Chemokine

Chemokines are a family of small cytokines, which are proteins secreted by cells. The name comes from their ability to induce directed chemotaxis in nearby responsive cells, making them chemotactic cytokines. These proteins are classified according to shared structural characteristics such as their very small size, as well as the presence of four cyzteine residues in conserved locations that form the key to their three-dimensional shape.

Chemokines are primarily used to guide the migration of cells, as cells are usually attracted by chemokines and follow the signal of increasing chemo-kine concentration toward areas that have greater chemokine concentrations. With chemokines serving like hormone-like mediators, they have been shown to have the ability of attracting immune system cells to specific sites in the human body. It has been found that chemokines are located in all vertebrates and also in some viruses and bacteria, but have not been found in animal life classified as invertebrates.

The discovery of the chemokines and the movement of cells has become extremely useful for medical research, especially with the human immune systems. Chemokines are seen as a method of preventing the spread of infections. Although chemo-kine research has resulted advances in a number of areas, it is also regarded as potentially rewarding in trying to help with the treatment of human immunodeficiency virus (HIV). This is because the entry of HIV into a host cell requires the participation of some of the cell surface proteins that normally serve as chemokine receptors. HIV infects helper T-cells by using a protein called gp120, and is embedded in its envelope. This leads to the gp120 protein binding itself to a molecule called CD4, which is found on the surface of the helper T-cell. This in turn leads to a large number of reactions that then allow the HIV genetic information to enter the cell. As a result, one of the areas of research into HIV has been into the binding of gp120 to CD4, which in turn exposes a region of gp120 that interacts with the chemokine receptors. Some researchers believe that looking into changes in the chemokine receptors may help find a way to treat HIV.