Virus-like particle

Mineral Salts Immunostimulatory adjuvants Lipid particles Particulate adjuvants Mucosal adjuvants Aluminium hydroxide, aluminium phosphate, calcium phosphate Saponins (e.g., QS21), MDP derivatives, bacterial DNA (CpG oligos), LPS, MPL and synthetic derivatives, lipopeptides, cytokines (e.g., GM-CSF, IL-2, IL-12) Liposomes, virosomes, iscoms, cochleates, emulsions (e.g., Freunds adjuvant, SAF, MF59 ) Poloxamer particles, virus-like particles, PLG microparticles Cholera toxin (CT), mutant toxin (e.g., LTK63, LTR72), heat labile enterotoxin (LT), microparticles, polymerized liposomes, chitosan... 

Bertolotti-Ciarlet, A., White, L. J., Chen, R., Prasad, B. V., and Estes, M. K. (2002). Structural requirements for the assembly of Norwalk virus-like particles. /. Virol. 76, 4044- 1055. 

Fig. 5.21 Cryoelectron micrograph of a single virus-like particle showing the well-defined protein coating of the 12 nm diameter Au nanoparticle (black disk). (Reprinted with permission from [98]. Copyright (2006) American Chemical Society).

Blessing, T., Remy, J.S., and Behr, J.P., Monomolecular collapse of plasmid DNA into stable virus-like particles, Proceedings of the National Academy of Sciences, United States of America, 1998, 95, 1427-1431. 

ErbacherP, Remy JS, Behr JP (1999) Gene transfer with synthetic virus-like particles via the integrin-mediated endocytosis pathway. Gene Ther 6 138-145... 

Viruses, like all pathogens, show host specificity, usually infecting only one or a restricted range of host species. The initial basis of specificity is the ability of the virus particle to attach to the host cell. If the amount of infectious virus is measured over a period of time in the host, it is seen to fall, after an initial lag period, remain low for a period of time, and then rise to even higher levels. The period during which the amount of virus is low is referred to as the eclipse period. The virus infection cycle can be divided into several events. 

Storni T, Ruedl C, Schwarz K, Schwendener RA, Renner WA, Bachmann ME. Nonmethylated CG motifs packaged into virus-like particles induce protective cytotoxic T cell responses in the absence of systemic side effects. J Immunol 2004 172(3) 1777-1785. 

Molecular Recognition of Ligands by Native Viruses and Virus-Like Particles as Studied by NMR Experiments... 

Hewat, E. A., Booth, T. F. and Roy, R (1994). Structure of correctly self-assembled bluetongue virus-like particles. /. Struct. Biol. 112,183-191. 

Production of Core and Virus-Like Particles with Baculovirus Infected Insect Cells... 

In this paper the fundamental aspects of process development for the production of core and virus-like particles with baculovirus infected insect cells are reviewed. The issues addressed include particle formation and monomer composition, chemical and physical conditions for optimal cell growth, baculovirus replication and product expression, multiplicity of infection strategy, and scale-up of the process. Study of the differences in the metabolic requirements of infected and non-infected cells is necessary for high cell density processes. In the bioreactor, the specific oxygen uptake rate (OURsp) plays a central role in process scale-up, leading to the specification of the bioreactor operational parameters. Shear stress can also be an important variable for bioreactor operation due to its influence on cell growth and product expression. 

Keywords. Virus-like particles, Baculovirus, Insect cells. Process development. Mathematical models... 

Viral structural proteins expressed by baculovirus infected insect cells assemble into multimeric structures that resemble viral core-like particles and virus-like particles (CLPs and VLPs, respectively). This presentation has brought the attention of researchers for the potential use of these structures as safe immunological reagents for virus or antibody detection in enzyme immuno assays, as vaccines, and more recently, as gene delivering systems for gene therapy [9]. 

Taking into account process integration, i.e. - cultivation and product purification, particle locaHsation is an important issue. Strategies to produce a secreted particle, either by manipulation of its composition or by co-expression of NS protein(s) will be also discussed, since this can lead to an easier purification process and to a decrease in product losses due to intracellular proteolysis. The production of Rotavirus-Hke particles and Bluetongue virus-like particles production will be used as examples to illustrate this point. 

The application of mathematical modelling to baculovirus infection and virus-like particle production was also successfully done to Parvovirus B19 viruslike particle production with two different baculovirus at low MOTs [18]. But in this model the same concepts proposed in the Licari and Bailey Model was applied, i. e. baculovirus infection follows Poisson distribution with mean and variance equal to a.MOI, but with co-infection with two single-vectors, each one encoding a specific viral protein. 

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