Severity Of Experimental Autoimmune Encephalomyelitis In Mice Research Articles

Naringenin confers protection against experimental autoimmune encephalomyelitis through modulating the gut-brain axis: A multiomics analysis

Multiple sclerosis (MS) is a disease of the central nervous system that involves the immune system attacking the protective covering of nerve fibers. This disease can be influenced by both environmental and genetic factors. Evidence has highlighted the critical role of the intestinal microbiota in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). The composition of gut microflora is mainly determined by dietary components, which, in turn, modulate host homeostasis. A diet rich in naringenin at 0.5% can effectively mitigate the severity of EAE in mice. However, there is little direct data on the impact of naringenin at optimal doses on EAE development, as well as its intestinal microbiota and metabolites. Our study revealed that 2.0% naringenin resulted in the lowest clinical score and pathological changes in EAE mice, and altered the gene expression profiles associated with inflammation and immunity in spinal cord tissue. We then used untargeted metabolomics and 16S rRNA gene sequences to identify metabolites and intestinal microbiota, respectively. Naringenin supplementation enriched gut microbiota in EAE mice, including increasing the abundance of Paraprevotellaceae and Comamonadaceae, while decreasing the abundance of Deltaproteobacteria, RF39, and Desulfovibrionaceae. Furthermore, the changes in gut microbiota affected the production of metabolites in the feces and brain, suggesting a role in regulating the gut-brain axis. Finally, we conducted a fecal transplantation experiment to validate that gut microbiota partly mediates the effect of naringenin on EAE alleviation. In conclusion, naringenin has potential immunomodulatory effects that are influenced to some extent by the gut microbiome.

Protective effect and mechanism of nicotinamide adenine dinucleotide against optic neuritis in mice with experimental autoimmune encephalomyelitis

Patients with multiple sclerosis (MS) are commonly accompanied by optic neuritis (ON) that causes retinal ganglion cell (RGC) death and even vision loss. Nicotinamide adenine dinucleotide (NAD+) can protect against cell apoptosis and attenuate MS-triggered symptoms. However, the effect of NAD+ on MS-triggered ON remains unclear. Herein, experimental autoimmune encephalomyelitis (EAE) was established by immunizing female C57BL/6 mice with MOG35-55 peptide. To investigate the effect of NAD+ on ON prevention and treatment, EAE mice received 250 mg/kg NAD+ daily via intraperitoneal injection after immunization and EAE onset, respectively. EX-527 (10 mg/kg, SIRT1 inhibitor) was intraperitoneally injected every two days to explore the role of SIRT1 in NAD+-induced therapeutic effect on EAE. NAD+ intervention attenuated the severity of EAE in mice. NAD+ intervention relieved inflammatory infiltration and CD3+ and CD4+ cell infiltration and decreased the number and activation of microglia and astrocytes in the optic nerve. NAD+ intervention also attenuated demyelination, axonal loss, oligodendrocyte apoptosis and oligodendrocyte progenitor cell recruitment and proliferation in the optic nerve and protected against RGC apoptosis in the retina. NAD+ intervention decreased pro-inflammatory cytokine mRNA and pro-apoptotic protein expression and enhanced anti-inflammatory cytokine mRNA expression and the SIRT1 signaling in the optic nerve and retina and regulated the Th1/Th17/Tregs immune response in the spleen. In addition, EX-527 reversed the therapeutic effect of NAD+ on EAE, suggesting that NAD+ prevented MS-triggered ON by activating the SIRT1 signaling pathway. This study shows the potential of NAD+ to be used as a drug in preventing and treating MS-related ON.

The combined treatment of NAD+ and atorvastatin ameliorates the development of experimental autoimmune encephalomyelitis in C57BL/6 mice

Multiple sclerosis (MS) is a demyelinating and degenerating disorder of the central nervous system impacting many patients worldwide. Due to the complex pathogenesis of MS, drugs to treat MS often show partial effectiveness. Earlier experiments have demonstrated that both atorvastatin and nicotinamide adenine dinucleotide (NAD+) may ameliorate experimental autoimmune encephalomyelitis (EAE), which is known as a classical model of MS, via different protective mechanisms. Since combination therapy can exhibit more beneficial effects than monotherapy, we observed the protective effects of combined treatment of atorvastatin and NAD+ in EAE mice. Our results showed that the combined treatment of these two drugs at half of their optimal dosages had synergistic effect to alleviate the severity of EAE in mice than treatment with each alone. The combined treatment of EAE mice with atorvastatin plus NAD+ relieved the clinical signs and histologic changes, increased the proportion of Treg cells, attenuated IL-17 production, reduced proinflammatory cytokine secretion of Th17 cells, and increased cytokine secretion of Treg cells. In addition, the combined treatment also diminished phosphorylation of both P38 MAPK and ERK, while elevated SIRT1 expression. Taken together, these data suggested that combined treatment with NAD+ and atorvastatin could attenuate the progression of EAE by synergistic immune regulation.

