STIMULATION OF INTERLEUKIN-6 PRODUCTION BY CORTICOTROPIN-RELEASING FACTOR

Based on the immune-modulating properties of corticotropin-releasing factor (CRF), the effect of this peptide for interIeukin-6 (IL-6) production was investigated. Using human peripheral blood mononuclear cells (MNC), the amount of bioactive IL-6 produced was significantly (P ≤ 0.05) increased by CRF (10-10 to 10-7 M range). However, the IL-6 production of lipopolysac-charide-treated MNC cultures was not modified. At concentrations of ≥ 10 nM, CRF and two analogous peptides (Tyr-CRF and α-helical CRF) elicited 16- to 21-fold stimulation of IL-6 production by MNC. Purified monocytes, but not purified lymphocytes, were the cells that responded to CRF action exhibiting nearly 19-fold stimulation at 100 nM concentration. The CRF-induced production of IL-6 cytokine by peripheral blood MNC may suggest a messenger role for this neurohormone in the feedback control of neuroendocrine-immune circuitry. © 1992.