Tumor Microenvironment Immune Activation

Tumor microenvironment (TME) immune activation refers to the process by which immune cells within and around a tumor become stimulated to recognize and attack cancer cells. The TME is a complex milieu composed of cancer cells, stromal cells, endothelial cells, extracellular matrix components, and a diverse array of immune cell populations. The balance between immunosuppressive and immunostimulatory signals in this environment determines whether the immune system can mount an effective antitumor response or if the tumor will evade immunity. Effective anti-tumor responses are associated with infiltration of activated cytotoxic T-cells, while high abundance of regulatory T-cells often correlates with immunosuppression. Proinflammatory cytokines correlate with better patient prognosis. Tumors exploit mechanisms like secretion of TGF-β, IL-10, expression of PD-L1/PD-L2, recruitment of MDSCs, and expansion of regulatory T-cells to dampen effective immune responses.

Checkpoint blockade; TAM reprogramming; viral vaccines/oncolytics