Interleukin-1 enhances XXXX 2,3-dioxygenase activity by increasing specific mRNA expression in human mononuclear phagocytes.

@entity3035 @entity1357 @entity1778 @entity379 @entity1192 @entity9218
The objective of this study was to determine the utility of the @entity1357 monocytic @entity1778 cell line as a model for analyzing molecular mechanisms involved in enhancement of @entity379 -induced @entity3035 dioxygenase ( @entity9218 ) activity by interleukin-1 ( @entity1192 ). Following treatment of @entity1357 cells with combinations of @entity379 and @entity1192 , @entity9218 activity and @entity9218 mRNA were quantified by HPLC and radioanalytic imaging of RT-PCR products, respectively. @entity1192 increased the amount of @entity9218 activity and the expression of @entity9218 mRNA in IFN-treated cells; @entity1192 alone had no effect on untreated @entity1357 cells. Because @entity9218 gene regulation might differ between immature @entity1357 cells and mature macrophages, experiments were repeated using primary macrophage cultures. @entity379 induced @entity9218 activity, and @entity9218 mRNA was expressed in a dose-dependent manner. In the presence of @entity1192 , 10 times less IFN was required to obtain the same amount of @entity9218 mRNA and @entity9218 activity. Furthermore, @entity1192 alone increased @entity9218 mRNA expression. It appears that unlike what was observed in @entity1357 cells, @entity1192 transcriptionally activates the @entity9218 gene in primary macrophages. However, increases in @entity9218 activity were not observed following treatment with @entity1192 alone. Although the @entity1357 cell may be used to model cytokine potentiation of IFN-induced @entity9218 activity, some differences in regulation between @entity1357 cells and primary macrophage cultures may exist.
