619 Evaluating the effectiveness of targeted ADC therapy in a patient-derived ex vivo tumoroid model, 3D-EX, for quantitative tumor cell killing

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A655-A655
Author(s):  
Jenny Kreahling ◽  
Jared Ehrhart ◽  
Mibel Pabon ◽  
Stephen Iwanowycz ◽  
Tina Pastoor ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Microenvironment ◽  
Tumor Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Confocal Imaging ◽  
Tumor Cell Death ◽  
Drug Conjugates ◽  
Tumor Cell Killing ◽  
Antibody Drug

BackgroundAntibody drug conjugates (ADCs) are an effective tool for site directed delivery of cytotoxic agents to cancer cells. Tailoring of ADC-specificity to the uniqueness of a patient‘s tumor can aid in direct-targeting of tumor cells and potentially improve drug responsiveness. Here we evaluate the potential of using an ADC therapy for targeted tumor cell death and immune cell activation in combination with checkpoint inhibitors in 3D tumoroids.MethodsAll human tumor samples were obtained with proper patient consent and IRB approval. Fresh patient tumor tissue of various histologic types including CRC and NSCLC were processed to generate uniform sized live 3D tumoroids measuring 150 µm in size. Treatment groups included a conjugated ADC therapeutic antibody alone or in combination with PD-1/PD-L1 inhibitors. Culture supernatants were collected for multiplex analysis of cytokine release in media. Additionally, flow cytometry was used to assess the activation profile of resident immune cells in combination with high-content confocal imaging to determine extent of tumor cell death in the intact tumor extracellular matrix.ResultsUsing fresh patient-derived tumoroids, we observed ADC-mediated cell death and activation of immune cells within the tumor microenvironment. Production of pro-inflammatory cytokines correlated with increased activation of tumor infiltrating immune cell populations. The improved immune response led to increased tumor cell killing within the 3D tumor microenvironment observed by high-content confocal imaging.ConclusionsIn this study we demonstrate that our physiologically relevant 3D tumoroid model is an effective system to assess novel antibody drug conjugates and to develop rational drug combinations with other immuno-oncology agents. Furthermore, implementation of 3D-EX platform, in the clinical setting, may also allow for determination of the most effective combinatorial immuno-oncology treatment strategies for individualized patient care.Ethics ApprovalThe study was approved by Chesapeake IRB Pro00014313.

557 Determining the efficacy of ADCC by the 3D-EX ex vivo platform utilizing tumoroids of fresh patient tumor samples with intact tumor microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A591-A591
Author(s):  
Jenny Kreahling ◽  
Jared Ehrhart ◽  
Stephen Iwanowycz ◽  
Mibel Pabon ◽  
Tina Pastoor ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Microenvironment ◽  
Tumor Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Ex Vivo ◽  
Cell Killing ◽  
Confocal Imaging ◽  
Tumor Cell Death ◽  
Tumor Cell Killing

BackgroundAntibody-dependent cell-mediated cytotoxicity (ADCC) is an effective tool where antibody-coated cells are targeted and killed by effector immune cells. The application of ADCC therapies has been expanded for both solid tumors as well as hematologic malignancies. However, the immunosuppressive mechanisms present in the immune tumor microenvironment (TME) pose a formidable challenge to immune cell efficacy in addition to hinderance of immune cell infiltration by tumor stromal elements. Hence, it is important to develop clinically relevant platforms to assess the efficacy of antibodies for ADCC. Here we utilized our 3D-EX platform using tumoroids of fresh patient tumor samples to assess ADCC-mediated tumor cell killing.MethodsAll human tumor samples were obtained with proper patient consent and IRB approval. Fresh patient tumor tissue of various histologic types including non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) was processed to generate uniform sized live 3D tumoroids measuring 150 µm in size. Treatment groups included cetuximab alone or in combination with nivolumab and/or ipilimumab. Culture supernatants were collected for multiplex analysis of cytokine release in media. Multiplex flow cytometry was used to assess the activation profile of tumor resident immune cells in combination with high-content confocal imaging to determine extent of ADCC-mediated tumor cell death in the intact tumor extracellular matrix.ResultsUsing fresh patient-derived tumor organoids, we observed ADCC-dependent death of EGFR expressing tumor cells. Flow cytometric analysis of immune cell populations demonstrated treatment mediated activation of resident immune cells, which coincided with cytokine profiles determined by Luminex multiplex cytokine analysis. Additionally, tumor cell killing observed through high-content confocal imaging and quantitative image analysis showed tumor cell death with the 3D tumoroids.ConclusionsIn this comprehensive study we demonstrate that the 3D-EX ex vivo model is a robust system to assess the efficacy of ADCC and to develop novel therapeutic combinations with other immuno-oncology therapies. Furthermore, implementation of this platform in clinical studies may also allow for determination of the most effective combinatorial immuno-oncology therapy strategies for specialized individual patient care.Ethics ApprovalThe study was approved by Chesapeake IRB Pro00014313.

