Induction of chronic human immunodeficiency virus infection is blocked in vitro by a methylphosphonate oligodeoxynucleoside targeted to a U3 enhancer element.

Oligodeoxynucleosides with internucleoside methylphosphonate linkages complementary to regions within U3 of human immunodeficiency virus type 1 were evaluated for their ability to block phorbol myristate acetate upregulation of virus in chronically infected promonocytic and T-lymphoblastoid cell lines. One such oligomer, targeted to an NF-kappa B enhancer element, inhibited phorbol myristate acetate induction of viral replication and tat-mediated trans activation of the human immunodeficiency virus long terminal repeat. The effect of this construct is contrasted with classical antisense methylphosphonate-derivatized oligomers complementary to initiation codon and splice acceptor sites of human immunodeficiency virus structural and regulatory genes. Its activity suggests a novel application of the modified oligonucleotide strategy in the blockade of viral induction from latently infected cells.