Rapid induction of allergen‐blocking IgG in dogs vaccinated with plant‐based, Der f 2‐expressing bioparticles

Background Allergen‐carrying virus‐like particles are effective and safe means of allergen immunotherapy (AIT) in rodent models. Objective To study the development of allergen‐blocking immunoglobulin (Ig)G in dogs injected with Der f 2‐carrying enveloped plant‐based bioparticles (eBPs). Materials and Methods Laboratory beagle dogs were injected intradermally (ID) or subcutaneously (SC) with Der f 2‐eBP three times at 2‐week intervals. A basophil mediator release assay was used to compare the reactivity of Der f 2‐eBPs to that of recombinant Der f 2. Allergen‐specific IgG serum levels were determined by immunoblotting and ELISA. The allergen‐blocking potential of postvaccination IgG was assessed by Pet Allergy Xplorer (PAX) macroarray and basophil mediator release inhibition assays. Results The amount of Der f 2 eBPs needed to induce basophil activation was 1000‐fold higher than that of the soluble natural allergen. In both immunisation groups, eBP injections caused no adverse events and induced Der f 2‐specific IgG, first detected on Day (D)14 and peaking on D41. The co‐incubation of sera with a Der f 2‐IgE‐rich canine serum pool resulted in a mean PAX inhibition of 70% (ID) to 80% (SC) on D41. For both groups, the inhibition of basophil mediator release reached 75% on D28 and D41. The percentage inhibition of PAX and mediator release correlated significantly with Der f 2 IgG levels. Conclusion and Clinical Relevance Intradermal and subcutaneous injections of Der f 2‐eBPs were safe and increased Der f 2‐specific IgG. The clinical benefit of immunotherapy will be evaluated in future trials enrolling atopic dogs allergic to house dust mites. Zusammenfassung Hintergrund Allergen‐tragende Virus‐ähnliche Partikel sind effektiv und eine sichere Methode der Allergen Immuntherapie (AIT) in Nagermodellen. Ziele Das Ziel der Studie war eine Untersuchung der Allergen‐blockierenden Immunglobuline (Ig)G bei Hunden, denen Der f 2‐beherbergende umhüllte Pflanzen‐basierte Bipartikel (eBPs) injiziert worden waren. Materialien und Methoden Laborbeagles wurde Der f 2‐eBP intradermal (ID) oder subkutan (SC) dreimal im Abstand von zwei Wochen‐Intervallen injiziert. Ein Basophile Mediatoren Freisetzungs‐Assay wurde verwendet, um die Reaktivität der Der f 2‐eBPs auf rekombinantes Der f 2 zu vergleichen. Es wurden Allergen‐spezifische IgG Serumwerte mittels Immunblotting und ELISA bestimmt. Das Allergen‐blockierende Potential von IgG nach Impfung wurde mittels Pet Allergy Xplorer