Pedro J. Ruiz

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.

Suppressive vaccination with DNA encoding a variable region gene of the T-cell receptor prevents autoimmune encephalomyelitis and activates Th2 immunity.

A variable region gene of the T–cell receptor, Vβ8.2, is rearranged, and its product is expressed on pathogenic T cells that induce experimental autoimmune encephalomyelitis (EAE) in H–2u mice after immunization with myelin basic protein (MBP). Vaccination of these mice with naked DNA encoding Vβ8.2 protected mice from EAE. Analysis of T cells reacting to the pathogenic portion of the MBP molecule indicated that in the vaccinated mice there was a reduction in the Thl cytokines interleukin–2 (IL–2) and interferon–γ. In parallel, there was an elevation in the production of IL–4, a Th2 cytokine associated with suppression of disease. A novel feature of DNA immunization for autoimmune disease, reversal of the autoimmune response from Thl to Th2, may make this approach attractive for treatment of Thl–mediated diseases like multiple sclerosis, juvenile diabetes and rheumatoid arthritis.

Combination of gene delivery and DNA vaccination to protect from and reverse Th1 autoimmune disease via deviation to the Th2 pathway

Using a combination of local gene delivery and tolerizing DNA vaccination, we demonstrate that codelivery of the interleukin-4 (IL-4) gene and a DNA vaccine encoding the self-peptide proteolipid protein 139-151 (PLP139-151) provides protective immunity against experimental autoimmune encephalomyelitis (EAE). We provide evidence for a mechanism whereby IL-4 expressed from the naked DNA is secreted and acts locally on autoreactive T cells via activation of STAT6 to shift their cytokine profile to T helper 2. We also show that DNA vaccines can be used to reverse established EAE by covaccination with the genes for myelin oligodendrocyte glycoprotein and IL-4. This treatment strategy combines the antigen-specific effects of DNA vaccination and the beneficial effects of local gene delivery.

An Immunomodulatory GpG Oligonucleotide for the Treatment of Autoimmunity via the Innate and Adaptive Immune Systems

Bacterial DNA and immunostimulatory CpG oligodeoxynucleotides (ODNs) activate the innate immune system to produce proinflammatory cytokines. Shown to be potent Th1-like adjuvants, stimulatory CpG motifs are currently used as effective therapeutic vaccines for various animal models of infectious diseases, tumors, allergies, and autoimmune diseases. In this study, we show that the application of an immunomodulatory GpG ODN, with a single base switch from CpG to GpG, can effectively inhibit the activation of Th1 T cells associated with autoimmune disease. Moreover, this immunomodulatory GpG ODN suppresses the severity of experimental autoimmune encephalomyelitis in mice, a prototypic Th1-mediated animal disease model for multiple sclerosis.

Late Pregnancy Suppresses Relapses in Experimental Autoimmune Encephalomyelitis: Evidence for a Suppressive Pregancy-Related Serum Factor

Women with multiple sclerosis have significantly diminished disease activity during pregnancy. The purpose of our study was to identify the underlying mechanism for the diminished disease activity. We found that during the period of late pregnancy there is protection against paralysis, during both the induction and effector phases of relapsing experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. We did not find any changes in the cytokine secretion profiles or the proliferative activity of autoreactive T cells from mice induced during late pregnancy compared with virgin controls. In mice mated after disease onset, the inflammatory histologic lesions did not clear, despite marked clinical improvement during pregnancy. We found evidence for a serum factor present in late pregnancy that suppresses T cell activation. In the presence of sera taken from mice late in pregnancy, the proliferative response and IL-2 production of proteolipid protein p139–151-specific T cells were significantly diminished as compared with stimulation in the presence of normal mouse sera. In conclusion, serum from late pregnancy has the capacity to down-regulate T cell responses and might be associated with the amelioration of disease activity in experimental autoimmune encephalomyelitis.

Systemic lupus erythematosus in mice, spontaneous and induced, is associated with autoimmunity to the C-terminal domain of p53 that recognizes damaged DNA.

