Anti-human immunodeficiency virus type 1 activity of phosphorothioate analogs of oligodeoxynucleotides: penetration and localization of oligodeoxynucleotides in HIV-1-infected MOLT-4 cells.

Phosphorothioate antisense oligodeoxynucleotide against HIV-1 rev (S-ODN-rev) inhibits virus-induced cytopathic effects (CPE) in acute infection and inhibits the expression of HIV-1 core protein, p24, in chronically infected cells in vitro. HIV-1 reverse transcriptase activity was not affected by S-ODN-rev at the high concentrations of 5-25 microM, which were 250-1250 times higher than the concentration required to achieve 100% HIV-1-induced CPE inhibition. [32P]-labeled S-ODN-rev was rapidly uptaken by MOLT-4 cells, whereas [32P]-SO-ODN-rev and [32P]-O-ODN-rev were not. In the observation of FITC-S-ODN-rev-treated MOLT-4 cells by a confocal laser scanning microscope, diffuse fluorescence was apparently observed in the cytoplasm. Interestingly, fluorescence signals were accumulated in the nuclear region of chronically infected MOLT-4/HIV-1 cells 60 min after incubation. FITC-labeled homooligomer, FITC-S-dC20 and FIT-C-S-dT20, also accumulated in the nucleus of MOLT-4/HIV-1 cells, but weak fluorescence was observed on the cell membrane and in the cytoplasm of the FITC-S-random treated MOLT-4/HIV-1 and MOLT-4 cells.