scholarly journals An engineered oncolytic vaccinia virus encoding a single-chain variable fragment against TIGIT induces effective antitumor immunity and synergizes with PD-1 or LAG-3 blockade

2021 ◽  
Vol 9 (12) ◽  
pp. e002843
Author(s):  
Shuguang Zuo ◽  
Min Wei ◽  
Tiancheng Xu ◽  
Lingkai Kong ◽  
Bohao He ◽  
...  
Keyword(s):  
T Cell ◽  
Antitumor Immunity ◽  
Complete Response ◽  
Immune Checkpoint Blockade ◽  
Oncolytic Viruses ◽  
Antitumor Efficacy ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Tumor Bearing ◽  
T Cell Infiltration

BackgroundIn addition to directly lysing tumors, oncolytic viruses also induce antitumor immunity by recruiting and activating immune cells in the local tumor microenvironment. However, the activation of the immune cells induced by oncolytic viruses is always accompanied by high-level expression of immune checkpoints in these cells, which may reduce the efficacy of the oncolytic viruses. The aim of this study is to arm the oncolytic vaccinia virus (VV) with immune checkpoint blockade to enhance its antitumor efficacy.MethodsThrough homologous recombination with the parental VV, an engineered VV-scFv-TIGIT was produced, which encodes a single-chain variable fragment (scFv) targeting T-cell immunoglobulin and ITIM domain (TIGIT). The antitumor efficacy of the VV-scFv-TIGIT was explored in several subcutaneous and ascites tumor models. The antitumor efficacy of VV-scFv-TIGIT combined with programmed cell death 1 (PD-1) or lymphocyte-activation gene 3 (LAG-3) blockade was also investigated.ResultsThe VV-scFv-TIGIT effectively replicated in tumor cells and lysed them, and prompt the infected tumor cells to secret the functional scFv-TIGIT. Compared with control VV, intratumoral injection of VV-scFv-TIGIT in several mouse subcutaneous tumor models showed superior antitumor efficacy, accompanied by more T cell infiltration and a higher degree of CD8+ T cells activation. Intraperitoneal injection of VV-scFv-TIGIT in a mouse model of malignant ascites also significantly improved T cell infiltration and CD8+ T cell activation, resulting in more than 90% of the tumor-bearing mice being cured. Furthermore, the antitumor immune response induced by VV-scFv-TIGIT was dependent on CD8+ T cells which mediated a long-term immunological memory and a systemic antitumor immunity against the same tumor. Finally, the additional combination of PD-1 or LAG-3 blockade further enhanced the antitumor efficacy of VV-scFv-TIGIT, increasing the complete response rate of tumor-bearing mice.ConclusionsOncolytic virotherapy using engineered VV-scFv-TIGIT was an effective strategy for cancer immunotherapy. Administration of VV-scFv-TIGIT caused a profound reshaping of the suppressive tumor microenvironment from ‘cold’ to ‘hot’ status. VV-scFv-TIGIT also synergized with PD-1 or LAG-3 blockade to achieve a complete response to tumors with poor response to VV or immune checkpoint blockade monotherapy.

scholarly journals GPR182 limits antitumor immunity via chemokine scavenging in mouse melanoma models

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Robert J. Torphy ◽  
Yi Sun ◽  
Ronggui Lin ◽  
Alayna Caffrey-Carr ◽  
Yuki Fujiwara ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Checkpoint ◽  
Antitumor Immunity ◽  
Cell Function ◽  
Tumor Infiltrating Lymphocytes ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Cell Infiltration ◽  
T Cell Infiltration ◽  
Deficient Mice

AbstractFor many solid tumors, immune checkpoint blockade therapy has become first line treatment, yet a large proportion of patients with immunologically cold tumors do not benefit due to the paucity of tumor infiltrating lymphocytes. Here we show that the orphan G Protein-Coupled Receptor 182 (GPR182) contributes to immunotherapy resistance in cancer via scavenging chemokines that are important for lymphocyte recruitment to tumors. GPR182 is primarily upregulated in melanoma-associated lymphatic endothelial cells (LECs) during tumorigenesis, and this atypical chemokine receptor endocytoses chemokines promiscuously. In GPR182-deficient mice, T cell infiltration into transplanted melanomas increases, leading to enhanced effector T cell function and improved antitumor immunity. Ablation of GPR182 leads to increased intratumoral concentrations of multiple chemokines and thereby sensitizes poorly immunogenic tumors to immune checkpoint blockade and adoptive cellular therapies. CXCR3 blockade reverses the improved antitumor immunity and T cell infiltration characteristic of GPR182-deficient mice. Our study thus identifies GPR182 as an upstream regulator of the CXCL9/CXCL10/CXCR3 axis that limits antitumor immunity and as a potential therapeutic target in immunologically cold tumors.

