Stimulation of glutathione peroxidase activity decreases HIV type 1 activation after oxidative stress.

Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this study, we demonstrate that selenium supplementation can effectively increase glutathione peroxidase (GPx) activity in latently infected T lymphocytes. The Se-supplemented cells exhibited an important protection against the cytotoxic and reactivating effects of hydrogen peroxide (H2O2). Concomitantly, NF-kappa B activation by H2O2 was also decreased in Se-supplemented cells. Selenium stimulation of GPx activity also induces a protective effect against cell activation by tumor necrosis factor alpha (TNF-alpha) but less significantly by phorbol esters such as PMA. These Se-mediated effects were specific because they were not found when AP-1 DNA-binding activity was studied after H2O2-induced stress. Hyperthermia was also studied because it could promote intracellular electron leakage in electron transport chains. Elevating the temperature to 42 degrees C did not induce NF-kappa B directly. Rather, it sensitized infected cells to subsequent oxidative stress by H2O2, demonstrating the importance of hyperthermia, often associated with opportunistic infections in the development of immunodeficiency. In this case, Se induced partial protection against the sensitizing effect of hyperthermia.