Fig. 1

The major approaches for modeling the immune-breast cancer organoids (BCOs). In reconstituted approach, BCOs are cultured in extracellular matrix (e.g., Matrigel) and submerged beneath tissue culture medium. Exogenous immune cells, such as stromal cells or additional immunocytes, are isolated and co-cultured with BCOs. In native tumor microenvironment (TME) models, the intrinsic immune microenvironment of tumor tissues is preserved without reconstruction. Tumor spheroids from digested tumor fractions can be mixed with collagen and added into organ-on-chips or microfluidic devices. In air-liquid interface (ALI) culture, minced tumor fragments containing both tumor cells and immune cells are embedded in collagen gels within an inner Transwell dish