title: Synthesis and characterization of different immunogenic viral nanoconstructs from rotavirus VP6 inner capsid protein.
abstract: In order to deliver low-cost viral capsomeres from a large amount of soluble viral VP6 protein from human rotavirus, we developed and optimized a biotechnological platform in Escherichia coli. Specifically, three different expression protocols were compared, differing in their genetic constructs, ie, a simple native histidine-tagged VP6 sequence, VP6 fused to thioredoxin, and VP6 obtained with the newly described small ubiquitin-like modifier (SUMO) fusion system. Our results demonstrate that the histidine-tagged protein does not escape the accumulation in the inclusion bodies, and that SUMO is largely superior to the thioredoxin-fusion tag in enhancing the expression and solubility of VP6 protein. Moreover, the VP6 protein produced according to the SUMO fusion tag displays well-known assembly properties, as observed in both transmission electron microscopy and atomic force microscopy images, giving rise to either VP6 trimers, 60 nm spherical virus-like particles, or nanotubes a few microns long. This different quaternary organization of VP6 shows a higher level of immunogenicity for the elongated structures with respect to the spheres or the protein trimers. Therefore, the expression and purification strategy presented here - providing a large amount of the viral capsid protein in the native form with relatively simple, rapid, and economical procedures - opens a new route toward large-scale production of a more efficient antigenic compound to be used as a vaccination tool or as an adjuvant, and also represents a top-quality biomaterial to be further modified for biotechnological purposes.
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bugli
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Caprettini
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Cacaci
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Martini
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Paroni Sterbini
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Torelli
authors.affiliation: Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze della Vita e dell'Ambiente, Università dell'Aquila, L'Aquila, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Della Longa
authors.affiliation: Istituto di Fisica, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Papi
authors.affiliation: Istituto di Fisica, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Palmieri
authors.affiliation: Istituto di Biochimica e Biochimica Clinica, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Giardina
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Brunella
authors.initials: B
authors.lastname: Posteraro
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.affiliation: Istituto di Biochimica e Biochimica Clinica, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Arcovito
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D001688:Biological Products / Q000378:metabolism / Q000627:therapeutic use; D036022:Capsid Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D005260:Female; D024861:Genetic Enhancement / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000737:chemistry / Q000627:therapeutic use*; D015202:Protein Engineering / Q000379:methods*; D012400:Rotavirus Infections / Q000276:immunology* / Q000517:prevention & control*; D016896:Treatment Outcome; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000627:therapeutic use
chemical_list: D000956:Antigens, Viral; D001688:Biological Products; D036022:Capsid Proteins; C061332:VP6 protein, Rotavirus; D014614:Vaccines, Synthetic
keywords: SUMO fusion tag; Virus-like particles; human rotavirus vaccine; protein-based nanotubes