Mast Cells, T regulatory Cells, Myeloid-derived Suppresor Cells and their Role in Prognosis of Different Tumors

Recent literature data indicate interesting, complex relationships among mast cell, T regulatory cells and myeloid-derived suppressor cells in tumor stroma for immune evasion and tumor prognosis. The negative impact of peritumoral mast cells on the prognosis of various tumors such as in hepatocellular carcinoma has been reported. However, the inhibitory or proliferative effect of mast cells on tumor growth depends on perplexing interactions among mast cell, tumor type, and other immune cells in the tumor microenvironment. The theory defining mast cells and Treg cell's functional interaction has been proposed by several recent reports as well. Mast cells firstly facilitate the accumulation of myeloid-derived suppresor cells into tumor stroma, and these cells could release IL-17 which draws Treg cells and further magnify immunosuppressive effect. Tumor proliferation and immune evasion takes place by the inequity between immune effector cell function and cells with suppressor / regulatory function in tumor stromas.