FUNCTIONAL-EFFECTS OF POLYMORPHISMS OF HOUSE-DUST MITE ALLERGENS

Background: Sequence polymorphisms have been found in cDNA clones of c ommercial house dust mites. Here we report on the polymorphisms of Der p 1 found in environmental mites and the effect of the polymorphisms on T cell proliferation. Methods: Sequences were obtained from DNA amp lified from single mites by PCR. Synthetic peptides were used to stimu late peripheral blood cells. Results: The polymorphism was limited to a few residues, but regional differences were detected in mites in Wag ga. T cells were specific for the polymorphisms, so that in 16 of 17 r esponses, stimulation was achieved with one form of the peptide. This included peptides with Ala and Val at position 124 in the immunodomina nt 110-133 region. Peptide 45-63 also stimulated frequently, but only with Tyr at position 50 and not His, a residue only found in commercia l mites. Conclusions: Polymorphisms of Der p 1 are found in the enviro nment and have a profound effect on polyclonal T cell stimulation to f requently recognised epitopes.