Characterization of a Major Allergen from Mongolian Oak, <b><i>Quercus mongolica</i></b>, a Dominant Species of Oak in Korea

Abstract

Background: Oaks are the most common trees in Korean forests, and Mongolian oak, Quercus mongolica, is the dominant species. However, no allergen has been characterized from Mongolian oak. In this study, we tried to characterize a major allergen from Mongolian oak. Methods: A molecule homologous to pathogenesis-related 10 (PR-10)-like protein, Que m 1, was cloned by RT-PCR. Its recombinant protein, along with Que a 1, an allergen from white oak (Q. alba), was produced. The allergenicity and diagnostic value of recombinant Que m 1, Que a 1, and Bet v 1 proteins were compared by ELISA using sera from oak-sensitized subjects. A basophil activation test was also performed using CD63 expression as an activation marker. Results: Que m 1 sequence shares 57.5-96.2% amino acid sequence identity with PR-10-like allergens from various plants. Specific IgE to recombinant Que m 1, Que a 1, and Bet v 1 were detected in 92.0, 74.0, and 38.0% of 50 serum samples from Korean tree pollinosis patients. Recombinant Que m 1 was able to inhibit IgE reactivity to Que a 1 and Bet v 1, indicating its strong cross-reactivity. The activation patterns of basophils from 5 patients were similar in terms of the CD63 expression and protein concentration of challenged Bet v 1 and Que m 1. Conclusions: A major allergen, Que m 1, was cloned, and its recombinant protein was produced from Mongolian oak, a dominant species in Korea. Recombinant Que m 1 is potentially useful for the diagnosis and treatment of tree pollinosis in Korea.

Characterization of the major allergen, Que ac 1, from sawtooth oak pollen

“…2 Nevertheless, diagnosis and immunotherapy for pollinosis are performed with products prepared from species (Q. alba) that are not native to Korea. 3 We are now reporting the full characterization of Que ac 1, a 17 kDa allergen, which was detected by IgE immunoblotting in a previous study. 2 Native (n) Que ac 1 was purified in three chromatography steps: anion exchange chromatography, hydrophobic interaction chromatography, and gel filtration (Figure 1A).…”

Allergens of Regional Importance in Korea

“…The most abundant oak species in Korea is the Mongolian oak. Que m 1 from Mongolian oak exhibited better diagnostic value than Bet v 1 ( 4 ). However, most Mongolian oaks are found in the mountains with sawtooth oak being common near villages.…”

Newly defined allergens in the WHO/IUIS Allergen Nomenclature Database during 01/2019‐03/2021

“… 27 PR‐10 allergens from birch and related trees of the families Betulaceae and Fagaceae are cross‐reactive and a major cause of allergic rhinitis. 28 Although published earlier, 29 Que m 1, the PR‐10 from the dominant Korean oak species Quercus mongolica , was only accepted in 2019 by the ANSC. Recombinant Que m 1 was able to inhibit IgE‐binding to Bet v 1, indicating a strong cross‐reactivity.…”