Figure 1.

Atorvastatin enhanced the expansion of myeloid‐derived suppressor cells (MDSCs) in vitro. (a) Mouse bone marrow (BM) cells were cultured in the presence of granulocyte–macrophage colony‐stimulating factor (GM‐CSF) (20 ng/ml) and 5 μm atorvastatin. DMSO was used as control. The frequency of MDSCs (CD11b⁺ Gr‐1⁺), MDSCs subsets, and dendritic cells (DCs) (CD11c⁺ MHC‐II⁺) were measured by flow cytometry analysis. Representative data from a single experiment (left), as well as mean + SEM of three independent experiments (right) are shown. (b) The suppressive function of atorvastatin‐derived and control granulocytic (G‐) MDSCs (CD11b⁺ Gr‐1^high) was determined. C57BL/6 mouse BM cells were cultured in the presence of GM‐CSF and interleukin‐6 (IL‐6) (20 ng/mL) for 5 days with atorvastatin or DMSO control. G‐MDSCs (CD11b⁺ Gr‐1^high) were purified by flow cytometric sorting. Allogeneic CD3⁺ T cells containing CD4⁺ and CD8⁺ T cells (from BALB/c mice) were stimulated with anti‐CD3/CD28 antibodies, and co‐cultured with isolated G‐MDSCs at different ratios for 3 days. CD4⁺ and CD8⁺ T‐cell proliferation was determined by CFSE dilution. Unstimulated T cells were used as a negative control. Representative data from a single experiment (left), as well as mean+SEM of three independent experiments (right) are shown. Ator, atorvastatin. *P < 0·05, **P < 0·01.