Pseudovirus
Cultivation of live pathogenic viruses can be dangerous, and gaining access to these virus strains is often a complex and time-consuming process, demanding Bio Safety Level 3 (BSL-3) laboratories.
A potential alternative to live viruses are Pseudo-typed Virus Particles (PV). PVs are viruses that contain the core structure and protein load of a surrogate virus, typically Human Immunodeficiency Virus (HIV), while expressing the envelope proteins of a different virus or virus variant.
Generally, PVs are produced by co-transfection of separate plasmids that express the viral backbone components and the envelope protein(s) of interest. Therefore, PVs can infect tropism-matched target cells but lack the genetic information required for de novo replication, making them a safer alternative to replication competent virus.
The incorporation of a reporter gene construct into the PV, such as luciferase or fluorescent protein, enables straightforward and fast quantitation of PV infection.
Takis pseudovirus service allows to assess antibodies’ neutralizing activity against a pseudovirus, thus enabling the in vitro study of the virus you are interested in. This service is ideal for:
- Screening animal serum or patient serum for neutralizing antibodies
- Validating inhibitors of the viral envelope protein-target cell receptor interaction
- Vaccine development
Example: Neutralization assay based on MERS Spike pseudo-typed lentivirus in DPP4-expressing HEK293T Cells
Fig. To produce MERS Spike pseudo-typed lentiviral particles, HEK-293T cells were co-transfected with pCMVR8.74, MERS WT-Spike pCAGGS and pLenti CMV Puro LUC plasmids. After transfection, pseudovirus-containing supernatant was collected and stored. For neutralization assay, HEK-293T-hDPP4 cells were harvested in a 96-well plate and transduced with MERS pseudovirus previously incubated with serial dilution of serum in order to obtain a dose-response curve. Cell transduction was measured by luciferase assay and neutralizing dose 50 (ND50) was calculated.