查看文章

Macrophage-derived chemokine (MDC) is a CC chemokine that recognizes the CCR4 receptor and is selective for T helper 2 (Th2) versus T helper 1 (Th1) cells. The present study was designed to investigate the effect of the prototypic Th2/Th1 cytokines, interleukin-4 (IL-4) and interferon-γ (IFN-γ), on the production of MDC by human monocytes. IL-4 and IL-13 caused a time-dependent (plateau at 24 hours) and concentration-dependent (EC₅₀ 2 and 10 ng/mL, respectively) increase of MDC mRNA levels in monocytes. Increased expression of MDC mRNA was associated with protein release in the supernatant. MDC expression and production induced by IL-4 and IL-13 were inhibited by IFN-γ. IFN-γ also suppressed the constitutive expression of MDC in mature macrophages and dendritic cells. These results delineate an amplification loop of polarized Th2 responses based on differential regulation of MDC …