Abstract

Oral Cancer is a wound that do not heal is a complex disease consists of heterogeneous tissue in their tumor microenvironment. Oral cancer accounts eighth most Common Cancer worldwide. Chronic inflammatory mediators released from immune cells in tumor microenvironment of oral cancer such as macrophages, T lymphocytes, dendritic cells ,Natural killer cells release cytokines, Chemokine#x2019;s and growth factors helps in generation of myeloid derived suppressor cells. Myeloid derived suppressor cells are derived from myeloid progenitor cells of bone marrow secretes inflammatory mediators iNOS, arginase-1, PGE2,IL-10 and IL-4 suppresses adaptive and innate immunity by interacting with macrophages ,T-cells, Natural killer cells and dendritic cells favours pro-tumoral activity by activating transcriptional factors (NF-KB,STAT -3,HIF) further progress in to oral cancer. Myeloid derived suppressor cells reduces T cell activation and function by Arginase-1, iNOS, peroxynitrate over expression and cysteine depletion. This article describes mainly about immune cells in tumor microenvironment especially macrophages, T lymphocytes, dendritic cells, Natural killer cells their interactions with myeloid derived suppressor cells.