EP16.01-027 MIF ImprovesImmune Microenvironmentof Lewis Lung Cancer Brain Metastases after Radiotherapy ViaReducing M2 Macrophages

Our previous studies showed that inhibition of MIF/CD74 signaling pathway can promote the transformation of intracranial macrophages from M2 to M1 type after radiotherapy activation, and play the role of radiosensitization in brain metastases(BMs). It is reported that M2 macrophages are the main components of tumor immunosuppression microenvironment, and the surface marker, ARG-1, can decompose the Arginine which is essential in the growth and development of T cells. Therefore, this paper will focus on the mechanism of MIF regulating tumor infiltrating lymphocytes (TILs) by inducing macrophage phenotype transformation.