CCK and the immune system: receptor mediated chemotaxis of rat and human macrophages

The ability of the peptide cholecystokinin (CCK) to induce monocyte chemotaxis was tested both in vivo and in vitro. In the in vitro assay, the activity of different forms of CCK on human monocytes was studied demonstrating the importance of sulfation on tyrosine for the chemotactic activity. CCK receptor antagonists benzotript and CR-1369 are able to block CCK 8 sulfated chemotaxis, thus suggesting the presence of CCK receptors on human monocytes. In both acute and chronic experiments, the peptide specifically increases the number of peritoneal macrophages, when injected into rat peritoneal cavity. These data suggest that immune system cell migration from one body compartment to another can be produced by a neuropeptide receptor-mediated process.