RATIONALE: Cyclophilins are large families of proteins that are ubiquitous, highly expressed and relatively conserved from diverse microorganisms to higher mammals. Several cyclophilins have been shown to be allergenic such as Bet v 7, and cyclophilin from Malassezia sympodialis. We recently identified several cyclophilins from house dust mites and allergenic fungi, and seek to cross compare their IgE binding capacities with human and murine cyclophilins. METHODS: We cloned and expressed cyclophilins from human, mouse, house dust mites (Dermatophagoides farinae and Suidasia medanensis) and fungi (Aspergillus fumigatus, Curvularia lunata and Saccharomyces cerevisiae) in Escherichia coli. The allergenicity of these orthologs was evaluated by immunoblotting using a consecutive panel of 151 sera from allergic individuals. IgE inhibition assays were performed using competitive ELISA. RESULTS: A total of 18/151 (11.9%) of the sera responded to fungal cyclophilins while 25/181 (13.8%) and 8/151 (5.3%) responded to dust mite and human cyclophilins, respectively. The IgE binding responses against both fungal cyclophilins (A. fumigatus and C. lunata) were highly correlated but differed significantly from dust mite cyclophilins. IgE inhibition assays show that fungal cyclophilins could totally cross inhibit one another but not dust mite cyclophilins. Both fungal and dust mite cyclophilins however could inhibit the IgE binding response to human cyclophilin. CONCLUSIONS: Cyclophilins from diverse sources are an important source of pan-allergens which may share some cross reactive and unique epitopes within their group of antigens.
Full conference title:
2006 American Academy of Allergy, Asthma, and Immunology Annual Meeting
- AAAAI 2006 (62nd)