TY - JOUR
T1 - Characterization of IgE epitopes of Cuc m 2, the major melon allergen, and their role in cross-reactivity with pollen profilins
AU - Tordesillas, L.
AU - Pacios, L. F.
AU - Palacín, A.
AU - Cuesta-Herranz, J.
AU - Madero, M.
AU - Díaz-Perales, A.
PY - 2010/1
Y1 - 2010/1
N2 - Background Plant profilins are described as minor allergens, although with some exceptions in foods such as melon, watermelon or orange. In fact, they could be responsible for many cross-reactions among distantly related species. This is likely to be a consequence of the presence of common epitopes. Objective To characterize the B epitopes of Cuc m 2, a model of plant food profilin, using phage display techniques and to compare with other profilins, such as those of timothy grass and birch pollen, and human I profilin, to understand the mechanism of cross-reaction among members of this family. Methods IgE of melon-allergic patients was used to select clones from a phage display 12 mer peptide library. After two rounds of screening, Cuc m 2-specific clones were eluted and the DNA insertion sequenced. The residues of each clone were mapped on the Cuc m 2 surface to define a mimotope, which was also localized on the three-dimensional surfaces of other profilins. Results Seventeen melon-allergic patients were selected. Sera from each of them recognized the melon profilin, Cuc m 2, but the majority also recognized Phl p 12 or Bet v 2, timothy grass-, and birch-pollen profilins, respectively. A Cuc m 2 mimotope was defined and mapped onto its surface giving the following sequence: S2W 3A5Y6D9H10T 111P112G113Q114N116M 117R121L122. The homologous residues in Phl p 12 and Bet v 2 had almost identical sequences. By contrast, the homologous sequence in human profilin showed many differences. Conclusions The identified mimotope could be involved in cross-reactions among food and pollen profilins. Many of these cross-reactions observed in the clinical realm could be explained by the presence of a common epitope found in food and pollen allergens. A new strategy of immunotherapy based on this IgE region could be used in alternative immunotherapy strategies.
AB - Background Plant profilins are described as minor allergens, although with some exceptions in foods such as melon, watermelon or orange. In fact, they could be responsible for many cross-reactions among distantly related species. This is likely to be a consequence of the presence of common epitopes. Objective To characterize the B epitopes of Cuc m 2, a model of plant food profilin, using phage display techniques and to compare with other profilins, such as those of timothy grass and birch pollen, and human I profilin, to understand the mechanism of cross-reaction among members of this family. Methods IgE of melon-allergic patients was used to select clones from a phage display 12 mer peptide library. After two rounds of screening, Cuc m 2-specific clones were eluted and the DNA insertion sequenced. The residues of each clone were mapped on the Cuc m 2 surface to define a mimotope, which was also localized on the three-dimensional surfaces of other profilins. Results Seventeen melon-allergic patients were selected. Sera from each of them recognized the melon profilin, Cuc m 2, but the majority also recognized Phl p 12 or Bet v 2, timothy grass-, and birch-pollen profilins, respectively. A Cuc m 2 mimotope was defined and mapped onto its surface giving the following sequence: S2W 3A5Y6D9H10T 111P112G113Q114N116M 117R121L122. The homologous residues in Phl p 12 and Bet v 2 had almost identical sequences. By contrast, the homologous sequence in human profilin showed many differences. Conclusions The identified mimotope could be involved in cross-reactions among food and pollen profilins. Many of these cross-reactions observed in the clinical realm could be explained by the presence of a common epitope found in food and pollen allergens. A new strategy of immunotherapy based on this IgE region could be used in alternative immunotherapy strategies.
KW - B epitopes
KW - Birch
KW - Cross-reactivity
KW - Cuc m 2
KW - Electrostatic potential
KW - Food allergy
KW - Melon
KW - Mimotopes
KW - Profilins
KW - Timothy grass
UR - http://www.scopus.com/inward/record.url?scp=72949113832&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2222.2009.03401.x
DO - 10.1111/j.1365-2222.2009.03401.x
M3 - Article
AN - SCOPUS:72949113832
SN - 0954-7894
VL - 40
SP - 174
EP - 181
JO - Clinical and Experimental Allergy
JF - Clinical and Experimental Allergy
IS - 1
ER -