IgE and IgG 4 antibodies from patients with mite allergy recognize different epitopes of Dermatophagoides pteronyssinusgroup II antigen (Der p 2)

Abstract

BACKGROUND: Der p 2, composed of 129 amino acids, is one of the major allergens of Dermatophagoides pteronyssinus . Several groups reported epitope mapping of IgE antibody but not of IgG or IgG subclass antibodies in Der p 2. OBJECTIVE: The purpose of this study was to compare the epitopes recognized by Der p 2–specific IgE antibodies with those recognized by IgG 4 antibodies. METHODS: Recombinant fusion proteins containing a full-length peptide or overlapping five fragments of Der p 2 were prepared and analyzed for their reactivity with IgE and IgG subclass antibodies in sera from patients with mite allergy by means of Western blot procedure. RESULTS: IgE antibodies in 12 of 13 sera tested bound to full-length Der p 2 (1-129). In 11 of these 12 sera, IgE antibodies bound to one or more of fragments 41-80, 64-105, or 81-129 but not to those of 1-40 or 20-63. Of the 11 sera in which the IgE antibodies to the fragments were detected, only four contained detectable levels of IgG 4 antibodies reactive to the fragments. The binding spectra of the IgG 4 antibodies against the fragments were rather wide and differed from those of IgE antibodies. CONCLUSION: Results revealed that there are differences in epitope recognition between IgE and IgG 4 antibodies; IgE antibodies recognize restricted parts of Der p 2 antigen compared with IgG 4. (J A LLERGY C LIN I MMUNOL 1996;97:638-45.)