In vivo transduction of hematopoietic stem cells after neonatal intravenous injection of an amphotropic retroviral vector in mice

Abstract

Hematopoietic stem cells (HSC) are important targets for gene therapy. Most protocols involve ex vivo modification, in which HSC are transduced in vitro and injected into the recipient. An in vivo delivery method might simplify HSC gene therapy. We previously demonstrated that iv injection of an amphotropic retroviral vector (RV) into newborn mice resulted in long-term expression from hepatocytes. The goal of this study was to determine if HSC were also transduced. After neonatal administration of 1 x 10(10) transducing units/kg of RV, peripheral blood cells had approximately 0.1 copy of RV per cell for up to 22 months. At 18 months, RV sequences were detected in T, B, and myeloid cells from bone marrow (BM). Unfractionated BM was transplanted into naive recipients after total body irradiation. Recipients maintained similar levels of the RV in their blood cells for 10 months, at which time RV sequences were present at the same integration site in all lineages of cells from BM. We conclude that neonatal iv injection of RV results in transduction of HSC in mice, which might be used for BM-directed gene therapy. Transduction of blood cells after liver-directed neonatal gene therapy might have adverse effects in patients, although no leukemias developed here.

Biomaterial-mediated retroviral gene transfer using self-assembled monolayers

“…For example, gene-activated biomaterials have been used in combination with bone grafts [4,18,22], arterial stents [38,46], and treatments to regulate angiogenesis [5]. Therapeutic retroviral particles have also been directly injected into bone defects to enhance tissue regeneration [47], administered intravenously to correct genetic diseases [48,49], and delivered to tumors to treat brain cancer [43]. Combining these approaches into a single strategy based on biomaterial-mediated retroviral gene delivery may significantly enhance the efficacy of these therapies.…”

Immune tolerance induced by platelet‐targeted factor VIII gene therapy in hemophilia A mice is CD4 T cell mediated

“…Cell sources (from rhF8-immunized animals) of an individual [35][36][37]. Expression of FVIII in hematopoietic cells has recently shown promise for treating HA with genetic therapy [17,[38][39][40][41], but low FVIII expression or the generation of FVIII inhibitors in vivo is still a problem, especially when employing clinically relevant non-myeloablative conditioning regimens [17,38,42,43]. Nevertheless, targeting FVIII transgene expression to HSCs under the control of a non-specific viral promoter has induced immune tolerance to FVIII when using an effective conditioning regimen, even though sustained transgene expression has been difficult to achieve [17,19,44].…”

Effects of mannosylated glycopolymers on specific interaction to bone marrow hematopoietic and progenitor cells derived from murine species

“…Genetic modification of HSCs can therefore potentially last a lifetime and may permanently cure hematologic disorders of which genetic deficiencies as the cause of the pathology. 15,16 However, the observed gene-transfer efficiency of HSCs has been relatively low, probably due to the nondividing nature of HSCs and because gene delivery into HSCs using viral vectors has caused hematopoietic malignance due to destruction of endogenous gene function with random chromosome insertion. For these reasons, novel trials have been developed with a nonviral vector system and other materials.…”