Lentiviral Vector System
Lentiviral expression vectors are one of the most effective vehicles to introduce and stably express different effector molecules (shRNA, sgRNA, cDNA, DNA fragments, antisense, ribozymes, etc.) or reporter constructs in almost any mammalian cell, including non dividing cells and whole model organisms. Lentiviral expression constructs packaged into pseudoviral particles can be transduced into cells with very high efficiency, approaching 100% in some cell types. Packaged lentiviral constructs can be transduced into even the most difficult to transfect cells, such as primary, stem, and differentiated cells with high efficiency.
A transduced lentiviral expression construct is integrated into cellular genomic DNA and provides stable, long-term expression of shRNA, sgRNA, cDNA or reporter gene. Endogenously expressed shRNA, sgRNA, or effectors provide long-term silencing or permanent knock-out of the target gene and allow the researcher to generate cell lines and transgenic organisms with a stable knockdown phenotype for functional studies. Expression of full-length cDNAs from integrated viral constructs is a unique tool to study gain-of-function effect for cellular phenotypes. As such, lentiviral vectors are an ideal delivery system for Cellecta’s pooled shRNA and sgRNA libraries.
Custom lentiviral constructs Cellecta offers to simplify your research include:
- Targeted CRISPR Gene Knockout Constructs
- shRNA Knockdown Constructs
- Custom cDNA Expression Constructs
- Custom Reporter Constructs
A lentiviral expression vector contains the genetic elements required for packaging, transduction, stable integration of the viral expression construct into genomic DNA, and expression of the shRNA, sgRNA, cDNA, or reporter. For production of high titer pseudoviral particles, producer cells (e.g., HEK 293 cells) need to be transiently co-transfected with both the expression construct and packaging plasmids. Lentiviral packaging plasmids provide all of the proteins essential for transcription and packaging of an RNA copy of the expression construct into recombinant pseudoviral particles.
Following transfection, the expression vector produces large numbers of the expression construct transcript that contains all of the functional elements (i.e., Psi, RRE, and cPPT) required for efficient packaging. The expression construct transcript is efficiently packaged into vesicular stomatitis virus (VSV-G) pseudotyped viral particles with helper proteins produced by the packaging plasmid. Expression constructs packaged in pseudoviral particles are secreted by producer cells in culture media and can be used directly to transduce expression constructs into target cells. The VSV-G pseudotyped viral particles efficiently mediate viral entry through lipid binding and plasma membrane fusion and can infect both mammalian and non-mammalian target cells.
Pseudotyped lentiviruses have been successfully used to infect many other cell types, including neuronal, dendritic, endothelial, retinal, pancreatic, hepatic, aortic smooth muscle cells, airway epithelia, skin fibroblasts, macrophages, etc. Lentivectors have been successfully used also for direct in vivo delivery and expression of transgenes in muscle, brain, airway epithelium, liver, pancreas, retina, and skin.
For information on the safety of our lentiviruses, please refer to the resources below.