P — Pseudotypes
Retroviral pseudotypes are widely used in virology research as tools for studying entry, host range, neutralizing antibodies, and antiviral drugs for enveloped viral pathogens that have a high consequence of infection, such as HIV or hepatitis C virus. A retroviral pseudotype is a recombinant viral particle in which the core and genome of one virus, typically a retrovirus, are packaged inside an envelope (membrane) possessing glycoproteins from another virus. Common systems use cores derived from Human immunodeficiency virus 1 or Murine leukemia virus combined with envelope proteins from viruses such as Ebola virus, Lassa virus, or SARS-CoV-2.
The production of retroviral pseudotypes typically involves co-transfection of producer cells with plasmids encoding (1) the retroviral gag and pol genes, which produce structural proteins and enzymes required for particle assembly and reverse transcription; (2) a reporter genome, such as luciferase or green fluorescent protein (GFP), flanked by retroviral long terminal repeats so it can be packaged into viral particles; (3) a plasmid encoding the envelope glycoprotein of the virus being studied. After transfection, the cells assemble viral particles containing the retroviral core and reporter genome, but displaying the heterologous viral envelope protein on their surface. These pseudotyped particles are released into the culture supernatant and can be collected and used to infect target cells.
The main use of retroviral pseudotypes is to study viral entry mechanisms without handling highly pathogenic viruses, allowing work to be performed in lower biosafety level laboratories. They are widely used in neutralization assays to measure antibody responses to viral glycoproteins, particularly in vaccine research. Pseudotypes are also used to study receptor usage, viral tropism, and the effects of mutations in viral envelope proteins. Additionally, they are useful for screening antiviral drugs that block viral entry.
Pseudotyping is an essential molecular virology technique that enables safe investigation of highly pathogenic viruses.
Retroviral pseudotypes are widely used in virology research as tools for studying entry, host range, neutralizing antibodies, and antiviral drugs for enveloped viral pathogens that have a high consequence of infection, such as HIV or hepatitis C virus. A retroviral pseudotype is a recombinant viral particle in which the core and genome of one virus, typically a retrovirus, are packaged inside an envelope (membrane) possessing glycoproteins from another virus. Common systems use cores derived from Human immunodeficiency virus 1 or Murine leukemia virus combined with envelope proteins from viruses such as Ebola virus, Lassa virus, or SARS-CoV-2.
The production of retroviral pseudotypes typically involves co-transfection of producer cells with plasmids encoding (1) the retroviral gag and pol genes, which produce structural proteins and enzymes required for particle assembly and reverse transcription; (2) a reporter genome, such as luciferase or green fluorescent protein (GFP), flanked by retroviral long terminal repeats so it can be packaged into viral particles; (3) a plasmid encoding the envelope glycoprotein of the virus being studied. After transfection, the cells assemble viral particles containing the retroviral core and reporter genome, but displaying the heterologous viral envelope protein on their surface. These pseudotyped particles are released into the culture supernatant and can be collected and used to infect target cells.
The main use of retroviral pseudotypes is to study viral entry mechanisms without handling highly pathogenic viruses, allowing work to be performed in lower biosafety level laboratories. They are widely used in neutralization assays to measure antibody responses to viral glycoproteins, particularly in vaccine research. Pseudotypes are also used to study receptor usage, viral tropism, and the effects of mutations in viral envelope proteins. Additionally, they are useful for screening antiviral drugs that block viral entry.
Pseudotyping is an essential molecular virology technique that enables safe investigation of highly pathogenic viruses.