CAG-Cre Lentivirus

Over the past few decades, defective HIV-1-dependent lentiviruses have become one of the most widely used gene transfer vectors. Lentiviruses are enveloped viruses with a diploid positive-strand RNA genome. Once infected with a host cell, the virus uses reverse transcriptase to transcribe its RNA into double-stranded DNA, which is then permanently integrated into the host cell chromosome. The modified lentivirus has all viral structural genes removed, leaving only the LTR sequence and packaging signal for the introduction of therapeutic genes, and still has the ability to infect cells. However, the viral genes required to produce new viral particles are no longer present. To improve viral safety, the 3’LTR of the transfer vector is also missing to ensure that the virus remains "self-inactivated" (SIN) after integration. The most advantageous feature of recombinant lentiviruses is that they can effectively regulate the transduction, integration, and long-term expression of genetic material in dividing and non-dividing cells. The pilot integration complex (PIC) allows the lentivirus to cross the nuclear membrane through the nuclear pore complex (NPC), enhancing the ability of the lentivirus to infect non-dividing cells. Most other retroviruses need to reach the host's nuclear chromatin when the nuclear pores break during mitosis. Since most cell types are considered quiescent in vivo, recombinant lentiviruses are the vector of choice for many in vivo applications. Furthermore, unlike adenoviruses, lentiviruses are not immunogenic in vivo.