EXPRESSION OF MONOCYTE CHEMOTACTIC PROTEIN-3 IN HUMAN MONOCYTES AND ENDOTHELIAL-CELLS

Monocyte chemotactic protein-3 (MCP-3) is a C-C chemokine which intera cts with the CCR1, CCR2 (MCP-1) and CCR3 receptors and has a distinct spectrum of action, The present study was designed to investigate whet her human endothelial cells (EC) and, by way of comparison, monocytes express MCP-3 and its regulation by pro-and anti-inflammatory cytokine s, Unstimulated human umbilical vein EC and monocytes did not express MCP-3, Bacterial lipopolysaccharides (LPS), IL-1 and TNF induced low b ut appreciable levels of MCP-3 transcripts. Interferon-gamma was a muc h weaker, but nevertheless active, inducer, MCP-3 transcripts were con siderably less abundant than those for MCP-1, IL-4, IL-13 and IL-10 di d not induce MCP-3 expression, These anti-inflammatory cytokines suppr essed cytokine-induced MCP-3 expression in monocytes, In contrast, IL- 4, IL-13 and IL-10 either did not affect or they amplified MCP-3 induc tion:in EC, EC-produced MCP-3 may be important in the regulation of ex travasation of receptor-expressing cells, including NK cells and eosin ophils.