Infiltrating Treg Cells Suppress Anti-Tumor Immunity in Tumor Microenvironment

Avoidance of immune-surveillance by tumor is one of the important hallmarks of cancer and tumor microenvironment adapts host immune system in favor of this immune-escape mechanism. One of the major immune components that is responsible for immune-escape of tumor is T-regulatory cell. Tregs are found to be elevated in the peripheral circulation of tumor patient and from the circulation they infiltrate to the tumor-site which depends on the interaction between chemokines and chemokine receptors. Infiltrated Tregs are potent immunosuppressors and foster tumor growth by suppressing the effectiveness of helper T cells, NK cells, dendritic cells and macrophages making a tolerogenic microenvironment in the tumorsite. Rapid regeneration of infiltrating Tregs in the tumor milieu aids to this process. Combined action of suppression and survival of tumor infiltrating Tregs in tumor microenvironment makes them a major stumbling block in the battle against cancer.