CLONING AND IMMUNOLOGICAL CHARACTERIZATION OF THE ALLERGEN HEL-A-2 (PROFILIN) FROM SUNFLOWER POLLEN

Sunflower (Helianthus annuus) sensitization is not always related with occupational allergy. We have isolated the allergen profilin (Hel a 2 ) from this Compositae plant, cloned and sequenced five cDNAs encoding for full-length or partial Hel a 2. Natural sunflower profilin reacte d with specific IgE in the 121 sera tested, at a frequency of 30.5%. E xpression of the cDNA encoding Hel a 2 in Escherichia coli and a simpl e purification procedure by poly-L-proline chromatography allowed immu nological characterization of the recombinant allergen. Binding of mon oclonal antibodies against sunflower profilin revealed that some epito pes responsible for antigen-specific IgG production were not present i n the recombinant allergen. High cross-reactivity has been found betwe en recombinant Hel a 2 and profilins from other Compositae plants and also from botanically distant plants. (C) 1998 Elsevier Science Ltd. A ll rights reserved.