Transient Expression and Immunogenicity Assessment of the Dermatophagoides pteronyssinus Der p 2 Allergen Produced in Nicotiana benthamiana

Background: House dust mites (HDM) are one of the significant indoor allergen sources which cause IgE-mediated responses in most of the allergic individuals. HDMs are found in human habitats worldwide and Der p 2 is one of the major clinically relevant HDM allergens involved in triggering allergic diseases. The recombinant production of Der p 2 in plant systems provides a cost-effective and viable platform for developing diagnostic kits and allergen-specific immunotherapy. Methods: The D. pteronyssinus Der p 2 allergen was transiently expressed in Nicotiana benthamiana and its immunogenicity was evaluated in mice. The Der p 2 coding sequence was cloned into a geminiviral plant expression vector and introduced into N. benthamiana leaves via Agrobacterium tumefaciens-mediated infiltration. Recombinant Der p 2 proteins were purified from the crude extracts and confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and Western blot. The immunogenicity of the plant-produced Der p 2 proteins was further evaluated by immunizing mice following a prime–boost immunization regimen, and Der p 2-specific antibody responses were assessed by ELISA. Results: Recombinant Der p 2 was successfully expressed and purified from N. benthamiana, and immunized mice developed high levels of Der p 2-specific IgG antibodies, with antibody titers increased after booster immunization. Conclusions: The results demonstrate that the transient expression of Der p 2 in plants is a feasible and effective strategy for producing immunologically active recombinant allergen proteins for diagnostic and potential clinical applications.