MODULATION OF CYTOKINE EXPRESSION IN MOUSE DENDRITIC CELL CLONES

Dendritic cells (DC) play an essential role in the induction of primar y immune responses; however, very little information is available on c ytokine production by DC. Here we determined the cytokine gene express ion profile of two immortalized DC clones, CB1 and D2SC/1, bath genera ted from mouse spleen but differing in their activation requirements. Among the cytokines tested, only transforming growth factor-beta 1 was transcribed constitutively, but its production was detected only in D 2SC/1 cells after treatment with granulocyte/macrophage colony-stimula ting factor (GM-CSF). GM-CSF also promoted transcription and synthesis of interleukin (IL)-1 beta in CB1 cells that need pretreatment with G M-CSF to present major histocompatibility complex class II-restricted antigens efficiently in vitro. Lipopolysaccharide (LPS) up-regulated g ene expression and induced release of tumor necrosis factor-alpha in b oth DC clones. In addition, LPS induced transcription of IL-1 alpha an d both gene expression and synthesis of IL-1 beta in D2SC/1 cells. Int erferon-gamma was ineffective in inducing cytokine gene expression, al though it augmented the antigen-presentation capacity of DC. IL-4, IL- 10 and IL-12 mRNA were not induced by any of the tested stimuli. The r esults suggest that DC have a limited cytokine gene expression pattern compared to macrophages and are heterogenous in some functional prope rties.