Lack of superinfection interference in retroviral vector producer cells.
Vesicular stomatitis virus G protein (VSV-G)-pseudotyped retroviral vectors have become more feasible for clinical gene transfer protocols since stable tetracycline (tet)-regulated packaging cell lines have become available. Here, we analyzed superinfection interference in VSV-G-pseudotyped and classic amphotropic packaging cell lines. No superinfection interference was observed in VSV-G-pseudotyped packaging cell lines. Thus, integrated retroviral vector genomes accumulated during culture. Similar results were obtained with the amphotropic packaging cells, but to a lesser degree. In addition, VSV-G packaging cells were susceptible to infection with vector particles devoid of envelope proteins, which are produced by these cells in high titers when VSV-G expression is suppressed by tetracycline. For both packaging systems, superinfection could be blocked by azidothymidine (AZT). With regard to safety, this study suggests that in clinical protocols amphotropic producer clones should be tested for superinfection interference and VSV-G packaging cells should always be cultured in the presence of AZT.
Heinrich-Pette-Institute für Experimentelle Virologie und Immunologie, Universität Hamburg, 20251 Hamburg, Germany.
B
B
Vogt
S
S
Roscher
B
B
Abel
M
M
Hildinger
A
A
Lamarre
C
C
Baum
D
D
von Laer
D002478:Cells, Cultured / Q000187:drug effects / Q000276:immunology / Q000821:virology*; D004266:DNA Virus Infections / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods; D018014:Gene Transfer Techniques; D019450:Genes, MDR / Q000235:genetics* / Q000502:physiology; D005822:Genetic Vectors; D006801:Humans; D019868:Kanamycin Kinase / Q000378:metabolism; D007763:Lac Operon / Q000502:physiology; D012190:Retroviridae / Q000235:genetics*; D013997:Time Factors; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics*; D014759:Viral Envelope Proteins / Q000235:genetics; D014779:Virus Replication / Q000502:physiology*; D015215:Zidovudine / Q000494:pharmacology
D014759:Viral Envelope Proteins; D015215:Zidovudine; D019868:Kanamycin Kinase