DERMATOPHAGOIDES-PTERONYSSINUS II-INDUCED INTERLEUKIN-4 AND INTERFERON-GAMMA EXPRESSION BY FRESHLY ISOLATED LYMPHOCYTES OF ATOPIC INDIVIDUALS

Cytokines are known to play a major role in mediating many of the immu nological and pathological features of allergic disease. Much of our u nderstanding of cytokine production in response to allergens has come from studying allergen-specific T cell clones following long-term in v itro o culture. This has largely been due to the lack of sufficiently sensitive assays to measure allergen-induced cytokine production by fr eshly isolated peripheral blood mononuclear cells (PBMCs). Here we hav e used the polymerase chain reaction to amplify reverse transcribed in terleukin-4 (IL-4) and IFN gamma mRNA expressed by allergen-stimulated PBMCs from a variety atopic individuals. Using Der p II, a major alle rgen of the house dust mite (HDM) Dermatophagoides pteronyssinus, we h ave demonstrated that cells from HDM-sensitive atopic patients (n = 12 ), can be induced to express either IL-4 alone (three patients), IL-4 and IFN gamma (six patients), IFN gamma alone (two patients) or neithe r cytokine (one patient). Cells from 13 non-atopic control individuals were also stimulated with Der p II and cytokine mRNA production was s tudied. None expressed IL-4, while seven of 13 transcribed IFN gamma. Our results suggest that atopic individuals have allergen-reactive T c ells at various stages of differentiation, with respect to the cytokin es they produce. The use of this technique will aid in the further und erstanding of specific cellular hypersensitivity in allergic disease.