7,8-DIHYDRONEOPTERIN UP-REGULATES INTERFERON-GAMMA PROMOTER IN T-CELLS

Activated cell-mediated immunity is accompanied by elevated concentrat ions of interferon-gamma leading to the secretion of neopterin-derivat ives which are known as sensitive immune activation markers in clinica l laboratory diagnosis. Recent data imply a potential role of neopteri n-derivatives in oxygen-free radical-mediated processes and a direct i mpact of 7,8-dihydroneopterin on tumor necrosis factor alpha-mediated programmed cell death. We report here that 7,8-dihydro-neopterin and h ydrogen peroxide upregulate the production of interferon-gamma, thereb y establishing an autocrine feed-back loop. Data put emphasis on the r ole of neopterin-derivates within the cytokine network.