Journal of leukocyte biology
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Dendritic cells (DCs) activate T cells and regulate their differentiation into T helper cell type 1 (Th1) and/or Th2 cells. To identify DCs with differing abilities to direct Th1/Th2 cell differentiation, we cultured mouse bone marrow progenitors in granulocyte macrophage-colony stimulating factor (GM), GM + interleukin (IL)-4, or GM + IL-15 and generated three distinct DC populations. The GM + IL-4 DCs expressed high levels of CD80/CD86 and major histocompatibility complex (MHC) class II and produced low levels of IL-12p70. ⋯ A similar pattern of T cell activation was observed after in vivo administration of DCs. These data suggest that IL-12p70 production alone, although necessary for Th1 differentiation, is not sufficient to induce Th1 responses. These studies have implications for the use of DC-based vaccines in immunotherapy of cancer and other clinical conditions.