Allergic diseases are a common health issue that affects all of humanity. Over 20% of the population suffers from allergic diseases such as allergic rhinitis and allergic asthma [1]. Allergies occur when the immune system overreacts to substances that are harmless to most individuals, such as pollen, dust mites, certain foods, and pharmaceuticals. In response, the immune system produces antigen-specific immunoglobulin E (sIgE), leading to symptoms like sneezing, coughing, skin rashes, and runny nose. Symptom control can be achieved by allergen avoidance and pharmaceuticals. Still, allergen-specific immunotherapy (ASIT) is currently the only therapeutic approach that can modify the immune response and prevent the development of allergic diseases [2]. However, ASIT relies on natural allergen extracts and has some limitations, including the potential to cause side effects or sensitization to new allergens. Recombinant allergens with modified IgE epitopes are known as hypoallergens. Hypoallergens are less likely to induce an allergen-specific IgE response and cause side effects but can elicit the T-cell response. Using hypoallergens in allergen-specific immunotherapy may help modulate the immune response to the target allergen and induce immune tolerance to it. Also, the use of hypoallergens in therapy reduces the risk of side effects such as allergy symptoms or even anaphylactic shock [3].
Airborne pollen is a common trigger of respiratory allergies, affecting many people worldwide [4]. Common mugwort (Artemisia vulgaris) is a highly allergenic plant that produces large amounts of wind-borne pollen. It is a major cause of allergic reactions in Europe, affecting 10% to 15% of pollinosis patients during its long-lasting flowering period [5]. One of the six allergen components of the common mugwort, Art v 3, was approved in 2003. However, its IgE epitopes, important for developing hypoallergens, remain unidentified [6].
This research aimed to create mutant variants of the allergen component Art v 3 and to conduct a primary antigenicity assay. Based on the literature review and bioinformatic analysis, amino acids potentially involved in IgE-binding epitope formation were identified and mutant variants of Art v 3 were generated by site-directed mutagenesis. Proteins were synthesized in E. coli and purified using Ni\(^{2+}\) affinity chromatography. Primary antigenicity tests were performed to assess whether the reactivity of the recombinant proteins with sIgE was reduced. The identification of IgE epitopes is important for the synthesis of hypoallergens, and antigenicity assays of these mutants will provide valuable insights into their therapeutic applications. The research is funded by the Research Council of Lithuania (LMTLT), agreement No S-MIP-24-41.