Synapsin-Cre-GFP Lentivirus

Commonly used viral vectors include adenovirus, retrovirus and lentivirus. Retrovirus vectors can only infect dividing cells and have limited capacity. Adenovirus generally cannot integrate into chromosomes and can only perform transient infection. Compared with other retroviruses, lentivirus (LV) has significant advantages such as being able to infect non-dividing cells, accommodating large exogenous gene fragments, and being able to express for a long time. Lentivirus does not produce any effective cellular immune response and can be used as a tool for in vitro gene delivery. Lentivirus vector-mediated transgenic expression can last for several months without observable pathological phenomena.

Lentivirus packaging systems generally consist of lentivirus expression vectors and lentivirus packaging vectors. The lentivirus packaging plasmid can provide all the auxiliary proteins required for transcription and packaging of RNA into recombinant pseudovirus vectors. In order to produce high-titer virus particles, it is necessary to co-transfect cells with expression vectors and packaging plasmids. The virus is packaged in the cell, and the packaged pseudovirus particles are secreted into the extracellular culture medium. After centrifugation to obtain the supernatant, it can be directly used for host cell infection. Lentivirus packaging systems are generally three-plasmid or four-plasmid packaging systems. Among them, the four-plasmid system is better in biosafety than the three-plasmid system, so it is more widely used.