In vitro study of the human immune response to the pollen allergens of Parietaria

An investigation is being made of the regulatory role of different cellular and molecular components in distinct phases of the immune response in allergy, using an experimental model consisting of an allergen with well defined physicochemical and immunochemical characteristics, allergen specific T-cell clones and lines and allergen and/or isotype specific B-cells. Allergy to Parietaria, a weed which in Southern Europe causes between 40 and 80% of adult pollinosis has been chosen as a model. An approach based on complementary deoxyribonucleic acid (cDNA) technology has been used to define a dodecapeptide with a dominant antigenic determinant which binds human IgE and IgG antibodies specific for the major allergens Par o 1 and Par j 1. Fusion proteins (beta-galactosidase and glutathion S-transferase) containing the epitope have also been obtained. Par o 1 and Par j 1 specific T-cell clones and lines have been obtained from peripheral blood lymphocytes and nonapeptides with dominant epitopes and with distinct ability of inducing a TH1 or a TH2 type of T-cell response have been defined.