The major conformational IgE-binding epitopes of hevein (Hev b6.02) are identified by a novel chimera-based allergen epitope mapping strategy.
A novel approach to localize and reconstruct conformational IgE-binding epitope regions of hevein (Hev b6.02), a major natural rubber latex allergen, is described. An antimicrobial protein (AMP) from the amaranth Amaranthus caudatus was used as an immunologically non-IgE-binding adaptor molecule to which terminal or central parts of hevein were fused. Hevein and AMP share a structurally identical core region but have different N-terminal and C-terminal regions. Only 1 of 16 hevein-allergic patients showed weak IgE binding to purified native or recombinant AMP. Chimeric AMP with the hevein N terminus was recognized by IgE from 14 (88%) patients, and chimeric AMP with the hevein C terminus was recognized by IgE from 6 (38%) patients. In contrast, chimeric AMP containing the hevein core region was recognized by IgE from only two patients. When both the N-terminal and C-terminal regions of hevein were fused with the AMP core, IgE from all 16 patients bound to the chimera. This chimera was also able to significantly inhibit (>70%) IgE binding to the native hevein. On the contrary, linear synthetic peptides corresponding to hevein regions in the AMP chimeras showed no significant IgE binding capacity in either enzyme-linked immunosorbent assay or inhibition enzyme-linked immunosorbent assay. These results suggest that the IgE binding ability of hevein is essentially determined by its N-terminal and C-terminal regions and that major IgE-binding epitopes of hevein are conformational. The chimera-based epitope mapping strategy described here provides a valuable tool for defining structural epitopes and creating specific reagents for allergen immunotherapy.
Karisola
Piia
P
Department of Biological and Environmental Science, University of Jyväskylä, P. O. Box 35 (YAB), FIN-40014 University of Jyvaskyla, Finland.
Alenius
Harri
H
Mikkola
Jari
J
Kalkkinen
Nisse
N
Helin
Jari
J
Pentikäinen
Olli T
OT
Repo
Susanna
S
Reunala
Timo
T
Turjanmaa
Kristiina
K
Johnson
Mark S
MS
Palosuo
Timo
T
Kulomaa
Markku S
MS
D000249:Adenosine Monophosphate / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000737:chemistry*; D000818:Animals; D023181:Antimicrobial Cationic Peptides; D002645:Chickens; D019992:Databases as Topic; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry*; D037102:Lectins / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D008958:Models, Molecular; D010452:Peptide Biosynthesis; D037121:Plant Lectins; D010940:Plant Proteins / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000485:Allergens; D023181:Antimicrobial Cationic Peptides; D000939:Epitopes; D037102:Lectins; D037121:Plant Lectins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C045875:hevein; D007073:Immunoglobulin E; D000249:Adenosine Monophosphate