The chicken Chemotactic and Angiogenic Factor (cCAF), a CXC chemokine

The chemokine cCAF (&cmacr;hicken &Cmacr;hemotactic and Angiogenic &Fmacr;actor), is the product of the 9E3/CEF4 gene. Its name reflects the biological properties of the protein: chemotactic and angiogenic. This CXC chemokine is highly homologous to human IL-8, both at the protein and gene level. Molecular modeling based on the known structure of IL-8 shows that the structure of cCAF is very similar to that of other CXC chemokines. Regulation of expression occurs both at the transcriptional and post-transcriptional levels. The cCAF protein is secreted very rapidly as a 9kDa molecule and can be cleaved in the N-terminus after secretion to produce a smaller form ( approximately 7kDa) that binds to ECM molecules. Plasmin, an enzyme present in the early stages of wound healing and in tumor stroma, cleaves the 9kDa to the 7kDa form. The biological properties of this chemokine and its patterns of expression in vivo strongly suggest that cCAF plays important roles in traumatic and pathological conditions.