Disassembly and reassembly of yeast‐derived recombinant human papillomavirus virus‐like particles (HPV VLPs)

Characterization of virus-like particles in GARDASIL® by cryo transmission electron microscopy

“…[25][26][27] Purification of the recombinant VLPs, and the disassembly/ reassembly process was previously described. 28,29 The protein concentration was determined with the Pierce bicinchoninic acid (BCA) protein assay method, and then verified with UV absorbance at 280 nm.…”

Replication and Assembly of Human Papillomaviruses

“…In fact, overnight incubation of PsV allows for the formation of additional disulfide bonds in a redox-dependent and cellular lysate-dependent fashion (Buck et al, 2005). Similarly, stabilization of VLPs has been reported through the removal of reducing agents, lowering of pH, and increasing of ionic strength (Mach et al, 2006). These experiments suggest that differences in the redox states of monolayer vs. organotypic culture may play a role in the structural discrepancies noted between immature synthetic papillomavirus particles and native virions.…”

“…Novel findings into the cross-neutralization potential of the N-terminal peptide of L2 highlight the potential utility of L1/L2 chimeric VLPs in eliciting an optimized immune response (Gambhira et al, 2007;Kondo et al, 2007). Advancements in VLP technology have also increased the disulfide-bonding-mediated stabilization of VLPs via the manipulation of buffers, by removing reducing agents, lowering pH, and increasing ionic strength (Mach et al, 2006). Most novel VLP production techniques seek to produce VLPs which appear more like native virions.…”

“…E1 and E2 proteins have been shown to regulate viral replication as well as the coordinated expression of the other early viral genes (Cripe et al, 1987;Gloss and Bernard, 1990;Mohr et al, 1990;Meyers et al, 1992;Conger et al, 1999). The spliced E1^E4 protein may affect the replication of viral genomes through the inhibition of the G2-to-M transition, while also interacting with cellular keratin networks, causing their collapse, thus allowing mature virions to escape from the cornified envelope (White et al, 1999;Bryan and Brown, 2000;Brown et al, 2006;Knight et al, 2006;Mach et al, 2006;Gambhira et al, 2007). E5, E6, and E7 proteins that are coded by the high-risk HPVs are oncogenic, since they are able to transform and stimulate the growth of cells (Androphy et al, 1987;Phelps et al, 1988;Bedell et al, 1991).…”

“…It is unknown if encapsidation of the viral genome takes place during capsid assembly or after; however, encapsidation is assisted by L2 and may be facilitated by E2 proteins (Heino et al, 2000;Gu et al, 2004;Holmgren et al, 2005). In the cornified envelope, E1^E4 proteins are thought to interact with cellular keratin networks, causing their collapse, thus allowing mature virions to escape from the cornified cells (Doorbar et al, 1986;Bryan and Brown, 2000;Brown et al, 2006;Mach et al, 2006;Gambhira et al, 2007). Mechanistic details concerning the host cell differentiation program that leads to the productive phase of the HPV life cycle are unclear.…”