Date Published: May 1, 2019
Publisher: Public Library of Science
Author(s): Rose Waldron, Jamie McGowan, Natasha Gordon, Charley McCarthy, E. Bruce Mitchell, David A. Fitzpatrick, Ben J. Mans.
The European house dust mite Dermatophagoides pteronyssinus is of significant medical importance as it is a major elicitor of allergic illnesses. In this analysis we have undertaken comprehensive bioinformatic and proteomic examination of Dermatophagoides pteronyssinus airmid, identified 12,530 predicted proteins and validated the expression of 4,002 proteins. Examination of homology between predicted proteins and allergens from other species revealed as much as 2.6% of the D. pteronyssinus airmid proteins may cause an allergenic response. Many of the potential allergens have evidence for expression (n = 259) and excretion (n = 161) making them interesting targets for future allergen studies. Comparative proteomic analysis of mite body and spent growth medium facilitated qualitative assessment of mite group allergen localisation. Protein extracts from house dust contain a substantial number of uncharacterised D. pteronyssinus proteins in addition to known and putative allergens. Novel D. pteronyssinus proteins were identified to be highly abundant both in house dust and laboratory cultures and included numerous carbohydrate active enzymes that may be involved in cuticle remodelling, bacteriophagy or mycophagy. These data may have clinical applications in the development of allergen-specific immunotherapy that mimic natural exposure. Using a phylogenomic approach utilising a supermatrix and supertree methodologies we also show that D. pteronyssinus is more closely related to Euroglyphus maynei than Dermatophagoides farinae.
House dust mites (HDM) are the most prevalent source of indoor allergens worldwide, with 1–2% of the total population experiencing an allergic response in their presence . HDM allergens are major causative agents in the pathogenesis of asthma, allergic rhinitis and atopic dermatitis . Protease allergens disrupt the epithelial barrier and activate immune cells resulting in the production of large amounts of proinflammatory cytokines [3, 4]. Sero-dominant allergens; Der p 1and Der p 2 account for 50–60% of IgE reactivity in individuals tested . Allergenic protein families represent only 2% of all protein families. Allergenicity and cross-reactivity is linked to the allergen family rather than allergen source . Use of publicly available allergen databases to query newly sequenced genomes for the presence of potentially allergenic or cross-reactive proteins has enormous potential in identifying new allergens.
Here we performed a comprehensive bioinformatic and proteomic examination of D. pteronyssinus airmid describing the expression of 4,002 proteins (S11 Data) and identified 332 potential allergens. High sensitivity mass spectrometry allowed for the description of novel D. pteronyssinus components in HD and facilitated qualitative assessment of MGA localisation. This research has expanded the knowledge of proteins utilised by D. pteronyssinus for key physiological processes and will form the basis for further research into biocontrol strategies for the medically important HDM.