GROWTH-HORMONE STIMULATES PRODUCTION OF INTERFERON-GAMMA BY HUMAN PERIPHERAL MONONUCLEAR-CELLS

There is substantial evidence for interactions between the immune and endocrine systems at different levels, In the present study we investi gated whether human growth hormone (hGH) could stimulate proliferation of interferon-gamma-secreting cells (IFN-gamma-SC), and production of IFN-gamma. Human peripheral blood mononuclear cells (PBMC) taken from 15 normal subjects were incubated with varying doses (200, 400, 600 a nd 800 ng/ml) of recombinant hGH, Samples of cells were also incubated with PBS buffer (without hGH) to serve as controls, Effects of hGH we re studied by enumerating IFN-gamma-SC and by measuring the concentrat ion of IFN-gamma using an Immunospot assay and an enzyme-linked immuno sorbent assay, respectively, The results showed that hGH significantly increased both the number of IFN-gamma-SC and the concentration of IF N gamma in a dose-dependent manner, The maximum effects were obtained in the presence of (400 ng/ml) hGH (15 +/- 5 IFN-gamma-SC/10(6) PBMC a nd 300 +/- 55 U/ml IFN-gamma) compared to controls (4 +/- 2 IFN-gamma- SC/10(6) PBMC and 50 +/- 10 U/ml IFN-gamma). The results of the presen t study suggest that hGH might influence the immune system by stimulat ing the proliferation of IFN-gamma-SC and the production of IFN-gamma.