ROLE OF CYTOKINES IN REGULATION OF ANTITUMOR IMMUNE RESPONSES

摘要

The Knowledge of immune effector cell functions and its regulation have grown rapidly in the past decade and have advanced the ability to manipulate host immunity for specific destruction of its own tumor cells. Host's resistance against tumor comprises of two major defense systems : innate and adaptive responses. The cells of immune system and immunological mediators such as cytokines, chemokines and hormones' regulate interaction between these two branches of host defense. Cytokines are soluble polypeptide signaling proteins that regulate the communication between effector cells and other host cells in course of an immune response to modulate tumor cell growth and survival. Distinct mechanisms that have been identified so far as antitumor immune responses include cytostasis, necrosis or apoptosis of tumor cells mediated by macrophages (Mφ), natural killer cell (NK), lymphokine activated killer cell (LAK) and generation of specific T cell mediated immunity. The repertoire of cytokines or chemokines present at the site of tumor determines the type of host immune responses against tumor. Thus cytokines promoting development of T cell mediated immunity can induce or enhance antitumor immunity while immunosuppressive cytokines present at the site of tumor can impair host antitumor immune response.