Cloned human T lymphocytes reactive with Dermatophagoides farinae (house dust mite): a comparison of T- and B-cell antigen recognition.

In this report, T-cell and B-cell recognition of the house dust mite Dermatophagoides farinae (D. far.) is compared. Nitrocellulose immunoblots of polyacrylamide gel electrophoresis (SDS-PAGE)-fractionated D. far. were added to proliferation assays to map the antigen specificity of cloned human helper T cells and a long-term line induced with D. far. T-cell recognition was of a polypeptide of molecular weight 9000-13,000, that migrates with the serologically defined allergen Der fII (12,500 MW). Since the cloned T cells, unlike the polyclonal response, failed to respond to Dermatophagoides pteronyssinus (D. pter.), this suggests that they recognize a species-specific epitope. In contrast, analysis of the B-cell response using Western blotting demonstrated that, in addition to Der fII, antibodies reactive with the major allergens Der fI (26,000 MW) and Der fIII (29,000 MW) were present in the serum. Similar specificities were seen in the antibody response to D. pter., and while it has been reported that the B-cell response to D. far. and D. pter. are predominantly cross-reactive, our observations suggest that species-specific CD4-positive T cells are present in the overall cellular response to D. far.