A safe packaging line for gene transfer: separating viral genes on two different plasmids.

摘要: A retrovirus packaging cell line was constructed by using portions of the Moloney murine leukemia virus in which gag, pol, and env genes helper were separated onto two different plasmids psi signal 3' long terminal repeat removed. The plasmid containing gag pol gene cotransfected into NIH 3T3 cells. Clones that produced high levels reverse transcriptase protein tested for their ability to package replication-defective vectors delta neo N2. One gag-pol clones (GP+E-86) able transfer G418 resistance recipient cells at a titer as 1.7 X 10(5) when it used 4 10(6) Supernatants transfected with intact parent gag-pol-env 3P0 had comparable titers (as 6.5 10(4) neo; N2). Tests recombination events might result showed no evidence generation replication-competent virus. These results suggest env, present on plasmids, may provide an efficient safe use retroviral transfer.