title: Retroviral transduction of quiescent haematopoietic cells using a packaging cell line expressing the membrane-bound form of stem cell factor.
abstract: Gene therapy vectors based on murine retroviruses are unable to transduce non-dividing cells. This has proven a particular problem in the haematopoietic system where the target cells of choice, the pluripotent stem cells are quiescent. In an attempt to circumvent this difficulty we have constructed a retroviral producer line that expresses the membrane bound form of human recombinant stem cell factor (SCF) on its cell surface. This should enable the retroviral producers to deliver a growth signal to the target cells simultaneous with their exposure to retrovirus. We tested the ability of these modified producers to transduce a growth factor-starved, SCF-dependent cell line (TF-1) and demon- strated that these cells, though quiescent, can still be successfully transduced. This approach was extended to targeting of umbilical cord blood CD34+ cells, a predominantly quiescent population that normally require the addition of cytokines for efficient transduction. Using the SCF-expressing producer line in the absence of exogenously added cytokines, we observed a marked stimulation in transduction efficiency over that achieved using the parent producer line alone. Colonies derived from these cells arising in semi-solid media were also shown to be positive for expression of a retrovirally encoded reporter gene.
authors.affiliation: Department of Haematology, Imperial College School of Medicine, St Mary's Campus, Norfolk Place, London W2 1PG, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sehgal
authors.forename: N
authors.initials: N
authors.lastname: Weeratunge
authors.forename: C
authors.initials: C
authors.lastname: Casimir
mesh_terms: D000818:Animals; D002455:Cell Division; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D051379:Mice; D012190:Retroviridae / Q000235:genetics*; D019089:Stem Cell Factor / Q000378:metabolism*; D014161:Transduction, Genetic / Q000235:genetics*
chemical_list: D019089:Stem Cell Factor