Fel d 1-expressing plant-derived bioparticle: A novel treatment for cat allergy

Allergen immunotherapy (AIT) is the only disease-modifying therapeutic approach for cat allergy, though it requires at least three years of treatment and can potentially induce severe systemic reactions. Plant-derived bioparticles expressing Fel d 1 allergen (Fel d 1 eBP) have been developed as a novel therapeutic candidate for cat allergy. Cellular and scRNA-seq analyses reveal that Fel d 1 eBP induce Th1 and IL-10 + T cells. We also demonstrate that Fel d 1 eBP targets the induction of protective metallothionine genes, CCL18 + monocytes and naïve B cells that are interferon responsive. Moreover, Fel d 1 eBP demonstrated reduced capacity to elicit basophil activation and histamine release, indicating their hypoallergenic nature. Administration of titrated doses of Fel d 1 eBP through skin prick test revealed that they are well-tolerated with reduced mean wheal compared to native Fel d 1 in open-label Phase 0 study. Altogether, we demonstrate that Fel d 1 eBP is hypo-allergenic and demonstrate tolerogenic properties making them a novel candidate for use in AIT for cat allergy.