scholarly journals IMMU-21. THE COMBINATION OF DELTA-24-ACT WITH AN IMMUNE CHECKPOINT INHIBITOR RESULTS IN ANTI-GLIOMA EFFECT AND IMMUNE MEMORY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii109-ii109
Author(s):  
Montserrat Puigdelloses ◽  
Virginia Laspidea ◽  
Marc Garcia-Moure ◽  
Daniel De la Nava ◽  
Dolores Hambardzumyan ◽  
...  
Keyword(s):  
Immune Checkpoint Inhibitor ◽  
Immune Cell ◽  
Checkpoint Inhibitor ◽  
Immune Memory ◽  
Long Term Survivors ◽  
Anti Tumour Effect ◽  
Murine Glioma

Abstract Oncolytic viruses have become promising therapeutic candidates to treat gliomas. Our group has developed Delta-24-ACT, an oncolytic adenovirus armed with the positive costimulatory ligand 4-1BBL which is capable to trigger the activation of T cells and thereby increase their antitumor immune response. Here we evaluate the anti-glioma effect of Delta-24-ACT alone or in combination with an immune checkpoint inhibitor. We observed that Delta-24-ACT was able to infect and kill murine glioma (GL261-5 and CT-2A) and also human glioma cell lines (U87-MG and U251-MG), while maintaining its replication in the latter. Of importance, Delta-24-ACT infection resulted in 4-1BBL expression on the membrane of glioma cells. Moreover, this ligand was functional and was able to stimulate CD8 lymphocytes in vitro, suggesting the potential of Delta-24-ACT to trigger an effective immune response. Furthermore, in vivo Delta-24-ACT showed anti-tumour effect in two murine glioma models by significantly increasing the median survival time and leading to long-term survivors. Mechanistic studies demonstrated an increase of the T cell infiltration and the activation of different immune cell populations by flow cytometry and a decrease of proliferative cells and tumour vessels by immunohistochemistry on FFPE brain samples. Importantly, the infiltrating lymphocytes also showed signs of exhaustion increasing the amount of IL-10 and the expression of PD-1. To overcome this exhaustion we combined Delta-24-ACT with an anti-PD-1 antibody. Evaluation of this combination in vivo further increased the median survival time of treated tumor-bearing mice and resulted in 50% long-term survivors. Rechallenge studies with the same cell line showed that combination treatment effectively protected these animals of developing tumors and therefore, the acquisition of immune memory. In summary, our data demonstrated that Delta-24-ACT induces a potent anti-tumour effect in vitro and in vivo as a result of the recruitment of immune cell populations modulating the immunosuppressive tumour microenvironment of glioma.

scholarly journals CD137 and PD-L1 targeting with immunovirotherapy induces a potent and durable antitumor immune response in glioblastoma models

2021 ◽  
Vol 9 (7) ◽  
pp. e002644
Author(s):  
Montserrat Puigdelloses ◽  
Marc Garcia-Moure ◽  
Sara Labiano ◽  
Virginia Laspidea ◽  
Marisol Gonzalez-Huarriz ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Tumor Microenvironment ◽  
Antitumor Effect ◽  
Immune Memory ◽  
Programmed Death ◽  
Long Term Survivors ◽  
Murine Glioma

BackgroundGlioblastoma (GBM) is a devastating primary brain tumor with a highly immunosuppressive tumor microenvironment, and treatment with oncolytic viruses (OVs) has emerged as a promising strategy for these tumors. Our group constructed a new OV named Delta-24-ACT, which was based on the Delta-24-RGD platform armed with 4-1BB ligand (4-1BBL). In this study, we evaluated the antitumor effect of Delta-24-ACT alone or in combination with an immune checkpoint inhibitor (ICI) in preclinical models of glioma.MethodsThe in vitro effect of Delta-24-ACT was characterized through analyses of its infectivity, replication and cytotoxicity by flow cytometry, immunofluorescence (IF) and MTS assays, respectively. The antitumor effect and therapeutic mechanism were evaluated in vivo using several immunocompetent murine glioma models. The tumor microenvironment was studied by flow cytometry, immunohistochemistry and IF.ResultsDelta-24-ACT was able to infect and exert a cytotoxic effect on murine and human glioma cell lines. Moreover, Delta-24-ACT expressed functional 4-1BBL that was able to costimulate T lymphocytes in vitro and in vivo. Delta-24-ACT elicited a more potent antitumor effect in GBM murine models than Delta-24-RGD, as demonstrated by significant increases in median survival and the percentage of long-term survivors. Furthermore, Delta-24-ACT modulated the tumor microenvironment, which led to lymphocyte infiltration and alteration of their immune phenotype, as characterized by increases in the expression of Programmed Death 1 (PD-1) on T cells and Programmed Death-ligand 1 (PD-L1) on different myeloid cell populations. Because Delta-24-ACT did not induce an immune memory response in long-term survivors, as indicated by rechallenge experiments, we combined Delta-24-ACT with an anti-PD-L1 antibody. In GL261 tumor-bearing mice, this combination showed superior efficacy compared with either monotherapy. Specifically, this combination not only increased the median survival but also generated immune memory, which allowed long-term survival and thus tumor rejection on rechallenge.ConclusionsIn summary, our data demonstrated the efficacy of Delta-24-ACT combined with a PD-L1 inhibitor in murine glioma models. Moreover, the data underscore the potential to combine local immunovirotherapy with ICIs as an effective therapy for poorly infiltrated tumors.