A precision medicine tool “Knowledge Frames” to explain poor results of STING agonist trials.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15632-e15632
Author(s):  
Al Blunt ◽  
Gerald L. Messerschmidt ◽  
Steve Gyorffy
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Cell ◽  
Precision Medicine ◽  
Immune Cells ◽  
Immune Cell ◽  
Human Organism ◽  
Interferon Production ◽  
Tumor Cell Death ◽  
Cell Homing ◽  
Public Data

e15632 Background: STING activating cyclic-di-nucleotides result in the production of interferons, activating immune cells. We show that “Precision Medicine Knowledge Frames” (PMKF) are analyses inherently involving 2 processes: Frame 1 – Bench Science - biochemical functions of the experimental product, and Frame 2 - Human Organism Level - actions from product biochemical effects to tumor cell killing. Methods: STING agonists meet this PMK frame1 and activate STING (step 1) effectively. Activated STING binds TBK1 (step 2), then phosphorylates IRF3 (step 3), enters the nucleus (step 4), dimerizes (step 5) and binds specific regions of the DNA (step 6) for interferon transcription (step 7), which are secreted (step 8). Frame 2, the Human Organism Level - final common pathway requires many additional actions: Interferon must interact with immune cells (step 9) [within tumor or peripheral locations]. Very warm or hot tumors [contain functional immune cells] actively allow trafficking (homing) to the tumor (step 10) and infiltrating the tumor microenvironment (step 11). An activated immune cell can kill the tumor cell(s) (step 12). Cold tumors may not allow homing (step 10) to the tumor and/or infiltration (step 11) of the microenvironment. Results: PMKF modeling was applied to STING administration public data. Lack of efficacy was predicted if one of the critical pathway steps to tumor cell death are dysfunctional. Early steps (Frame 1) to interferon production and excretion into the environment occur within normal cells (antigen presenting cells) predictably. However, in the setting of malignancy, Frame 2 steps are often aberrant at the Organism Level. Cold tumors do not allow immune cell homing (step 10) and inhibit tumor infiltration (Step 11), tumor cell localization and killing of the tumor cell (step 12). Conclusions: STING Agonist are cutting edge therapies that perform PMKF Frame 1 well and increase interferon production. Application of the PMKF - Frame 2 demonstrate poor clinical activity may be explained by poor immune cell homing, infiltration and functional killing within the cold tumor microenvironment (dysfunctional steps 10, 11 and 12). Population selection may improve these results.

scholarly journals 620 Tumor cell-intrinsic STING pathway is activated in the presence of cues from immune cells and contributes to the anti-tumor activity of tumor cell-targeted STING agonist antibody-drug conjugates

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A656-A656
Author(s):  
Naniye Malli Cetinbas ◽  
Travis Monnell ◽  
Winnie Lee ◽  
Kalli Catcott ◽  
Chen-Ni Chin ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cancer Cell ◽  
Immune Cells ◽  
Antibody Drug Conjugates ◽  
Drug Conjugates ◽  
Primary Monocyte ◽  
Sting Pathway ◽  
Anti Tumor Activity ◽  
Antibody Drug

