title: Detailed characterization of Act d 12 and Act d 13 from kiwi seeds: implication in IgE cross-reactivity with peanut and tree nuts.
abstract: BACKGROUND
  Act d 12 (11S globulin) and Act d 13 (2S albumin) are two novel relevant allergens from kiwi seeds that might be useful to improve the diagnostic sensitivity and the management of kiwifruit-allergic patients.
  
  
  OBJECTIVE
  To perform a comprehensive structural and immunological characterization of purified Act d 12 and Act d 13 from kiwi seeds.
  
  
  METHODS
  Sera from 55 well-defined kiwifruit-allergic patients were used. Act d 12 and Act d 13 were purified by chromatographic procedures. Circular dichroism, mass spectrometry, concanavalin A detection, immunoblotting, enzyme-linked immunosorbent assays, basophil activation tests, and IgE-inhibition experiments were used.
  
  
  RESULTS
  Act d 12 and Act d 13 were purified from kiwi seeds to homogeneity by combining size-exclusion, ion-exchange, and RP-HPLC chromatographies. Both purified allergens preserve the structural integrity and display typical features of their homologous counterparts from the 11S globulin and 2S albumin protein families, respectively. These allergens are released from kiwi seeds after oral and gastric digestion of whole kiwifruit, demonstrating their bioavailability after ingestion. The allergens retain the capacity to bind serum IgE from kiwifruit-allergic patients, induce IgE cross-linking in effector-circulating basophils, and display in vitro IgE cross-reactivity with homologous counterparts from peanut and tree nuts.
  
  
  CONCLUSIONS
  Purified Act d 12 and Act d 13 from kiwi seeds are well-defined molecules involved in in vitro IgE cross-reactivity with peanut and tree nuts. Their inclusion in component-resolved diagnosis of kiwifruit allergy might well contribute to improve the diagnostic sensitivity and the management of kiwifruit-allergic patients.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Chemistry, Complutense University of Madrid, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Sirvent
authors.forename: B
authors.initials: B
authors.lastname: Cantó
authors.forename: F
authors.initials: F
authors.lastname: Gómez
authors.forename: N
authors.initials: N
authors.lastname: Blanca
authors.forename: J
authors.initials: J
authors.lastname: Cuesta-Herranz
authors.forename: G
authors.initials: G
authors.lastname: Canto
authors.forename: M
authors.initials: M
authors.lastname: Blanca
authors.forename: R
authors.initials: R
authors.lastname: Rodríguez
authors.forename: M
authors.initials: M
authors.lastname: Villalba
authors.forename: O
authors.initials: O
authors.lastname: Palomares
mesh_terms: D029042:Actinidia / Q000276:immunology*; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000008:administration & dosage / Q000276:immunology*; D052179:Antigens, Plant / Q000008:administration & dosage / Q000276:immunology*; D010367:Arachis / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism; D008297:Male; D009754:Nuts / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D012639:Seeds / Q000276:immunology*; D055815:Young Adult
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D007073:Immunoglobulin E
keywords: 11S globulin Act d 12; 2S albumin Act d 13; component-resolved diagnosis; kiwifruit allergy; peanut and tree nuts cross-reactivity