Measuring Suppressive Activity and Autophagy in Myeloid-Derived Suppressor Cells

Myeloid-derived suppressor cells (MDSC) are potent suppressor cells that accumulate in tumor microenvironment and inhibit anti-tumor responses. Assessment of cell-autonomous MDSC responses allows the precise characterization of MDSCs in various disease settings and elucidates the underlying mechanisms of MDSC-mediated immune suppression. Here we describe a protocol for the isolation of tumor infiltrating or splenic MDSC, as well as their subpopulations, from melanoma-inoculated mice using Fluorescent Activated Cell Sorting (FACS). We further provide protocols for investigation of the autophagy pathway and ex vivo assessment of MDSC suppressive function using lymph node responder cells. These assays allow a comprehensive characterization of MDSC in murine experimental models.