BACKGROUND: It is known that immunotherapy promotes the development of allergen-specific Thl-like lymphocytes whose products are effective in inhibiting clinical response of sensitized atopic patients to allergen exposure. At the single cell level in short term culture, however, IL-4 and IL-5 are co-expressed, while IL-4 and IFN-y are exclusively expressed. OBJECTIVE: IL-4, IL-5, and IFN-y mRNA were measured in Der pI-specific T-cell clones (TCCs) to evaluate whether expression of cytokine in allergen-specific TCC is fixed regardless of stimuli. METHOD: Seven Der pI-specific TCCs were made from two asthmatics sensitive to D. pteronyssinus. IL-4, IL-5, and IFN-y mRNA were measured by RT-PCR in these TCCs after antigen-specific (Der pI) and nonspecific (PHA + TPA) stimuli. RESULTS: IL-4 and IL-5 mRNA were expressed in four and six of seven TCCs, but IFN-y mRNA was not expressed in any TCCs after Der pI-specific stimuli. Meanwhile, after the stimulus of TPA plus PHA, IFN-y mRNA as well as IL-4 and IL-5 mRNA were expressed in four of seven TCCs, and in one TCC, only IFN-y mRNA was expressed without expression of IL-4 mRNA. CONCLUSION: The expression of cytokine may be variable in allergen-specific TCC according to the type and amount of stimuli.
Asthma ; Clone Cells* ; Humans ; Immunotherapy ; Interleukin-4* ; Interleukin-5* ; Lymphocytes ; RNA, Messenger* ; T-Lymphocytes*