TRANSFER OF AN ANTI-HIV-1 RIBOZYME GENE INTO PRIMARY HUMAN-LYMPHOCYTES

We reported previously that human CD4(+) T cell lines stably expressin g a hairpin ribozyme targeted to the human immunodeficiency virus type 1 (HIV-1) U5 leader sequence were resistant to challenge with diverse HIV-1 viral clones and clinical isolates (Yamada et al., 1994). To si mulate more closely the in vivo infection process for investigations o f anti-HIV-1 ribozyme gene therapy, we developed a system to transfer this ribozyme gene into freshly isolated human peripheral blood lympho cytes (PBLs) using a murine retrovirus vector. Following transduction and G418 selection, human PBLs from multiple donors expressed the ribo zyme and resisted challenge by HIV-1 viral clones and clinical isolate s, while control vector-transduced PBLs remained fully permissive for HIV-1 infection. No inhibition of an HIV-2 clone lacking the target wa s seen in ribozyme-expressing PBLs. Ribozyme expression had no effect on viability or proliferation kinetics of the primary lymphocytes. Thi s study is the first demonstration in primary human T cells of resista nce to HIV-1 infection conferred by gene transfer. A human clinical tr ial is in development to test further the safety and efficacy of this ribozyme in PBLs of HIV-1-infected patients in vivo.