Clonal analysis of human T-cell responses to fractionated house dust mite antigens (Dermatophagoides pteronyssinus).
In the present study, we investigated the cellular basis of house dust mite-driven immune responsiveness in an atopic individual with perennial rhinitis. We established 40 human T-cell clones (CD3+, 4+, 8-) reactive to Dermatophagoides pteronyssinus (Dp) antigen under the restriction of HLA-DR. By using the crude Dp antigen and its 14 molecular weight (MW) fractions, we analyzed the distribution of T-cell-recognizing sites in the whole Dp extract. We tested T-cell-mediated immunity through two parameters; the identification of Dp fractions inducing T-cell proliferation, and the ability of T-cell clones to secrete IL-2, IL-4, and IFN-gamma. According to a prominent peak among fraction-driven T-cell proliferation, we observed that T-cell clones that recognized 45,000- to 95,000-MW fractions were common, while clones reactive to 15,000- to 25,000-MW fractions were less frequent. Several clones were also reactive to antigens of Dermatophagoides farinae or other insects. Based on the responses of cloned T cells, we observed at least 9 distinct T epitopes in crude Dp antigen. These T-cell clones had a heterogenous secretory pattern of cytokines. T-cell clones showed no association between their ability to produce regulatory cytokine and their recognition of particular Dp fractions.
Department of Otorhinolaryngology, Okayama University Medical School, Japan.
M
M
Okano
T
T
Nagano
T
T
Ono
Y
Y
Masuda
N
N
Ohta
D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D039741:Antigens, Dermatophagoides; D002999:Clone Cells / Q000276:immunology; D003429:Cross Reactions; D016207:Cytokines / Q000096:biosynthesis; D004391:Dust; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008925:Mites / Q000276:immunology*; D012882:Skin Tests; D013601:T-Lymphocytes / Q000276:immunology*
D000485:Allergens; D039741:Antigens, Dermatophagoides; D016207:Cytokines; D004391:Dust