T cell suppression to limit effective tumour cell killing
Regulatory T cells (Tregs) are a heterogeneous subset of CD4+ T cells with immunosuppressive properties that are required to maintain immune homeostasis and self-tolerance, dampen inflammation, and prevent autoimmunity. Tregs function by inhibiting the activities of CD4+ and CD8+ effector T cells, natural killer (NK) cells, NKT cells, and antigen-presenting cells through multiple mechanisms.
Myeloid-derived suppressor cell (MDSC) regulatory T cells (Tregs), and type 2-polarized macrophages (M2) are intrinsically associated with the tumour microenvironment. The suppressive cells' function is to attenuate the activation of T-cells and limit effective tumour cell killing. With the addition of molecules that interfere with the suppression cell, the T cells cross-talk will result in restoration of T cell activation and tumour cell killing.