[Analysis and Regulation of Interferon-Gamma Production by Peripheral Blood Lymphocytes from Patients with Bronchial Asthma].

As with normal lymphocytes, small amounts of interferon-gamma (IFN-gamma) were spontaneously produced by lymphocytes from patients with bronchial asthma, and this bronchial asthma, and this production was markedly enhanced by concanavalin A (Con A) stimulation. Distinct from normal lymphocytes, however, IFN-gamma synthesis from patients' lymphocytes decreased in a dose dependent manner on stimulation with Dermatophagoides farinae (Df) antigen. IFN-gamma-producing cells are defined as being of the CD4+ 45RO+ T cell subset, which failed to produce IFN-gamma in Df-stimulated patients' lymphocytes. As the decreased production of IFN-gamma by antigenic stimulation was exclusively induced by Df antigen, but not by ovalbumin (OVA) or Japanese cedar (JC) antigen, it is concluded that Df antigen specifically suppressed IFN-gamma production in patients' lymphocytes. The IFN-gamma synthesis from normal lymphocytes was suppressed by the addition of IL-4 in a dose dependent manner. Moreover, anti-IL-4 antibody dose dependently enhanced IFN-gamma production from Df-stimulated patients' lymphocytes but not from unstimulated lymphocytes. These results indicate that IFN-gamma production by patients' lymphocytes is suppressed by the endogenous IL-4. Reduced IFN-gamma production in patients' lymphocytes on stimulation with Df antigen may lead to the overproduction of IgE in vivo.