BackgroundSTING pathway agonism has emerged as a potential therapeutic mechanism to stimulate an innate anti-tumor immune response. While in principle systemic administration of a STING agonist would have many therapeutic benefits, including the delivery of STING to all tumor lesions, such an approach may be limited by toxicity. Antibody-drug conjugates (ADCs) constitute a proven therapeutic modality that is ideally suited to allow systemic administration while stimulating the innate immunity in a targeted manner. We have previously demonstrated that targeted delivery of a STING agonist with an ADC induces robust anti-tumor immune responses.MethodsHerein we investigated the mechanism of action of tumor cell-targeted STING agonist ADCs. We evaluated STING pathway activation and anti-tumor activity elicited by ADCs harboring either wild type (wt) or mutant Fc deficient in Fcγ receptor (FcγR) binding in wt or STING knockout (ko) cancer cell mono-cultures, immune cell co-cultures, and in in vivo tumor models.ResultsConsistent with previous reports, the majority of cancer cell lines tested failed to induce STING pathway following STING agonist payload treatment in mono-cultures. In cancer cell:THP1 monocytic cell co-cultures, tumor-targeted STING agonist ADCs with wt Fc exhibited robust STING activation, whereas Fc-mutant ADCs or non-targeted control ADCs had minimal activity. Similar results were obtained when THP1 cells were treated in plates coated with target antigen without cancer cells, demonstrating STING activation in THP1 cells following FcγR-mediated uptake of antigen-bound ADCs. Tumor-targeted Fc-wt ADCs led to marked induction of STING pathway and cancer cell-killing in cancer cell:PBMC or primary monocyte co-cultures, and complete tumor regressions in in vivo tumors. Surprisingly, while at reduced levels relative to the Fc-wt ADCs, Fc-mutant ADCs exhibited significant activity in these in vitro and in vivo models, suggesting that tumor cell-intrinsic STING pathway may be activated in the presence of cues from immune cells. Consistently, STING agonist payload treatment in the presence of conditioned media from PBMC and primary monocyte but not from THP1 cultures, led to STING activation in cancer cell mono-cultures. Moreover, Fc-mutant ADCs had diminished activity in STING ko cancer cell:PBMC or primary monocyte co-cultures, demonstrating the contribution of tumor cell-intrinsic STING activation to the anti-tumor activity elicited by tumor cell-targeted STING agonist ADCs.ConclusionsIn conclusion, we demonstrated that tumor cell-targeted STING agonist ADCs induce robust anti-tumor activity through mechanisms involving both FcγR and tumor antigen-mediated ADC internalization and subsequent induction of STING pathway in immune cells and tumor cells.

scholarly journals Ionizing radiation improves RIG-I mediated immunotherapy through enhanced p53 activation in malignant melanoma

2021 ◽  
Author(s):  
Silke Lambing ◽  
Stefan Holdenrieder ◽  
Patrick Müller ◽  
Christian Hagen ◽  
Stephan Garbe ◽  
...  
Keyword(s):  
Cell Death ◽  
Malignant Melanoma ◽  
Tumor Cell ◽  
Low Dose ◽  
Immune Cell ◽  
Cytotoxic T Cell ◽  
Great Promise ◽  
Type I ◽  
Tumor Cell Death

