CLONING, EXPRESSION, AND FUNCTIONAL-CHARACTERIZATION OF RAT MIP-2 - A NEUTROPHIL CHEMOATTRACTANT AND EPITHELIAL-CELL MITOGEN

Macrophage inflammatory protein-2 (MIP-2) is a member of a family of cytokines that play roles in inflammatory, immune, and wound healing responses, To clone the cDNA for rat MIP-2, RNA was isolated from the lungs of Fischer 344 rats after instillation of lipopolysaccharide, Reverse transcription-polymerase chain reaction was performed by using synthetic oligonucleotide primers designed from the mouse MIP-2 cDNA sequence, A cDNA containing the coding region of rat MIP-2 was cloned and sequenced, Comparison to the mouse MIP-2 cDNA demonstrated 90.3% homology at the nucleotide level and 86% homology at the amino acid level. The rat MIP-2 cDNA was expressed in Escherichia coli and protein evaluated for bioactivity, The recombinant rat MIP-2 was chemotactic for rat neutrophils but did not stimulate migration of rat alveolar macrophages or human peripheral blood eosinophils or lymphocytes, In addition, the recombinant rat MIP-2 and the related rat chemokine, KC/CINC stimulated proliferation of rat alveolar epithelial cells but not fibroblasts in vitro.