Cytokine-induced neutrophil chemoattractant 3 (CINC-3) has been found to be expressed by cytokine-stimulated rat alveolar macrophages and fibroblasts. Based on its protein and DNA sequences, CINC-3 (also known as rat MIP-2, GRO beta and CXCL2) is a member of the alpha (CXC) subfamily of chemokines.
CINC-3 cDNA encodes a 100 amino acid (aa) residue precursor protein with a 31 aa signal peptide that is cleaved to yield a 69 aa mature secreted protein. The protein sequence of rat CINC-3 shares approximately 88% identity with murine MIP-2. Characteristic of ELR containing CXC chemokines, CINC-3 is known to be a potent chemotactic factor for rat neutrophils in vitro and in vivo. On the basis of cross-desensitization results of the various CINC proteins, it has been postulated that rat neutrophils have at least two classes of CINC receptors: a class of CINC-3 specific receptors as well as a second common receptor shared by all CINCs.