Total flavonoids of astragalus attenuates experimental autoimmune encephalomyelitis by suppressing the activation and inflammatory responses of microglia via JNK/AKT/NFκB signaling pathway

BackgroundMicroglia-mediated neuroinflammation is one of the most prominent characteristics of multiple sclerosis (MS), a chronic demyelination disease. As one of the main active ingredients in Astragali radix, total flavonoids of Astragalus (TFA) has multiple pharmacological effects such as immunomodulation, anti-inflammation and and anti-tumor. However, little is known about whether TFA could inhibit microglia-mediated neuroinflammation in MS. PurposeThis study was aimed to elucidate whether TFA could inhibit microglia-mediated neuroinflammation in MS. Study designIn the present study, we explored the protective effect of TFA on experimental autoimmune encephalomyelitis (EAE), an animal model of MS, in mice for the first time, and discussed its mechanism from the aspect of anti-microglia-mediated neuroinflammation. MethodsThe mice received oral administration of TFA (25 and 50 mg/kg) daily from two days before immunization and continued until day 21 post-immunization. The effect of TFA on EAE in mice and its mechanism were investigated by ELISA, Western blot, real-time PCR, luciferase reporter assay, histopathology and immunohistochemistry. ResultsTFA were shown to alleviate the severity of EAE in mice. It inhibited the excessive activation of microglia both in spinal cords of EAE mice and in LPS-stimulated BV-2 cells, evidenced by weakening the production of inflammatory mediators such as NO, TNF-α, IL-6, and IL-1β markedly at either protein or mRNA level. Further study demonstrated that TFA repressed the phosphorylation, nuclear translocation and transcriptional activity of NFκB, and inhibited the activation of AKT and JNK signaling in BV-2 cells induced by LPS. The agonists of AKT and JNK, anisomycin and SC79, could partly abolish the inhibitory effect of TFA on the production of inflammatory mediators in BV-2 cells induced by LPS. ConclusionsTaken together, our results clarified that TFA inhibited microglia-mediated inflammation in EAE mice probably through deactivating JNK/AKT/NFκB signaling pathways. The novel findings may lay a theoretical foundation for the clinical application of TFA in the treatment of MS.

Sex-Specific Effects of Microglia-Like Cell Engraftment during Experimental Autoimmune Encephalomyelitis.

Multiple sclerosis (MS) is a chronic neuroinflammatory disorder of the central nervous system (CNS) that usually presents in young adults and predominantly in females. Microglia, a major resident immune cell in the CNS, are critical players in both CNS homeostasis and disease. We have previously demonstrated that microglia can be efficiently depleted by the administration of tamoxifen in Cx3cr1CreER/+Rosa26DTA/+ mice, with ensuing repopulation deriving from both the proliferation of residual CNS resident microglia and the engraftment of peripheral monocyte-derived microglia-like cells. In this study, tamoxifen was administered to Cx3cr1CreER/+Rosa26DTA/+ and Cx3cr1CreER/+ female and male mice. Experimental autoimmune encephalomyelitis (EAE), a widely used animal model of MS, was induced by active immunization with myelin oligodendrocyte glycoprotein (MOG) one month after tamoxifen injections in Cx3cr1CreER/+Rosa26DTA/+ mice and Cx3cr1CreER/+ mice, a time point when the CNS niche was colonized by microglia derived from both CNS microglia and peripherally-derived macrophages. We demonstrate that engraftment of microglia-like cells following microglial depletion exacerbated EAE in Cx3cr1CreER/+Rosa26DTA/+ female mice as assessed by clinical symptoms and the expression of CNS inflammatory factors, but these findings were not evident in male mice. Higher major histocompatibility complex class II expression and cytokine production in the female CNS contributed to the sex-dependent EAE severity in mice following engraftment of microglia-like cells. An underestimated yet marked sex-dependent microglial activation pattern may exist in the injured CNS during EAE.

