T-helper type 2 cell differentiation occurs in vitro following in vivo atorvastatin treatment. (a) Interleukin (IL)-4-reporter (green fluorescent protein (GFP)-enhanced transcript) mice were fed daily with 1, 5 or 10 mg/kg/day atorvastatin (AT) for 12 days starting 2 days prior to immunization with myelin basic protein Ac1-11. Splenic T cells were washed, taken into culture and evaluated daily for production of IL-4-reporting GFP. Ex vivo IL-4 production by T cells was also evaluated by (b) intracellular cytokine staining (day 0, gated on CD4+ T cells) and (c) enzyme-linked immunosorbent assay (supernatants taken at the time points indicated); mice injected subcutaneously daily with 150 μg glatiramer acetate (GA) in phosphate-buffered saline (PBS) served as positive control. Five mice/group were used. Shown is one representative finding out of three independent experiments performed. FITC, fluorescein isothiocyanate.