The activation of the innate immune receptor RIG-I is a promising approach in immunooncology and currently under investigation in clinical trials. RIG-I agonists elicit a strong immune activation in both tumor and immune cells and induce both direct and indirect immune cell-mediated tumor cell death which involves tumor-specific cytotoxic T-cell response and type I interferon-driven innate cytotoxic immunity. Besides RIG-I, irradiation is known to induce cytotoxic DNA damage resulting in tumor debulking followed by the induction of tumor-specific immunity. To date, it is unclear whether the molecular antitumor effects of RIG-I and irradiation are additive or even synergize. Here, we investigated the combination of RIG-I activation with radiotherapy in melanoma. We found that low dose x-ray irradiation enhanced the extent and immunogenicity of RIG-I mediated tumor cell death in human and murine melanoma cell lines and in the murine B16 melanoma model in vivo. Pathway analysis of transcriptomic data revealed a central role for p53 downstream of the combined treatment, which was corroborated using p53-/- B16 cells. In vivo, the additional effect of irradiation on immune cell activation and inhibition of tumor growth was lost in mice carrying p53-knockout B16 tumors, while the response to RIG-I stimulation in those mice was maintained. Thus, our results identify p53 as pivotal for the synergy of RIG-I with irradiation, resulting in potent induction of immunogenic tumor cell death. Consequently, low dose radiotherapy holds great promise to further improve the efficacy or RIG-I ligands especially in patients with malignant melanoma or other tumors exhibiting a functional p53 pathway.

174 An ex vivo tumoroid model of fresh patient tumors (3D-ACT) to assess efficacy of cellular therapy in immuno-oncology

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A188-A188
Author(s):  
Stephen Iwanowycz ◽  
Jared Ehrhart ◽  
Mibel Pabon ◽  
Tina Pastoor ◽  
Jenny Kreahling ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Cell ◽  
Ex Vivo ◽  
Cell Killing ◽  
Confocal Imaging ◽  
Flow Cytometry Analysis ◽  
Car T ◽  
Engineered T Cells ◽  
Tumor Cell Killing

BackgroundAdoptive T cell therapy (ACT) strategies have achieved substantial advances in the treatment of malignant tumors. Some of the unique challenges posed to ACT by solid tumors include locating target cells, as well as entering and surviving the complex tumor microenvironment. To develop better ACT applications and identify combination therapies to enhance tumor cell killing efficacy of ACT it is imperative to develop preclinical platforms that recapitulate the complexity of patient tumor microenvironment (TME). The goal of this study was to develop an integrated confocal-based high-throughput, high-content real time imaging platform to assess immunogenic tumor cell killing (TCK) activity of ACT applications such as CAR-T and TCR using fresh patient tumor samples.MethodsAll patient tumor samples were obtained with patient consent and relevant IRB approval. For the confocal imaging platform, unpropagated 3D tumoroids with intact TME measuring 150 micron in size were prepared from fresh tumor samples of renal cell carcinoma (RCC), colorectal carcinoma (CRC) and non-small cell lung cancer (NSCLC) using proprietary technology developed at Nilogen Oncosystems. Engineered T-cells were labeled with different fluorescent cell tracker dyes to monitor cell migration and locations within tumoroids by confocal analysis. Comprehensive flow cytometry analysis was performed to corroborate confocal imaging findings from TCK and multiplex cytokine release assays used to assess changes in the TME.ResultsOur studies demonstrated that the confocal-based high-content real time imaging platform described here, combined with a custom image analysis algorithm, allowed for monitoring of treatment-mediated tumor cell killing with structural and functional analysis of engineered T-cells in intact 3D tumoroids. The penetration rate of CAR-T and TCR cells into tumoroids as well as associated tumor cell death varied significantly between different tumor types. Flow cytometry analysis allowed for monitoring of the activation status and viability of engineered T-cells, and treatment-mediated changes in tumor resident immune cell populations.ConclusionsOur data indicated that the immunosuppressive tumor microenvironment may have implications for the application of ACT. Use of the ex vivo platform described here (3D-ACT) may aid in the validation of combinatorial therapies that block or deplete suppressive factors present within the TME, allowing these therapies to overcome mechanisms associated with dysfunction in CAR-T and TCR cell applications.Ethics ApprovalThe study was approved by Chesapeake IRB Pro00014313.

scholarly journals EXTH-44. INHIBITION OF MerTK ACTIVATES GLIOBLASTOMA-ASSOCIATED MACROPHAGES AND INDUCES TUMOR CELL DEATH IN GLIOMA MICROENVIRONMENT

