Effects of a diabetes-like environment in vitro on cytokine production by mouse splenocytes

Elevated levels of glucose and free fatty acids as well as changes in the cytokine production are common features of both type 1 and type 2 diabetes. Especially regarding type 1 diabetes, immunological factors are believed to be responsible for much of the disease pathology. The aim of this study was to investigate whether the diabetic environment in itself could affect cytokine production. Spleen cells from normal mice were cultured for 96 h with addition of different concentrations of glucose (2.8, 5.6, 11.1, 28 mM) or the free fatty acid palmitate (50-100 μM). Cytokine supernatant secretions and mRNA expressions were determined. The cytokine production was highest in cells cultured at 11.1 mM glucose. TNFα and IFNγ secretion was decreased by high glucose. Palmitate and/or the ethanol used to dissolve it had a suppressive effect on the secretion of all the investigated cytokines. This effect was counteracted by an elevated glucose concentration for TNFα and IFNγ, but not IL-10. In conclusion, our data suggest that metabolic aberrations characterizing a diabetic environment can have a direct impact on cytokine production by immune cells.