Cross-reactivity within the profilin panallergen family investigated by comparison of recombinant profilins from pear (Pyr c 4), cherry (Pru av 4) and celery (Api g 4) with birch pollen profilin Bet v 2

J Chromatogr B Biomed Sci Appl. 2001 May 25;756(1-2):315-25. doi: 10.1016/s0378-4347(01)00090-1.

Abstract

Profilin is a panallergen which is recognised by IgE from about 20% of birch pollen- and plant food-allergic patients. Little is known about epitope diversity among these homologous proteins, and about the correlation between IgE-cross-reactivity and allergenic reactivity. Plant food profilins from pear (Pyr c 4) and cherry (Pru av 4) were cloned by polymerase chain reaction and produced in Escherichia coli BL21. The profilins were purified as non-fusion proteins by affinity chromatography on poly-(L-proline)-Sepharose and characterized by immunoblotting, IgE-inhibition experiments and histamine release assays. The coding regions of the cDNA of pear and cherry profilin were identified as a 393 bp open reading frame. The deduced amino acid sequences showed high identities with birch pollen profilin Bet v 2 (76-83%) and other allergenic plant profilins. Pyr c 4 and Pru av 4 were investigated for their immunological properties in comparison with profilins from celery (Api g 4) and birch pollen (Bet v 2). Fourty-three of 49 patients (88%), preselected for an IgE-reactivity with Bet v 2 showed specific IgE-antibodies to the recombinant pear protein, 92% of the sera were positive with the recombinant cherry allergen and 80% of the sera were reactive with the celery protein. Inhibition experiments showed a strong cross-reactivity of IgE with profilins from plant food and birch pollen. However, IgE binding profiles also indicated the presence of epitope differences among related profilins. All investigated profilins, Pyr c 4, Pru av 4, Api g 4 and Bet v 2, presented almost identical allergenic properties in cellular mediator release tests. Therefore, cross-reactivities between related profilins may explain pollen-related allergy to food in a minority of patients. The nucleotide sequences reported have been submitted to the Genbank database under accession numbers AF129424 (Pyr c 4) and AF129425 (Pru av 4).

Publication types

  • Comparative Study

MeSH terms

  • Allergens / immunology*
  • Allergens / isolation & purification
  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Contractile Proteins*
  • Cross Reactions*
  • DNA Primers
  • DNA, Complementary
  • Histamine Release
  • Humans
  • Microfilament Proteins / immunology*
  • Microfilament Proteins / isolation & purification
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • Profilins
  • Recombinant Proteins / immunology
  • Recombinant Proteins / isolation & purification
  • Sequence Homology, Amino Acid

Substances

  • Allergens
  • Contractile Proteins
  • DNA Primers
  • DNA, Complementary
  • Microfilament Proteins
  • Profilins
  • Recombinant Proteins

Associated data

  • GENBANK/AF129424
  • GENBANK/AF129425