Efficient retrovirus-mediated transfer of the multidrug resistance 1 gene into autologous human long-term repopulating hematopoietic stem cells

Abstract

Pre-clinical studies indicate that efficient retrovirus-mediated gene transfer into hematopoietic stem cells and progenitor cells can be achieved by co-localizing retroviral particles and target cells on specific adhesion domains of fibronectin. In this pilot study, we used this technique to transfer the human multidrug resistance 1 gene into stem and progenitor cells of patients with germ cell tumors undergoing autologous transplantation. There was efficient gene transfer into stem and progenitor cells in the presence of recombinant fibronectin fragment CH-296. The infusion of these cells was associated with no harmful effects and led to prompt hematopoietic recovery. There was in vivo vector expression, but it may have been limited by the high rate of aberrant splicing of the multidrug resistance 1 gene in the vector. Gene marking has persisted more than a year at levels higher than previously reported in humans.

A novel gene transfer strategy that combines promoter and transgene activities for improved tumor cell inhibition

“…Retroviral transduction of HSC's with MDR1 45 has been extensively studied and attempted clinically, but with generally disappointing results due to low transduction efficiencies and lack of expression of the transgene, 46,47 though improved transduction protocols and a modified MDR1 cDNA have partially remedied this situation. 48,49 Additional advantages may be offered in the case of pCLPG-mediated delivery of the MDR1 cDNA since a drug used for chemotherapy, and which activates p53, should, in turn, activate MDR1 expression from the pCLPG virus in the hematopoietic cells, protecting and selecting them for continued proliferation.…”

Picolinic acid- or desferrioxamine-inducible autocrine activation of macrophages engineered to produce IFNγ: an approach for gene therapy

“…Translational application requires the manipulation of primary cells to be used as a source of Mf. 33 The possibilities of transducing bone marrow stem cells and to differentiate them into Mf or of engineering human mononuclear cells in vitro are reasonable approaches to obtain engineered Mf, 5,6,34 and experiments are underway to address these issues.…”

In vivo selective expansion of gene-modified hematopoietic cells in a nonhuman primate model

“…[4][5][6][7][8] Although in vivo selection of transduced cells with the MDR-1 gene appeared feasible in mice, 4 it has been difficult to document such selection in nonhuman primates or humans. [5][6][7][8] In vivo selection with the MDR-1 gene may have resulted from selection at the level of relatively mature precursor cells, not at the level of HSCs, since HSCs express the MDR-1 gene. [9][10][11] In addition, aberrant splicing of the vector-derived MDR-1 transcript has been shown in human hematopoietic cells, which lead to the generation of nonfunctional, truncated MDR-1 gene product.…”