Available online 23 June 2022, 104574

3D multicellular tumor spheroids are useful for discovery of novel immunotherapies.

3D tumor spheroids were used to test TAM-inhibiting and TAM-reprograming compounds.

CSF1R inhibitor limit infiltration of monocytes into 3D tumor spheroids.

CD40 ligand and poly I:C induce M1 phenotype serving as potential anti-cancer drugs.

2D and 3D cultured macrophages are differently affected by immunomodulating drugs.

In vitro cancer models that can identify novel immunomodulating compounds are essential. Using a 3D multicellular tumor spheroid (MCTS) model comprising cancer cells, fibroblasts, and macrophages, we tested tumor-associated macrophage (TAM)-inhibiting compounds (CCL2 Ab, CSF1R inhibitor, CSF1R Ab) and TAM-reprograming compounds (poly I:C, CD40 Ab, CD40 ligand) for their effects on monocyte infiltration and polarization in tumor spheroids. For characterization of macrophage polarization, we measured the expression of CD206, CD163, CD86, MHC II, CD40, and CD14 and measured 43 soluble factors in the 3D MCTS cultures. 2D macrophage models were evaluated for comparison. A CSF1R inhibitor prevented infiltration of monocytes into pancreatic cancer spheroids, and macrophages treated with the inhibitor showed decreased expression of M2 markers. Treatment with a CD40 ligand and poly I:C induced M1 macrophage polarization in our models. We propose that these models can be used to improve the drug screening process of anti-cancer immunotherapies targeting macrophages.

3D cancer model

multicellular tumor spheroid

tumor-associated macrophage

immunotherapy

CD40 agonist

TLR ligand

CSF1R inhibitor

tumor microenvironment

tumor-associated macrophage

multicellular tumor spheroid

polyinosinic:polycytidylic acid

toll-like receptor (TLR)

carboxyfluorescein succinimidyl ester

paraffin-embedded cancer cell-fibroblast spheroids

© 2022 The Authors. Published by Elsevier Inc.