Figure 1.

The tumor immune microenvironment can be generated in organoids by two types of approaches. In reconstituted models, organoids containing exclusively tumor cells, often from physically and enzymatically dissociated tissues, are cultured in extracellular matrix domes (e.g., Matrigel or BME-2) and submerged beneath tissue culture medium. Exogenous immune cells, such as those from autologous peripheral blood or tumor, are isolated and subsequently co-cultured with grown organoids. In holistic native TME models, the intrinsic immune microenvironment of tumor specimens is preserved along with tumor cells without reconstitution. Tumor spheroids from digested tumor tissues can be mixed with collagen and injected into microfluidic culture devices. Alternatively, in air-liquid interface (ALI) culture, minced primary tissue fragments containing both tumor cells and immune components are embedded in collagen gels within an inner transwell dish. The top of the collagen gel is exposed to air, allowing cells access to a sufficient oxygen supply. Abbreviation: NK, natural killer.