Co-delivery of allergen epitope fragments and R848 inhibits food allergy by inducing tolerogenic dendritic cells and regulatory T cells

Abstract

Background

Food allergy (FA) is a significant public health problem. The therapeutic efficacy for FA is unsatisfactory currently. The breakdown of intestinal immune tolerance is associated with the pathogenesis of FA. Therefore, it is of great significance to develop novel therapeutic methods to restore immune tolerance in treating FA.

Methods

We proposed an oral administration strategy to treat FA by co-delivering food allergen epitope fragment (peptide: IK) and adjuvant R848 (TLR7 ligand) in the mPEG–PDLLA nanoparticles (PPLA-IK/R848 NPs). The generation of tolerogenic dendritic cells (DCs) and regulatory T cells (Tregs) induced by PPLA-IK/R848 NPs were evaluated in vitro and in vivo. The therapeutic effects of PPLA-IK/R848 NPs were also assessed in an OVA-induced FA model.

Results

PPLA-IK/R848 NPs could efficiently deliver IK to DCs to drive DCs into the tolerogenic phenotypes and promote the differentiation of Tregs in vitro and in vivo, significantly inhibited FA responses through the recovery of intestinal immune tolerance.

Conclusion

Oral administration of PPLA-IK/R848 NPs could efficiently deliver IK and R848 to intestinal DCs and stimulate DCs into allergen tolerogenic phenotype. These tolerogenic DCs could promote the differentiation of Tregs, which significantly protected mice from food allergic responses. This study provided an efficient formulation to alleviate FA through the recovery of immune tolerance.

Keywords:

• food allergy
• co-delivery
• allergen epitope fragment
• R848
• dendritic cells
• Tregs

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (No. 81460252, No.31570932); Basic Research Project of Science and Technology Program of Shenzhen (No.JCYJ20160429171931438, No.JCYJ20180306171552582) and China Postdoctoral Science Foundation (2017M622662).

Author contributions

All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.