scholarly journals IMMU-39. TIM-3 APTAMER IN COMBINATION WITH RADIOTHERAPY RESULTS IN ENHANCED SURVIVAL IN DIPG MODELS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii113-ii113
Author(s):  
Naiara Martinez-Velez ◽  
Marc Garcia-Moure ◽  
Montserrat Puigdelloses ◽  
Virginia Laspidea ◽  
Iker Ausejo ◽  
...  
Keyword(s):  
Overall Survival ◽  
Immune Memory ◽  
Effector Cells ◽  
Genomic Knowledge ◽  
Trial Testing ◽  
Long Term Survivors ◽  
Mouse Glioma ◽  
Anti Tumour Effect ◽  
Murine Glioma

Abstract Pediatric diffuse midline gliomas-H3-K27M-mutant are aggressive brain tumours that arise during childhood. Despite new advances in genomic knowledge and the significant number of clinical trial testing new targeted therapies, patient outcome is still insufficient. Cancer immunotherapy is opening new therapeutic options representing a hope for this orphan disease. Aptamers are single-stranded nucleic acid ligands design to achieve a remarkable affinity and specificity to their targets, comparable to antibodies. TIM-3, is a potential immune checkpoint target, typically involved in T-cell exhaustion. Recent studies showed that TIM-3 is also expressed in tumour and glial cells and it plays an important role in brain tumour responses mediated by myeloid cells. In this work, we examined the anti-tumour effect of an aptamer against TIM-3 alone or in combination with radiotherapy. Of importance, we tested TIM-3 aptamer in a murine glioma and DIPG model, where we not observed any toxicity. TIM-3 administration increased overall survival but was unable to control the disease. Of importance, TIM-3 combination with radiotherapy improved the overall survival of treated mice when compared with single treatments leading to 50% of long-term survivors. TIM-3 aptamer administration increase T-infiltration in the tumour site compared to non-treated or library control. Mechanistic studies performed on day 16 showed an increase in CD8 effector cells, a decrease in T-regulators Foxp3+ cells and an increase in IFN-gamma expression suggesting the triggering of an antitumor-immune response. Rechallenge experiments demonstrated immune memory in the long-term responders that led to reject tumour re-implantation, confirming that TIM-3 aptamer treatment in combination with RT elicits specific antitumor immunity in mouse glioma models. These results suggest that immuno-therapies approaches in combination with radiotherapy would be worth exploring in the treatment of deadly DMG-H3K27-Mutant tumours.

scholarly journals Effects of irradiation of recipient mice on the behavior and leukemogenic potential of factor-dependent hematopoietic cell lines

Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 190-197 ◽  
Author(s):  
U Duhrsen ◽  
D Metcalf
Keyword(s):  
Latent Period ◽  
Leukemic Cells ◽  
Hematopoietic Organs ◽  
Radiation Induced ◽  
Leukemia Development ◽  
Long Term Survivors ◽  
Hematopoietic Cell Lines

Abstract After intravenous (IV) injection with factor-dependent FDC-P1 cells, irradiated DBA/2 and BALB/c mice developed transplantable leukemias owing to neoplastic transformation of the injected cells in vivo. Increasing the radiation dose shortened the preleukemic latent period, and in female mice the frequency of leukemia development was higher and the latent period shorter than in male mice. In the preleukemic period, the injected FDC-P1 cells rapidly increased in number in hematopoietic organs of irradiated animals, reaching peak levels 3 to 5 weeks after injection; factor-independent transformed cells were not detected before day 45. In unirradiated animals, these events were delayed by several weeks, and long-term survivors did not harbor detectable FDC-P1 cells. FDC-P1 cells sampled from preleukemic mice frequently showed atypical colony formation and reduced cloning efficiency in vitro, suggesting the occurrence of a distinct preleukemic change. U16.6 cells produced leukemia only in irradiated recipients, and the leukemic cells usually remained factor dependent. The two contrasting models should be of value in further analyzing the mechanisms underlying radiation- induced leukemias.

