Pseudoviral Particle (VLP) Production

What are viral pseudotyped particles (or pseudoviral particles, or pseudovirus, "PP", viral like particles "VLP") ?
“Viral pseudotyped particles are enveloped virus particles that harbor heterologous envelope glycoproteins on their surface and a genome lacking essential gene. ...They have proven to be very useful tools used in research with many applications, such as enabling the study of entry pathways of enveloped viruses … ” [Jean Kaoru Millet, etc. Bio Protoc. 2016 Dec 5;6(23): e2035]

    Figure 1. Outline of the production of the MLV-based spike-pseudotyped particles.

    (Reference:  Construction and applications of SARS-CoV-2 pseudoviruses: a mini review, Int J Biol Sci. 2021 Apr 10;17(6):1574-1580)

We have generated replication-deficient MLV-based Coronavirus Spike-pseudotyped particles for critically important SARS-CoV-2 spike variants. MLV or MuLV (murine leukemia virus) -based virus system is a better choice than HIV-based lentivirus system for making pseudoviral particles in regards of lab safety and product quality. Gag-Pol is the only component from MLV.


Figure 2. . Illustration of the replication-deficient MLV particle pseudotyped with SARS-CoV-2 Spike protein.

Figure 3. EM views of our MLV-based spike-pseudotyped particles.  

If you need a SARS-CoV-2 spike pseudovirus for a variant that is not a current catelog item, we can custom make it. The turn around time is typically 3 weeks. Please inquire:

With our SARS-CoV-2 (or SARS-1 or MERS) spike PP items and stable cell lines (i.e. HEK293-ACE2, vero, CHO), researchers could do a lot:

      1) study the interactions between Spike and the host cell receptor(s) in specific conditions;
      2) validate the candidates that blocks the interaction between Spike and the host cell receptor(s);
      3) screen convalescent serum samples for neutralizing antibodies, etc.

Selected citations of our MLV-based SARS-CoV-2 spike-pseudotype particles:
1.  Immunogenicity and Neutralizing Activity Comparison of SARS-CoV-2 Spike Full-Length and Subunit Domain Proteins in Young Adult and Old-Aged Mice. Vaccines (Basel). 2021 Apr; 9(4): 316
2. A novel linker-immunodominant site (LIS) vaccine targeting the SARS-CoV-2 spike protein protects against severe COVID-19 in Syrian hamsters. Emerg Microbes Infect. 2021; 10(1): 874–884
3. Serum Antibody Profile of a Patient With Coronavirus Disease 2019 Reinfection. Clinical Infectious Diseases, 2021, 72(10), e659–e662
4. Metallodrug ranitidine bismuth citrate suppresses SARS-CoV-2 replication and relieves virus-associated pneumonia in Syrian hamsters. Nat. Microbiol. 5, 1439–1448 (2020)

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