scholarly journals 49 In situ phenotypic analysis of T cells in the tumor microenvironment of a pre-clinical model of non-small cell lung cancer (NSCLC) by tissue sectioning and whole-mount immunofluorescence imaging

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A52-A52
Author(s):  
Elen Torres ◽  
Stefani Spranger
Keyword(s):  
T Cells ◽  
Spatial Distribution ◽  
T Cell ◽  
Spatial Location ◽  
Cell Infiltration ◽  
Cell Populations ◽  
Tumor Bearing ◽  
T Cell Infiltration ◽  
Volume Imaging ◽  
Whole Mount

BackgroundUnderstanding the interactions between tumor and immune cells is critical for improving current immunotherapies. Pre-clinical and clinical evidence has shown that failed T cell infiltration into lung cancer lesions might be associated with low responsiveness towards checkpoint blockade.1 For this reason, it is necessary to characterize not only the phenotype of T cells in tumor-bearing lungs but also their spatial location in the tumor microenvironment (TME). Multiplex immunofluorescence staining allows the simultaneous use of several cell markers to study the state and the spatial location of cell populations in the tissue of interest. Although this technique is usually applied to thin tissue sections (5 to 12 µm), the analysis of large tissue volumes may provide a better understanding of the spatial distribution of cells in relation to the TME. Here, we analyzed the number and spatial distribution of cytotoxic T cells and other immune cells in the TME of tumor-bearing lungs, using both 12 µm sections and whole-mount preparations imaged by confocal microscopy.MethodsLung tumors were induced in C57BL/6 mice by tail vein injection of a cancer cell line derived from KrasG12D/+ and Tp53-/- mice. Lung tissue with a diverse degree of T cell infiltration was collected after 21 days post tumor induction. Tissue was fixed in 4% PFA, followed by snap-frozen for sectioning. Whole-mount preparations were processed according to Weizhe Li et al. (2019) 2 for tissue clearing and multiplex volume imaging. T cells were labeled with CD8 and FOXP3 antibodies to identify cytotoxic or regulatory T cells, respectively. Tumor cells were labeled with a pan-Keratin antibody. Images were acquired using a Leica SP8 confocal microscope. FIJI3 and IMARIS were used for image processing.ResultsWe identified both cytotoxic and regulatory T cell populations in the TME using thin sections and whole-mount. However, using whole-mount after tissue clearing allowed us to better evaluate the spatial distribution of the T cell populations in relation to the tumor structure. Furthermore, tissue clearance facilitates the imaging of larger volumes using multiplex immunofluorescence.ConclusionsAnalysis of large lung tissue volumes provides a better understanding of the location of immune cell populations in relation to the TME and allows to study heterogeneous immune infiltration on a per-lesion base. This valuable information will improve the characterization of the TME and the definition of cancer-immune phenotypes in NSCLC.ReferencesTeng MW, et al., Classifying cancers based on T-cell infiltration and PD-L1. Cancer Res 2015;75(11): p. 2139–45.Li W, Germain RN, and Gerner MY. High-dimensional cell-level analysis of tissues with Ce3D multiplex volume imaging. Nat Protoc 2019;14(6): p. 1708–1733.Schindelin J, et al, Fiji: an open-source platform for biological-image analysis. Nat Methods 2012;9(7): p. 676–82.

scholarly journals Rethinking immune checkpoint blockade: ‘Beyond the T cell’

2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo
Keyword(s):  
Immune System ◽  
T Cell ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Antitumor Immunity ◽  
Checkpoint Inhibitors ◽  
Clinical Success ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.

scholarly journals Agonistic CD40 antibody therapy induces tertiary lymphoid structures but impairs the response to immune checkpoint blockade in glioma

2021 ◽  
Author(s):  
Luuk van Hooren ◽  
Alessandra Vaccaro ◽  
Mohanraj Ramachandran ◽  
Konstantinos Vazaios ◽  
Sylwia Libard ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Antibody Therapy ◽  
Immune Checkpoint Blockade ◽  
Cytotoxic T Cell ◽  
Systemic Delivery ◽  
T Cell Infiltration ◽  
Tertiary Lymphoid Structures ◽  
Lymphoid Structures

AbstractGliomas are brain tumors characterized by immunosuppression. Immunostimulatory agonistic CD40 antibodies (αCD40) are in clinical development for solid tumors but are yet to be evaluated for glioma. Here, systemic delivery of αCD40 led to cytotoxic T cell dysfunction and impaired the response to immune checkpoint inhibitors in preclinical glioma models. This was associated with an accumulation of suppressive CD11b+ B cells. However, αCD40 also induced tertiary lymphoid structures (TLS). In human glioma, TLS correlated with increased T cell infiltration indicating enhanced immune responses. Our work unveils the pleiotropic effects of αCD40 therapy in glioma, which is of high clinical relevance.

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