scholarly journals Effects of irradiation of recipient mice on the behavior and leukemogenic potential of factor-dependent hematopoietic cell lines

Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 190-197 ◽  
Author(s):  
U Duhrsen ◽  
D Metcalf
Keyword(s):  
Latent Period ◽  
Leukemic Cells ◽  
Hematopoietic Organs ◽  
Radiation Induced ◽  
Leukemia Development ◽  
Long Term Survivors ◽  
Hematopoietic Cell Lines

After intravenous (IV) injection with factor-dependent FDC-P1 cells, irradiated DBA/2 and BALB/c mice developed transplantable leukemias owing to neoplastic transformation of the injected cells in vivo. Increasing the radiation dose shortened the preleukemic latent period, and in female mice the frequency of leukemia development was higher and the latent period shorter than in male mice. In the preleukemic period, the injected FDC-P1 cells rapidly increased in number in hematopoietic organs of irradiated animals, reaching peak levels 3 to 5 weeks after injection; factor-independent transformed cells were not detected before day 45. In unirradiated animals, these events were delayed by several weeks, and long-term survivors did not harbor detectable FDC-P1 cells. FDC-P1 cells sampled from preleukemic mice frequently showed atypical colony formation and reduced cloning efficiency in vitro, suggesting the occurrence of a distinct preleukemic change. U16.6 cells produced leukemia only in irradiated recipients, and the leukemic cells usually remained factor dependent. The two contrasting models should be of value in further analyzing the mechanisms underlying radiation- induced leukemias.

scholarly journals Nanoparticle delivery of immunostimulatory oligonucleotides enhances response to checkpoint inhibitor therapeutics

2020 ◽  
Vol 117 (24) ◽  
pp. 13428-13436 ◽  
Author(s):  
Colin G. Buss ◽  
Sangeeta N. Bhatia
Keyword(s):  
Animal Models ◽  
Tumor Growth ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitor ◽  
Checkpoint Inhibitor ◽  
Checkpoint Inhibitors ◽  
Engineered Nanoparticles ◽  
Therapeutic Effects

The recent advent of immune checkpoint inhibitor (CPI) antibodies has revolutionized many aspects of cancer therapy, but the efficacy of these breakthrough therapeutics remains limited, as many patients fail to respond for reasons that still largely evade understanding. An array of studies in human patients and animal models has demonstrated that local signaling can generate strongly immunosuppressive microenvironments within tumors, and emerging evidence suggests that delivery of immunostimulatory molecules into tumors can have therapeutic effects. Nanoparticle formulations of these cargoes offer a promising way to maximize their delivery and to enhance the efficacy of checkpoint inhibitors. We developed a modular nanoparticle system capable of encapsulating an array of immunostimulatory oligonucleotides that, in some cases, greatly increase their potency to activate inflammatory signaling within immune cells in vitro. We hypothesized that these immunostimulatory nanoparticles could suppress tumor growth by activating similar signaling in vivo, and thereby also improve responsiveness to immune checkpoint inhibitor antibody therapies. We found that our engineered nanoparticles carrying a CpG DNA ligand of TLR9 can suppress tumor growth in several animal models of various cancers, resulting in an abscopal effect on distant tumors, and improving responsiveness to anti-CTLA4 treatment with combinatorial effects after intratumoral administration. Moreover, by incorporating tumor-homing peptides, immunostimulatory nucleotide-bearing nanoparticles facilitate antitumor efficacy after systemic intravenous (i.v.) administration.

scholarly journals Cocoa: antioxidant and immunomodulator

2009 ◽  
Vol 101 (7) ◽  
pp. 931-940 ◽  
Author(s):  
Emma Ramiro-Puig ◽  
Margarida Castell
Keyword(s):  
Cell Function ◽  
Immune Cell ◽  
Cell Signalling ◽  
Antioxidant Properties ◽  
High Dose ◽  
T Helper ◽  
T Helper 1

