Retroviruses and Lentiviruses Service
Creative BioMart Vir-Sci accumulate years of experience in producing high quality retrovirus and lentivirus particles for scientists in both academia and industry. By using highly standardized and efficient methods, we permit smart design of viral transfer vector as well as rapid production of high-titer viruses.
Retroviral and Lentiviral Packaging System
Currently, lentivirus and retrovirus transfection are among the most efficient methods of gene delivery for both in vitro and in vivo applications. Specific DNA was produced via viral reverse transcriptase before integrating into the genome of host cells. In terms of its safe use, the biggest concern is the risk of generating replication-competent virus through integrating events between structural elements in the viral vector and the packaging cell line. To minimize these concerns, viral accessory genes are removed and essential genes are instead provided in trans by the packaging and envelope plasmids. Typically, the following components were co-transfected into the packaging cell line in order to generate viral particles:
- Transfer plasmid encoding genes of interest. The transgene sequence is inserted between the long terminal repeat (LTR) sequences, which will be integrated into the host genome upon viral transduction.
- Packaging plasmid encoding viral Gag-Pol. Gag is a structural precursor protein for orchestrating viral assembly, and Pol is a reverse transcriptase responsible for transcribing viral RNA into double-stranded DNA.
- Envelope plasmid determining the infectivity or range of cells a virus can infect.
Differences Between Retrovirus and Lentivirus
- Common retroviruses are derived from Moloney murine leukemia virus or murine stem cell virus, while lentiviruses are based on the HIV-1 virus.
- Lentiviruses can infect both non-dividing and actively dividing cells whereas retroviruses are only capable of infecting dividing cell types.
Features of Retrovirus and Lentivirus
- Stable integration. Unlike traditional transfection which typically leads to transient delivery into host cells due to the loss of DNA over time, retrovirus and lentivirus transduction are able to permanently deliver genes into host cells due to the integration of the viral elements into the host genome.
- High viral titer. With highly optimized protocol, lentiviral and retroviral vectors can be packaged into high-purity viral particles (greater than 109 infectious unit per ml), thus allowing high transduction efficiency in mammalian cells as well as live animals.
- Broad tropism. VSV-G pseudotyped envelop protein enables broad tropism to infect many primary and hard-to-transfect cells.
- Large packaging capacity up to 9 kb, allowing insertion of multiple transgenes into a single transfer vector.
Figure 1. Simplified schematic illustration of general retroviral and lentiviral packaging system.
Retrovirus and Lentivirus Service Advantages
- Custom design and construction of retroviral and lentiviral vectors
- High titer levels and flexible production scales
- Highly optimized protocols with high packaging efficiency
- Short turnaround time to accelerate your research
- Strict QC testing to determine titer
- Ready for transduction upon delivery
- Competitive price in the market
- Expert technical support
Workflow of Retrovirus and Lentivirus Preparation
The retroviruses and lentiviruses service provided by Creative BioMart Vir-Sci ensures ready-to-transduce and high-titer virus particles at flexible production scales. Ship your own viral construct or simply tell us your need, and we’ll handle vector construction as well. Please feel free to contact us for more service information.
References
- Naldini, L.; et al. In vivo gene delivery and stable transduction of nondividing cells by a lentiviral vector. Science. 1996, 272(5259): 263-267.
- Desfarges, S.; Ciuffi, A. Retroviral integration site selection. Viruses. 2010, 2(1): 111-130.