title: The FBMD-1 stroma cell line secretes a unique moiety which can increase retroviral transduction of lineage-committed and primitive human peripheral blood progenitor cells.
abstract: Peripheral blood progenitor cells are a prime target for gene therapy approaches. As recent data point to the relevance of soluble stroma factors for the efficient transduction of progenitor cells, we tested the stroma-conditioned medium (SCM) of the two cell lines FBMD-1 and L88/5 as well as desulfated and O-sulfated heparin (HS dS and HS OS) for their effect on transduction of peripheral blood progenitor cells. We transduced CD34+ cells of nine tumor patients with the retroviral SF-MDR vector containing the human multidrug resistance 1 (MDR1) gene under serum-free conditions on the fibronectin fragment CH-296 with or without SCM. Provirus-specific polymerase chain reaction showed a median 1.6-fold higher integration rate of the transgene into committed progenitor cells for the group with added FBMD-1 SCM (P=.008). This was maintained after 2 (P=.02) and, as a trend, after 5 weeks of stroma-dependent long-term culture. We found a median 1.5-fold increase in rhodamine-123 (Rh-123) exclusion in myeloid lineage-committed progeny cells following transduction in the presence of FBMD-1 SCM (P=.0004). After 2 or 5 weeks of long-term culture, a significantly higher proportion of Rh-123(dull) cells could still be detected in the FBMD-1 SCM transduction group (P=.003 and P=.04, respectively). L88/5 SCM or HS OS or HS dS was not effective as supplement for improving gene transfer. The FBMD-1 stroma cell line appears to secrete a unique moiety, which can increase retroviral transduction of lineage-committed and primitive progenitor cells. The FBMD-1 stroma activity is not attributable to heparan sulfate.
authors.affiliation: German Cancer Research Center, Research Program Diagnostics and Experimental Therapy, Heidelberg D0200, Germany.
authors.forename: E C
authors.initials: EC
authors.lastname: Buss
authors.forename: B
authors.initials: B
authors.lastname: Schiedlmeier
authors.forename: A D
authors.initials: AD
authors.lastname: Ho
authors.forename: W J
authors.initials: WJ
authors.lastname: Zeller
authors.forename: S
authors.initials: S
authors.lastname: Fruehauf
mesh_terms: D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D001769:Blood / Q000378:metabolism*; D019070:Cell Lineage; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005260:Female; D005353:Fibronectins / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood*; D016133:Polymerase Chain Reaction; D012190:Retroviridae / Q000235:genetics*; D012235:Rhodamines / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology* / Q000378:metabolism*; D013997:Time Factors; D014161:Transduction, Genetic; D019076:Transgenes
chemical_list: D018952:Antigens, CD34; D016895:Culture Media, Serum-Free; D005353:Fibronectins; D012235:Rhodamines