Cocoa, a product consumed since 600 BC, is now a subject of increasing interest because of its antioxidant properties, which are mainly attributed to the content of flavonoids such as ( − )-epicatechin, catechin and procyanidins. Moreover, recent findings suggest a regulatory effect of cocoa on the immune cells implicated in innate and acquired immunity. Cocoa exerts regulatory activity on the secretion of inflammatory mediators from macrophages and other leucocytesin vitro. In addition, emerging data fromin vivostudies support an immunomodulating effect. Long-term cocoa intake in rats affects both intestinal and systemic immune function. Studies in this line suggest that high-dose cocoa intake in young rats favours the T helper 1 (Th1) response and increases intestinal γδ T lymphocyte count, whereas the antibody-secreting response decreases. The mechanisms involved in this activity are uncertain; nonetheless, because redox-sensitive pathways control immune cell function, the action of cocoa flavonoids on modulating cell signalling and gene expression deserves investigation.

scholarly journals In Vivo Pharmacokinetics, Biodistribution and Toxicity of Antibody-Conjugated Gold Nanoparticles in Healthy Mice

2020 ◽  
Vol 16 (6) ◽  
pp. 985-996
Author(s):  
Noami Daems ◽  
Bart Verlinden ◽  
Karen Van Hoecke ◽  
Thomas Cardinaels ◽  
Sarah Baatout ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Immune Cell ◽  
Serum Marker ◽  
Cancer Therapies ◽  
Multiple Dosing ◽  
Altered Liver ◽  
Kidney Liver

Cetuximab-conjugated gold nanoparticles are known to target cancer cells, but display toxicity towards normal kidney, liver and endothelial cells in vitro. In this study, we investigated their pharmacokinetics, biodistribution and toxicity after intravenous administration in healthy mice. Our data showed that these nanoparticles were rapidly cleared from the blood and accumulated mainly in the liver and spleen with long-term retention. Acute liver injury, inflammatory activity and vascular damage were transient and negligible, as confirmed by the liver functionality tests and serum marker analysis. There was no sign of altered liver, kidney, lung and spleen morphology up to 4 weeks post-injection. After 6 months, kidney casts and splenic apoptosis appeared to be more prevalent than in the controls. Furthermore, occasional immune cell infiltration was observed in the lungs. Therefore, we recommend additional in vivo studies, in order to investigate the long-term toxicity and elimination of gold nanoparticles after multiple dosing in their preclinical validation as new targeted anti-cancer therapies.

scholarly journals CXCL13 expression in mouse 4T1 breast cancer microenvironment elicits anti-tumor immune response by regulating immune cell infiltration

2021 ◽  
Author(s):  
Qizhi Ma ◽  
Yue Chen ◽  
Qing Qin ◽  
Fuchun Guo ◽  
Yong-sheng Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Immune Cell ◽  
Nk Cell ◽  
Immune Memory ◽  
Breast Cancer Cell Lines ◽  
Cancer Type ◽  
Cancer Microenvironment ◽  
Clinical Prognosis

Abstract Breast cancer is the most commonly diagnosed cancer type and the leading cause of cancer-related deaths among women worldwide. Previous studies have reported contradictory performance of chemokine CXC motif ligand 13 (CXCL13) in breast cancer. In this study, TCGA database analysis revealed that CXCL13 was overexpressed in various human cancers including breast carcinoma, and associated with good clinical prognosis in breast cancer. Flow cytometry detection also found up-regulated intracellular CXCL13 expression in human breast cancer cell lines. To explore the possible role of CXCL13 in breast cancer microenvironment, mouse triple negative breast cancer (TNBC) was lentivirally transfected to stably overexpress mouse CXCL13 (4T1-CXCL13). Both parental 4T1 and 4T1-CXCL13 strains showed no in vitro and in vivo endogenous cell surface CXCR5 expression. In immune-competent BALB/c mice, the in vivo tumor growth of 4T1-CXCL13 was significantly inhibited and even completely eradicated, accompanied with increased infiltrations of CD4+, CD8 + T lymphocytes and CD11b + CD11c + DCs. Further investigations showed that CXCL13 expression in 4T1 tumor microenvironment elicited long-term anti-tumor immune memory, and rejection of distal parental tumor. The anti-tumor activity of CXCL13 was remarkedly impaired in BALB/cA-nu nude mice, or in BALB/c mice with CD8 + T lymphocyte or NK cell depletion. Our investigation indicated that CXCL13 expression in TNBC triggered effective anti-tumor immunity by chemoattracting immune cell infiltrations, and could be considered as a novel prognostic marker for TNBC.

