CORTICOTROPIN-RELEASING HORMONE MODULATES CYTOKINES RELEASE IN CULTURED HUMAN PERIPHERAL-BLOOD MONONUCLEAR-CELLS

immune and neuroendocrine systems interact at various levels. In parti cular, either cytokines activate the hypothalamus-pituitary-adrenal ax is (HPA) or corticotropin-releasing hormone (CRH) induces the release of beta-endorphin from peripheral human mononuclear cells. The aim of the present study was to investigate whether CRH may affect cytokine p roduction and activity in human peripheral blood mononuclear cells (PB MC). Primary cultures of human PBMC and monocytes were used. They were incubated in presence of different doses of synthetic human CRH. Medi a were collected and interleukin-1beta (IL-1beta) and interleukin-6 (I L-6) levels were measured by ELISA, while interferon-gamma (IFN-gamma) levels were measured by bioassay. In addition, phytohemoagglutinin-in duced lymphocyte proliferation was evaluated by testing [H-3]thymidine incorporation in the presence of various doses of CRH. CRH significan tly increased IL-6 release from PBMC (p<0.01). The addition of CRH to PBMC significantly decreased IFN-gamma levels, in a dose dependent man ner (p<0.01). No significant effect of CRH was observed on lymphocyte proliferation or IL-1beta production. The present results suggest a ro le for CRH as' a paracrine mediator for human immune cells, increasing the evidence of a clear correlation between immune and neuroendocrine system.