...flanked by LTRs; ~8 kb packaging capacity Packaging plasmid — contains packaging genes gag and pol Envelope...of these packaging components. Therefore, gamma-retroviruses may not be efficiently packaged by lentiviral...to lentiviral packaging methods . The three plasmids described above (envelope, packaging, and transfer... . Production Using Packaging Cell Lines Gamma-retroviral vectors can be packaged using helper-free cell...envelope and packaging plasmids. Unless multiple recombination events occur between the packaging, envelope...simpler genomes, containing only the necessary packaging genes, while lentiviruses also contain accessory...lentiviruses and gamma-retroviruses use the same packaging genes. However, they are different viruses and...