LONG-LIVED TH2 CLONES SPECIFIC FOR SEASONAL AND PERENNIAL ALLERGENS CAN BE DETECTED IN BLOOD AND SKIN BY THEIR TCR-HYPERVARIABLE REGIONS

We investigated the longevity of allergen-specific Th cells derived fr om patients suffering from either allergic rhinitis or atopic dermatit is. T cell clones (TCC) specific for seasonal and perennial allergens were raised. To determine whether these TCC were long-lived in vivo, P BMC and allergen-specific polyclonal T cell lines, collected and estab lished inside a period of up to 4 years, were screened for the TCC of interest, For this purpose, a T cell tracing protocol was established in which oligonucleotides specific for the TCR beta-chain hypervariabl e junctional region were used as tools to identify each particular TCC , Seven pollen-specific TCC and two house dust mite-specific TCC, with a Th2-like cytokine production pattern in vitro, were demonstrated to be long-lived memory T cells in vivo. Specificity of the tracing prot ocol was ascertained bg TCR sequence analysis. We conclude that allerg en-specific TCC can persist for years, evidence for which can be monit ored in blood, but also in the target organ of the allergic disorder. The data indicate that in vitro-characterized, allergen-specific, long -lived TCC may well reflect a repertoire of T lymphocytes of pathogene tic importance in vivo.