Submitted on April 18, 2007
Revised on February 28, 2008
Sustained Expression of 
1-antitrypsin After Transplantation of Manipulated Hematopoietic Stem Cells
Andrew A Wilson1*, Letty W Kwok1, Avi-Hai Hovav2, Sarah J Ohle1, Frederic F Little1, Alan Fine1, and Darrell N Kotton1
1 Boston University School of Medicine, The Pulmonary Center, Boston, MA, USA,
2 The Hebrew University, Institute of Dental Sciences, Jerusalem, Israel
* To whom correspondence should be addressed. E-mail: awilson{at}bu.edu.
Inherited mutations in the human alpha-1 antitrypsin (AAT) gene lead to deficient circulating levels of AAT protein and a predisposition to developing emphysema. Gene therapy for individuals deficient in AAT is an attractive goal, because transfer of a normal AAT gene into any cell type able to secrete AAT should reverse deficient AAT levels and attenuate progression of lung disease. Here we present an approach for AAT gene transfer based on the transplantation of lentivirally-transduced hematopoietic stem cells (HSCs). We developed a novel dual-promoter lentiviral system to transfer normal human AAT cDNA as well as a fluorescent tracking "reporter gene" into murine HSCs. Following transplantation of 3000 transduced HSCs into irradiated mouse recipients, we demonstrate simultaneous and sustained systemic expression of both genes in vivo for at least 31 weeks. The stem cells transduced with this protocol maintain multipotency, self-renewal potential, and the ability to reconstitute the hematopoietic systems of both primary and secondary recipients. This lentiviral-based system may be useful for investigations requiring the systemic secretion of anti-proteases or cytokines relevant to the pathogenesis of a variety of lung diseases.
