the bidirectional cross-talks between pDCs and γδT cells both from healthy donor’s blood, patient’s blood and tumor micro-environment. Our study highlighted that melanoma hijacked γδT cells to escape from immune control, and revealed that circulating and tumor-infiltrating γδT cell features are promising potential biomarkers of clinical evolution. We also demonstrated crucial bidirectional interactions between these key potent immune players though type I and II IFN and BTN3A that are dysfunctional in the context of melanoma. Reversion of the dysfunctional bidirectional cross-talks in melanoma context could be achieved by specific cytokine administration and immune checkpoint targeting. We also revealed an increased expression of BTN3A on circulating and tumor-infiltrating pDCs and γδT cells from melanoma patients but stressed out its potential functional impairment.Thus, our study uncovered that melanoma hijacked pDCs/ γδT cells bidirectional interplay to escape from immune control, and pointed out BTN3A dysfunction. Such understanding will help harnessing and synergizing the power of these potent immune cells to design new therapeutic approaches exploiting their antitumor potential while counteracting their skewing by tumors to improve patient outcomes. Our findings pave the way to manipulate these potent and promising cell partners to design novel immunotherapeutic strategies and restore appropriate immune responses in cancers, infections and autoimmune diseases
Lachaud, Sophie. „Régulation de l'expression de PD-L1 dans le mélanome : identification de cibles thérapeutiques au moyen d’un crible génétique pour traiter le mélanome cutané TIE1 Regulates PD-L1 Expression in Melanoma“. Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL065.
Der volle Inhalt der QuelleCutaneous melanoma arises from melanocytes, the pigment-producing cells of the skin. is responsible for approximately 75% of deaths due to skin cancers. This tumor account for approximately 1% of cutaneous melanoma, but is responsible for 75% of deaths due to skin cancer. Its aggressiveness is coming from its highly metastatic potential and once it is disseminated, chances of survival decrease drastically. Treatment by surgery is efficient when it is diagnosed early. Though, until recently, for metastatic or unresectable melanoma, treatments were quite limited.The arrival of immunotherapies to treat advanced melanoma arouse a lot of hope. These monoclonal antibodies boost the immune system in order to kill cancer cells. The most recent and efficient are the ones targeting the programmed cell death protein 1 or its ligand (PD-1/PD-L1). The main role of PD-1 immune checkpoint is to limit the activation of engaged peripheral T cells. Indeed, the activation of T cells by the interaction of its TCR with MHC/peptide complexes leads to IFNγ; secretion. This cytokine will induce the expression of PD-L1 and PD-L2 at the plasma membrane of surrounding cells. The engagement of PD-1 with its main ligand PD-L1 leads to the inhibition of CD8+ T lymphocytes. This feedback loop attenuates T-cell responses and limits the extent of immune-mediated tissue damage that can happen with an excessive immune response. Some cancer, including melanoma which is highly immunogenic, escape the immune system by taking advantage of this mechanism to overexpress PD-L1 and inhibit effector functions and proliferation of CD8+ T lymphocytes. Immunotherapies targeting PD-1 or PD-L1 with monoclonal antibodies were then deployed to disrupt the interaction between the two partners and restore, at least partially, T-cell activity against cancer cells and drive to tumor regression. Most of the time, basal PD-L1 expression in melanoma is low and is strongly increased by IFNγ, produced by immune cells like CD8+ T lymphocytes. Thus, preventing IFNγ-induced PD-L1 expression would restore the effector functions of LT CD8+ and avoid tumor progression as anti-PD-1/PD-L1.This aim of my thesis project was to make use of a genetic screen to identify positive regulators of the expression of PD-L1 at the plasma membrane of melanoma with a genetic screen by focusing on druggable genes. This screen was based on a shRNA library targeting genes coding for a protein for which an inhibitor already exists or harboring a structure or an activity that could lead to drug development. The bioinformatic analysis led to the identification of new regulators that positively regulate PD-L1 at the plasma membrane of melanoma that could serve as therapeutic targets for melanoma treatment
Lequeux, Audrey. „Impact du ciblage du domaine de liaison de HIF-1α avec HIF-1β sur le paysage immunitaire du mélanome Targeting HIF-1 Alpha Transcriptional Activity Drives Cytotoxic Immune Effector Cells into Melanoma and Improves Combination Immunotherapy Hijacker of the Antitumor Immune Response: Autophagy is Showing its Worst Facet Impact of Hypoxic Tumor Microenvironment and Tumor Cell Plasticity on The Expression of Immune Checkpoints Improving Cancer Immunotherapy by Targeting the Hypoxic Tumor Microenvironment: New Opportunities and Challenges“. Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL026.
