Interleukin-4 Gene Expression in Human Peripheral Blood Mononuclear Cells

Interleukin-4 (IL-4) mRNA was detected in normal human peripheral blood mononuclear cells (PBMC) stimulated with concanavalin A by Northern blot analysis. The signal was undetectable in PBMC before the stimulation, but became detectable 3 hrs after the stimulation and reached a maximum in 3–6 h and disappeared gradually thereafter. Immunosuppressive drugs such as ciclosporin, hydrocortisone and prednisolone inhibited the IL-4 mRNA expression dose dependently. Interferon-γ did not show any inhibitory effect on IL-4 gene expression.