HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 2006-0699v1 25/10/2660    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Matsui, H. Articles by Lillicrap, D. Search for Related Content PubMed PubMed Citation Articles by Matsui, H. Articles by Lillicrap, D.

TRANSLATIONAL AND CLINICAL RESEARCH

Ex Vivo Gene Therapy for Hemophilia A That Enhances Safe Delivery and Sustained In Vivo Factor VIII Expression from Lentivirally Engineered Endothelial Progenitors

^aDepartment of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada;
^bDepartment of Pediatrics, Nara Medical University, Kashihara City, Nara, Japan;
^cVascular Biology Center and Division of Hematology Oncology Transplantation, University of Minnesota Medical School, Minneapolis, Minnesota, USA;
^dLady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada

Key Words. Hemophilia A • Lentivirus • Blood outgrowth endothelial cells • Ex vivo gene therapy

Correspondence: David Lillicrap, M.D., Department of Pathology and Molecular Medicine, Richardson Laboratory, Queen's University, Kingston, Ontario, Canada K7L 3N6. Telephone: 613-548-1304; Fax: 613-548-1356; e-mail: lillicrap{at}cliff.path.queensu.ca

Received on November 1, 2006; accepted for publication on June 20, 2007.

First published online in STEM CELLS EXPRESS  July 5, 2007.


Novel therapeutic strategies for hemophilia must be at least as effective as current treatments and demonstrate long-term safety. To date, several small clinical trials of hemophilia gene transfer have failed to show the promise of preclinical evaluations. Therefore, we wanted to develop and evaluate the feasibility of a novel ex vivo gene transfer strategy whereby cells derived from progenitor cells are engineered to express factor VIII (FVIII) and then implanted subcutaneously to act as a depot for FVIII expression. Circulating blood outgrowth endothelial cells (BOECs) were isolated from canine and murine blood and transduced with a lentiviral vector encoding the canine FVIII transgene. To enhance safety, these cells were implanted subcutaneously in a Matrigel scaffold, and the efficacy of this strategy was compared with i.v. delivery of engineered BOECs in nonhemophilic nonobese diabetic/severe combined immunodeficiency mice. Therapeutic levels of FVIII persisted for 15 weeks, and these levels of stable expression were extended to 20 weeks when the cytomegalovirus promoter was replaced with the thrombomodulin regulatory element. Subsequent studies in immunocompetent hemophilic mice, pretreated with tolerizing doses of FVIII or with transient immunosuppression, showed therapeutic FVIII expression for 27 weeks before the eventual return to baseline levels. This loss of transgene expression appears to be due to the disappearance of the implanted cells. The animals treated with either of the two tolerizing regimens did not develop anti-FVIII antibodies. Biodistribution analysis demonstrated that BOECs were retained inside the subcutaneous implants. These results indicate, for the first time, that genetically modified endothelial progenitor cells implanted in a subcutaneous scaffold can provide sustained therapeutic levels of FVIII and are a promising and safe treatment modality for hemophilia A.

Disclosure of potential conflicts of interest is found at the end of this article.

This article has been cited by other articles:

				S. F. De Meyer, H. Deckmyn, and K. Vanhoorelbeke von Willebrand factor to the rescue Blood, May 21, 2009; 113(21): 5049 - 5057. [Abstract] [Full Text] [PDF]

				M. van den Biggelaar, E. A.M. Bouwens, N. A. Kootstra, R. P. Hebbel, J. Voorberg, and K. Mertens Storage and regulated secretion of factor VIII in blood outgrowth endothelial cells Haematologica, May 1, 2009; 94(5): 670 - 678. [Abstract] [Full Text] [PDF]

				Q. Shi, S. A. Fahs, D. A. Wilcox, E. L. Kuether, P. A. Morateck, N. Mareno, H. Weiler, and R. R. Montgomery Syngeneic transplantation of hematopoietic stem cells that are genetically modified to express factor VIII in platelets restores hemostasis to hemophilia A mice with preexisting FVIII immunity Blood, October 1, 2008; 112(7): 2713 - 2721. [Abstract] [Full Text] [PDF]

				A. W. Nienhuis Development of gene therapy for blood disorders Blood, May 1, 2008; 111(9): 4431 - 4444. [Abstract] [Full Text] [PDF]