CLONING AND EXPRESSION OF THE PANALLERGEN PROFILIN AND THE MAJOR ALLERGEN (OLE-E-1) FROM OLIVE TREE POLLEN

Background: Olive tree (Olea europaea) pollen allergy is one of the ma in causes of allergy in Mediterranean countries and some areas of Nort h America. Objective: To clone olive allergens and to characterize imm unologically the purified recombinant allergens. Methods: Full-length complementary deoxyribonucleic acid (cDNA) strands encoding olive alle rgens (Ole e 1) were cloned by polymerase chain reaction amplification and sequenced. Recombinant proteins were produced in Escherichia coli by the use of two different expression systems. Immunoreactivity of t he recombinant proteins was tested by ELISA and Western blot with seru m from patients with allergy to olive. Results: Significant sequence p olymorphism was found in both allergens, The panallergen profilin was expressed as a nonfusion protein and was purified to homogeneity after a single step of affinity chromatography with a poly-1-proline Sephar ose column. One cDNA encoding an Ole e 1 isoform was expressed as a fu sion protein consisting of the glutathione S-transferase of Schistosom a japonicum and Ole e 1. The fusion protein was purified to homogeneit y by gel filtration chromatography and affinity chromatography with a glutathione-Sepharose column, and digested with thrombin. Both recombi nant allergens shared B cell epitopes with the corresponding natural a llergens. Conclusion: IgE-reactive Ole e 1 and olive profilin expresse d in bacteria were purified after simple chromatographic procedures an d may be useful for diagnostic purposes.