Although ultracentrifugation is a method broadly used to purify VLPs, it has the potential to be damaging for fragile particles.
By isolating VLPs it is possible to distinguish integrated prophage genomes from phage genomes that are associated with viral particles.
Serological assays based on virus-like particles (VLPs) make it possible to detect HPV antibodies likely indicative of previous exposure to HPV infection.
A recombinant bacteria-derived protein has the advantage over mammalian cell-culture derived VLPs as it can be produced rapidly, inexpensively, and in higher yield, and likely can be quantified more precisely for diagnostic applications.
This assay provides only a comparative assessment of VLP formation since it only accounts for VLPs that are able to incorporate and passage minigenomes.
Using chemical cross-linkers, any antigen can be placed directionally onto the VLP surface, rendering it highly immunogenic.
In the analysis of the VLP entry we performed, it is worthy of note that the 18-4s VLpseudotypedped with the fusion defective VSV-G or with "null" VLPs did not induce a significant increase of the cell fluorescence compared with the mock challenged cells.
Although virus-derived transient expression systems have been extensively used for the production of pharmaceutical proteins, including VLPs, in plants, it is only recently that this technology has been used to express active enzymes, with a view to manipulate plant metabolism.
However, the Env protein is folded and exposed on the VLP in the same way it is present on native virus.
For this reason it was interesting to see whether removal of most of the N terminal domain, without abolishing VLP formation or leading to an amorphous VLP suspension, would render relatively stable and homogenous VLPs in which epitopes instead of being internalized would become exposed at the outside.
