Background Lentils are oftentimes responsible for allergic reactions to legumes in Mediterranean children. clinical findings. Results The lentil-allergic patients specifically recognized IgE-binding epitopes located in the C-terminal region between peptide 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 three-dimensional structure Troxacitabine of a homologous soy vicilin suggests that the Len c 1 epitopes identified are uncovered on the surface of the molecule. Conclusion Several IgE-binding sequential epitopes Troxacitabine of Len c 1 have been identified. Epitopes are located in the C-terminal region and are predicted to be Rabbit polyclonal to ALG1. uncovered on the surface of the protein. Epitope diversity is Troxacitabine usually positively correlated with IgE levels pointing to a more polyclonal IgE response. Keywords: lentil allergy peptide microarray epitope recognition epitope diversity Len c 1 Key messages This study is the first to explore and locate IgE-binding B-cell epitopes of lentil allergens using a peptide microarray immunoassay. Combining the findings of the microarray Troxacitabine immunoassay with clinical characteristics and IgE levels shows a positive correlation. Introduction Lentils together with chickpea are important causes for IgE-mediated food hypersensitivity in the Mediterranean.1-4 Other legumes such as peanut and soybean are legumes most frequently involved in allergic reactions in the United States the United Kingdom and Japan. The major allergens from soybean and especially peanut have been extensively studied 5 however more interest has been shown recently in chickpea and lentil allergens.1 In Spain allergy to lentils is the fifth most common cause of food allergy in the pediatric population.1 Ten percent of children with food allergy have a convincing clinical history of allergy to lentils. Lentils frequently induce systemic symptoms such as wheeze rhinorrhea and disseminated urticaria symptoms.2 Lentil has also been implicated in food-dependent exercise-induced anaphylaxis.4 Over 50% of individuals allergic to lentil are also allergic to chickpea and green pea.2 Inhibition experiments and oral challenge tests suggest a high degree of in vitro and in vivo cross-reactivity.2 Several allergens from lentil have been characterized to date including Len c 1.01 1.02 and 2. Len c 1.01 (Len c 1) is a protein of approximately 50 kDa that has been identified as a mature vicilin chain.12 Three genetic isoforms of this allergen have been described: Len c 1.0101 Len c 1.0102 and Len c 1.0103. Len c 1.02 is a 12-16 kDa protein the β-subunit of lentil vicilin that is probably produced by means of posttranslational proteolytic processing of the precursor Len c 1.01. Len c 2 is usually a distinct 66 kDa protein corresponding to a seed-specific biotinylated protein.12 13 A clear structural relationship between Len c 1.01 and several allergens Troxacitabine of the vicilin family including Ara h 1 Jug r 2 Ana o 1 Ses i 3 and subunits of soybean conglycinin has been described.14 Studies have shown IgE binding to a 50 kDa band in lentil extract in more than 65% of patients 15 later described as Len c 1.01. 77% of the lentil allergic patients recognized the purified Len c 1.12 However the location of the IgE binding sequential epitopes of the major lentil protein Len c 1 remains unknown. Here we report the mapping of IgE binding epitopes of Len c 1 using a peptide microarray based immunoassay (MIA). This sensitive technique allowed us to rapidly study several sets of the protein simultaneously using only a minute quantity of sera. Methods Patients Thirty-three lentil allergic patients were recruited from the Hospital Fundación Jimenez Diaz (Madrid Spain; n=5) from the Hospital Ni?o Jesús (Madrid Spain; n= 24) and from Mount Sinai Medical Center (New York USA; n=4) from 2004 to 2006. Written informed consent was obtained from all subjects (or the legal guardian for children) before their inclusion in the study. The diagnosis of IgE-mediated lentil allergy was.