Recent immunological data demonstrated that dendritic cells preferentially recognize advanced glycation end product (AGE) modified proteins, upregulate expression of the receptor for AGE (RAGE), and consequently bias the immune response towards allergy.
Peanut extract was characterized by mass spectrometry (MS) to elucidate the specific residues and specific AGE modifications found in raw and roasted peanuts and on rAra h 1 that was artificially glycated by incubation with glucose or xylose. The binding of the RAGE-V1C1 domain to peanut allergens was assessed by PAGE and Western analysis with anti-Ara h 1, 2, and 3 antibodies. IgE binding to rAra h 1 was also assessed using the same methods.
AGE modifications were found on Ara h 1 and Ara h 3 in both raw and roasted peanut extract. No AGE modifications were found on Ara h 2. MS and Western blot analysis demonstrated RAGE binds selectively to Ara h 1 and Ara h 3 derived from peanut extract whereas the analysis failed to demonstrate Ara h 2 binding to RAGE. rAra h 1 with no AGE modifications did not bind RAGE, however after AGE modification with xylose, rAra h 1 bound to RAGE.
AGE modifications to Ara h 1 and Ara h 3 can be found in both raw and roasted peanuts. RAGE was demonstrated to selectively interact with AGE modified rAra h 1. If sensitization to peanut allergens occurs in dendritic cells via RAGE interactions, these cells are likely interacting with modified Ara h 1, and Ara h 3, and not Ara h 2.