Lawrence Steinman

The HMG-CoA reductase inhibitor, atorvastatin, promotes a Th2 bias and reverses paralysis in central nervous system autoimmune disease

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. 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. 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)-β. Conversely, STAT4 phosphorylation was inhibited and secretion of Th1 cytokines (IL-2, IL-12, interferon (IFN)-γ and tumour necrosis factor (TNF)-α) 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-γ-inducible transcription at multiple MHC class II transactivator (CIITA) promoters and suppressed class II upregulation. Atorvastatin suppressed IFN-γ-inducible expression of CD40, CD80 and CD86 co-stimulatory molecules. l-Mevalonate, the product of HMG-CoA reductase, reversed atorvastatins 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.

Limited heterogeneity of T cell receptors from lymphocytes mediating autoimmune encephalomyelitis allows specific immune intervention

Experimental allergic encephalomyelitis (EAE) is an induced autoimmune disease mediated by CD4+ T lymphocytes. Analysis of T cell receptors of myelin basic protein-specific encephalitogenic T cell clones derived from six different PL/J (H-2u) or (PL/J x SJL) F1 (H-2uxs) mice revealed a limited heterogeneity in primary structure. In vivo, the majority of T lymphocytes recognize the N-terminal MBP-nonapeptide in association with I-Au and utilize the V beta 8 gene element. cDNA-sequencing showed that all T cell receptors from a panel of such T cell clones, grown in vitro, share the same V alpha gene segment. Despite heterogeneity in the D-J regions, the clones unexpectedly display a striking similarity in fine specificity. Based on these results, prevention and reversal of autoimmune disease with V beta 8-specific monoclonal antibodies was achieved.

Autoantigen microarrays for multiplex characterization of autoantibody responses

We constructed miniaturized autoantigen arrays to perform large-scale multiplex characterization of autoantibody responses directed against structurally diverse autoantigens, using submicroliter quantities of clinical samples. Autoantigen microarrays were produced by attaching hundreds of proteins, peptides and other biomolecules to the surface of derivatized glass slides using a robotic arrayer. Arrays were incubated with patient serum, and spectrally resolvable fluorescent labels were used to detect autoantibody binding to specific autoantigens on the array. We describe and characterize arrays containing the major autoantigens in eight distinct human autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. This represents the first report of application of such technology to multiple human disease sera, and will enable validated detection of antibodies recognizing autoantigens including proteins, peptides, enzyme complexes, ribonucleoprotein complexes, DNA and post-translationally modified antigens. Autoantigen microarrays represent a powerful tool to study the specificity and pathogenesis of autoantibody responses, and to identify and define relevant autoantigens in human autoimmune diseases.

Multiple sclerosis: a two-stage disease

The pathogenesis of multiple sclerosis consists of an inflammatory and neurodegnerative phase. Better understanding of these stages has aided the development of specific therapeutic targets.

Induction of a non-encephalitogenic type 2 T helper-cell autoimmune response in multiple sclerosis after administration of an altered peptide ligand in a placebo- controlled, randomized phase II trial

In this ‘double-blind’, randomized, placebo-controlled phase II trial, we compared an altered peptide ligand of myelin basic protein with placebo, evaluating their safety and influence on magnetic resonance imaging in relapsing–remitting multiple sclerosis. A safety board suspended the trial because of hypersensitivity reactions in 9% of the patients. There were no increases in either clinical relapses or in new enhancing lesions in any patient, even those with hypersensitivity reactions. Secondary analysis of those patients completing the study showed that the volume and number of enhancing lesions were reduced at a dose of 5 mg. There was also a regulatory type 2 T helper-cell response to altered peptide ligand that cross-reacted with the native peptide.

T helper type 1 and 17 cells determine efficacy of interferon-[beta] in multiple sclerosis and experimental encephalomyelitis

Interferon-β (IFN-β) is the major treatment for multiple sclerosis. However, this treatment is not always effective. Here we have found congruence in outcome between responses to IFN-β in experimental autoimmune encephalomyelitis (EAE) and relapsing-remitting multiple sclerosis (RRMS). IFN-β was effective in reducing EAE symptoms induced by T helper type 1 (TH1) cells but exacerbated disease induced by TH17 cells. Effective treatment in TH1-induced EAE correlated with increased interleukin-10 (IL-10) production by splenocytes. In TH17-induced disease, the amount of IL-10 was unaltered by treatment, although, unexpectedly, IFN-β treatment still reduced IL-17 production without benefit. Both inhibition of IL-17 and induction of IL-10 depended on IFN-γ. In the absence of IFN-γ signaling, IFN-β therapy was ineffective in EAE. In RRMS patients, IFN-β nonresponders had higher IL-17F concentrations in serum compared to responders. Nonresponders had worse disease with more steroid usage and more relapses than did responders. Hence, IFN-β is proinflammatory in TH17-induced EAE. Moreover, a high IL-17F concentration in the serum of people with RRMS is associated with nonresponsiveness to therapy with IFN-β.

