ADENOVIRUS VECTORS AS TRANSCOMPLEMENTING TEMPLATES FOR THE PRODUCTIONOF REPLICATION-DEFECTIVE RETROVIRAL VECTORS

We have generated an adenovirus containing a retroviral vector sequenc e encoding the neomycin phosphotransferase (neo) gene (AV-LXSN). AV-LX SN transduction of retroviral packaging cell lines led to production o f LXSN retroviral vector with alternative viral envelopes; exposure of target cells to retroviral containing supernatants confirmed envelope specific tropism. Retroviral titers (G418(R) cfu/ml) were comparable to those produced by standard techniques. Retrovirus could be detected in supernatants within 24 hours of AV-LXSN transduction and persisted as long as 120 hours. Southern blot analysis of DNA purified from pop ulations of G418(R) cells showed the presence of a single neo containi ng restriction fragment of the appropriate size that could only be gen erated by reverse transcription of LXSN to produce LXSN provirus. This adeno-retroviral chimeric vector system could simplify the generation and testing of different retroviral vectors, particularly where asses sment of vectors with alternative envelopes carrying novel targeting l igands is required. (C) 1998 Academic Press.