Cytokines are the chemical messengers released by the cells that help in the communication between the different cells. Cytokines are mainly secreted by the immune cells that act on other cells for coordinated immune response. Cytokines binds with high affinity to specific receptors present on the target cells and the cells that show response to the cytokines are either: 1) by same cell that secreted called autocrine, 2) by a neighboring cell called paracrine or 3) by a distant cell reached through the circulation called endocrine. Cytokines released by the immune cells causes inflammation and also activation of innate and adaptive immune response.
Cytokines are of three types: monokines, lymphokines and interleukins. The cytokines that are released by the mononuclear phagocytic cells are called monokines, the cytokines that are released by activated lymphocytes are termed as lymphokines and the cytokines that act as mediator between lymphocytes are called interleukins. Cytokines are not stored as preformed proteins. But their synthesis occurs by gene transcription and the mRNAs formed are also short lived. They are formed according to the need by immune responses. The production of one cytokine can influence the synthesis of other cytokines. They either produce some cascades, or suppress or increase the production of other cytokines. The effects produce by them can be antagonistic and synergistic. In addition to this, the cytokines are also involved in regulating metabolism, maintaining tissue homeostasis in adult organisms and wound healing.
Last date updated on February, 2021