Chitosan microparticles loaded with yeast-derived PCV2 virus-like particles elicit antigen-specific cellular immune response in mice after oral administration

Abstract

BackgroundPorcine circovirus type 2 (PCV2)-associated diseases are a major problem for the swine industry worldwide. In addition to improved management and husbandry practices, the availability of several anti-PCV2 vaccines provides an efficient immunological option for reducing the impact of these diseases. Most anti-PCV2 vaccines are marketed as injectable formulations. Although these are effective, there are problems associated with the use of injectable products, including laborious and time-consuming procedures, the induction of inflammatory responses at the injection site, and treatment-associated stress to the animals. Oral vaccines represent an improvement in antigen delivery technology; they overcome the problems associated with injection management and facilitate antigen boosting when an animals’ immunity falls outside the protective window.MethodsChitosan microparticles were used as both a vehicle and mucosal adjuvant to deliver yeast-derived PCV2 virus-like particles (VLPs) in an attempt to develop an oral vaccine. The physical characteristics of the microparticles, including size, Zeta potential, and polydispersity, were examined along with the potential to induce PCV2-specific cellular immune responses in mice after oral delivery.ResultsFeeding mice with PCV2 VLP-loaded, positively-charged chitosan microparticles with an average size of 2.5 μm induced the proliferation of PCV2-specific splenic CD4+/CD8+ lymphocytes and the subsequent production of IFN-γ to levels comparable with those induced by an injectable commercial formulation.ConclusionChitosan microparticles appear to be a safe, simple system on which to base PCV2 oral vaccines. Oral chitosan-mediated antigen delivery is a novel strategy that efficiently induces anti-PCV2 cellular responses in a mouse model. Further studies in swine are warranted.

Effect of the ultrastructure of chitosan nanoparticles in colloidal stability, quorum quenching and antibacterial activities

“…The -potential of isolated IC-NPs and CC-NPs was estimated in two different saline environments, namely 1 mM KCl and 85 mM NaCl. The first saline environment, with low ionic strength and neutral pH, is customarily employed by our group [66][67][68][69][70][71] and others [72][73][74] to compare the -potential values of CS-based NPs. The second saline environment, 85 mM NaCl, is the one chosen for the fabrication of IC-NPs and CC-NPs, as described above.…”

Biological Nanoparticles in Vaccine Development

“…Hybrid formulations may provide the controlled release needed to develop effective oral vaccines. Chitosan microparticle vaccines were used to encapsulate VLPs derived from porcine circovirus type 2 (PCV2), which was administered to mice via oral gavage ( Bucarey et al, 2014 ). The immune response of the orally-administered chitosan-encapsulated PCV2-VLPs was compared to a subcutaneously administered, commercially available PCV2 vaccine.…”

Sneaking Out for Happy Hour: Yeast-Based Approaches to Explore and Modulate Immune Response and Immune Evasion

“…Yeast mutant strains carrying higher amounts of chitin increase activation of macrophages and show reduced colonization capacity and virulence [116]. Moreover, chitosan microparticles derived from chitin increase mucosal and systemic immune responses by improving cell permeability and antigen stability [117]. Whereas mammalian proteins rarely have exposed mannose residues, fungi use mannose as their preferred sugar [118].…”