Novel sequences and epitopes of diagnostic value derived from the Anisakis simplex Ani s 7 major allergen
Autor(es): Rodriguez, E.; Anadon, A. M.; Garcia-Bodas, E.; Romaris, F.; Iglesias, R.; Garate, T.; Ubeira, F. M.
Resumo: Anisakis simplex allergens may cause severe allergic reactions in infected patients. Human anisakiasis can be specifically diagnosed by detection of immunoglobulin E (IgE) antibodies against O-deglycosylated nAni s 7 allergen captured by monoclonal antibody (mAb) UA3 (UA3-ELISA), although the nature of this important allergen is unknown. The aim of this study was to clone and characterize the Ani s 7 major allergen, and to obtain a recombinant fragment suitable for serodiagnosis. An Anisakis cDNA library was screened with mAb UA3 and a cDNA clone (rAni s 7) encoding a 1096-amino acid fragment of Ani s 7 (GenBank: EF158010) was identified. Bioinformatic tools and immunological and biochemical techniques were used to characterize the allergen obtained. The rAni s 7 fragment comprised 19 repeats of a novel CX17-25CX9-22CX8CX6 tandem repeat motif not seen in any previously reported protein sequence. An internal (435)Met-(713)Arg fragment of the rAni s 7 (t-Ani s 7) was expressed in Escherichia coli and evaluated for serodiagnostic utility. Indirect enzyme-linked immunosorbent assay (ELISA) with t-Ani s 7 identified as positive the same 60 sera as UA3-ELISA. The sequence MCQCVQKYGTEFCKKRLA from rAni s 7 was identified as the epitope recognized by mAb UA3, and is the target for over 60% of human IgE antibodies that react with O-deglycosylated nAni s 7. In addition to their clear value for serodiagnosis of human anisakiasis, the nature of the novel sequences and epitopes identified in the Ani s 7 allergen are of interest for a better understanding of the mechanisms operating in Anisakis-induced allergy.
Palavras-Chave: Ani s 7; Anisakis; Allergen; motif; Tandem repeat; UA3
Imprenta: Allergy, v. 63, n. 2, p. 219-225, 2008
Identificador do objeto digital: 10.1111/j.1398-9995.2007.01564.x
Descritores: Aedes aegypti - DNA ; Aedes aegypti - Immunology ; Aedes aegypti - Molecular screening
Data de publicação: 2008
