Table 1.

Overview of currently established tumor organoid-immune cell co-culture systems.

Co-culture approach	Tissue of origin	Sample type	Species	Immune cell type	Duration (days)	Functionality	Refs
Holistic approach	MC38 CRC cell line/Melanoma	Cell implantation orthotopically/Surgical specimens	MDOTS/PDOTS	T cells, B cells, granulocytic, monocytic lineages, dendritic cells,	9 days	Preserve immune cell reaction to immune checkpoint inhibitors	(39)
	MC38 CRC cell line	Subcutaneous mouse tumors	MDOTS	T cells	5 days	Preserve immune cell reaction to CDK4 and CDK6 inhibitors plus immune checkpoint inhibitors	(40)
	Colon, pancreas, and lung (14 distinct tissue sites)	Subcutaneous mouse tumors/Surgical specimens	MDOTS/PDOTS	Macrophages, T cells, NK cells, and B cells	30 days	Preserve the TCR repertoire of the original fresh tumor	(41)
	CRC or lung cancer	Surgical specimens	PDOTS	CD45+ tumour-resident leukocytes	>10 days	In vitro survival of CD45+ cells	(42)
	Breast	Surgical specimens	PDOTS	Peripheral blood and tumour-derived γδ T cells	2-3 w	Preserve γδ T cell activation and tumour cell line cytolysis	(43)
Reconstitution approach	Gastric cancer	Triple-transgenic mouse model	MDOTS	CD8+ splenocytes and bone marrow-derived DCs	2 days	Organoid cytolysis	(44)
	Pancreatic cancer	Surgical specimens	PDOTS	peripheral blood lymphocytes & CAFs	6 days	Tumor-dependent lymphocyte infiltration and activation of myofibroblast-like CAFs	(45)

MDOTS, murine-derived organotypic tumor spheroids; PDOTS, patient-derived organotypic tumor spheroids;

CAFs, cancer-associated fibroblasts.