Amino acid metabolism related to immune tolerance by MDSCs

Myeloid-derived suppressor cells (MDSCs) are present in most cancer patients. Due to their significant role in blocking immune responses, MDSCs are strategic obstacles to immunotherapy that require activation of the host's cell-mediated and innate immune responses. Following a brief description of the immunosuppressive MDSCs, the authors review the discovered mechanisms of amino acid metabolism that MDSCs use to suppress the activation of T cells. Given the heterogeneity of MDSCs and the variety of suppressive mechanisms employed by MDSCs, it is essential to understand which group of these cells and mechanisms are dominant.