Expression of zeta molecules is decreased in NK cells from HIV-infected patients

Cytolysis by natural killer (NK) cells is impaired in HIV infection. We inv estigated whether the expression of zeta (zeta) molecules. essential elemen ts of signalling initiated upon ligation of, e.g., CD16, is reduced and if so, whether this reduction could be involved in defective cytolysis. FAGS a nalysis revealed significantly lower levels of zeta in NK cells from AIDS p atients compared to cells from patients without AIDS and healthy controls. CD16-dependent cytolysis by NK cells correlated with expression of zeta mol ecules and CD16, the latter possibly related to zeta expression. No correla tion was observed between CD16-independent cytolysis and zeta expression. R educed expression of zeta molecules by NK cells from HIV-infected patients thus correlates with disease progression and may, ill part, explain the def ective cytolysis by these cells. (C) 1999 Federation of European Microbiolo gical Societies. Published by Elsevier Science B.V. All rights reserved.