Feasibility of cord blood stem cell manipulation with high-energy shock waves: an in vitro and in vivo study.
OBJECTIVE
Cord blood CD34+ cells are more uncommitted than their adult counterparts as they can be more easily maintained and expanded in vitro and transduced with lentiviral vectors. The aim of this study was to evaluate whether pretreatment with high-energy shock waves (HESW) could further enhance the expansion of cord blood progenitors and the transduction efficiency with lentiviral vectors.


METHODS
Human cord blood CD34+ cells underwent HESW treatment with a wide range of energy and number of shots (from 0.22 mJ/mm2 to 0.43 mJ/mm2 and from 200 to 1500 shots). Cells were then evaluated both for their in vitro expansion ability and in vivo engraftment in primary, secondary, and tertiary NOD/SCID mice. The transduction efficiency with a lentiviral vector (LV) was also evaluated in vitro and in vivo.


RESULTS
Cell viability following HESW ranged from 75 to 92%. Pretreatment with HESW significantly improved early progenitor cell expansion after short-term suspension culture. Upon transplantation in primary NOD/SCID mice, the HESW treatment enhanced progenitor cell engraftment (total human CD45(+)CD34+ cells were 10% in controls and 14.5% following HESW, human CD45(+)CD34(+)CD38(-) cells were 0.87% in controls and 1.8% following HESW). HESW treatment enhanced the transduction of a GFP+ lentiviral vector (e.g., at day 42 of culture 6.5% GFP+ cells in LV-treated cell cultures compared to 11.4% of GFP+ cells in HESW-treated cell cultures). The percentage of human GFP+ cell engrafting NOD/SCID mice was similar (34% vs 26.4% in controls); however, the total number of human cells engrafted after HESW was higher (39.6% vs 15%).


CONCLUSIONS
The pretreatment of CD34+ cells with HESW represents a new method to manipulate the CD34+ population without interfering with their ability to both expand and engraft and it might be considered as a tool for genetic approaches.
Berger
Massimo
M
Department of Pediatrics, Regina Margherita Children's Hospital, University of Turin, Turin, Italy. massimo.berger@unito.it
Frairia
Roberto
R
Piacibello
Wanda
W
Sanavio
Fiorella
F
Palmero
Alessandra
A
Venturi
Claudio
C
Pignochino
Ymera
Y
Berta
Laura
L
Madon
Enrico
E
Aglietta
Massimo
M
Fagioli
Franca
F
D000818:Animals; D018952:Antigens, CD34; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005240:Feasibility Studies; D005312:Fetal Blood / Q000166:cytology*; D006085:Graft Survival / Q000528:radiation effects; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000528:radiation effects*; D019220:High-Energy Shock Waves; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D014183:Transplantation, Heterologous
D018952:Antigens, CD34