What is a pseudovirus (PSV)?

Papillomavirus-based gene transfer vectors, also known as pseudoviruses (PsV), have become standard tools for studying papillomavirus assembly, cellular entry and neutralization and may have future utility as laboratory gene transfer tools or vaccine vehicles. This protocol outlines methods for PsV production.

Are pseudoviruses safe to handle?

Although these viruses are much safer to handle than the virus from which they originated, the conformational structure of the surface proteins of pseudoviruses closely resembles that of the native virus. Such similarities in the surface protein structure allow pseudoviruses to remain effective in their ability to enter cells.

How do pseudoviruses replicate?

Genes inside pseudoviruses are usually altered or modified to abolish native surface protein expression. An additional plasmid is then used to express alternative surface proteins, producing a pseudovirus that can infect susceptible host cells but can only replicate intracellularly for a single round10, 11.

Why can’t pseudoviruses produce viral surface proteins on their own?

The modified genetic material of pseudoviruses prevents these particles from producing viral surface proteins on their own unless an additional plasmid or stable cell line that expresses such proteins are made available to the pseudovirus.