Gammaretrovirus MLV
Lentiviral vectors (LVs) are effective gene delivery vehicles that are being widely used in scientific trials. At present, several gammaretroviral envelope glycoproteins (GPs) have been used to pseudotype LVs and murine leukemia virus (MLV) viral envelope GP is included. Creative Biolabs now offers the state-of-the-art MLV-GP derived pseudotyped LVs construction and production services to meet the demand in basic research and preclinical applications.
Background of Gammaretrovirus MLV
The MLV is among the first retroviruses discovered and is classified as simple Retroviridae due to its minimal encoding capacity. MLV particle is pleomorphic, but roughly spherical, with a diameter of ~100-120 nm. The genome of MLV has been used as the starting material in the development of vectors for gene therapy and it can be divided into coding and noncoding regions and is shown schematically in Figure 1.
Figure 1. Schematic representation of the immature MLV particle and MLV genome. (Rodrigues, 2011)
Prototypical gammaretroviruses encode only the three polyproteins which will be used in the assembly of progeny virus particles. They are the Gag polyprotein, the Pol protein, and the envelope protein. Among them, the MLV envelope protein is glycosylated and then cleaved in the Golgi into two fragments, the N-terminal surface GP (gp70SU) and the C-terminal transmembrane protein p15ECTM.
Figure 2. MLV envelope protein. (Rein, 2011)
Pseudotyping Strategy with Glycoprotein
Variations in the viral envelope GPs, used to pseudotype LVs, can alter vector performance, such as stability, titers, host range, and tissue tropism. MLV targets xenotropic and polytropic retrovirus receptor 1 (XPR1) cell surface receptor which is expressed in a broad range of human tissues including brain, lymph node, liver kidney and testis. Pseudotyping with MLV GP would allow targeting of XPR1-expressing tissues. The modified MLV-GP offers an alternative pseudotyping strategy for XPR1-mediated gene delivery.
Creative Biolabs offers high quality and comprehensive services concerning the generation of LVs pseudotyped with the envelope GP of different MLV clones and with chimeric envelope GP variants derived from MLV and other viruses (such as gibbon ape leukemia virus). Besides, technicists at Creative Biolabs also supply high titer and ultra purity MLV-GP pseudotyped lentivirus vectors production services for our worldwide clients.
Figure 3. Summary of XPR1 expression.
Generating LVs pseudotyped with GPs derived from MLV may modulate the physicochemical properties of the LVs, their interaction with the host immune system, and their host tropism. If you are interested in our MLV-GP optimization services of LV, please feel free to contact us for more information details and the scientists of Creative Biolabs will have a further in-depth discussion on your project.
References
- Rodrigues, A.; et al. (2011). Production of retroviral and lentiviral gene therapy vectors: challenges in the manufacturing of lipid enveloped virus. Viral gene therapy.
- Rein, A. (2011). Murine leukemia viruses: objects and organisms. Advances in virology.
