TY - JOUR
T1 - IgE cross-inhibition between Ara h 1 and Ara h 2 is explained by complex formation of both major peanut allergens
AU - Warmenhoven, Hans J. M.
AU - Hulsbos, Luuk
AU - Dreskin, Stephen C.
AU - Akkerdaas, Jaap H.
AU - Versteeg, Serge A.
AU - van Ree, Ronald
N1 - Funding Information: Research was funded by Amsterdam University Medical Centers. Publisher Copyright: © 2023 The Authors
PY - 2023/8
Y1 - 2023/8
N2 - Background: Surprisingly, IgE cross-reactivity between the major peanut allergens Ara h 1, 2, and 3 has been reported despite very low sequence identities. Objective: We investigated the unexpected cross-reactivity between peanut major allergens. Methods: Cross-contamination of purified natural Ara h 1, 2, 3, and 6 was assessed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), Western blot test, liquid chromatography–tandem mass spectrometry (LC-MS/MS), and sandwich enzyme-linked immunosorbent assay (ELISA). IgE cross-reactivity was studied with sera of peanut-allergic patients (n = 43) by ELISA and ImmunoCAP inhibition using both intact natural and recombinant allergens and synthetic peptides representing postulated Ara h 1 and Ara h 2 cross-reactive epitopes. Results: Both purified nAra h 1 and nAra h 3 were demonstrated to contain small but significant amounts of Ara h 2 and Ara h 6 (<1%) by sandwich ELISA, SDS-PAGE/Western blot analysis, and LC-MS/MS. IgE cross-inhibition between both 2S albumins and Ara h 1 and Ara h 3 was only observed when using natural purified allergens, not recombinant allergens or synthetic peptides. Apparent cross-reactivity was lost when purified nAra h 1 was pretreated under reducing conditions, suggesting that Ara h 2 and Ara h 6 contaminations may be covalently bound to Ara h 1 via disulfide interactions. Conclusion: True cross-reactivity of both peanut 2S albumins with Ara h 1 and Ara h 3 could not be demonstrated. Instead, cross-contamination with small quantities was shown to be sufficient to cause significant cross-inhibition that can be misinterpreted as molecular cross-reactivity. Diagnostic tests using purified nAra h 1 and nAra h 3 can overestimate their importance as major allergens as a result of the presence of contaminating 2S albumins, making recombinant Ara h 1 and Ara h 3 a preferred alternative.
AB - Background: Surprisingly, IgE cross-reactivity between the major peanut allergens Ara h 1, 2, and 3 has been reported despite very low sequence identities. Objective: We investigated the unexpected cross-reactivity between peanut major allergens. Methods: Cross-contamination of purified natural Ara h 1, 2, 3, and 6 was assessed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), Western blot test, liquid chromatography–tandem mass spectrometry (LC-MS/MS), and sandwich enzyme-linked immunosorbent assay (ELISA). IgE cross-reactivity was studied with sera of peanut-allergic patients (n = 43) by ELISA and ImmunoCAP inhibition using both intact natural and recombinant allergens and synthetic peptides representing postulated Ara h 1 and Ara h 2 cross-reactive epitopes. Results: Both purified nAra h 1 and nAra h 3 were demonstrated to contain small but significant amounts of Ara h 2 and Ara h 6 (<1%) by sandwich ELISA, SDS-PAGE/Western blot analysis, and LC-MS/MS. IgE cross-inhibition between both 2S albumins and Ara h 1 and Ara h 3 was only observed when using natural purified allergens, not recombinant allergens or synthetic peptides. Apparent cross-reactivity was lost when purified nAra h 1 was pretreated under reducing conditions, suggesting that Ara h 2 and Ara h 6 contaminations may be covalently bound to Ara h 1 via disulfide interactions. Conclusion: True cross-reactivity of both peanut 2S albumins with Ara h 1 and Ara h 3 could not be demonstrated. Instead, cross-contamination with small quantities was shown to be sufficient to cause significant cross-inhibition that can be misinterpreted as molecular cross-reactivity. Diagnostic tests using purified nAra h 1 and nAra h 3 can overestimate their importance as major allergens as a result of the presence of contaminating 2S albumins, making recombinant Ara h 1 and Ara h 3 a preferred alternative.
KW - Ara h 1
KW - Ara h 2
KW - Peanut allergens
KW - cross-reactivity
KW - impurities
UR - http://www.scopus.com/inward/record.url?scp=85156159975&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.jaci.2023.03.025
DO - https://doi.org/10.1016/j.jaci.2023.03.025
M3 - Article
C2 - 37028524
SN - 0091-6749
VL - 152
SP - 436-444.e6
JO - Journal of allergy and clinical immunology
JF - Journal of allergy and clinical immunology
IS - 2
ER -