The tumor suppressor molecule p53 features a regulatory domain at the C terminus that recognizes damaged DNA. Since damaged DNA might be involved in activating anti‐DNA autoantibodies, we tested whether autoimmunity to the C terminus of p53 might mark murine systemic lupus erythematosus (SLE). We now report that MRL / MpJ‐Faslpr mice, which spontaneously develop SLE, produce antibodies both to the C terminus of p53 and to a monoclonal antibody (PAb‐421) that binds the p53 C terminus. Anti‐idiotypic antibodies to PAb‐421 (sampled as monoclonal antibodies) could also bind DNA. Thus, the PAb‐421 antibody mimics DNA, and the anti‐idiotypic antibody to PAb‐421 mimics the p53 DNA‐binding site. This mimicry was functional; immunization of BALB / c mice to PAb‐421 induced anti‐DNA antibodies and antibodies to the C terminus of p53, and most of the mice developed an SLE‐like disease. Immunization of C57BL / 6 mice to PAb‐421 induced antibodies to p53, but not to its C‐terminal domain. The C57BL / 6 mice also did not develop anti‐DNA antibodies or the SLE‐like disease. Thus, network autoimmunity to the domain of p53 that recognizes damaged DNA can be a pathogenic feature in SLE in genetically susceptible strains of mice.

Inhibition of Epidermal Growth Factor Receptor Tyrosine Kinase Ameliorates Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is an autoimmune synovitis characterized by the formation of pannus and the destruction of cartilage and bone in the synovial joints. Although immune cells, which infiltrate the pannus and promote inflammation, play a prominent role in the pathogenesis of RA, other cell types also contribute. Proliferation of synovial fibroblasts, for example, underlies the formation of the pannus, while proliferation of endothelial cells results in neovascularization, which supports the growth of the pannus by supplying it with nutrients and oxygen. The synovial fibroblasts also promote inflammation in the synovium by producing cytokines and chemokines. Finally, osteoclasts cause the destruction of bone. In this study, we show that erlotinib, an inhibitor of the tyrosine kinase epidermal growth factor receptor (EGFR), reduces the severity of established collagen-induced arthritis, a mouse model of RA, and that it does so by targeting synovial fibroblasts, endothelial cells, and osteoclasts. Erlotinib-induced attenuation of autoimmune arthritis was associated with a reduction in number of osteoclasts and blood vessels, and erlotinib inhibited the formation of murine osteoclasts and the proliferation of human endothelial cells in vitro. Erlotinib also inhibited the proliferation and cytokine production of human synovial fibroblasts in vitro. Moreover, EGFR was highly expressed and activated in the synovium of mice with collagen-induced arthritis and patients with RA. Taken together, these findings suggest that EGFR plays a central role in the pathogenesis of RA and that EGFR inhibition may provide benefits in the treatment of RA.

Immunomodulation of Experimental Autoimmune Encephalomyelitis with Ordered Peptides Based on MHC-TCR Binding Motifs

T cell-mediated destruction of the myelin sheath causes inflammatory damage of the CNS in multiple sclerosis (MS). The major T and B cell responses in MS patients who are HLA-DR2 (about two-thirds of MS patients) react to a region between residues 84 and 103 of myelin basic protein (1 ). The crystal structure of HLA-DR2 complexed with myelin basic protein84–102 confirmed that Lys91 is the major TCR contact site, whereas Phe90 is a major anchor to MHC and binds the hydrophobic P4 pocket (2 ). We have tested peptides containing repetitive 4-aa sequences designed to bind critical MHC pockets and to interfere with T cell activation. One such sequence, EYYKEYYKEYYK, ameliorates experimental autoimmune encephalomyelitis in Lewis rats, an animal model of MS.

Poverty, Depression, or Lost in Translation? Ethnic and Language Variation in Patient-Reported Outcomes in Rheumatoid Arthritis.

Despite advances in therapies, disparities in outcomes have been documented for rheumatoid arthritis (RA) patients for both ethnicity and English language proficiency. The goals of these analyses were to compare differences in RA patient‐reported outcomes, by both self‐identification of ethnicity and English language proficiency, and to identify factors that might explain differences among groups.

Immunomodulatory vaccination in autoimmune disease

The development of vaccines is arguably the most significant achievement in medicine to date. The practice of innoculation with the fluid from a sore to protect from a disease actually dates back to ancient China; however, with the introduction of Jenners smallpox vaccine, and greater understanding of the immune system, vaccines have become specific and systematic. Traditional vaccines have used killed pathogens (hepatitis A and the Salk polio vaccines), immunogenic subunits of a given pathogen (hepatitis B subunit vaccine), or live attenuated pathogens (measles, mumps, rubella, Sabin polio vaccines) to generate protective immunity. Currently, a new generation of vaccines that use the genetic material of a pathogen to elicit protective immunity are being developed. Although the most widespread and successful use of vaccines today remains in the arena of infectious diseases, manipulations of immune responses to protect against cancers, neurologic diseases, and autoimmunity are being explored rigorously.