Characterization of allergens from Trisetum paniceum pollen: an important aeroallergen in Mediterranean continental climatic areas.

BACKGROUND

Trisetum paniceum is a grass plant which is characteristic of a Mediterranean continental climate and has been described as one of the major causes of type I allergy in the Madrid region.

OBJECTIVES

To identify and characterize the allergens of Trisetum paniceum pollen.

METHODS

Allergenic extracts were prepared by 24 h incubation of pollens in a buffered solution. Proteins were analysed by a new two-dimensional system in which agarose plates were used for isoelectric focusing. Two-dimensionally resolved proteins were electrically transferred to Immobilon membranes and the allergens immunochemically detected. Proteins from six grass pollens were bound to a membrane and incubated with a pool of serum from grass-pollen-sensitized patients. The bound IgE antibodies were then eluted and used to identify the proteins of Trisetum paniceum pollen that allergenically crossreact with allergens from other pollen grasses.

RESULTS

Relative to total protein content, Trisetum paniceum pollen had a high proportion of reactive proteins. On the basis of their molecular characteristics, allergens could be classified as group 1, 2, 4 and 5 components yet included an atypical proportion of basic components. All identified allergens were crossreactive with allergens from the remaining grass pollens studied.

CONCLUSIONS

Trisetum paniceum pollen contains a high proportion of allergens and these include a group of basic proteins which are not detected in other phylogenetically related pollens and could be of allergological interest.