INHIBITION OF HIV-1 REPLICATION BY AN ANTI-TAT HAMMERHEAD RIBOZYME

Tat is a virally expressed regulatory protein involved in the replicat ion of HIV-1, the etiological agent of AIDS. To investigate the effect of tat inhibition on HIV replication, we constructed a retroviral vec tor to express an anti-tat hammerhead ribozyme as part of the 3' untra nslated region of beta-galactosidase transcripts. Initial testing of t his vector in tat-expressing COS-7 cells reduced tat activity by 85-95 % as measured by tat-dependent CAT assays. Amphotropic and HIV-pseudot yped retroviral particles generated with this vector were used in HIV challenge experiments to determine the ability of this reagent to cont rol HIV replication. CD4(+) peripheral blood lymphocytes (PBLs) stably transduced with this vector were subsequently challenged with HIV. Th ese cells were able to resist HIV infection for up to 20 days as measu red by cell death and reverse transcriptase activity. These data yield proof of principle that a pseudotyped retroviral vector can target an d deliver a protective ribozyme to CD4(+) cells. (C) 1998 Academic Pre ss.