Antigenic relation between house dust and a dust mite, Dermatophagoides farinae , by a fractionation method

Abstract

Both house dust and mite ( Dermatophagoides farinae Hughes, 1961) extracts were filtrated through Sephadex G-50 and 200 with I 131-labeled human serum albumin and phenol as indicators. Protein and sugar contents of each constituent were determined by absorbance at 280 mμ and by a slightly modified anthrone method, respectively. The end point of skin test-eliciting capacity with twofold dilutions of each fraction was determined in 6 house dust-sensitive subjects. The tube numbers of the eluent of the house dust or the mite extract containing the most potent antigen eliciting skin reactions in house dust-sensitive subjects agreed with each other, but these fractions did not necessarily match the protein or sugar content. Moreover, these potent fractions did not appear to match the antigen producing precipiting bands against antiserum of the experimental animals. Consequently, it was thought that the most allergenic constituent in house dust and mites is not necessarily the most antigenic in experimental animals. Considering the location of the most potent, active eluate in allergic subjects on Sephadex, the molecular weight of such antigen was thought to be larger than 10,000 but smaller than 69,000, and the composition of such antigen was considered to be probably a protein and polysaccharide conjugate. Further study in this line is in progress.