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.