Abstract 2788: VB6-845d tumor cell killing elicits biologic features of immunogenic cell death

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.

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Using Ultrasound to Enhance Tumor Cell Killing by Doxorubicin-Loaded Particles

10.26226/morressier.57d6b2bcd462b8028d88d1cf ◽

2016 ◽

Author(s):

Anh-Vu Do

Keyword(s):

Tumor Cell ◽

Cell Killing ◽

Enhance Tumor Cell ◽

Tumor Cell Killing

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Cellular cytotoxicity is a form of immunogenic cell death

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2019-000325 ◽

2020 ◽

Vol 8 (1) ◽

pp. e000325 ◽

Cited By ~ 3

Author(s):

Luna Minute ◽

Alvaro Teijeira ◽

Alfonso R Sanchez-Paulete ◽

Maria C Ochoa ◽

Maite Alvarez ◽

...

Keyword(s):

T Cells ◽

Cell Death ◽

Dendritic Cells ◽

Tumor Cell ◽

Tumor Cells ◽

Cd8 T Cells ◽

Immunogenic Cell Death ◽

Cell Debris ◽

Tumor Cell Death ◽

Mhc Multimer

BackgroundThe immune response to cancer is often conceptualized with the cancer immunity cycle. An essential step in this interpretation is that antigens released by dying tumors are presented by dendritic cells to naive or memory T cells in the tumor-draining lymph nodes. Whether tumor cell death resulting from cytotoxicity, as mediated by T cells or natural killer (NK) lymphocytes, is actually immunogenic currently remains unknown.MethodsIn this study, tumor cells were killed by antigen-specific T-cell receptor (TCR) transgenic CD8 T cells or activated NK cells. Immunogenic cell death was studied analyzing the membrane exposure of calreticulin and the release of high mobility group box 1 (HMGB1) by the dying tumor cells. Furthermore, the potential immunogenicity of the tumor cell debris was evaluated in immunocompetent mice challenged with an unrelated tumor sharing only one tumor-associated antigen and by class I major histocompatibility complex (MHC)-multimer stainings. Mice deficient inBatf3,Ifnar1andSting1were used to study mechanistic requirements.ResultsWe observe in cocultures of tumor cells and effector cytotoxic cells, the presence of markers of immunogenic cell death such as calreticulin exposure and soluble HMGB1 protein. Ovalbumin (OVA)-transfected MC38 colon cancer cells, exogenously pulsed to present the gp100 epitope are killed in culture by mouse gp100-specific TCR transgenic CD8 T cells. Immunization of mice with the resulting destroyed cells induces epitope spreading as observed by detection of OVA-specific T cells by MHC multimer staining and rejection of OVA+EG7 lymphoma cells. Similar results were observed in mice immunized with cell debris generated by NK-cell mediated cytotoxicity. Mice deficient inBatf3-dependent dendritic cells (conventional dendritic cells type 1, cDC1) fail to develop an anti-OVA response when immunized with tumor cells killed by cytotoxic lymphocytes. In line with this, cultured cDC1 dendritic cells uptake and can readily cross-present antigen from cytotoxicity-killed tumor cells to cognate CD8+T lymphocytes.ConclusionThese results support that an ongoing cytotoxic antitumor immune response can lead to immunogenic tumor cell death.

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