scholarly journals A Small Molecule Antagonist of PD-1/PD-L1 Interactions Acts as an Immune Checkpoint Inhibitor for NSCLC and Melanoma Immunotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Wang ◽  
Tingxuan Gu ◽  
Xueli Tian ◽  
Wenwen Li ◽  
Ran Zhao ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Monoclonal Antibodies ◽  
Small Molecule ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitor ◽  
Checkpoint Inhibitor ◽  
Small Molecule Antagonist ◽  
Programmed Death

Immune checkpoint inhibitors, such as monoclonal antibodies targeting programmed death 1 (PD-1) and programmed death ligand-1 (PD-L1), have achieved enormous success in the treatment of several cancers. However, monoclonal antibodies are expensive to produce, have poor tumor penetration, and may induce autoimmune side effects, all of which limit their application. Here, we demonstrate that PDI-1 (also name PD1/PD-L1 inhibitor 1), a small molecule antagonist of PD-1/PD-L1 interactions, shows potent anti-tumor activity in vitro and in vivo and acts by relieving PD-1/PD-L1-induced T cell exhaustion. We show that PDI-1 binds with high affinity to purified human and mouse PD-1 and PD-L1 proteins and is a competitive inhibitor of human PD-1/PD-L1 binding in vitro. Incubation of ex vivo activated human T cells with PDI-1 enhanced their cytotoxicity towards human lung cancer and melanoma cells, and concomitantly increased the production of granzyme B, perforin, and inflammatory cytokines. Luciferase reporter assays showed that PDI-1 directly increases TCR-mediated activation of NFAT in a PD-1/PD-L1-dependent manner. In two syngeneic mouse tumor models, the intraperitoneal administration of PDI-1 reduced the growth of tumors derived from human PD-L1-transfected mouse lung cancer and melanoma cells; increased and decreased the abundance of tumor-infiltrating CD8+ and FoxP3+ CD4+ T cells, respectively; decreased the abundance of PD-L1-expressing tumor cells, and increased the production of inflammatory cytokines. The anti-tumor effect of PDI-1 in vivo was comparable to that of the anti-PD-L1 antibody atezolizumab. These results suggest that the small molecule inhibitors of PD-1/PD-L1 may be effective as an alternative or complementary immune checkpoint inhibitor to monoclonal antibodies.

Low-dose photodynamic therapy promotes a cytotoxic immunological response in a murine model of pleural mesothelioma

2020 ◽  
Vol 58 (4) ◽  
pp. 783-791
Author(s):  
Sabrina Cavin ◽  
Aspasia Gkasti ◽  
Julien Faget ◽  
Yameng Hao ◽  
Igor Letovanec ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Immune Checkpoint ◽  
Tumour Growth ◽  
Low Dose ◽  
Immune Checkpoint Inhibitor ◽  
Immune Cell ◽  
Checkpoint Inhibitor ◽  
Pleural Mesothelioma ◽  
Tumour Control

Abstract OBJECTIVES Malignant pleural mesothelioma (MPM) is a deadly disease with limited treatment options. Approaches to enhance patient immunity against MPM have been tested but shown variable results. Previously, we have demonstrated interesting vascular modulating properties of low-dose photodynamic therapy (L-PDT) on MPM. Here, we hypothesized that L-PDT vascular modulation could favour immune cell extravasation in MPM and improve tumour control in combination with immune checkpoint inhibitors. METHODS First, we assessed the impact of L-PDT on vascular endothelial E-selectin expression, a key molecule for immune cell extravasation, in vitro and in a syngeneic murine model of MPM. Second, we characterized the tumour immune cell infiltrate by 15-colour flow cytometry analysis 2 and 7 days after L-PDT treatment of the murine MPM model. Third, we determined how L-PDT combined with immune checkpoint inhibitor anti-CTLA4 affected tumour growth in a murine MPM model. RESULTS L-PDT significantly enhanced E-selectin expression by endothelial cells in vitro and in vivo. This correlated with increased CD8+ T cells and activated antigen-presenting cells (CD11b+ dendritic cells and macrophages) infiltration in MPM. Also, compared to anti-CTLA4 that only affects tumour growth, the combination of L-PDT with anti-CTLA4 caused complete MPM regression in 37.5% of animals. CONCLUSIONS L-PDT enhances E-selectin expression in the MPM endothelium, which favours immune infiltration of tumours. The combination of L-PDT with immune checkpoint inhibitor anti-CTLA4 allows best tumour control and regression.

Sign in / Sign up

Export Citation Format

Share Document