Production of a chimeric allergen derived from the major allergen group 1 of house dust mite species in Nicotiana benthamiana.

Plants are widely accepted as a general platform for the large-scale production of recombinant proteins, which has been demonstrated by the successful expression of various exogenous proteins. Using plants as a bioreactor for mass production of target proteins for vaccines is thought to show the most potential. This study explores whether a chimeric allergen R8, derived from the major allergen group 1 of house dust mites species (Dermatophagoides farinae and Dermatophagoides pteronyssinus), is expressed in tobacco. The highly efficient and useful Tobacco mosaic virus RNA-based overexpression (TRBO) vector was used to investigate expression of the R8 molecule in tobacco by agroinfection. Presence of R8 was detected using SDS-PAGE and Western blotting. Purified allergens were characterized using IgE-binding activity assay and allergen-specific immunotherapy (ASIT) in murine asthmatic models. The recombinant R8 was successfully expressed in tobacco leaves. The pro-peptide was observed in the herbaceous leaf extracts. This protein exhibits properties similar to the parental allergen ProDer f 1 expressed in Escherichia coli or tobacco with respect to IgE immunoreactivity. R8 also rectifies imbalance of TH1/TH2 cells. An herbaceous plant expression system model allows mass production of R8, which might be used in the future for diagnosis of asthma or production of a candidate vaccine for allergen-specific immunotherapy of asthma.