Characterization of Anti-CCR5 Ribozyme-Transduced CD34+ Hematopoietic Progenitor Cells in Vitro and in a SCID-hu Mouse Model in Vivo

Jirong Bai, Santhi Gorantla, Nirmal Banda, Laurence Cagnon, John Rossi, Ramesh Akkina

Research output: Contribution to journalArticlepeer-review

91 Scopus citations


The cellular entry of HIV is mediated by the specific interaction of viral envelope glycoproteins with the cell-surface marker CD4 and a chemokine receptor (CCR5 or CXCR4). Individuals with a 32-base-pair (bp) deletion in the CCR5 coding region, which results in a truncated peptide, show resistance to HIV-1 infection. This suggests that the downregulation of CCR5 expression on target cells may prevent HIV infection. Therefore, ribozymes that inhibit the CCR5 expression offer a novel approach for anti-HIV gene therapy. To assess the effect of an anti-CCR5 ribozyme (R5Rbz) on macrophage differentiation, CD34+ hematopoietic progenitor cells were transduced with a retroviral vector carrying R5Rbz and allowed to differentiate in the presence of appropriate cytokines. R5Rbz-transduced CD34+ cells differentiated normally into mature macrophages that carried CD14 and CD4 surface markers, expressed the anti-CCR5 ribozyme, and showed significant resistance to viral infection upon challenge with the HIV-1 BaL strain. Using an in vivo thymopoiesis model, the effect of R5Rbz on stem cell differentiation into thymocytes was evaluated by reconstituting SCID-hu mice thymic grafts with ribozyme-transduced CD34+ cells. FACS analysis of cell biopsies at 4 and 6 weeks postengraftment for HLA, CD4, and CD8 markers showed comparable levels of reconstitution and similar percentages of subpopulations of thymocytes between grafts receiving R5Rbz-transduced and control CD34+ cells. RT-PCR assays demonstrated the expression of the anti-CCR5 ribozyme in CD4+, CD8+, and CD4+/CD8+ thymocyte subsets derived from R5Rbz-transduced CD34+ cells. These results indicate that anti-CCR5 ribozyme can be introduced into hematopoietic stem cells without adverse effects on their subsequent lineage-specific differentiation and maturation. The expression of anti-CCR5 ribozymes in HIV-1 target cells offers a novel gene therapy strategy to control HIV infection.

Original languageEnglish (US)
Pages (from-to)244-254
Number of pages11
JournalMolecular Therapy
Issue number3
StatePublished - Mar 2000
Externally publishedYes


  • AIDS; HIV-1 gene therapy; chemokine CCR5 coreceptor; ribozyme gene therapy; CD34 progenitor cells; stem cell gene therapy; SCID-hu mouse model

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology
  • Genetics
  • Pharmacology
  • Drug Discovery


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