Overexpression of CXCR4 on human CD34+ progenitors increases their proliferation, migration, and NOD/SCID repopulation.
A major limitation to clinical stem cell-mediated gene therapy protocols is the low levels of engraftment by transduced progenitors. We report that CXCR4 overexpression on human CD34+ progenitors using a lentiviral gene transfer technique helped navigate these cells to the murine bone marrow and spleen in response to stromal-derived factor 1 (SDF-1) signaling. Cells overexpressing CXCR4 exhibited significant increases in SDF-1-mediated chemotaxis and actin polymerization compared with control cells. A major advantage of CXCR4 overexpression was demonstrated by the ability of transduced CD34+ cells to respond to lower, physiologic levels of SDF-1 when compared to control cells, leading to improved SDF-1-induced migration and proliferation/survival, and finally resulting in significantly higher levels of in vivo repopulation of nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice including primitive CD34+/CD38(-/low) cells. Importantly, no cellular transformation was observed following transduction with the CXCR4 vector. Unexpectedly, we documented lack of receptor internalization in response to high levels of SDF-1, which can also contribute to increased migration and proliferation by the transduced CD34+ cells. Our results suggest CXCR4 overexpression for improved definitive human stem cell motility, retention, and multilineage repopulation, which could be beneficial for in vivo navigation and expansion of hematopoietic progenitors.
Kahn
Joy
J
Department of Immunology, Weizmann Institute of Science, Rehovot, Israel.
Byk
Tamara
T
Jansson-Sjostrand
Lottie
L
Petit
Isabelle
I
Shivtiel
Shoham
S
Nagler
Arnon
A
Hardan
Izhar
I
Deutsch
Varda
V
Gazit
Zulma
Z
Gazit
Dan
D
Karlsson
Stefan
S
Lapidot
Tsvee
T
D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D002465:Cell Movement; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006085:Graft Survival; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology*; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D019718:Receptors, CXCR4 / Q000235:genetics*; D033581:Stem Cell Transplantation; D014183:Transplantation, Heterologous
D018952:Antigens, CD34; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D019718:Receptors, CXCR4