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi91-vi91
Author(s):  
Yu-Ting Su ◽  
Madison Butler ◽  
Lee Hwang ◽  
Dragan Maric ◽  
Shelton Earp ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Growth ◽  
Tumor Microenvironment ◽  
Tumor Cell ◽  
Colony Formation ◽  
Glioblastoma Cells ◽  
Tumor Cell Death ◽  
Glioma Microenvironment

Abstract BACKGROUND Glioblastoma-associated macrophages and microglia (GAMs) are the predominant immune cells in the tumor microenvironment. Activation of MerTK, a receptor tyrosine kinase, triggers efferocytosis and polarizes GAMs to an immunosuppressive phenotype, promoting glioma growth. Our previous findings showed that UNC2371, a small-molecule inhibitor of MerTK, induced a less immunosuppressive phenotype of GAMs. Here, we investigate the role of MerTK inhibition on glioblastoma cells in the tumor microenvironment in vitro and in vivo. METHODS Cytotoxicity of UNC2371 in glioblastoma cells was determined by cell viability and colony formation assays. The protein expression of MerTK, AKT, and Erk were quantified by Western blotting in UNC2371-treated glioblastoma cells. A syngeneic GL261 mouse orthotopic glioblastoma model was used to evaluate the survival benefit of UNC2371 treatment. Fluorescent multiplex immunohistochemistry (IHC) was used to evaluate the expression of CD206, an anti-inflammatory marker on GAMs in murine brain tumor tissues. RESULTS UNC2371 inhibited GBM cell growth with an EC50 < 100 nM in both human U251 and mouse GL261 glioma cells, but not in GAMs. UNC2371-induced cell death and decreased cell proliferation were demonstrated by colony formation assays. UNC2371 decreased protein expression of phosphorylated MerTK, AKT, and Erk, which are essential for cell survival signaling, in U251 and GL261 cells. Furthermore, UNC2371 treatment prolonged survival in the mouse orthotopic GL261 glioblastoma model, suggesting that UNC2371 induces glioma cell death. A decreased of CD206+ GAMs was found in mice glioma tissues by fluorescent multiplex IHC, consistent with our previous findings in the in vitro cell-based assays. These data suggest that in addition to alleviate immunosuppression in the glioma microenvironment, UNC2371 directly inhibits GBM cell growth in vitro and in vivo. CONCLUSION Our findings suggest that UNC2371 has a therapeutic benefit via promoting GAM polarization towards proinflammatory status in the glioblastoma microenvironment and unexpectedly, inducing tumor cell death.

scholarly journals Autophagic Markers in Chordomas: Immunohistochemical Analysis and Comparison with the Immune Microenvironment of Chordoma Tissues

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2169
Author(s):  
Georgia Karpathiou ◽  
Maroa Dridi ◽  
Lila Krebs-Drouot ◽  
François Vassal ◽  
Emmanuel Jouanneau ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Positive Association ◽  
Immunohistochemical Analysis ◽  
Vascular Density ◽  
Immune Microenvironment ◽  
Significant Positive Association ◽  
Sequestosome 1 ◽  
Cell Expression

Chordomas are notably resistant to chemotherapy. One of the cytoprotective mechanisms implicated in chemoresistance is autophagy. There are indirect data that autophagy could be implicated in chordomas, but its presence has not been studied in chordoma tissues. Sixty-one (61) chordomas were immunohistochemically studied for autophagic markers and their expression was compared with the expression in notochords, clinicopathological data, as well as the tumor immune microenvironment. All chordomas strongly and diffusely expressed cytoplasmic p62 (sequestosome 1, SQSTM1/p62), whereas 16 (26.2%) tumors also showed nuclear p62 expression. LC3B (Microtubule-associated protein 1A/1B-light chain 3B) tumor cell expression was found in 44 (72.1%) tumors. Autophagy-related 16‑like 1 (ATG16L1) was also expressed by most tumors. All tumors expressed mannose-6-phosphate/insulin-like growth factor 2 receptor (M6PR/IGF2R). LC3B tumor cell expression was negatively associated with tumor size, while no other parameters, such as age, sex, localization, or survival, were associated with the immunohistochemical factors studied. LC3B immune cell expression showed a significant positive association with programmed death-ligand 1 (PD-L1)+ immune cells and with a higher vascular density. ATG16L1 expression was also positively associated with higher vascular density. Notochords (n = 5) showed different immunostaining with a very weak LC3B and M6PR expression, and no p62 expression. In contrast to normal notochords, autophagic factors such as LC3B and ATG16L1 are often present in chordomas, associated with a strong and diffuse expression of p62, suggesting a blocked autophagic flow. Furthermore, PD-L1+ immune cells also express LC3B, suggesting the need for further investigations between autophagy and the immune microenvironment.

