title: Physicochemical and immunological assessment of engineered pure protein particles with different redox states.
abstract: The development of subunit antigen delivery formulations has become an important research endeavor, especially in cases where a whole cell vaccine approach has significant biosafety issues. Particle-based systems have shown particular efficacy due to their inherent immunogenicity. In some cases, fabrication techniques can lead to changes in the redox states of encapsulated protein antigens. By employing a uniform, well-characterized, single-protein system, it is possible to elucidate how the molecular details of particle-based protein antigens affect their induced immune responses. Using mesoporous silica-templated, amide bond-stabilized ovalbumin particles, three types of particles were fabricated from native, reduced, and oxidized ovalbumin, resulting in particles with different physicochemical properties and immunogenicity. Phagocytosis, transcription factor activation, and cytokine secretion by a mouse macrophage cell line did not reveal significant differences between the three types of particles. Oxidation of the ovalbumin, however, was shown to inhibit the intracellular degradation of the particles compared with native and reduced ovalbumin particles. Slow intracellular degradation of the oxidized particles was correlated with inefficient antigen presentation and insignificant levels of T cell priming and antibody production in vivo. In contrast, particles fabricated from native and reduced ovalbumin were rapidly degraded after internalization by macrophages in vitro and resulted in significant T cell and B cell immune responses in vivo. Taken together, the current study demonstrates how the redox state of a protein antigen significantly impacts the immunogenicity of the particulate vaccine formulations.
authors.affiliation: †ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Katelyn T
authors.initials: KT
authors.lastname: Gause
authors.affiliation: †ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: †ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Cui
authors.affiliation: ‡Melbourne Dental School, Oral Health CRC, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Neil M
authors.initials: NM
authors.lastname: O'Brien-Simpson
authors.affiliation: ‡Melbourne Dental School, Oral Health CRC, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Lenzo
authors.affiliation: ‡Melbourne Dental School, Oral Health CRC, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Reynolds
authors.affiliation: †ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D055598:Chemical Phenomena; D016207:Cytokines / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008958:Models, Molecular; D010047:Ovalbumin / Q000737:chemistry* / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D010084:Oxidation-Reduction; D010587:Phagocytosis; D011487:Protein Conformation; D015202:Protein Engineering; D059748:Proteolysis; D000067996:RAW 264.7 Cells; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D016207:Cytokines; D010047:Ovalbumin
keywords: biodegradation; immunostimulation; macrophage; phagocytosis; subunit antigen; vaccine