IN-VITRO EVALUATION OF THE EFFECT OF AZT IN COMBINATION WITH TWO ANTIOXIDANTS AND A NF-KB INHIBITOR

D. A. RIVA; P. N. FERNÁNDEZ LARROSA; L. A. MARTÍNEZ PERALTA; F. C. COULOMBIÉ; S. E. MERSICH

Rio de Janeiro, Brasil

Conferencia; 3st IAS Conference on HIV pathogenesis and treatment; 2005

Introduction: Reservoirs of HIV-1-latently infected cells might be depleted by two ways: (1) use of cytotoxic agents that eliminate the reservoir or (2) modulation of latent virus for targeting by antiviral drugs. Among (1), butylated hydroxyanisole (BHA), a synthetic antioxidant which interacts with phospholipid membranes and reduced glutathione (GSH), a regulator of cellular redox potential were chosen. Sulfasalazine (Sul), an inhibitor of the transcription factor NF-kB, GSH and BHA might be included in (2). The objective of this study was to investigate the action of azidothymidine (AZT), in combination with BHA, GSH or Sul, on chronically infected CD4+ T cells. Methods: HIV-1 chronically infected, H9/HTLV-IIIB (H9+) and uninfected control (H9) cells were incubated in the presence of AZT or a combination of AZT with different agents, at no cytotoxic doses. After 24 hs, p24 antigen levels were assessed on cell supernatants and a cell viability assay, based on a tetrazolium salt (MTT) was performed. Results: Combination of AZT with BHA decreased cell viability (26%) and increased p24 levels (22%) in H9+ cell supernatants, as compared to untreated control cells. Combination of AZT with GSH had no effect on both parameters. Interestingly, the combination of AZT with Sul reduced cell viability of H9+ cells (31%) while p24 levels diminished (18%). Conclusions: Increased cytotoxicity of AZT plus BHA could be related to a higher permeability to AZT, thus, increase of p24 (p<0.05), would be the result of an increase in cell death. Although Sul plus AZT was cytotoxic to H9+ cells, p24 production was significantly reduced (p<0.05) as compared to individual drugs, suggesting that the relationship between virus expression and NF-kB activity could be a clue in this reduction. Thus, combination of AZT with BHA or Sul might represent two different ways to modulate infection in chronically infected cells.