Ribozyme gene therapy for HIV infection Intracellular immunization of lymphocytes and CD34+ cells with an anti-HIV-1 ribozyme gene

Abstract

The ultimate goal of gene therapy for HIV infection is to repopulate the immune system with genetically altered cells that would resist infection. We previously reported that a hairpin ribozyme that cleaves HIV-1 RNA in U5 suppressed the replication of diverse strains of HIV-1, including clinical isolates, in human at-cell lines and primary T-cells. Transduction of CD34+ cells enriched from cord blood of normal or HIV-infected donors also yielded stable ribozyme expression and no apparent effect on phenotype or proliferation of the transduced cells. Furthermore, the macrophages progeny cells were resistant to HIV infection. Currently, to minimize the chance of viral resistance as well as to increase anti-viral potency, we developed vectors expressing two ribozymes or a fusion RRE-ribozyme gene. The fusion molecule displayed both a decoy and enhanced ribozyme activity. A phase I clinical protocol to test the safety and function of a double ribozyme vector in ex vivo transduced human PBL has been approved by the NIH RAC, and a second trial for autologous reinfusion of gene altered CD34+ cells derived from cord blood for HIV infected newborns is planned.