Efficient gene transfer to hematopoietic progenitor cells using SV40-derived vectors

Area of Science:

• Gene Therapy
• Hematopoietic Stem Cell Biology
• Viral Vector Technology

Background:

• Hematopoietic progenitor cells are crucial for blood cell formation.
• Efficient and stable gene delivery to these cells is a challenge in gene therapy.
• Recombinant simian virus 40 (rSV40) vectors offer high transduction efficiency.

Purpose of the Study:

• To evaluate the efficacy of rSV40 vectors for ex vivo and in vivo gene delivery to hematopoietic progenitor cells.
• To assess transgene expression and stability in human and simian cells.
• To investigate the potential of rSV40 vectors for therapeutic applications in CD34+ cell-derived diseases.

Main Methods:

• Transduction of human fetal bone marrow (HFBM) and rhesus macaque bone marrow CD34+ cells with rSV40 vectors (SV(HBS) and SV(Aw)).
• Assessment of transgene carriage and expression using PCR and immunochemistry.
• Transplantation of transduced cells into SCID mice and evaluation of in vivo gene expression and stability.

Main Results:

• High efficiency transduction of CD34+ cells with rSV40 vectors, achieving up to 60% gene-marked colonies after single transduction.
• Sequential transduction increased gene marking to over 95% expression of the transgene (HIV-1 integrase antibody).
• Sustained and stable transgene expression (>50%) observed in vivo in mouse bone marrow three months post-transplantation, suggesting genomic integration.

Conclusions:

• rSV40 vectors are highly efficient in transducing human and primate hematopoietic progenitor cells without selection.
• Transgene expression is stable and long-lasting in vivo, indicating potential for genomic integration.
• The high transduction efficiency of rSV40 vectors holds promise for treating diseases affecting CD34+ cells and their derivatives.