Arsenic trioxide ameliorates experimental autoimmune encephalomyelitis in C57BL/6 mice by inducing CD4+ T cell apoptosis

BackgroundMultiple sclerosis (MS) is an immune-mediated disease of the central nervous system characterized by severe white matter demyelination. Because of its complex pathogenesis, there is no definite cure for MS. Experimental autoimmune encephalomyelitis (EAE) is an ideal animal model for the study of MS. Arsenic trioxide (ATO) is an ancient Chinese medicine used for its therapeutic properties with several autoimmune diseases. It is also used to inhibit acute immune rejection due to its anti-inflammatory and immunosuppressive properties. However, it is unclear whether ATO has a therapeutic effect on EAE, and the underlying mechanisms have not yet been clearly elucidated. In this study, we attempted to assess whether ATO could be used to ameliorate EAE in mice.MethodsATO (0.5 mg/kg/day) was administered intraperitoneally to EAE mice 10 days post-immunization for 8 days. On day 22 post-immunization, the spinal cord, spleen, and blood were collected to analyze demyelination, inflammation, microglia activation, and the proportion of CD4+ T cells. In vitro, for mechanistic studies, CD4+ T cells were sorted from the spleen of naïve C57BL/6 mice and treated with ATO and then used for an apoptosis assay, JC-1 staining, imaging under a transmission electron microscope, and western blotting.ResultsATO delayed the onset of EAE and alleviated the severity of EAE in mice. Treatment with ATO also attenuated demyelination, alleviated inflammation, reduced microglia activation, and decreased the expression levels of IL-2, IFN-γ, IL-1β, IL-6, and TNF-α in EAE mice. Moreover, the number and proportion of CD4+ T cells in the spinal cord, spleen, and peripheral blood were reduced in ATO-treated EAE mice. Finally, ATO induced CD4+ T cell apoptosis via the mitochondrial pathway both in vitro and in vivo. Additionally, the administration of ATO had no adverse effect on the heart, liver, or kidney function, nor did it induce apoptosis in the spinal cord.ConclusionsOverall, our findings indicated that ATO plays a protective role in the initiation and progression of EAE and has the potential to be a novel drug in the treatment of MS.

Characterization of Mice with a Platelet-Specific Deletion of the Adapter Molecule ADAP.

The adhesion and degranulation-promoting adapter protein (ADAP) is expressed in T cells, NK cells, myeloid cells, and platelets. The involvement of ADAP in the regulation of receptor-mediated inside-out signaling leading to integrin activation is well characterized, especially in T cells and in platelets. Due to the fact that animal studies using conventional knockout mice are limited by the overlapping effects of the different ADAP-expressing cells, we generated conditional ADAP knockout mice (ADAPfl/fl PF4-Cretg) (PF4, platelet factor 4). We observed that loss of ADAP restricted to the megakaryocytic lineage has no impact on other hematopoietic cells even under stimulation conditions. ADAPfl/fl PF4-Cretg mice showed thrombocytopenia in combination with reduced plasma levels of PF4 and transforming growth factor β1 (TGF-β1). In vitro, platelets from these mice revealed reduced P-selectin expression, lower levels of TGF-β1 release, diminished integrin αIIbβ3 activation, and decreased fibrinogen binding after stimulation with podoplanin, the ligand of C-type lectin-like receptor 2 (CLEC-2). Furthermore, loss of ADAP was associated with impaired CLEC-2-mediated activation of phospholipase Cγ2 (PLCγ2) and extracellular signal-regulated kinase 1/2 (ERK1/2). Induction of experimental autoimmune encephalomyelitis (EAE) in mice lacking ADAP expression in platelets caused a more severe disease. In vivo administration of TGF-β1 early after T cell transfer reduced EAE severity in mice with loss of ADAP restricted to platelets. Our results reveal a regulatory function of ADAP in platelets in vitro and during autoimmune disease EAE in vivo.

Alpinia oxyphylla Fruit Extract Ameliorates Experimental Autoimmune Encephalomyelitis through the Regulation of Th1/Th17 Cells.

Alpinia oxyphylla is a traditional Chinese medicine widely used for treating diarrhea, ulceration, and enuresis. Moreover, A. oxyphylla is effective for cognitive function improvement and nerve regeneration. Multiple sclerosis (MS) is a chronic neuronal inflammatory autoimmune disease that commonly affects young adults in high-latitude regions. The aim of this study was to evaluate the beneficial effects of A. oxyphylla in an experimental autoimmune encephalomyelitis (EAE) mouse model, which is an extensively used model for human MS. The ethanolic extract of A. oxyphylla fruit (AO-1) was orally administered to EAE mice. Our results showed AO-1 significantly reduced EAE symptoms. Histopathological analysis showed AO-1 reduced demyelination, inflammation, gliosis, and axonal swelling in the spinal cord. Furthermore, immunohistochemistry and quantitative polymerase chain reaction (qPCR) studies revealed that the infiltration of CD4+, CD8+ T cells, and CD11b+ monocytes into the spinal cord decreased in the AO-1-treated group. Mechanistically, the Th1 transcription factor T-bet, Th17 transcription factor retinoic acid receptor–related orphan receptor γ (RORγt), and inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17 were reduced in the spinal cords of mice treated with AO-1. The expression levels of T-bet and RORγt were also lowered in the spleens of those mice. Further in vitro study showed AO-1 inhibited production of IFN-γ, IL-2, and tumor necrosis factor-α from MOG35-55-peptide-stimulated splenocytes. One component isolated from AO-1, yakuchinone A, inhibited IL-17 production in vitro and reduced EAE symptoms in the mice. Collectively, our results indicate that AO-1 ameliorated the severity of EAE in mice and may involve the regulation of Th1/Th17 response. A. oxyphylla warrants further investigation, particularly regarding its clinical benefits for MS.

P38MAPK/SGK1 signaling regulates macrophage polarization in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is characterized with multifocal demyelination resulting from activation and infiltration of inflammatory cells into the central nerve system. Recent reports suggest that p38 mitogen-activated protein kinase (MAPK) / serum- and glucocorticoid-inducible protein kinase 1 (SGK1) signaling pathway contributes to the pathology of MS through regulation of immunity. However, the role of this signaling pathway in MS-related macrophage activation and polarization has not been studied. Here, we used an experimental autoimmune encephalomyelitis (EAE) model for MS to study the role of p38MAPK/SGK1 signaling in the macrophage polarization and its effects on the development and severity of EAE. Here, we found that p38MAPK/SGK1 signaling is required for IL4-induced M2 macrophage polarization in vitro. Chitin-induced M2 macrophage polarization reduces the severity of EAE in mice. Generation of an adeno-associated virus (AAV) carrying sh-p38 or sh-SGK1 under the control of a CD68 promoter successfully knockdown p38 or SGK1 levels in vitro and in vivo. Treatment with AAV-sh-p38 or AAV-sh-SGK1 abolished the effects of Chitin on macrophage polarization and the severity of EAE. Thus, our data suggest that p38MAPK/SGK1 signaling induces M2 macrophage polarization, which reduces the severity of EAE, a model for MS.

Hydrogen-Rich Saline Ameliorates Experimental Autoimmune Encephalomyelitis in C57BL/6 Mice Via the Nrf2-ARE Signaling Pathway

Multiple sclerosis (MS) is a chronic and inflammatory disease of the central nervous system that is associated with demyelination, neurodegeneration, and sensitivity to oxidative stress. Hydrogen-rich saline (HRS) is efficacious in preventive and therapeutic applications for many disorders because of its antioxidant and anti-inflammatory properties. Here, we determined the effect of HRS in experimental autoimmune encephalomyelitis (EAE), which is a generally accepted model of the immuno-pathogenic mechanisms underlying MS. We found that HRS reduced the severity of EAE in mice and alleviated inflammation and demyelination. Furthermore, treatment with HRS attenuated oxidative stress in EAE mice. Finally, the results of our study suggest that activation of the Nrf2-ARE pathway plays a critical role in the protective effects of HRS in EAE mice.

Impaired regulatory T cell function in autoimmune diseases: are microRNAs the culprits?

Impaired regulatory T cell function in autoimmune diseases: are microRNAs the culprits?

