Abstract 3877: A unique layered 3D stromal tissue model for in vitro evaluation of immunologic agents and immune cell infiltration into microenviroment

Abstract

Abstract Background The modulation of the immune system is a proven key target for cancer therapy, however, the complex interplay between immune cells and cancer cells in cancer microenvironment remains only partially understood. In addition, the currently available in vitro cancer microenvironment models are not designed to study the immunologic agents and a role of immune cells. Here, we developed a unique layered 3D stromal tissue model comprising immune, stromal and cancer cells. Method Layered 3D stromal tissue model was constructed by culturing fibroblasts and endothelial cells coated with extracellular matrix (ECM) and natural polysaccharide. Morphological analysis of the layered 3D stromal tissues and co-cultured tumor were evaluated by HE stain, immunohistochemistry and immunofluorescence (IF). For cytotoxicity assay, cancer cell lines were seeded on or in the 3D stromal tissue and incubated with peripheral blood mononuclear cell (PBMC) and Programmed cell death 1 (PD-1) blockade with Nivolumab. Remaining cancer cells post drug treatment were quantified by IF and imaging analysis. Result The co-cultured stromal tissues were multi-layered (approximately 20 layers), had microvascular formation. Hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) derived from fibroblast cells played important roles in tube formation. Moreover, the position of cancer cells in 3D stromal tissue was manipulated easily. PBMC infiltration into 3D stromal tissue and the interaction between PBMC and cancer cells were visualized. High level of programmed cell death ligand 1 (PD-L1) expression on cancer cells correlated with a higher response to PD-1 blockade in vitro as well as clinical trials. Conclusion We present a unique layered 3D cell culture system based on stromal/cancer/immune cells to study immunologic agents and immune cell infiltration in cancer microenvironment. Our 3D model has the ability to reflect in vivo conditions closer than 2D model and provide a tool for in vitro tumor infiltrating lymphocyte (TIL) or immunologic agent testing. Citation Format: Rii Morimura, Isana Nada, Kei Tsukamoto, Eiji Shinozaki, shiro kitano. A unique layered 3D stromal tissue model for in vitro evaluation of immunologic agents and immune cell infiltration into microenviroment [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 3877.