N-ACETYLCYSTEINE ENHANCES ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY INNEUTROPHILS AND MONONUCLEAR-CELLS FROM HEALTHY-ADULTS AND HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PATIENTS

Patients with AIDS have decreased levels of the intracellular antioxid ant, glutathione, in their circulating lymphocytes and plasma. N-acety lcysteine (NAC) increases intracellular stores of glutathione and has direct antioxidant properties. In this study, the effects of glutathio ne and NAC on the cytotoxicity of neutrophils and mononuclear cells we re tested using cells from healthy controls and human immunodeficiency virus (HIV)-infected patients, NAC (1 and 5 mM) enhanced the antibody -dependent cellular cytotoxicity (ADCC) of neutrophils from healthy ad ult controls and HIV-infected adults and children, The antineoplastic drug, 1,3 bis(2-chloroethyl)-1-nitrosourea (BCNU), which depletes intr acellular glutathione, inhibited the ADCC of neutrophils; the addition of NAC partially reversed this inhibition. Similar effects of BCNU an d NAC were seen when the cytotoxicity of mononuclear cells was tested using CEM tumor cells bearing the HIV gp120 antigen as targets. Thus, NAC enhances various forms of cytotoxicity and may be beneficial to AI DS patients whose defects in leukocyte cytotoxicity may be due to glut athione depletion.