Cytokines are small proteins that regulate immunity and inflammation by binding to specific receptors on target cells. There are many types of cytokines and receptors, with interleukin being the broadest category. Cytokine activity can be blocked by antagonistic molecules that either change the shape of the cytokine or bind to the receptor without activating it.
Cytokines are small proteins secreted by certain cells to regulate immunity and inflammation within the body. They act on target cells by binding to specific proteins found on the cell membrane, called receptors. Each cytokine can only bind to a specific cytokine receptor, which regulates the activities of both the cytokines and the affected cells.
There are many different types of cytokines and cytokine receptors. They are classified according to the type of cell that produces the cytokines and the structure and function of both the cytokine and the cytokine receptor. The broadest category of cytokines stimulate the multiplication and differentiation of the different cells involved in an immune response. It consists mainly of the cytokine interleukin (IL). These cytokines are produced by one type of leukocyte, a type of white blood cell, and activate another leukocyte.
The structure of both the cytokine and the cytokine receptor is highly specific, so that only one type of cytokine can bind to a cytokine receptor. This does not mean that cytokine production and activation are equally specific. Some cells produce several types of cytokines, and some target cells have more than one type of cytokine receptor on their membrane so that they can be stimulated by more than one type of cytokine.
When a cytokine binds to its corresponding receptor, the receptor becomes activated. Usually, this means that a secondary messenger within the cell is stimulated by the cytokine receptor. The secondary messenger then causes the reactions that change the behavior of the cell. Common responses of a cell to cytokine stimulation include the increase or decrease in the expression of receptor proteins on the cell membrane, the secretion of molecules, which may be other cytokines, and cell growth and multiplication.
Cytokine activity can be blocked by antagonistic molecules. These molecules can decrease the efficiency of cytokines in two ways. First, the antagonist can bind to the cytokine itself. This in turn will cause the cytokine to change its shape so that it can no longer bind to the cytokine receptor. Since the cytokine can no longer bind to the receptor molecule, the immune response is disrupted.
Second, the antagonists can have a similar, almost identical shape to the cytokine. When an antagonist has the same shape as a cytokine, it can bind to the cytokine receptor. When an antagonist binds to the receptor, it prevents the cytokine from binding there. Although the antagonist is bound to the receptor molecule on the cell membrane surface, it does not activate the receptor, thus the target cell is not stimulated either.
Protect your devices with Threat Protection by NordVPN
