IgE-mediated reactions to autoantigens in allergic diseases

Background: There is increasing evidence that IgE-mediated reactivity again st autoantigens could play a role in the pathology of severe chronic atopic diseases. Methods: Human mitochondrial managenese superoxide dismutase (Mn SOD), acidic ribosomal P-2 protein and cyclophilins were cloned by PCR, exp ressed as inclusion body proteins in Escherichia coli, purified by Ni2+ che late affinity chromatography, refolded in vitro and used for further experi ments, Results: Human MnSOD, PZ ribosomal protein and cyclophilins respecti vely, show sequence identity and similarity of >50% and 70% to the correspo nding allergens of Aspergillus fumigatus. The human proteins were able to b ind IgE from sera of individuals sensitized to the mould proteins and to el icit strong skin reactions of the immediate type in these individuals. Conc lusions:These observations provide evidence for autoreactivity to human pro teins in allergic persons chronically sensitized to environmental allergens from A. fumigatus which share a high degree of sequence homology to the co rresponding human proteins.