A novel peanut allergy immunotherapy: Plant-based enveloped Ara h 2 Bioparticles activate dendritic cells and polarize T cell responses to Th1

Charlotte Castenmiller; Noémi Anna Nagy; Pascal Zion Kroon; Lydia Auger; Réjean Desgagnés; Caroline Martel; Lucie Mirande; Bertrand Morel; Joannie Roberge; Virginie Stordeur; Guy Tropper; Louis Philipe Vézina; Ronald van Ree; Véronique Gomord; Esther Christina de Jong

doi:10.1016/j.waojou.2023.100839

A novel peanut allergy immunotherapy: Plant-based enveloped Ara h 2 Bioparticles activate dendritic cells and polarize T cell responses to Th1

World Allergy Organ J. 2023 Nov 10;16(11):100839. doi: 10.1016/j.waojou.2023.100839. eCollection 2023 Nov.

Authors

Charlotte Castenmiller¹, Noémi Anna Nagy¹, Pascal Zion Kroon¹, Lydia Auger², Réjean Desgagnés², Caroline Martel², Lucie Mirande³, Bertrand Morel³, Joannie Roberge², Virginie Stordeur³, Guy Tropper², Louis Philipe Vézina², Ronald van Ree^{1

4}, Véronique Gomord³, Esther Christina de Jong¹

Affiliations

¹ Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam Institute for Infection & Immunity, University of Amsterdam, Amsterdam, the Netherlands.
² Angany Inc., Québec, Canada.
³ Angany Innovation, Val-de-Reuil, France.
⁴ Department of Otorhinolaryngology, Amsterdam University Medical Centers, Amsterdam, the Netherlands.

Abstract

Introduction: As the only market-authorized allergen immunotherapy (AIT) for peanut allergy is accompanied by a high risk of side effects and mainly induces robust desensitization without sustained efficacy, novel treatment options are required. Peanut-specific plant-derived eBioparticles (eBPs) surface expressing Ara h 2 at high density have been shown to be very hypoallergenic. Here, we assessed the dendritic cell (DC)-activating and T cell polarization capacity of these peanut-specific eBPs.

Methods: Route and kinetics of eBP uptake were studied by (imaging) flow cytometry using monocyte-derived DCs incubated with fluorescently-labelled Ara h 2 eBPs or natural Ara h 2 (nAra h 2) in the presence or absence of inhibitors that block pathways involved in macropinocytosis, phagocytosis, and/or receptor-mediated uptake. DC activation was monitored by flow cytometry (maturation marker expression) and ELISA (cytokine production). T cell polarization was assessed by co-culturing DCs exposed to Ara h 2 eBPs or nAra h 2 with naïve CD4⁺ T cells, followed by flow cytometry assessment of intracellular IFNγ⁺ (Th1) and IL-13⁺ (Th2), and CD25⁺CD127^-Foxp3⁺ regulatory T cells (Tregs). The suppressive activity of Tregs was tested using a suppressor assay.

Results: Ara h 2 eBPs were taken up by DCs through actin-dependent pathways. They activated DCs demonstrated by an induced expression of CD83 and CD86, and production of TNFα, IL-6, and IL-10. eBP-treated DCs polarized naïve CD4⁺ T cells towards Th1 cells, while reducing Th2 cell development. Furthermore, eBP-treated DCs induced reduced the frequency of Foxp3⁺ Tregs but did not significantly affect T cell IL-10 production or T cells with suppressive capacity. In contrast, DC activation and Th1 cell polarization were not observed for nAra h 2.

Conclusion: Ara h 2 eBPs activate DCs that subsequently promote Th1 cell polarization and reduce Th2 cell polarization. These characteristics mark Ara h 2 eBPs as a promising novel candidate for peanut AIT.

Keywords: Allergen immunotherapy; Dendritic cell; Microparticle; Peanut allergy; T cell.