Acidity-responsive polyphenol-coordinated nanovaccines for improving tumor immunotherapy via bidirectional reshaping of the immunosuppressive microenvironment and controllable release of antigens

Biomater Sci. 2024 Jun 11;12(12):3175-3192. doi: 10.1039/d4bm00490f.

Abstract

The tumor immunosuppressive microenvironment (TIME) and uncontrollable release of antigens can lower the efficacy of nanovaccine-based immunotherapy (NBI). Therefore, it is necessary to develop a new strategy for TIME reshaping and controllable release of antigens to improve the NBI efficacy. Herein, an acidity-responsive Schiff base-conjugated polyphenol-coordinated nanovaccine was constructed for the first time to realize bidirectional TIME reshaping and controllable release of antigens for activating T cells. In particular, an acidity-responsive tannic acid-ovalbumin (TA-OVA) nanoconjugate was prepared via a Schiff base reaction. FeIII was coordinated with TA-OVA to produce a FeIII-TA-OVA nanosystem, and 1-methyltryptophan (1-MT) as an indoleamine 2,3-dioxygenase inhibitor was loaded to form a polyphenol-coordinated nanovaccine. The coordination between FeIII and TA could cause photothermal ablation of primary tumors, and the acidity-triggered Schiff base dissociation of TA-OVA could controllably release OVA to realize lysosome escape, initiating the body's immune response. More importantly, oxidative stress generated by a tumor-specific Fenton reaction of Fe ions could promote the polarization of tumor-associated macrophages from the M2 to M1 phenotype, resulting in the upregulation of cytotoxic T cells and helper T cells. Meanwhile, 1-MT could downregulate immunosuppressive regulatory T cells. Overall, such skillful combination of bidirectional TIME reshaping and controllable antigen release into one coordination nanosystem could effectively enhance the NBI efficacy of tumors.

MeSH terms

  • Animals
  • Cancer Vaccines / administration & dosage
  • Cancer Vaccines / chemistry
  • Cancer Vaccines / immunology
  • Cell Line, Tumor
  • Ferric Compounds / chemistry
  • Hydrogen-Ion Concentration
  • Immunotherapy*
  • Mice
  • Mice, Inbred C57BL
  • Nanoconjugates / chemistry
  • Nanoparticles / chemistry
  • Nanovaccines
  • Ovalbumin* / administration & dosage
  • Ovalbumin* / chemistry
  • Ovalbumin* / immunology
  • Polyphenols* / chemistry
  • Polyphenols* / pharmacology
  • Schiff Bases* / chemistry
  • Tannins* / chemistry
  • Tannins* / pharmacology
  • Tryptophan / analogs & derivatives
  • Tryptophan / chemistry
  • Tumor Microenvironment* / drug effects

Substances

  • Ovalbumin
  • Polyphenols
  • Tannins
  • Schiff Bases
  • 1-methyltryptophan
  • Cancer Vaccines
  • Tryptophan
  • Nanoconjugates
  • Ferric Compounds
  • Nanovaccines