antigenic-liposomes-for-generation-of-disease-specific-antibodies

Antigenic Liposomes for Generation of Disease-specific Antibodies

Antibody responses provide critical protective immunity to a wide array of pathogens. There remains a high interest in generating robust antibodies for ...

University of Alberta

This work investigates the formulation and in vivo efficacy of dendritic cell (DC) targeted plasmid DNA loaded biotinylated chitosan nanoparticles for nasal immunization against nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) as antigen. The induction of antigen-specific mucosal and systemic immune response at the site of virus entry is a major challenge for vaccine design. Here, we designed a strategy for noninvasive receptor mediated gene delivery to nasal resident DCs. The pDNA loaded biotinylated chitosan nanoparticles were prepared using a complex coacervation process and characterized for size, shape, surface charge, plasmid DNA loading and protection against nuclease digestion. The pDNA loaded biotinylated chitosan nanoparticles were targeted with bifunctional fusion protein (bfFp) vector for achieving DC selective targeting. The bfFp is a recombinant fusion protein consisting of truncated core-streptavidin fused with anti-DEC-205 single chain antibody (scFv). The core-streptavidin arm of fusion protein binds with biotinylated nanoparticles, while anti-DEC-205 scFv imparts targeting specificity to DC DEC-205 receptor. We demonstrate that intranasal administration of bfFp targeted formulations along with anti-CD40 DC maturation stimuli enhanced magnitude of mucosal IgA as well as systemic IgG against N protein. The strategy led to the detection of augmented levels of N protein specific systemic IgG and nasal IgA antibodies. However, following intranasal delivery of naked pDNA no mucosal and systemic immune responses were detected. A parallel comparison of targeted formulations using intramuscular and intranasal routes showed that the intramuscular route is superior for induction of systemic IgG responses compared with the intranasal route. Our results suggest that targeted pDNA delivery through a noninvasive intranasal route can be a strategy for designing low-dose vaccines.

Dendritic cell targeted chitosan nanoparticles for nasal DNA immunization against SARS CoV nucleocapsid protein.

In this study, we demonstrate a simple strategy for enhanced immune response using a two-component dendritic cell (DC) targeted antigen delivery system. One component consists of a recombinant bifunctional fusion protein (bfFp) used for DC targeting, whereas, the other component is made of biotinylated PLGA nanoparticles that encapsulate the antigen. The fusion protein (bfFp) made of a truncated core-streptavidin fused to anti-DEC-205 single chain antibody (scFv) was mixed with ovalbumin-loaded biotinylated NPs that were formulated using biotin-PEG (2000)-PLGA, and the combination, bfFp functionalized NPs was used for DC targeted antigen delivery. In vitro DC uptake studies revealed a 2-fold higher receptor-mediated uptake of bfFp functionalized NPs when compared to non-targeted NPs. Immunization of the mice with the bfFp functionalized NPs in conjunction with DC maturation stimulus (anti-CD40 mAb) enhanced OVA-specific IgG and IgG subclass responses. Splenocytes of these mice secreted significantly higher levels of Th1 (IFN-γ and IL-2) cytokines upon ex vivo restimulation with OVA. The promising outcomes of the bfFp functionalized DC targeted system support its use as a versatile vaccine delivery system for the design of monovalent or polyvalent vaccines.

Dharmendra Raghuwanshi

Department of Chemistry

University of Alberta

Antigenic Liposomes for Generation of Disease-specific Antibodies

Dharmendra Raghuwanshi

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University of Alberta

Antigenic Liposomes for Generation of Disease-specific Antibodies

Department of Chemistry