Statin therapy and autoimmune disease: from protein prenylation to immunomodulation

Statins have been prescribed extensively for their cholesterol-lowering properties and efficacy in cardiovascular disease. However, compelling evidence now exists that statins also have extensive immunomodulatory properties that operate independently of lipid lowering. Consequently, much attention has been directed towards their potential as therapeutic agents for the treatment of autoimmune disease. Modulation of post-translational protein prenylation seems to be a key mechanism by which statins alter immune function. In this Review, the effect of statin therapy on immune function, and how this relates to the pathogenesis of autoimmune disease, is reviewed alongside current opinion of what the key biological targets of statins are.

How to successfully apply animal studies in experimental allergic encephalomyelitis to research on multiple sclerosis.

In their Point of View entitled “Experimental Allergic Encephalomyelitis: A Misleading Model of Multiple Sclerosis,” Sriram and Steiner 1 wrote, “The most disappointing aspect of EAE [experimental allergic encephalomyelitis] as a potential model for MS is its almost total inability to point toward a meaningful therapy or therapeutic approach for MS.” Actually, EAE has led directly to the development of three therapies approved for use in multiple sclerosis (MS): glatiramer acetate, mitoxantrone, and natalizumab. Several new approaches to MS are in clinical trials based on positive indications in preclinical work relying on EAE. New clues to the pathogenesis of MS and new potential surrogate markers for MS are shown from research involving EAE when it is critically coupled with actual findings in MS. There are pitfalls in overreliance on the EAE model, or on any animal model for any human disease. Nevertheless, over the past 73 years, the EAE model has proved itself remarkably useful for aiding research on MS. Ann Neurol 2006;60:12–21

Selection for T-cell receptor Vβ-Dβ-Jβ gene rearrangements with specificity for a myelin basic protein peptide in brain lesions of multiple sclerosis

MULTIPLE sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system in which a restricted cellular immune response has been observed. In order to establish whether such T cell responses are likely to be antigen-specific particularly with regard to myelin basic protein (MBP), we analysed T-cell receptor (TCR) gene rearrangements directly from MS brain plaques, using the polymerase chain reaction on reverse transcribed messenger RNA, and compared these with TCR of previously described MBP-specific T cell clones from MS and the rat model experimental allergic encephalomyelitis. Rearranged Vβ5.2 genes were detected in the brains of all patients who were HLA DRB1*1501, DQA1*0102, DQB1*0602, DPB1*0401. The Vβ5.2–Dβ–Jβ sequences in these MS brain plaques revealed five motifs. One of the common motifs was identical to that described for the VDJ region of a Vβ5.2 T-cell clone. This clone was from an MS patient who was HLA DRB1*1501, DQB1*0602, DPB1*0401, and it was cytotoxic towards targets containing the MBP peptide 89–106 (ref. 1). The deduced amino-acid sequence of this VDJ rearrangement, Leu-Arg-Gly, has also been described in rat T cells cloned from experimental allergic encephalomyelitis lesions, which are specific for MBP peptide 87–99 (ref. 2). VDJ sequences with specificity for this MBP epitope constitute a large fraction (40%) of the TCR Vβ5.2 N(D)N rearrangements in MS lesions. The capacity of rat T cells with these VDJ sequences to cause experimental allergic encephalomyelitis2 and the prevalence of such sequences in demyelinated human lesions indicate that T cells with this rearranged TCR may be critical in MS.

Proteomic analysis of active multiple sclerosis lesions reveals therapeutic targets

Understanding the neuropathology of multiple sclerosis (MS) is essential for improved therapies. Therefore, identification of targets specific to pathological types of MS may have therapeutic benefits. Here we identify, by laser-capture microdissection and proteomics, proteins unique to three major types of MS lesions: acute plaque, chronic active plaque and chronic plaque. Comparative proteomic profiles identified tissue factor and protein C inhibitor within chronic active plaque samples, suggesting dysregulation of molecules associated with coagulation. In vivo administration of hirudin or recombinant activated protein C reduced disease severity in experimental autoimmune encephalomyelitis and suppressed Th1 and Th17 cytokines in astrocytes and immune cells. Administration of mutant forms of recombinant activated protein C showed that both its anticoagulant and its signalling functions were essential for optimal amelioration of experimental autoimmune encephalomyelitis. A proteomic approach illuminated potential therapeutic targets selective for specific pathological stages of MS and implicated participation of the coagulation cascade.