Lentiviral vectors essentials

Lentiviral vectors are gene transfer tools derived from viruses. They are used to deliver specific genes into target cells. All pathogenic and replicative properties of the viruses are removed, preserving only their gene transporting capabilities.

Lentiviral vectors can integrate into dividing or non-dividing cells. The number of copies of a sequence that integrate into the host DNA, can vary but is managed by controlling the dosage of lentiviral vectors applied to the target cells. Integration of the selected genetic material into the host genome is always random and stable.

For first and second generation lentiviral vectors, the site of integration can be unpredictable potentially leading to undesired secondary effects, such as oncogenesis. However, the risk of adverse secondary effects is very low when third generation lentiviral vectors are used.

Lentiviral vectors: the most versatile gene transfer tool

There are several tools available on the market for the transfer of genetic material into host cells. The most commonly used are non-viral methods of transfection, adeno-associated viral vectors (AAV), and lentiviral vectors. Each method has both advantages and disadvantages for specific applications, as shown below:

Examples DNA
transfection
AAV Lentiviral
vectors
Gene transfer into
immortalized cell lines
check-orange check-orange * check-orange
Gene transfer into
primary cells
check-orange ** check-orange * check-orange
Gene transfer into
stem cells
Cross Cross check-orange
Gene transfer in vivo Cross check-orange * check-orange

 

*The use of AAVs for the transfer of genetic material is limited by the length of the sequence of interest and by the pseudotype.
**Cell toxicity which is induced by non-viral methods of transfection can be problematic for the study of gene expression in primary cells.

From transfection to transduction

Advantages and disadvantages for each gene transfer tool depend on their technical characteristics such as expression, genome status, or insertion length.

  Transfection Adenoviral associated vectors Lentiviral vectors
WT Virus No viral sequences Linear single strand DNA Linear single strand RNA
Insert size No limit 4,5 kb 10 kb
Expression Transient
No dose effect
Transient/Stable
No dose effect
Stable
Dose effect
Genome status Episomal Episomal Integrated
Target cells Dividing Dividing and quiescent Dividing and quiescent
Applications Mostly in vitro immortalized cells In vivo In vitro, In vivo Immortalized & primary cells

 

Natural advantages of lentiviral vectors

Compared to other viral vectors, lentiviral vectors feature strong advantages due to the natural effectiveness of lentiviruses. By nature, lentiviruses are the most effective infectious agents, transferring genetic material into their hosts. The natural advantages of lentiviral vectors are:  

  • Gene delivery into dividing and non-dividing cells.
  • Gene delivery for applications, ranging from in-vitro transduction to in-vivo injection
  • Stable expression of the gene of interest thanks to its integration into the host’s DNA and, thus the host’s genome

Additional benefits of lentiviral vectors from Vectalys

No toxicity to target cells:

  • Vectalys’ purification processes prevent target cell toxicity. Transducing your target eukaryotic cells with our purified lentiviral vectors does not affect the viability of the cells, their capacity to proliferate in-vitro, or their ability to progress along a differentiation pathway.

100% transduction efficiency:

  • The high concentration of our lentiviral vector preparations allows for the transduction of all cell types (immortalized, primary, or stem cells). By simply increasing the multiplicity of infection (MOI), or the number of lentiviral vectors applied per cell, it is possible to achieve up to 100% efficient cell transduction.

100% transduction of immortalized cells:

100% transduction of primary & stem cells: