Atorvastatin (0.05, 0.1, 1, or 10 mg/kg/d) was administered daily by oral gavage to mice (5 per group) starting 9 days prior to immunization with MBP Ac1-11. of atorvastatin and GA in MS. Introduction MS is an inflammatory autoimmune CNS demyelinating disease that is thought to be mediated in part by myelin-specific lymphocytes (1C3). Different classes of immunomodulatory providers with distinct mechanisms of action are authorized for MS treatment (4C6). However, the current MS medications are only partially effective; they can be associated with side effects and potential toxicities, and there is ongoing debate concerning long-term effectiveness of certain providers (7, 8). While one strategy to improve MS therapy is definitely RAF1 to develop novel providers that may have greater effectiveness, it is important to identify existing or novel classes of medicines that may match one another in combination to provide additive or synergistic benefit (9). Glatiramer acetate (GA, also referred to as Copaxone and copolymer 1) is an immunomodulatory agent authorized for treatment of relapsing-remitting MS (5). GA is definitely a synthetic fundamental random copolymer composed of tyrosine (Y), glutamate (E), alanine (A), and lysine Clindamycin (K) that appears to preferentially affect T cells specific for CNS autoantigens (10), altering their antigen/MHC acknowledgement in a manner similar to that of modified peptide ligands (11). Sustained treatment with GA in MS individuals has been associated with the secretion of protecting Th2 cytokines by some myelin-reactive CD4+ T cells (12, 13). Recent data from GA-treated MS individuals suggest that GA also mediates immunomodulatory activity on APCs, advertising secretion of antiinflammatory cytokines and inhibiting secretion of proinflammatory cytokines (14C17). One can envisage that an agent that augments GA-mediated immunomodulation of myelin-reactive lymphocytes or APCs could enhance the effectiveness of GA in MS therapy (9, 18). Recent studies have shown that oral cholesterol-lowering HMG-CoA reductase inhibitors (known as statins) have immunomodulatory properties that may be beneficial in the treatment of T cellCmediated, organ-specific autoimmune diseases and additional inflammatory conditions (19C21). Promising results were acquired in initial medical trials screening simvastatin (Zocor) and atorvastatin (Lipitor) in MS (22) and RA (23), respectively. Atorvastatin is currently being tested inside a placebo-controlled trial in early MS (http://immunetolerance.org/staycis/). In EAE models, atorvastatin has been shown to promote differentiation and development of myelin protein-reactive regulatory Th2 cells and to suppress upregulation of MHC class II and costimulatory molecules on APCs, indicating that the beneficial immunomodulatory effects of statins may involve both APC and T cell compartments (24, 25). Mevalonate, the product of HMG-CoA reductase, can reverse most, if not all, statin-induced immune effects on Clindamycin APCs (24, 26) and T cells (24, 25, 27), indicating that statins mediate immunomodulation by interfering with synthesis of mevalonate and its isoprenoid metabolites that are involved in posttranslational changes of GTP-binding signaling molecules. As atorvastatin treatment can promote the development of protecting myelin-reactive Th2 cells and does so utilizing a different mechanism of action than GA, we have tested whether atorvastatin could augment the restorative and immunomodulatory effects of GA on myelin-reactive T cells in EAE. In this statement we demonstrate that atorvastatin and GA can match each other inside a synergistic manner in EAE treatment. Clinical EAE was prevented or reversed in mice by combination therapy using suboptimal doses of atorvastatin and GA and was associated with reduced CNS swelling and less demyelination than in mice treated with either drug only at the same doses. This combination therapy was associated with enhanced secretion of protecting Th2 cytokines and reduced production of proinflammatory Th1 cytokines. Monocytes treated with this combination secreted a type II antiinflammatory cytokine pattern and advertised Th2 differentiation of naive myelin-specific T cells, suggesting that 1 mechanism that contributed to the development of this medical and immunomodulatory synergy occurred at the level of the APC. Our results highlight how the EAE model can be used in preclinical screening Clindamycin to identify complementary activity between providers that might be regarded as for combination therapy in MS. Results Atorvastatin and GA in combination do not antagonize each other. While it is considered advantageous to combine.