Cloning and expression of cDNA coding for a new allergen from the house dust mite, Dermatophagoides farinae: homology with human heat shock cognate proteins in the heat shock protein 70 family.

An immunoreactive clone, which shares no homology with the major allergens, Der f I and Der f II, was isolated by screening of a Dermatophagoides farinae cDNA library with rabbit antiserum raised against an extract of the house dust mite and sera from patients with mite allergy. The deduced amino acid sequence of the cDNA of the clone is significantly homologous, up to 65.5%, to the carboxyl-terminal region of the heat shock cognate protein (hsc) 71 in the heat shock protein (hsp) 70 family. A pool of the recombinant protein-specific IgE purified from mite-allergic sera recognized a 67 kDa protein on a blot of ATP-binding components partially purified from the mite body extract, while the antibody did not bind to the major allergens. We conclude that the recombinant protein, one of several important allergens, may be a protein in the heat shock protein 70 family from the house dust mite, D. farinae.