tetano
Editor, Senior Moderator
J Virol. 2014 Dec 17. pii: JVI.03025-14. [Epub ahead of print]
[h=1]Structural basis for development of avian virus capsids to display influenza virus proteins for induction of protective immunity.[/h] Pascual E[SUP]1[/SUP], Mata CP[SUP]1[/SUP], G?mez-Blanco J[SUP]1[/SUP], Moreno N[SUP]2[/SUP], B?rcena J[SUP]2[/SUP], Blanco E[SUP]2[/SUP], Rodr?guez-Frandsen A[SUP]3[/SUP], Nieto A[SUP]4[/SUP], Carrascosa JL[SUP]5[/SUP], Cast?n JR[SUP]6[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Bioengineering of viruses and virus-like particles (VLP) is a well-established approach in the development of new and improved vaccines to viral and bacterial pathogens. We report here that the capsid of a major avian pathogen, infectious bursal disease virus (IBDV), can accommodate heterologous proteins to induce protective immunity. The structural units of the ∼70-nm-diameter T=13 IBDV capsid are trimers of VP2, which is made as a precursor (pVP2). The pVP2 C-terminal domain has an amphipathic α-helix that controls VP2 polymorphism. In the absence of VP3 scaffolding protein, pVP2 intermediates bearing this α-helix assemble into genuine VLP only when expressed with an N-terminal His tag (protein HT-VP2-466). HT-VP2-466 capsids are optimal for protein insertion, as they are large enough (∼78,000 nm[SUP]3[/SUP] cargo space) and are assembled from a single protein. We explored HT-VP2-466-based chimeric capsids, initially using enhanced green fluorescent protein (EGFP). VLP assembly yield was efficient when we coexpressed EGFP-HT-VP2-466 and HT-VP2-466 from two recombinant baculoviruses. The native EGFP structure (∼240 copies/virion) was successfully inserted in a functional form, as VLP were fluorescent, and three-dimensional cryo-electron microscopy showed EGFP molecules incorporated at the inner capsid surface. Immunization of mice with purified EGFP-VLP particles elicited anti-EGFP antibodies. We also inserted hemagglutinin (HA) and matrix (M2) protein epitopes derived from the mouse-adapted A/PR/8/34 influenza virus and engineered several HA- and M2-derived chimeric capsids. Mice immunized with VLP containing the HA stalk, an M2 fragment, or both antigens developed full protection against viral challenge.
[h=4]IMPORTANCE:[/h] Virus-like particles (VLP) are multimeric protein cages that mimic the infectious virus capsid and are potential candidates for non-living vaccines that induce long-lasting protection. Chimeric VLP can display or include foreign antigens, which could be a conserved epitope to elicit broadly neutralizing antibodies, or several variable epitopes effective against a large number of viral strains. We report the biochemical, structural and immunological characterization of chimeric VLP derived from infectious bursal disease virus (IBDV), an important poultry pathogen. To test the potential of IBDV VLP as a vaccine vehicle, we used the enhanced green fluorescent protein and two fragments derived from hemagglutinin and the M2 matrix protein of the human murine-adapted influenza virus. The IBDV capsid protein fused to influenza virus peptides formed assemblies able to protect mice against viral challenge. Our studies establish the basis for a new generation of multivalent IBDV-based vaccines.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID: 25520499 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25520499
[h=1]Structural basis for development of avian virus capsids to display influenza virus proteins for induction of protective immunity.[/h] Pascual E[SUP]1[/SUP], Mata CP[SUP]1[/SUP], G?mez-Blanco J[SUP]1[/SUP], Moreno N[SUP]2[/SUP], B?rcena J[SUP]2[/SUP], Blanco E[SUP]2[/SUP], Rodr?guez-Frandsen A[SUP]3[/SUP], Nieto A[SUP]4[/SUP], Carrascosa JL[SUP]5[/SUP], Cast?n JR[SUP]6[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Bioengineering of viruses and virus-like particles (VLP) is a well-established approach in the development of new and improved vaccines to viral and bacterial pathogens. We report here that the capsid of a major avian pathogen, infectious bursal disease virus (IBDV), can accommodate heterologous proteins to induce protective immunity. The structural units of the ∼70-nm-diameter T=13 IBDV capsid are trimers of VP2, which is made as a precursor (pVP2). The pVP2 C-terminal domain has an amphipathic α-helix that controls VP2 polymorphism. In the absence of VP3 scaffolding protein, pVP2 intermediates bearing this α-helix assemble into genuine VLP only when expressed with an N-terminal His tag (protein HT-VP2-466). HT-VP2-466 capsids are optimal for protein insertion, as they are large enough (∼78,000 nm[SUP]3[/SUP] cargo space) and are assembled from a single protein. We explored HT-VP2-466-based chimeric capsids, initially using enhanced green fluorescent protein (EGFP). VLP assembly yield was efficient when we coexpressed EGFP-HT-VP2-466 and HT-VP2-466 from two recombinant baculoviruses. The native EGFP structure (∼240 copies/virion) was successfully inserted in a functional form, as VLP were fluorescent, and three-dimensional cryo-electron microscopy showed EGFP molecules incorporated at the inner capsid surface. Immunization of mice with purified EGFP-VLP particles elicited anti-EGFP antibodies. We also inserted hemagglutinin (HA) and matrix (M2) protein epitopes derived from the mouse-adapted A/PR/8/34 influenza virus and engineered several HA- and M2-derived chimeric capsids. Mice immunized with VLP containing the HA stalk, an M2 fragment, or both antigens developed full protection against viral challenge.
[h=4]IMPORTANCE:[/h] Virus-like particles (VLP) are multimeric protein cages that mimic the infectious virus capsid and are potential candidates for non-living vaccines that induce long-lasting protection. Chimeric VLP can display or include foreign antigens, which could be a conserved epitope to elicit broadly neutralizing antibodies, or several variable epitopes effective against a large number of viral strains. We report the biochemical, structural and immunological characterization of chimeric VLP derived from infectious bursal disease virus (IBDV), an important poultry pathogen. To test the potential of IBDV VLP as a vaccine vehicle, we used the enhanced green fluorescent protein and two fragments derived from hemagglutinin and the M2 matrix protein of the human murine-adapted influenza virus. The IBDV capsid protein fused to influenza virus peptides formed assemblies able to protect mice against viral challenge. Our studies establish the basis for a new generation of multivalent IBDV-based vaccines.
Copyright ? 2014, American Society for Microbiology. All Rights Reserved.
PMID: 25520499 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/25520499