Lentiviral vectors pseudotyped with murine ecotropic envelope: increased biosafety and convenience in preclinical research.
OBJECTIVE
Lentiviral vectors are increasingly used for preclinical models of gene therapy and other forms of experimental transgenesis. Due to the broad tropism and the ability for concentration by ultracentrifugation, most lentiviral vector preparations are produced using the vesicular stomatitis virus glycoprotein (VSV-g) protein as envelope. Recently, Hanawa and colleagues have demonstrated that the ecotropic envelope protein of murine leukemia viruses allows efficient pseudotyping of HIV-1-derived vector particles. However, this method has found little acceptance, despite potential advantages.


METHODS
We produced lentiviral vectors pseudotyped with murine ecotropic envelope using a four-plasmid transient transfection system and evaluated their performance in murine fibroblasts and hematopoietic cells.


RESULTS
Titers of lentiviral "ecotropic" supernatants were only slightly lower than those produced with VSV-g, could be concentrated by overnight centrifugation (13,000g), and efficiently transduced murine fibroblasts and hematopoietic cells but not human cells. Our Institutional Biosafety Committee agreed on the production and use of replication-defective lentiviral vectors pseudotyped with murine ecotropic envelope under biosafety level 1 (BL1) conditions with additional BL2 practices. We also obtained useful guidelines for the work with human infectious lentiviral vectors.


CONCLUSIONS
For the researcher, "ecotropic" lentiviral vectors significantly improve the convenience of daily work, compared to the conditions required for lentiviral pseudotypes that are capable of infecting human cells. High efficiency and superior biosafety in combination with convenient handling will certainly boost the potential applicability of this important vector system.
Schambach
Axel
A
Department of Hematology, Hemostaseology and Oncology, Hannover Medical School, Germany.
Galla
Melanie
M
Modlich
Ute
U
Will
Elke
E
Chandra
Saurabh
S
Reeves
Lilith
L
Colbert
Melissa
M
Williams
David A
DA
von Kalle
Christof
C
Baum
Christopher
C
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000009:adverse effects*; D016086:Lentivirus / Q000235:genetics*; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice; D016133:Polymerase Chain Reaction
D017931:DNA Primers