Der volle Inhalt der QuelleHypoxia is a major feature of solid tumors and is able to induce a tumor immunosuppressive microenvironment. Here, we investigated the impact of inhibiting of the binding domain of HIF-1α to HIF-1β on the immune landscape of B16-F10 melanoma. Targeting this binding domain inhibits the transcriptional activity of HIF-1α in B16-F10 cells in vitro. In vivo, inhibiting the transcriptional activity of HIF-1α in B16-F10 melanoma shows a significant decrease in tumor growth and a consistent improvement in mice survival. Tumor growth is restored in immunodeficient mice, highlighting the critical role of the immune system in controlling melanoma growth. The phenotyping of intra-melanoma immune cells reveals an increase in Natural Killer (NK), CD4+ T cells, regulatory T cells, M1 and M2 macrophages and dendritic cells. NK depletion restores tumor growth in our experimental model, highlighting the role of NK cells in melanoma surveillance. The alteration of the immune landscape that we observed also correlates with a clear increase of secreted CCL5 and CCL2. In conclusion, this study highlights the role of HIF-1α in controlling the growth and the immune landscape of B16-F10 melanoma. It indicates the opportunity of combining HIF-1α inhibitors with immune checkpoint blockade to extend immune checkpoint blockade efficiency and therapeutic benefit to a larger number of cancer patients
Ben, Saad Elham. „Étude de l'endocytose du récepteur PD-1 dans les lymphocytes T humains“. Thesis, 2019. http://hdl.handle.net/1866/23924.
Der volle Inhalt der QuellePD-1 (Programmed Cell death protein -1) is a co-inhibitory receptor expressed on the surface of activated T cells. It plays an important role in maintaining peripheral tolerance and protecting against autoimmune and inflammatory diseases. However, permanent expression of PD-1 and its ligands PD-L1/ PD-L2 (PD-Ls) disrupts the immune response against pathogens and tumor cells. Immune checkpoint blockade (ICB) targeting the PD-1/PD-Ls axis has revolutionized the treatment of many cancers. Nivolumab (nivo) and pembrolizumab (pembro) are two anti-PD-1 monoclonal antibodies (mAb) that block the interaction between PD-1 and its ligands. They have shown promising results in the treatment of multiple types of cancers such as melanoma, non-small cell lung cancer, renal cell carcinoma, etc. Surprisingly, despite the success of anti-PD-1 in cancer immunotherapy, no-one has defined the destiny of surface PD-1 following antibody binding. Therefore, the objective of my master thesis was to define the fate of surface PD-1 following antibody binding and whether different anti-PD-1 Abs in the clinic differ in their ability to induce PD-1 endocytosis. The study of PD-1 endocytosis was performed on human T lymphocytes obtained from peripheral blood of healthy donors and activated with anti-CD3/anti-CD28 Ab or concanavalin A to express PD-1 receptor. Data analysis by flow cytometry showed that following anti-PD-1 Ab binding, 50% of PD-1 becomes endocytosed by 30min. In addition, we found that the PD-1 receptor is internalised upon its engagement with nivo and pembro and that most of the receptor is endocytosed within 30 min. However, 32 to 50% of the receptors are resistant to endocytosis. The comparative analysis of nivo and pembro has revealed a statistically significant difference (p=0.03) between the internalisation rate of the PD-1/nivo complex versus PD-1/pembro (46% versus 25% by 30min, respectively). Even at high concentrations of pembro, nivo induces better internalization of PD-1, suggesting that nivo could be more effective than pembro. Our study showed for the first time that ICB involves not only in the blockade of PD-1/PD-Ls interaction, but also in the endocytosis of PD-1 receptors from the surface of human T-cells, which differs between nivolumab and pembrolizumab. These results could be exploited to increase the therapeutic potential of nivolumab and pembrolizumab in cancer treatment. Keywords: PD-1 receptor, PD-1 ligands, T lymphocytes, Immune checkpoint blockade, Anti-PD1 antibodies, Nivolumab, Pembrolizumab, Endocytosis, Cancer