Inhibition of human immunodeficiency virus by using an oligonucleoside methylphosphonate targeted to the tat-3 gene.

Antiviral effects were characterized for two oligodeoxyribonucleoside methylphosphonates synthesized in an antisense (3'-TCTTAACC-5') or a sense (5'-AGAATTGG-3') orientation, based on the RNA sequence of the first splice acceptor site of the tat-3 gene of human immunodeficiency virus (HIV) (5'...AGAAUUGG...3'). The development of syncytial cells and supernatant reverse transcriptase was inhibited by a single exposure to the antisense HIV, and HIV RNA synthesis was inhibited by both antisense and sense methylphosphonates but not by a control herpes simplex virus antisense sequence.