During inflammation and host defense, numerous cellular products are released and cooperate in orchestrating the response of the immune system. Cellular communication is one of these processes that are essential for optimal immunosurveillance. Small protein mediators, termed “chemokines,” have been identified which are released during infection to direct the coordinated trafficking of immune cells. When released within the microenvironmental milieu, a chemokine concentration gradient is established and target cells expressing the cognate chemokine receptor migrate towards the area of highest concentration. Since cells are exposed to multiple chemokines at any given point in time, this gradient is important in allowing target cells to make an executive decision and focus their response.
The chemokine and chemokine receptor nomenclature has evolved from a function-based system, to one which is now based on the number and position of conserved cysteine residues located at the amino terminus. Hence, chemokines and chemokine receptors have been classified into four separate groups: CXC, CC, C, and CX3C. Chemokines can also be grouped into categories based on their level of ex
The chemokines CCL2/monocyte chemoattractant protein (MCP)-l and CCL5/regulated upon activation, normal T cell expressed and secreted (RANTES) are abundantly expressed in numerous disease states and potent chemoattractants of leukocytes. ex