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Abstract B142: Co-culture of tumor organoids with immune cells for immuno-oncology drug development

Hubrecht organoid technology (HUB) can in vitro preserve and propagate patient-derived epithelial cancer cells whilst still maintaining tumour heterogeneity and genetic features. Co-culture of tumor organoids with peripheral blood lymphocytes or tumor-infiltrating lymphocytes (TIL) can potentially expand tumor-specific T cells that mediate explicit killing of tumor organoids. Recapitulating the tumor microenvironment (TME) by co-culture of tumor organoids with immune cells is highly attractive for immuno-oncology (IO) drug development, and will provide an efficient and refined approach for assessing the immune modulatory and tumor killing effects of IO drug candidates, such as monoclonal antibodies, CAR-T, CAR-NK and small molecules. In this study, we aimed to establish and validate IO assay platform using co-culture methods of organoids with various immune cells. We used the HUBorganoid approach to create panels of patient-derived (PDO), patient-derived-xenograft (PDX)-derived organoids (PDXO) and murine tumor-derived tumor organoids, followed by co-culturing with corresponding cytotoxic T cells. We developed tumor organoid killing assays using both flow cytometry-based methods and real-time imaging by IncuCyte as readouts in 96-well format. Tumor-reactivity of T cells to organoids was analysed by T cell proliferation, IFNg ELISA in the culture medium, and intracellular staining of IFNg in T cells. Co-culture of tumor organoids expressing various antigens was also used to evaluate antibody dependent cell mediated cytotoxicity (ADCC) by NK cells, and complement dependent cytotoxicity (CDC) and antibody dependent phagocytosis by macrophages for monoclonal antibody drugs. We have profiled the expression of immune inhibitory molecules on various tumor organoids and assessing the effect of immune checkpoint blockade (e.g. anti-PD-1/PD-L1) in organoid-immune cell co-culture. Our preliminary data demonstrated the feasibility of in vitro patient-derived model system in the field of IO research using tumor organoid co-culture with immune cells, and their application in IO target and drug discovery. Citation Format: Zhongliang Li, Jun Zhou, Rui Zhang, Fei Wang, Shuzong Wang, Xiaoxi Xu, Yujun Huang, Henry Li. Co-culture of tumor organoids with immune cells for immuno-oncology drug development [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B142. doi:10.1158/1535-7163.TARG-19-B142