Macrophage Plasticity and Function in the Lung Tumour Microenvironment Revealed in 3D Heterotypic Spheroid and Explant Models

In non-small cell lung cancer (NSCLC), stroma-resident and tumour-infiltrating macrophages may facilitate an immunosuppressive tumour microenvironment (TME) hamper immunotherapeutic responses. Analysis of tumour-associated macrophage (TAM) plasticity in NSCLC is largely lacking. We established a novel, multi-marker, dual analysis approach for assessing monocyte-derived (M?) polarisation M1/M2 phenotypic plasticity. developed flow cytometry-based, two-marker (CD64 CD206) CD14+ cells. The phenotype immune function vitro-induced TAMs was studied heterotypic spheroid tumour-derived explant model NSCLC. Heterotypic spheroids explants skewed M?s from M1- (CD206loCD64hi) to M2-like (CD206hiCD64lo) phenotype. Lipopolysaccharide (LPS) IFN? treatment reversed M? polarisation, indicating the M?s. Importantly, antigen-specific CD8+ T responses were reduced presence explant-conditioned M?s, but not spheroid-conditioned suggesting are likely more relevant TME than line-derived spheroids. Our data indicates importance functional analyses within subsets advantages ex vivo immunomodulation studies. highlight using provide tool studying therapeutic interventions designed reprogram M?-induced immunosuppression.