Inhibition of human immunodeficiency virus type 1 (HIV-1) replication by HIV-1-based lentivirus vectors expressing transdominant Rev

Retrovirus vectors expressing transdominant-negative mutants of Rev (TdRev) inhibit human immunodeficiency virus type 1 (HIV-1) replication by prevent ing the nuclear export of unspliced viral transcripts, thus inhibiting the synthesis of Gag-Pol, Env, and genomic RNA. The use of HIV-1-based vectors to express TdRev would have the advantage of allowing access to nondividing hematopoietic cells. It would also provide additional levels of protection by sequestering the viral regulatory proteins Tat and Rev, competing for e ncapsidation into wild-type virions, and inhibiting reverse transcription. Here we describe HIV-1-based vectors that express TdRev, These vectors cont ain mutations in the splicing signals or replacement of the Rev-responsive element by the simian retrovirus type 1 constitutive transport element, mak ing them less sensitive to the inhibitory effects of TdRev, In addition, ov erexpression of Rev and the use of an HIV-1 helper plasmid that drives high levels of Gag-Pol synthesis were used to transiently overcome the inhibiti on by TdRev of the synthesis of Gag-Pol during vector production. SupT1 cel ls transduced with these vectors were more resistant to HIV-1 replication t han cells transduced with Moloney murine leukemia virus-based vectors expre ssing TdRev, Furthermore, we show that these vectors can be mobilized by th e wild-type virus, reducing the infectivity of virions escaping inhibition and conferring protection against HIV-1 replication to previously untransdu ced cells.