A DNA aptamer recognizes the Asp f 1 allergen of Aspergillus fumigatus

Abstract

Allergies are caused by the binding of IgE antibodies onto specific sites on allergens. However, in the assessment of exposure to airborne allergens, current techniques such as whole spore counts fail to account for the presence of these allergenic epitopes that trigger allergic reactions. The objective of the research is to develop a DNA aptamer for the Asp f 1 allergen of the pathogenic fungus Aspergillus fumigatus, using an IgE-binding epitope of the allergen as the target for aptamer selection. Through in vitro SELEX, an aptamer has been produced that binds with nanomolar affinity to the Asp f 1 IgE-epitope. The aptamer is also able to recognize the native Asp f 1 allergen, and does not bind to allergenic proteins from non-target mold species such as Alternaria alternata. Production of this aptamer provides proof-of-principle that allergen measurement methods can be developed to indicate the potent fraction, or allergenicity, of allergens.

Single-stranded DNA (ssDNA) production in DNA aptamer generation

“…In the DNA aptamer generation against 1,3-b-D-glucans and Asp f1 allergen of the pathogenic fungus Aspergillus, the asymmetric PCR product (following 8 PCR cycles with only 15 pmol forward primer) was used directly on these targets without any prior purification step. 57,58 Equivalently, Ogawa and colleagues have applied the asymmetric PCR product directly for incubation onto the Arg-Gly-Asp region of the fibronectin immobilized agarose gel column. 59 Asymmetric PCR is the most economical method of generating ssDNA from very low starting material (dsDNA template).…”

Inhibition of an Allergen–Antibody Reaction Related to Japanese Cedar Pollinosis Using DNA Aptamers Against the Cry j 2 Allergen

“…In this study, we evaluated whether eight aptamers previously identified as Cry j 2 ligands [12] inhibit the allergenantibody reaction between Cry j 2 and IgE collected from a patient with Japanese cedar pollinosis. Although several anti-allergen aptamers have been reported for use in sensing techniques, aptamers that can regulate immune response to allergens have not been developed to date [15][16][17][18]. To the best of our knowledge, this is the first report to demonstrate the inhibition of an allergen-antibody reaction using aptamers.…”

DNA aptamers that target human glioblastoma multiforme cells overexpressing epidermal growth factor receptor variant III in vitro

“…The ability of aptamers to distinguish small differences in cell-surface antigens indicates the great potential of using the Cell-SELEX approach for the selection of new biomarkers to identify and isolate subpopulations of various cancer stem cells. In addition to specific target recognition [16,17] , aptamers can be designed to target a desired region or in a sequential manner to refine their functions [18,19] . They also possess several advantages over naturally occurring antibodies [20] , including the ease of synthesis, their stability under standard conditions, a lack of immunogenicity, rapid tissue penetration, and the ease of immobilization and modification on chemical devices.…”