Fig. 3.

Interleukin (IL-10) regulation in T-helper type 1 (Th1) switching cells is not dependent on isoprenylation, vitamin D3 or cellular cholesterol content. Purified human CD4⁺ T cells stimulated in vitro with plate-bound α-CD3 (2 μgml⁻¹) + α-CD46 (5 μgml⁻¹) and recombinant human interleukin-2 (rhIL-2) (50Uml⁻¹) were cultured for 36 h in the presence of selected metabolites and inhibitors as indicated. a Representative flow cytometric analysis of intracellular interferon-γ (IFNγ) and IL-10 staining of cells treated with different formulations of statin (data representative of three independent donors). b Normalised frequency of IL-10⁺ cells cultured in the presence of inhibitors for farnesyl-PP transferase (FTase I inhibitor) (left) (n = 4), geranylgenaryl transferase I (GGTI-298) (centre) (n = 4) and Rab geranylgeranyl transferase (psoromic acid) (right) (n = 5). c Normalised frequency of IL-10⁺ cells cultured with 5μM atorvastatin (AT) and increasing concentrations of farnesylpyrophosphate (FPP) (left) and geranylgeranylphyrophosphate (GGPP) (right) and mevalonic acid (MA) as control (n = 5). d Normalised frequency of IL-10⁺ cells cultured in the presence of increasing concentrations of U18666A (n = 6). e Normalised frequency of IL-10⁺ cells cultured with 5 μM atorvastatin (AT) and increasing concentrations of calcitriol and mevalonic acid (MA) as a control (n = 5). f Normalised total cellular cholesterol content measured by liquid chromatography mass spectrometry. The [cholesterol –H₂O + H]⁺ ion was the dominant adduct for cholesterol and relative intensity is shown for this ion (n = 3). Graphs show independent donors (dots) normalised to 0μM dose of atorvastatin; bars represent median values. *<0.05 denote a significant difference compared to untreated cells by Friedman test with post hoc Dunn’s correction (d)