Article

Successful transduction of liver in hemophilia by AAV-Factor IX and limitations imposed by the host immune response.

The Children's Hospital of Philadelphia, 3615 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA.
Nature Medicine (Impact Factor: 28.05). 04/2006; 12(3):342-7. DOI: 10.1038/nm1358
Source: PubMed

ABSTRACT We have previously shown that a single portal vein infusion of a recombinant adeno-associated viral vector (rAAV) expressing canine Factor IX (F.IX) resulted in long-term expression of therapeutic levels of F.IX in dogs with severe hemophilia B. We carried out a phase 1/2 dose-escalation clinical study to extend this approach to humans with severe hemophilia B. rAAV-2 vector expressing human F.IX was infused through the hepatic artery into seven subjects. The data show that: (i) vector infusion at doses up to 2 x 10(12) vg/kg was not associated with acute or long-lasting toxicity; (ii) therapeutic levels of F.IX were achieved at the highest dose tested; (iii) duration of expression at therapeutic levels was limited to a period of approximately 8 weeks; (iv) a gradual decline in F.IX was accompanied by a transient asymptomatic elevation of liver transaminases that resolved without treatment. Further studies suggested that destruction of transduced hepatocytes by cell-mediated immunity targeting antigens of the AAV capsid caused both the decline in F.IX and the transient transaminitis. We conclude that rAAV-2 vectors can transduce human hepatocytes in vivo to result in therapeutically relevant levels of F.IX, but that future studies in humans may require immunomodulation to achieve long-term expression.

2 Followers
 · 
148 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Induced pluripotent stem cells (iPSCs) are a seminal breakthrough in stem cell research and are promising tools for advanced regenerative therapies in humans and reproductive biotechnology in farm animals. iPSCs are particularly valuable in species in which authentic embryonic stem cell (ESC) lines are yet not available. Here, we describe a nonviral method for the derivation of bovine iPSCs employing Sleeping Beauty (SB) and piggyBac (PB) transposon systems encoding different combinations of reprogramming factors, each separated by self-cleaving peptide sequences and driven by the chimeric CAGGS promoter. One bovine iPSC line (biPS-1) generated by a PB vector containing six reprogramming genes was analyzed in detail, including morphology, alkaline phosphatase expression, and typical hallmarks of pluripotency, such as expression of pluripotency markers and formation of mature teratomas in immunodeficient mice. Moreover, the biPS-1 line allowed a second round of SB transposon-mediated gene transfer. These results are promising for derivation of germ line-competent bovine iPSCs and will facilitate genetic modification of the bovine genome.
    Cellular Reprogramming 04/2015; DOI:10.1089/cell.2014.0080. · 2.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Induced pluripotent stem cells (iPSCs) are a seminal breakthrough in stem cell research and are promising tools for advanced regenerative therapies in humans and reproductive biotechnology in farm animals. iPSCs are particularly valuable in species in which authentic embryonic stem cell (ESC) lines are yet not available. Here, we describe a nonviral method for the derivation of bovine iPSCs employing Sleeping Beauty (SB) and piggyBac (PB) transposon systems encoding different combinations of reprogramming factors, each separated by self-cleaving peptide sequences and driven by the chimeric CAGGS promoter. One bovine iPSC line (biPS-1) generated by a PB vector containing six reprogramming genes was analyzed in detail, including morphology, alkaline phosphatase expression, and typical hallmarks of pluripotency, such as expression of pluripotency markers and formation of mature teratomas in immunodeficient mice. Moreover, the biPS-1 line allowed a second round of SB transposon-mediated gene transfer. These results are promising for derivation of germ line-competent bovine iPSCs and will facilitate genetic modification of the bovine genome.
    04/2015; 17(2):131-140. DOI:10.1089/cell.2014.0080
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: The sensory epithelium of the cochlea is a complex structure containing hair cells, supporting cells and auditory nerve endings, all of which degenerate after hearing loss in mammals. Biological approaches are being considered to preserve and restore the sensory epithelium after hearing loss. Of particular note is the ectopic expression of the Atoh1 gene, which has been shown to convert residual supporting cells into hair cells with restoration of function in some cases. Areas covered: In this review, hair cell development, spontaneous regeneration and hair cell regeneration mediated by Atoh1 gene therapy in the cochlea are discussed. Expert opinion: Gene therapy can be safely delivered locally to the inner ear and can be targeted to the sensory epithelium of the cochlea. Expression of the Atoh1 gene in supporting cells results in their transformation into cells with the appearance and function of immature hair cells but with the resulting loss of the original supporting cell. While the feasibility of Atoh1 gene therapy in the cochlea is largely dependent on the severity of the hearing loss, hearing restoration can be achieved in some situations. With further advances in Atoh1 gene therapy, hearing loss may not be as permanent as once thought.
    Expert Opinion on Biological Therapy 02/2015; 15(3):1-14. DOI:10.1517/14712598.2015.1009889 · 3.65 Impact Factor

Full-text

Download
3 Downloads
Available from
Mar 6, 2015