TUMOR-NECROSIS-FACTOR RECEPTOR P55 MEDIATES INDUCTION OF HIV TYPE-1 EXPRESSION IN CHRONICALLY INFECTED U1 CELLS

Tumor necrosis factor alpha (TNF-alpha) is a potent inducer of human i mmunodeficiency virus type 1 (HIV-1) expression in chronically infecte d cells. The aim of this study was to investigate the role played by t he two known TNF-alpha receptors, TNFR-p55 and TNFR-p75, in the activa tion of HIV-1 expression. As a model system the latently infected huma n promonocytic cell line U1 was stimulated with mild-type TNF-alpha wi th TNF-alpha muteins that specifically bind to one or the other recept or or with receptor-specific monoclonal antibodies, Induction of HIV-1 expression, measured by p24 core antigen capture enzyme-linked immuno sorbent assay (ELISA), was found to be exclusively triggered by TNFR-p 55 stimulation, However, our results also showed that the addition of TNFR-p75-specific ligands negatively modulated the HIV-1 expression in duced via TNFR-p55.