PO-374 A 3D image-based quantification of organoid-immune cell interactions in the presence of immuno-modulators

Introduction Increasing the number of cancer patients that benefit from immunotherapies and maintain durable responses requires understanding of cellular mechanisms that govern anti-tumour immune responses. However, this is hampered by a lack of appropriate pre-clinical testing models that are both clinically relevant and practical. Therefore, we have set up a robust in vitro assay that allows image based high-throughput analysis of 3D cultures. Here, immune cells are co-cultured with cancer cells in a 3D environment which recapitulates the tumour micro-environment and its complex cellular interactions. Specifically, infiltration of immune cells into the organoids and their killing are visualised and measured, which enables a better understanding of the immune-modulatory profile of different immunotherapies. Material and methods Autologous colon organoids from normal and tumour tissue (Hubrecht Organoid Technology) from several patients were cultured in a 3D environment. Immune cells with and without activation were added and their infiltration into organoids and subsequent killing was visualised using high-content microscopy. Quantification of immune cell effects was achieved with morphometric analysis with OMiner TM software. Results and discussions 3D image-based analysis of organoid-immune cell interactions demonstrated differential responses to immune-modulation between normal and tumour tissues and highlighted patient related differences. These results elucidate the effect of immune cell targeting normal colon tissue and discriminate immune-tumour cell interactions depending on activation status of T cells. The 3D environment, both for the cell culture and image analysis, allows for measurement of spatially resolved information, not accessible by monolayer cultures or biochemical assays. Conclusion The 3D assay presented here allows the analysis of immuno-oncology drug effects on different cell types that engage in a more physiologically relevant spatial setting than when culturing them in traditional 2D cultures. Using image-based analysis, immune-tumour interactions can be visualised and quantified. Analysis of both healthy and tumour tissue from the same patient allows for better prediction of clinical outcome versus non-specific cytotoxic reactions. This new and innovative platform can empower immunotherapy drug developers with a tool to select the most promising candidates and understand their mechanism of action, which ultimately translate to better clinical performance.