Modular Nanodevices for Creation of Smart Adaptable Vaccine Delivery Vehicles

Tarek M. Fahmy Dept. of Biomedical Engineering, Yale University

Several key variables are needed in the design of effective vaccines (Figure 1). The first variable is the form of the antigen itself. A second necessary component of a vaccine involves potentiating or stimulating the innate and adaptive arms of the immune system to the antigen subunit. Finally, to affect optimal stimulation to a given antigen a formulation is needed that delivers the correct amount of antigen in a repetitive or sustained fashion, to the appropriate immune cells and to the appropriate compartments within those cells.

SUMMARY

We describe a generalizable “smart nanoparticle” vaccine delivery system using a simple, modular approach that can be easily adapted to the requirements of a particular vaccine. Our approach tethers individual DC recognition, Transepithelial and protective elements into the surface of the nanodevice constructed from biocompatible polyester poly (lactic-co-glycolic acid) (PLGA). The core of the device is loaded with antigen or elements facilitating targeted release of antigen into the correct intracellular compartments. In this work the use of biodegradable polymer nanoparticles as a platform for designing vaccines is being systematically and quantitatively explored.

OBJECTIVES

1) Engineering individual nanoparticulate recognition units that effectively target DCs.2) Examination of the uptake of the nanodevice by cultured dendritic cells and determiningthe efficacy of antigen presentation.3) Engineering nanoparticulates to transit through epithelial cell layers.4) Engineering‘smart’ protective coatings facilitating transport through low pH and corrosive environments.

Blank Particles

Dendritic cells were isolated and primed with blank nanospheres (No OVA ), unmodified OVA particles (Untargeted), LPS-modified OVA nanospheres (LPS-OVA), blank nanospheres with soluble OVA (Soluble OVA), or blank nanospheres with soluble OVA and soluble LPS (Soluble OVA +Soluble LPS) and co-cultured with splenocytes from an OT-1 transgenic mouse. IL-2 release was measured by ELISA.

Vaccination against the West Nile Virus E-Protein

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N=10 per groupAnimals injected with live virulent virus on day 0.

In Vivo Vaccination

Enhanced Antigen-Specific Cellular Proliferation with DC targeted nanoparticle vaccines

Proliferation of spleen cells from mice subcutaneously or orally vaccinated with ovalbumin-encapsulating nanospheres.. Isolated spleen cells were challenged with different doses of ovalbumin antigen in a plate. Nanospheres modified with LPS encapsulating OVA , nanospheres encapsulating OVA with no external modification (Untargeted ), blank particles with no OVA and no surface modification (No OVA). Mice (N=3)

SUBCUTANEOUSVACCINATION

ORALVACCINATION

LPS-OVA

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No OVA

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OVA Release

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Particle size was analyzed using SEM images and were found to be an average of 100-200 nm. Ovalbumin (OVA) was encapsulated as the model antigen and a release profile (insert) was deduced using a protein assay.

Targeting Dendritic Cells

LPS/Particles

Lipopolysaccharide modified nanoarpticles encapsulating a dye are preferentially internalized by dendritic cells

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In Vitro Vaccination

Effective Antigen-Specific T cell Proliferation in vitro with DC targeted nanoparticles

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No OVASoluble OVA+Soluble LPS

Work supported by NSF-NIRT Award: 0609326