Abstract 4543: Phenotypic screening of bispecific antibodies in 3D tumor immune cell cocultures

Abstract

Abstract INTRODUCTION The co-culture of tumor and immune cells in 3D enables a better recapitulation of the complex interactions between cells and the tumor microenvironment. High content analysis can be used to evaluate the effects of diverse immunotherapeutics on anti-tumor immune responses in a 3D setting. Functional read-outs can include active migration of immune cells towards tumoroids, infiltration of immune cells into the tumoroids and tumor killing. Here, we have applied high content analysis to quantify the effects of bi-specific antibodies targeting both the tumor and the T cells in 3D culture in a 384 well plate format. MATERIAL and METHODS Tumoroids generated from various cancer cell types were cultured in 3D in an extracellular matrix-rich protein hydrogel. Partially HLA-matching T cells isolated from healthy PBMCs donors were added with or without activation to the 3D culture and their infiltration into tumoroids and subsequent killing was visualized using high-content microscopy. Quantification of effects on immune cells and tumoroids was achieved with morphometric analysis with OMinerTM software. RESULTS and DISCUSSION Image-based analysis enabled the assessment of tumor-immune cell interactions and tumor killing in 3D co-cultures. The activation status of T cells determined the level of immune cell infiltration and killing of the tumoroids. T cell engaging bi-specific antibodies enhanced infiltration and tumor killing and was associated with increased IFNγ levels in culture supernatants. CONCLUSION Here we demonstrated the enhanced immune cell infiltration and tumor killing induced by bi-specific antibodies that simultaneously engage both T cells and tumors in a 3D setting. This assay represents a more physiologically relevant approach to enable cancer immunotherapy drug developers to evaluate the activity of novel immunotherapeutic molecules and better understand their mechanism of action. Citation Format: Lidia Daszkiewicz, Gera Goverse, Nataliia Beztsinna, Benjamin Visser, Lois van der Drift, Kuan Yan, Leo Price. Phenotypic screening of bispecific antibodies in 3D tumor immune cell cocultures [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4543.