Identification of IgE sequential epitopes of lentil (Len c 1) by means of peptide microarray immunoassay.
BACKGROUND
Lentils are often responsible for allergic reactions to legumes in Mediterranean children. Although the primary sequence of the major allergen Len c 1 is known, the location of the IgE-binding epitopes remains undefined.


OBJECTIVE
We sought to identify IgE-binding epitopes of Len c 1 and relate epitope binding to clinical characteristics.


METHODS
One hundred thirty-five peptides corresponding to the primary sequence of Len c 1 were probed with sera from 33 patients with lentil allergy and 15 nonatopic control subjects by means of microarray immunoassay. Lentil-specific IgE levels, skin prick test responses, and clinical reactions to lentil were determined. Epitopes were defined as overlapping signal above interslide and intraslide cutoffs and confirmed by using inhibition assays with a peptide from the respective region. Hierarchic clustering of microarray data was used to correlate binding patterns with clinical findings.


RESULTS
The patients with lentil allergy specifically recognized IgE-binding epitopes located in the C-terminal region between peptides 107 and 135. Inhibition experiments confirmed the specificity of IgE binding in this region, identifying different epitopes. Linkage of cluster results with clinical data and lentil-specific IgE levels displayed a positive correlation between lentil-specific IgE levels, epitope recognition, and respiratory symptoms. Modeling based on the 3-dimensional structure of a homologous soy vicilin suggests that the Len c 1 epitopes identified are exposed on the surface of the molecule.


CONCLUSIONS
Several IgE-binding sequential epitopes of Len c 1 have been identified. Epitopes are located in the C-terminal region and are predicted to be exposed on the surface of the protein. Epitope diversity is positively correlated with IgE levels, pointing to a more polyclonal IgE response.
Vereda
Andrea
A
Elliot and Roslyn Jaffe Food Allergy Institute, Division of Allergy and Immunology, Department of Pediatrics, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
Andreae
Doerthe A
DA
Lin
Jing
J
Shreffler
Wayne G
WG
Ibañez
Maria Dolores
MD
Cuesta-Herranz
Javier
J
Bardina
Ludmilla
L
Sampson
Hugh A
HA
D000293:Adolescent; D000485:Allergens / Q000235:genetics / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D000939:Epitopes / Q000737:chemistry; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000235:genetics / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood* / Q000235:genetics / Q000276:immunology; D027806:Lens Plant / Q000235:genetics / Q000276:immunology*; D008297:Male; D046228:Microarray Analysis; D008958:Models, Molecular; D055314:Seed Storage Proteins / Q000235:genetics / Q000276:immunology*
D000485:Allergens; D000939:Epitopes; D055314:Seed Storage Proteins; D007073:Immunoglobulin E; C015575:vicilin protein, plant
Allergy. 1999 Nov;54(11):1209-14
10604559
J Allergy Clin Immunol. 2008 Mar;121(3):737-743.e10
18234310
Mol Nutr Food Res. 2009 Nov;53(11):1462-8
19810019
Biochimie. 2005 Jun;87(6):499-506
15935274
Mol Immunol. 2009 May;46(8-9):1796-804
19251323
J Allergy Clin Immunol. 2000 Nov;106(5):955-61
11080720
J Allergy Clin Immunol. 2009 Aug;124(2):315-22, 322.e1-3
19577281
J Allergy Clin Immunol. 2008 Sep;122(3):589-94
18774394
J Allergy Clin Immunol. 2005 Oct;116(4):893-9
16210066
J Agric Food Chem. 2009 Feb 11;57(3):938-43
19138084
Methods Mol Biol. 2009;524:259-72
19377951
J Allergy Clin Immunol. 2010 Mar;125(3):695-702, 702.e1-702.e6
20226304
J Allergy Clin Immunol. 2004 May;113(5):821-30; quiz 831
15131562
Ann Allergy Asthma Immunol. 1996 Dec;77(6):480-2
8970438
J Immunol. 2005 Dec 15;175(12):8116-22
16339549
Allergol Immunopathol (Madr). 2003 May-Jun;31(3):151-61
12783766
J Allergy Clin Immunol. 2003 Dec;112(6):1208-15
14657885
Allergy. 2007 Jul;62(7):758-65
17573723
J Allergy Clin Immunol. 2009 Feb;123(2):452-8
18996574
J Investig Allergol Clin Immunol. 2008;18(6):465-8
19123439
Ann Allergy Asthma Immunol. 2008 Aug;101(2):179-84
18727474
J Allergy Clin Immunol. 2004 Apr;113(4):776-82
15100687