Inhibition of HIV-1 replication by novel lentiviral vectors expressing transdominant Rev and HIV-1 env antisense.

Retroviral vectors expressing transdominant negative mutants of Rev (TdRev) inhibit HIV-1 replication by preventing the nuclear export of unspliced viral transcripts, thus inhibiting the synthesis of Gag-Pol, Env and reducing the levels of genomic RNA available for packaging. Due to these effective mechanisms of inhibition, production of HIV-1-based lentiviral vectors expressing TdRev has been difficult. Here we describe HIV-based vectors in which expression of TdRev is negatively regulated by Rev expression. In these vectors, we maintained the wild-type HIV-1 Tat/Rev exons and intron configuration and its mode of splicing regulation. The second Rev exon was mutated to encode TdRev. Inhibition of TdRev expression by Rev during vector production yields high titer vector preparations. A second vector containing an additional anti-HIV gene (env-antisense) was constructed by flipping a 1.2-kb env fragment contained within the Tat/TdRev intron. SupT1 cells and primary CD4+ lymphocytes transduced with these vectors inhibit HIV-1 replication and show a preferential advantage for survival. Although these vectors are poorly mobilized to secondary target cells by wild-type HIV-1, they reduce the infectivity of the wild-type virions escaping inhibition.