Co-delivery of antigens and immunostimulants via a polymersome for improvement of antigen-specific immune response

J Mater Chem B. 2020 Jul 14;8(26):5620-5626. doi: 10.1039/d0tb00892c. Epub 2020 Jun 15.

Abstract

Cellular uptake of antigens (Ags) by antigen-presenting cells (APCs) is vital for effective functioning of the immune system. Intramuscular or subcutaneous administration of vaccine Ags alone is not sufficient to elicit optimal immune responses. Thus, adjuvants are required to induce strong immunogenicity. Here, we developed nanoparticulate adjuvants that assemble into a bilayer spherical polymersome (PSome) to promote the cellular uptake of Ags by APCs. PSomes were synthesized by using a biodegradable and biocompatible block copolymer methoxy-poly(ethylene glycol)-b-poly(d,l-lactide) to encapsulate both hydrophilic and lipophilic biomacromolecules, such as ovalbumin (OVA) as a model Ag and monophosphoryl lipid A (MPLA) as an immunostimulant. After co-encapsulation of OVA and MPLA, the PSome synthetic vehicle exhibited the sustained release of OVA in cell environments and allowed efficient delivery of cargos into APCs. The administration of PSomes loaded with OVA and MPLA induced the production of interleukin-6 and tumor necrosis factor-alpha cytokines by macrophage activation in vitro and elicited effective Ag-specific antibody responses in vivo. These findings indicate that the nano-sized PSome may serve as a potent adjuvant for vaccine delivery systems to modulate enhanced immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen-Antibody Reactions
  • Antigen-Presenting Cells / chemistry*
  • Antigen-Presenting Cells / immunology
  • Female
  • Lipid A / analogs & derivatives*
  • Lipid A / chemistry
  • Lipid A / immunology
  • Mice
  • Mice, Inbred C57BL
  • Molecular Structure
  • Nanoparticles / chemistry*
  • Ovalbumin / chemistry*
  • Ovalbumin / immunology
  • Particle Size
  • Polymers / chemical synthesis
  • Polymers / chemistry*
  • RAW 264.7 Cells
  • Surface Properties

Substances

  • Lipid A
  • Polymers
  • Ovalbumin
  • monophosphoryl lipid A