Cloning, bioinformatics analysis, and expression of the dust mite allergen Der f 5 of Dermatophagoides farinae

Abstract

Crude extracts of house dust mites are used clinically for diagnosis and immunotherapy of allergic diseases, including bronchial asthma, perennial rhinitis, and atopic dermatitis. However, crude extracts are complexes with non-allergenic antigens and lack effective concentrations of important allergens, resulting in several side effects. Dermatophagoides farinae (Hughes; Acari: Pyroglyphidae) is one of the predominant sources of dust mite allergens, which has more than 30 groups of allergen. The cDNA coding for the group 5 allergen of D. farinae from China was cloned, sequenced and expressed. According to alignment using the VECTOR NTI 9.0 software, there were eight mismatched nucleotides in five cDNA clones resulting in seven incompatible amino acid residues, suggesting that the Der f 5 allergen might have sequence polymorphism. Bioinformatics analysis revealed that the matured Der f 5 allergen has a molecular mass of 13604.03 Da, a theoretical pI of 5.43 and is probably hydrophobic and cytoplasmic. Similarities in amino acid sequences between Der f 5 and allergens of other domestic mite species, viz. Der p 5, Blo t 5, Sui m 5, and Lep d 5, were 79, 48, 53, and 37%, respectively. Phylogenetic analysis indicated that Der f 5 and Der p 5 clustered together. Blo t 5 and Ale o 5 also clustered together, although Blomia tropicalis and Aleuroglyphus ovatus belong to different mite families, viz. Echimyopodidae and Acaridae, respectively.

Environmental assessment and exposure control of dust mites: a practice parameter

“…Der f 5 and Der p 5 are more similar to each other than to Blo t 5 and Ale o 5, most likely because they belong to different mite families (Echimyopodidae vs Acaridae). 344 …”

Dermatophagoides farinae allergen Der f 9: Cloning, expression, purification, characterization and IgE‐binding in children with atopic asthma

“…D. farinae were cultured and isolated as we previously reported . Total RNA was isolated using RNA isolator (TaKaRa Biotech, Dalian, China.…”

“…As in much of the world, house dust mite hypersensitivity, particularly to D. farinae , is common in China . To better understand house dust mite hypersensitivity, our laboratory has cloned and expressed several allergens from D. farinae . The current study sought to clone the group 9 allergen from D. farinae (Der f 9), which has not yet been listed in the website of allergen nomenclature (http://www.allergen.org/).…”

“…7 To better understand house dust mite hypersensitivity, our laboratory has cloned and expressed several allergens from D. farinae. [8][9][10][11][12][13][14][15][16] The current study sought to clone the group 9 allergen from D. farinae (Der f 9), which has not yet been listed in the website of allergen nomenclature (http://www.allergen.org/). These results will provide a foundation for improved diagnosis and treatment of house dust mite allergy in China and worldwide.…”

Cross-Reactivity between Major IgE Epitopes of Family 5 Allergens from <b><i>Dermatophagoides pteronyssinus</i></b> and <b><i>Blomia tropicalis</i></b>

“…Several studies show the importance of group 5 allergens in respiratory diseases [9, 11-14]. Others show that Der p 5 is strongly related to the development of asthma in allergic patients [3, 15, 16] and that significantly higher concentrations of specific IgE (sIgE) to Der p 5 can be observed in asthmatic patients.…”