Tolerance induction to peach using glycosylated nanostructures including Pru p 3-Epitope

RATIONALE: Food-specific immunotherapy is a promising treatment for LTP-syndrome. Immunotherapy using T-cell peptides from Pru p 3 together with CpG, as an adjuvant, have shown to induce protection from anaphylaxis in a murine model of peach allergy, which persists after ending treatment. Functionalization with multivalent mannose ligands can enhance dendritic cell (DC) targeting and a Th1/Treg response. We propose a novel sublingual immunotherapy (SLIT) to peach with mono- and tetravalent systems that combines a Pru p 3 T-cell peptide with mannose dendrons.

METHODS: LTP-peach anaphylactic mice were treated sublingually with different concentrations of D₁ManPrup3 or D₄ManPrup3. Mice were challenged intraperitoneally with Pru p 3 one/four weeks after SLIT. Tolerance was assessed by changes in body temperature, determination of Pru p 3-sIgE and -sIgG1 by ELISA and ELISpot and lymphocyte proliferative response, Treg cell (CD4⁺CD25^highFoxP3⁺) and DC (CD11c⁺CD103⁺) percentages and cytokine production by flow cytometry.

RESULTS: Only mice receiving D₁ManPrup3 at 2nmol were protected from anaphylaxis, with no change in body temperature and a significant decrease of Pru p 3-sIgE and -sIgG1 antibodies and secreting cells compared to non-treated. Moreover, a significant decrease of Pru p 3-specific CD4⁺ T-cells and an increase of CD4⁺CD25^highFoxP3⁺cells were found, alongside shifts to a regulatory pattern (IL10⁺/IFNγ⁺) in CD4⁺ T-cells and CD11c⁺CD103⁺ DC. These changes were maintained for four weeks after stopping treatment.

CONCLUSIONS: The peptide monomeric glycodendron, D₁ManPrup3, represents a promising new specific immunotherapy approach that does not require additional adjuvant. It is easily synthesized, induces protection from anaphylaxis and persists in suppressing clinical symptoms after ending treatment.