Immunomodulatory properties of cyclic hexapeptide oxytocin antagonists

A pharmacological manipulation of cryptocrine cell-to-cell signaling was tested by the investigation of the immunomodulatory properties of novel cyclic hexapeptide oxytocin (OT) antagonists (MSD Research Laboratories). The compounds were found to significantly inhibit the productions of IL-1ß and IL-6 elicited by anti-CD3 treatment oh human whole blood cells cultures (WBC). Cytokine productions were more significantly reduced by OT antagonists in WBC derived from female volunteers than in those obtained from male donors, suggesting an influence of sex steroids on the expression of NHP receptors by immune cells. These observations support the concept of novel immunomodulating approaches through immune-specific neuropeptide antagonists, as well as the pharmacological value of such strategies in selective immunotherapy.