Variation in IgE binding potencies of seven Artemisia species depending on content of major allergens

Abstract

Background Artemisia weed pollen allergy is important in the northern hemisphere. While over 350 species of this genus have been recorded, there has been no full investigation into whether different species may affect the allergen diagnosis and treatment. This study aimed to evaluate the variations in amino acid sequences and the content of major allergens, and how these affect specific IgE binding capacity in representative Artemisia species. Methods Six representative Artemisia species from China and Artemisia vulgaris from Europe were used to determine allergen amino acid sequences by transcriptome, gene sequencing and mass spectrometry of the purified allergen component proteins. Sandwich ELISAs were developed and applied for Art v 1, Art v 2 and Art v 3 allergen quantification in different species. Aqueous pollen extracts and purified allergen components were used to assess IgE binding by ELISA and ImmunoCAP with mugwort allergic patient serum pools and individual sera from five areas in China. Results The Art v 1 and Art v 2 homologous allergen sequences in the seven Artemisia species were highly conserved. Art v 3 type allergens in A. annua and A. sieversiana were more divergent compared to A. argyi and A. vulgaris. The allergen content of Art v 1 group in the seven extracts ranged from 3.4% to 7.1%, that of Art v 2 from 1.0% to 3.6%, and Art v 3 from 0.3% to 10.5%. The highest IgE binding potency for most Chinese Artemisia allergy patients was with A. annua pollen extract, followed by A. vulgaris and A. argyi, with A. sieversiana significantly lower. Natural Art v 1-3 isoallergens from different species have almost equivalent IgE binding capacity in Artemisia allergic patients from China. Conclusion and clinical relevance There was high sequence similarity but different content of the three group allergens from different Artemisia species. Choice of Artemisia annua and A. argyi pollen source for diagnosis and immunotherapy is recommended in China.

Peach allergen Pru p 1 content is generally low in fruit but with large variation in different varieties

“…In China, there are three common sensitization patterns to peach allergen component: monosensitization to Pru p 1, cosensitization to Pru p 3 and Pru p 4, and monosensitization to Pru p 3 7,18 . Most peach allergic patients in China are positive to Pru p 3 due to primary sensitization to Pru p 3 and cross‐reactive to Artemisia pollen LTPs 3,7,27 . The frequency of reactivity to Pru p 1 and Pru p 1 sIgE level is much lower than that of Pru p 3 in China 3,7 .…”

“…7,18 Most peach allergic patients in China are positive to Pru p 3 due to primary sensitization to Pru p 3 and cross-reactive to Artemisia pollen LTPs. 3,7,27 The frequency of reactivity to Pru p 1 and Pru p 1 sIgE level is much lower than that of Pru p 3 in China. 3,7 This phenomenon may be related to the following two factors: first, a low chance of sensitization to birch pollen allergen PR-10 that cross-reacts with Pru p 1, 28 due to the very limited number of birch trees in densely populated cities in Northern China and the virtual absence of birch trees in Southern China; second, the Pru p 1 content in peach fruit is very low.…”

Allergenic Properties and Molecular Characteristics of PR-1 Proteins

“…Artemisia vulgaris ( 27 ) belongs to one of the largest families of flowering plants, the Compositae or Asteraceae . It is a weed widely spread in temperate regions and subtropics of Europe, North America, and Asia ( 28 , 29 ). Among these, Art v 1, Art v 2, Art v 3, and Art v 7 have been shown to be the most relevant allergens ( 28 , 29 ).…”

“…Artemisia vulgaris. As an example, Artemisia annua (Art an 2) has been recognized as an important source of allergen, and together with Artemisia argyi (Art ar 2) and Artemisia sieversiana (Art si 2), they are recommended for immunotherapy in Chinese allergic patients(29).…”

Allergens of Regional Importance in Korea

“…In Korea, 26 mugwort species have been recorded with Artemisia princeps being the most prevalent ( 12 ). Fortunately, a high sequence identity of three groups of allergens (Art v 1, 2, and 3) from different species and almost equivalent IgE binding capacity of these allergens were reported, allowing diagnosis and immunotherapy with commercialized mugwort extracts ( 13 , 14 ).…”