Chemokines Definition

Chemokines are signalling proteins that are produced by immune system cells and promote cell migration. Because it is derived from chemotaxis, or movement in response to a chemical stimulus, and cytokines, which are tiny proteins implicated in cell signalling, their name is suggestive of their function.

In other words, chemokines are cytokines that stimulate mobility. Chemokines have important roles in immunological reactions as secondary pro-inflammatory mediators triggered by primary pro-inflammatory mediators, as well as in homeostasis, where they control cell mobility to maintain immune system health and normal functioning.

Chemokine receptors are primarily found on the surface of white blood cells, which is not surprising (cells predominantly involved in immunological reactions). Chemokines have been identified in all vertebrates, as well as certain unicellular species like viruses and bacteria, but none have been found in non-vertebrates.

Chemokines are small proteins that range in size from 8 to 10 kDa. There are several varieties, but they are all quite similar. The majority of them have four cysteine amino acids in common, two of which are utilised to categorise all chemokines into four kinds.

The categorization of chemokines into the CC, CXC, C, and CX3C kinds is based on two amino acids close to the N-terminus. CXC chemokines contain one amino acid between the two cysteine residues; C chemokines have just two cysteines instead of four, one of which is at the N-terminus; and CX3C chemokines have three amino acids between the two cysteines. These four kinds of chemokines have the following structures: