Fel d 1 surface expression on plant‐made eBioparticles combines potent immune activation and hypoallergenicity

Plant‐based enveloped Ara h 2 bioparticles display exceptional hypo‐allergenicity

“…The e BP platform, first tested with house dust mite (Der p 2) and cat dander (Fel d 1) allergens, demonstrated significantly stronger immunogenicity than alum‐adsorbed allergen, and close to a 1000‐fold reduction in allergenicity shown by the basophil activation test (BAT) and the rat basophilic leukaemia (RBL) cell test 4,5 . In the present study, hypo‐allergenicity of Ara h 2 e BPs was first evaluated by reduction of IgE binding using ImmunoCAP inhibition.…”

“…These differences compared to Ara h 2 e BPs may be explained by the localization of dominant IgE epitopes, which either remain available or become shielded off in the one‐directional positioning of the allergens on the surface of the particles. Nevertheless, all three allergen e BPs are exceptionally hypo‐allergenic in functional assays with allergenic effector cells (mast cells, RBL, BAT) 4,5 . This may be caused by insufficient FcεR cross‐linking due to the restricted freedom of movement of the allergens on the e BPs, while soluble allergen can freely move around.…”

“…4 The eBP platform, first tested with house dust mite (Der p 2) and cat dander (Fel d 1) allergens, demonstrated significantly stronger immunogenicity than alum-adsorbed allergen, and close to a 1000fold reduction in allergenicity shown by the basophil activation test (BAT) and the rat basophilic leukaemia (RBL) cell test. 4,5 In the present study, hypo-allergenicity of Ara h 2 eBPs was first evaluated by reduction of IgE binding using ImmunoCAP inhibition. A pool of sera from eight Ara h 2-sensitized patients was incubated with dilution series of either nAra h 2 or the Ara h 2 eBP, followed by quantification of IgE binding to the recombinant Ara h 2 ImmunoCAP (f423; Thermo Fisher Scientific, Uppsala, Sweden).…”

“…Nevertheless, all three allergen eBPs are exceptionally hypo-allergenic in functional assays with allergenic effector cells (mast cells, RBL, BAT). 4,5 This may be caused by insufficient FcεR cross-linking due to the restricted freedom of movement of the allergens on the eBPs, while soluble allergen can freely move around. Moreover, there is limited space for the 150-200 nm eBPs to bind to the surface of a ~ 1.5 μm large cell, decreasing effective FcεR cross-linking by steric hindrance.…”

Plant‐produced Der p 2‐bearing bioparticles activate Th1/Treg‐related activation patterns in dendritic cells irrespective of the allergic background

“…Earlier reports based on eBP-rFel d 1/-rAra h 2 show even (far) higher reductions in basophil degranulation. 4,5 It can be hypothesized that IgE binding capacities and related effector cell activation might be linked to the localization of the respective dominant IgE epitopes, which might either be exposed or shielded off due to the one-directional allergen anchorage on the eBP surface. 5 Other factors contributing to deviating allergenic potency might include differences in the density of surface expression as well as size and charge of the eBPs.…”