Improved gene transfer into canine hematopoietic repopulating cells using CD34-enriched marrow cells in combination with a gibbon ape leukemia virus–pseudotype retroviral vector

Sustained multilineage gene persistence and expression in dogs transplanted with CD34+ marrow cells transduced by RD114-pseudotype oncoretrovirus vectors

“…5,6 These changes included use of fibronectin fragment CH-296, addition of cytokine combinations with activity in early hematopoietic cells, and use of the gibbon ape leukemia virus (GALV) pseudotype. Although initial gene transfer efficiencies of more than 20% were achieved, long-term levels usually declined to between 0.1% and 5%.…”

Therapeutic Modulation of DNA Damage and Repair Mechanisms in Blood Cells

“…Other viral envelope glycoproteins have been discovered and tested (Akkina et al, 1996;Cone & Mulligan, 1984); these include the gibbon ape leukemia virus (GALV) envelope (Wilson et al, 1989), the feline endogenous retrovirus (RD114) envelope (Porter et al, 1996), and the vesicular stomatitis virus G glycoprotein (VSVG) envelope (Emi et al, 1991). When GALV-versus amphotropic-pseudotyped gammaretroviral vectors were compared, GALV-pseudotyped vectors had higher marking than vectors with amphotropic envelopes in both human progenitors (von Kalle et al, 1994) and baboon repopulating cells (Kiem et al, 1999). The VSVG envelope has undergone extensive testing and has been attractive to the community since it can be substantially concentrated via ultracentrifugation to increase viral titers (Burns et al, 1993).…”

“…Additionally, since the dog leukocyte antigen type I and II loci are fully characterized, this provides the opportunity to evaluate gene-therapy based approaches in an allogeneic transplantation setting (Ladiges et al, 1990;Maris & Storb, 2002;Nyberg et al, 2004;Suter et al, 2004;Venkataraman et al, 2007;Wagner et al, 1999). Due to the clinical applicability of the results obtained in the dog model, a large amount of effort has been devoted to optimizing the conditions in the dog model which include optimizing the procedures to mobilize HSCs, culture these cells ex vivo, as well as transduce them with retroviral vectors and achieve efficient engraftment in vivo (Goerner et al, 1999;Goerner et al, 2001;Horn et al, 2004a;Kiem et al, 2007;Kiem et al, 1996a;Kiem et al, 1999). In terms long-term primary and secondary transplantation studies in canines, more than 80% of the granulocytes can now be marked by in vivo selection of cells expressing the MGMT P140K Neff et al, 2005).…”

“…It has been widely appreciated for some time now, that cell division of the retrovirally transduced cells is essential for stable integration of gamma-retroviral vectors into the host genome (Lewis & Emerman, 1994;Miller et al, 1990). Due to the highly quiescent nature of the hematopoietic cells, cytokines that promote cell division in primitive hematopoietic cells have been utilized over the years and in combination with Retronectin-coated plates-to enhance proximity of retroviral particles and cells-have resulted in fairly high levels of transfer into hematopoietic stem and progenitor cells derived from mice, canines and primates (Horn et al, 2002b;Kiem et al, 1999;Kurre et al, 2002;Rosenzweig et al, 1999). There are generally 3 disadvantages in using a gamma-retroviral vector to transduce hematopoietic cells.…”

True

“…226 However, retroviral transduction of HSC presents a number of technical problems: (1) HSC comprised, at least partly, of the CD34 + CD38 − fraction, are rare cells (less than 0.05% of total adult bone marrow mononuclear cells) and require highperformance cell separation devices for purification; (2) they reside in a quiescent state and require growth factor stimulation prior to retroviral transduction; and (3) there is a poor transduction efficiency of human HSC with amphotropic retroviral vectors as compared to murine HSC where transduc- Table 3 Targets for gene therapy using hematopoietic cells 227 In both a nonhuman primate and canine competitive repopulation assay, Kiem et al 16,228 reported a significantly increased gene marking of peripheral blood leukocytes with GALV-pseudotyped vectors as compared to amphotropic vectors. As with amphotropic envelope receptor, transduction efficiency using GALV-pseudotyped vectors correlates with the levels of GALV receptor mRNA in CD34 + cells.…”