Lentivirus is classified as retroviridae. The pre-integration complex of the lentivirus nuclear protein has the characteristics of phagocytosis, and the viral genome translocates to the nucleus, so that it can infect and replicate in the non-mitotic cells. This feature makes it an ideal transfer vector for gene therapy.
Several typical lentivirus are detailed below.
HIV （Human immunodeficiency virus）
EIAV （Equine infectious anemia virus）
EIAV （Equine infectious anemia virus）
SIV （Simian immunodeficiency virus）
Above all, HIV is mostly studied.
Generation of recombinant lentivirus: transient transfection method. It means that packaging plasmids and the vector plasmid transiently transfect cells (such as 293T) to construct high-expressing cell lines and then to produce recombinant lentivirus. This method is very successful, and most of the laboratories use it. Besides, envelope plasmid, packaging plasmid and vector plasmid altogether transfect 293T cells (using calcium phosphate coprecipitation method) to get producing cells. Finally, a large number of lentivirus vectors are obtained by the recombinant lentiviruses secreted and cultured in the medium.
The generation of recombinant lentiviruses through Three Plasmid Expressing System:
The experimental process of the lentivirus packaging is as follows:
1.To obtain the target genes according to the relevant information (sequence, gene sequence number) of the target genes;
2.To choose the corresponding carriers according to customer's requests;
3.Construction of the target genes on the lentivirus vectors to obtain the recombinant vectors with target genes;
4.Sequencing, identification and high-purified (no endotoxin) extraction of recombinant plasmids;
5.293FT cells are transfected by high-purified recombinant vectors and lentivirus plasmid to do virus packaging and collect the supernatant;
6.To Enrich and purify the viruses by ultrafiltration and ultracentrifugation; 7.293T cells are infected with the viruses and screened with drugs and then to construct stable expression cell lines.