scholarly journals 492 Integration of high dimensional datasets in an immunocompetent mammary mouse model reveals pathways of tolerance and resistance to immune checkpoint blockade

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A528-A528
Author(s):  
Lin Ma ◽  
Jian-Hua Mao ◽  
Mary Helen Barcellos-Hoff ◽  
Jade Moore
Keyword(s):  
Tumor Microenvironment ◽  
Immune Cells ◽  
Transforming Growth Factor ◽  
Immune Cell ◽  
Systemic Disease ◽  
Ct Imaging ◽  
High Dimensional ◽  
Cytokine Signaling ◽  
Immune Infiltrate ◽  
Pet Ct

BackgroundCheckpoint inhibitors can induce robust and durable responses in a subset of patients. Extending this benefit to more patients could be facilitated by better understanding of how interacts with immune cells with the tumor microenvironment, which is a critical barrier to control both local and systemic disease. The composition and pattern of the immune infiltrate associates with the likelihood of response to immunotherapy. Inflamed tumors that exhibit a brisk immune cell infiltrate are responsive, while those in which immune cells are completely or partially excluded are not. Transforming growth factor β (TGFβ) is immunosuppressive and associated with the immune excluded phenotype.MethodsUsing an immune competent mammary tumor derived transplant (mTDT) model recently developed in our lab, exhibits inflamed, excluded or deserts immune infiltrate phenotypes based on localization of CD8 lymphocytes. Using whole transcriptome deep sequencing, cytof, and PET-CT imaging, we evaluated the tumor, microenvironment, and immune pathway activation among immune infiltrate phenotypes.ResultsThree distinct inflamed tumors phenotypes were identified: ‘classically’ inflamed characterized by pathway evidence of increased CD8+ T cells and decreased PD-L1 expression, inflamed tumors with pathways indicative of neovascularization and STAT3 signaling and reduced T cell mobilization, and an inflamed tumor with increased immunosuppressive myeloid phenotypes. Excluded tumors were characterized by TGFβ gene expression and pro-inflammatory cytokine signaling (e.g. TNFα, IL1β), associated with decreased leukocytes homing and increased immune cell death of cells. We visualized and quantified TGFβ activity using PET-CT imaging of 89Zr-fresolimumab, a TGFβ neutralizing antibody. TGFβ activity was significantly increased in excluded tumors compared to inflamed or desert tumors, which was supported by quantitative pathology (Perkin Elmer) of its canonical signaling target, phosphorylated SMAD2 (pSMAD2). pSMAD2 was positively correlated with PD-L1 expression in the stroma of excluded tumors. In contrast, in inflamed tumors, TGFβ activity positively correlated with increased F4/80 positive macrophages and negatively correlated with expression of PD-L1. CyTOF analysis of tumor and spleen immune phenotypes revealed increased trafficking of myeloid cells in mice bearing inflamed tumors compared to excluded and deserts.ConclusionsThe immunocompetent mTDT provides a model that bridges the gap between the immune landscape and tumor microenvironment. Integration of these high-dimensional data with further studies of response to immunotherapies will help to identify tumor features that favor response to treatment or the means to convert those that are unresponsive.

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