Eotaxin

Eotaxin is a potent eosinophil chemoattractant which was originally purified from bronchoalveolar lavage fluid of guinea pigs sensitized by aerosol challenge with ovalbumin. Microsequencing of the purified protein revealed the guinea pig eotaxin to be a member of the beta (CC) chemokine family of inflammatory and immunoregulatory cytokines. cDNA clones for guinea pig, mouse and human eotaxin have recently been isolated. Mouse eotaxin cDNA encodes a 97 amino acid protein from which the amino-terminal 23 amino acid are cleaved to generate the 74 amino acid mature mouse eotaxin. Mature mouse eotaxin is approximately 60% identical to mature human and guinea pig eotaxin. In addition, mouse eotaxin also shows high amino acid sequence identity to members of the MCP family. Mouse eotaxin is chemotactic for eosinophils, but not mononuclear cells or neutrophils. Eotaxin mRNA is expressed in a variety of tissues. The expression of eotaxin mRNA is induced in cultured endothelial cells in response to IFN-?. In addition, eotaxin mRNA is also induced in response to the transplantation of IL-4-secreting tumor cells. The CC chemokine receptor 3 (CCR3) has now been identified to be a specific human eotaxin receptor.