3D co-culture models demonstrate radiation-mediated activation of tumor-associated macrophages

Abstract Type I IFN signaling mediated by STING pathway is important for the induction of radiation-stimulated adaptive immune responses in responsive tumors. Macrophages recruited to tumors following radiotherapy (RT) can influence response RT. Reprogramming immunosuppressive M2-like macrophages exhibit a more activated M1-like phenotype help improve therapies. Here, we hypothesize that 3D co-culture model cancer cells and will be contextually relevant events occurring used study crosstalk occurs between these vivo. We initially optimized seeding densities murine MC38 colorectal carcinoma develop spheroids consistent size. Using GFP+ Hoechst stained MC38, imaged development localization during spheroid formation. Next, were exposed 12 Gy radiation on day 1. Viability co-cultures was assessed 4 using flow cytometry staining CD80, CD86, MHC Class II, CD69 CD206 expression. ligand, cyclic di-AMP (CDA) treated as positive controls. CDA treatment significantly increased CD80/86 expression co-cultures. Treatment with showed similar effect. Interestingly, derived from MyD88 Lyz2Cre, fl/fland knockout mice also significant increase CD40, suggesting macrophage activation independent or signaling. Ongoing studies aim explore pathways irradiation further cross-validate phenotypes observed vivo