Lentivirus vector system is a very efficient vector tool for stably integrating foreign genes into mammalian cells. In addition to conventional plasmid transfection, this system is also one of the most commonly used methods to transfer foreign genes into mammalian cells. Because of the flexibility of target gene and promoter selection and the universality of transfection cell types, lentivirus vector system has become a very popular foreign gene expression system.
Lentiviral vector comes from human immunodeficiency virus (HIV) and belongs to retrovirus family. The genome of wild type lentivirus is a linear double positive stranded RNA.
After the construction of lentivirus recombinant vector, it was transfected into packaging cells together with auxiliary plasmid. In packaging cells, DNA fragments between two long terminal repeats (LTRs) will be transcribed into RNA, which will be packaged into virus particles by viral proteins expressed by auxiliary plasmids. The packaged live virus will be released into the supernatant, which can be directly collected or further concentrated to transfect target cells.
When the virus transmits to the target cell, the viral RNA released into the host cell is reverse transcribed into double stranded DNA with the help of reverse transcriptase, and then randomly integrated into the genome of the host cell. In viral vectors, DNA fragments and viral genomes located in the two LTRs will be stably integrated into the genomes of target cells.
Through modification and optimization, our lentivirus vector deleted the genes related to virus packaging and transduction (these genes are expressed by auxiliary plasmids and used in the virus packaging process), so that the lentivirus particles produced are replication defective. That is, packaged viruses only have the ability to transmit to target cells, but cannot replicate in large numbers in target cells, so they have high biological safety.
For more information on lentivirus gene expression vectors, please refer to the following literature.