Poly(anhydride) nanoparticles as adjuvants for mucosal vaccination

Area of Science:

• Immunology
• Nanotechnology
• Biomaterials

Background:

• Conventional nanoparticles have limited targeting ability in the gut for mucosal immunization.
• Low immune responses from conventional nanoparticles necessitate strategies for enhanced vaccine delivery.
• Biomimetic approaches using microbial colonization compounds are explored to improve nanoparticle targeting.

Purpose of the Study:

• To enhance vaccine delivery and mucosal immune responses using ligand-coated polymeric nanoparticles.
• To investigate the efficacy of flagellin and mannosamine coatings on poly(anhydride) nanoparticles for oral immunization.
• To assess the immune tropism and antigen uptake of modified nanoparticles within the gastrointestinal tract.

Main Methods:

• Poly(anhydride) nanoparticles were synthesized and coated with either flagellin or mannosamine.
• Nanoparticles were administered orally to assess their immunomodulatory effects.
• Serum antibody titers (IgG2a and IgG1) were measured to evaluate the immune response.
• The tropism of nanoparticles to specific gut sites, like the ileum and Peyer's patches, was investigated.

Main Results:

• Ligand-coated nanoparticles (flagellin and mannosamine) induced stronger and more balanced IgG2a and IgG1 serum titers compared to control nanoparticles.
• Control nanoparticles elicited a typical Th2 immune response.
• Flagellin- and mannosylated-nanoparticles demonstrated high tropism to the ileum.
• Enhanced uptake by antigen-presenting cells in Peyer's patches was observed for ligand-coated nanoparticles.

Conclusions:

• Coating poly(anhydride) nanoparticles with flagellin or mannosamine significantly enhances oral vaccine-induced immune responses.
• The enhanced Th1 response is likely due to improved targeting and uptake of nanoparticles in the ileum and Peyer's patches.
• This biomimetic strategy offers a promising approach for developing more effective mucosal vaccines.