Molecular cloning of rat monocyte chemoattractant protein-1 (MCP-1) and its expression in rat spleen cells and tumor cell lines.

Rat monocyte chemoattractant protein-1 (MCP-1) cDNA was cloned. A cDNA library was constructed from mRNA extracted from Con A-stimulated rat spleen cells. After 2 rounds of screening with a radiolabeled oligonucleotide probe and DNA sequencing from plasmid DNAs, one clone which encoded for MCP-1 was obtained. The cDNA clone comprises 665 base pairs with an open reading frame which encodes for 148 amino acid protein. Spleen cells expressed a significant amount of MCP-1 mRNA without stimulus. But higher expression was observed when cells were stimulated with Con A. MCP-1 mRNA was also expressed in tumor cell lines, although the amount of expressed MCP-1 mRNA was different among cell lines.