Differentiation of Murine Myeloid-Derived Suppressor Cells

Myeloid-derived suppressor cells (MDSCs) are frequently defined as a heterogeneous population of immature cells belonging to the myeloid lineage which possess strong immunosuppressive activities. These cells ultimately derive from myeloid progenitors mainly present in the bone marrow that undergo a dysregulated differentiation pathway, ending up with the systemic mobilization of MDSCs of “monocytic” or “granulocytic” characteristics. Here we will review the current knowledge on MDSC differentiation mostly in murine cancer models, and reflect on whether MDSCs represent a unique, well-defined distinct myeloid lineage or just immature stages of myeloid cells.