1. Department of Neurology and Neurological Sciences, Beckman Center for Molecular Medicine, Stanford University, Stanford, California 94305, USA
2. Department of Pathology (Neuropathology), Stanford University, Stanford, California 94305, USA
3. Department of Neurology, University of California San Francisco, 521 Parnassus Avenue, San Francisco, California 94143, USA
4. Present address: Department of Medicine, California Pacific Medical Center, 2333 Buchanan Street, San Francisco, California 94115, USA

Correspondence to: Scott S. Zamvil² Correspondence and requests for materials should be addressed to S.S.Z. (e-mail: Email: zamvil@itsa.ucsf.edu).

Abstract

Statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, which are approved for cholesterol reduction, may also be beneficial in the treatment of inflammatory diseases^{1, 2, 3}. Atorvastatin (Lipitor) was tested in chronic and relapsing experimental autoimmune encephalomyelitis, a CD4⁺ Th1-mediated central nervous system (CNS) demyelinating disease model of multiple sclerosis^{4, 5}. Here we show that oral atorvastatin prevented or reversed chronic and relapsing paralysis. Atorvastatin induced STAT6 phosphorylation and secretion of Th2 cytokines (interleukin (IL)-4, IL-5 and IL-10) and transforming growth factor (TGF)-. Conversely, STAT4 phosphorylation was inhibited and secretion of Th1 cytokines (IL-2, IL-12, interferon (IFN)- and tumour necrosis factor (TNF)-) was suppressed. Atorvastatin promoted differentiation of Th0 cells into Th2 cells. In adoptive transfer, these Th2 cells protected recipient mice from EAE induction. Atorvastatin reduced CNS infiltration and major histocompatibility complex (MHC) class II expression. Treatment of microglia inhibited IFN--inducible transcription at multiple MHC class II transactivator (CIITA) promoters and suppressed class II upregulation. Atorvastatin suppressed IFN--inducible expression of CD40, CD80 and CD86 co-stimulatory molecules. l-Mevalonate, the product of HMG-CoA reductase, reversed atorvastatin's effects on antigen-presenting cells (APC) and T cells. Atorvastatin treatment of either APC or T cells suppressed antigen-specific T-cell activation. Thus, atorvastatin has pleiotropic immunomodulatory effects involving both APC and T-cell compartments. Statins may be beneficial for multiple sclerosis and other Th1-mediated autoimmune diseases.

1. Department of Neurology and Neurological Sciences, Beckman Center for Molecular Medicine, Stanford University, Stanford, California 94305, USA
2. Department of Pathology (Neuropathology), Stanford University, Stanford, California 94305, USA
3. Department of Neurology, University of California San Francisco, 521 Parnassus Avenue, San Francisco, California 94143, USA
4. Present address: Department of Medicine, California Pacific Medical Center, 2333 Buchanan Street, San Francisco, California 94115, USA

Correspondence to: Scott S. Zamvil² Correspondence and requests for materials should be addressed to S.S.Z. (e-mail: Email: zamvil@itsa.ucsf.edu).