The immunoregulatory effect of Rho kinase inhibitor Fasudil on macrophages in a mouse model of experimental autoimmune encephalomyelitis

Objective To investigate the immunoregulatory effect of Fasudil-modified macrophages on cell transferred experimental autoimmune encephalomyelitis (EAE) in a mouse model. Methods Female C57BL/6 mice were immunized with MOG35-55 to establish the model of EAE. The encephalomyelitic mononuclear cells (MNCs) were isolated from spleen of mice with EAE on day 9 after immunization and treated with or without Fasudil for 72 h in vitro. Several assays including the flow cytometry analysis, Griess reaction and ELISA were performed to analyze the M1 and M2 phenotypes of macrophages, the production of NO and the levels of cytokines, respectively. The cultured MNCs (5×107 cells) were resuspended in 500 μl of PBS and transferred into naive C57BL/6 recipients via intraperitoneal injection. Two groups including the PBS-MNCs group and the Fasudil-MNCs group were set up. The body weights and clinical scores of the mice in each group were recorded in every other days after the induction of EAE in the recipients. Results The Fasudil treated MNCs affected the induction of EAE in adoptive cell transferred mice. The expression of CD16/32, iNOS and IL-12 on F4/80-macrophages were decreased, while the expression of CD206, CD23 and IL-10 on F4/80-macrophages were increased upon the treatment of Fasudil, indicating that Fasudil improved the differentiation of macrophages from M1 to M2 phenotypes. Moreover, Fasudil inhibited the production of NO and enhanced the expression of Arginase-1. Conclusion Fasudil ameliorated the clinical severity of EAE in mice by promoting the transformation of macrophages from M1 to M2 phenotype. Key words: Fasudil; Experimental autoimmune encephalomyelitis; Macrophage; Anti-inflammation

Sulforaphane ameliorates the development of experimental autoimmune encephalomyelitis by antagonizing oxidative stress and Th17-related inflammation in mice

Sulforaphane (SFN) is an organosulfur compound present in vegetables and has potent anti-oxidant and anti-inflammatory activities. This study was aimed at investigating the effect of treatment with SFN on inflammation and oxidative stress, and the potential mechanisms underlying the action of SFN in experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. Treatment with SFN significantly inhibited the development and severity of EAE in mice, accompanied by mitigating inflammatory infiltration and demyelination in the spinal cord of mice. The protective effect of SFN was associated with significantly improved distribution of claudin-5 and occludin, and decreased levels of MMP-9 expression, preserving the blood–brain barrier. Furthermore, the protection of SFN was also related to decreased levels of oxidative stress in the brains of mice by enhanced activation of the Nrf2/ARE pathway and increased levels of anti-oxidant HO-1 and NQO1 expression. In addition, treatment with SFN inhibited antigen-specific Th17 responses and enhanced IL-10 responses. Our data indicated that treatment with SFN inhibited EAE development and severity in mice by its anti-oxidant activity and antagonizing autoimmune inflammation. Our findings suggest that SFN and its analogues may be promising reagents for intervention of multiple sclerosis and other autoimmune diseases.

Intravenous tolerance effectively overcomes enhanced pro-inflammatory responses and experimental autoimmune encephalomyelitis severity in the absence of IL-12 receptor signaling

Intravenous (i.v.) administration of autoantigen effectively induces Ag-specific tolerance against experimental autoimmune encephalomyelitis (EAE). We and others have shown enhanced EAE severity in mice lacking IL-12 or its receptor, strongly suggesting an immunoregulatory effect of IL-12 signaling. To examine the role of IL-12 responsiveness in autoantigen-induced tolerance in EAE, we administered autoantigen i.v. in two distinct treatment regimes to wildtype and IL-12Rβ2−/− mice, immunized to develop EAE. Administration at the induction phase suppressed EAE in wildtype and IL-12Rβ2−/− mice however the effect was somewhat less potent in the absence of IL-12Rβ2. Expression of pro-inflammatory cytokines such as IFN-γ, IL-17 and IL-2, was inhibited in wild-type tolerized mice but less so in IL-12Rβ2−/− mice. I.v. antigen was also effective in suppressing disease in both genotypes when given during the clinical phase of disease with similar CNS inflammation, demyelination and peripheral inflammatory cytokine profiles observed in both genotypes. There was however a mild impact of a lack of IL-12 signaling on Treg induction during tolerance induction compared to WT mice in this treatment regime. These findings show that the enhanced severity of EAE that occurs in the absence of IL-12 signaling can be effectively overcome by i.v. autoantigen, indicating that this therapeutic effect is not primarily mediated by IL-12 and that i.v. tolerance could be a powerful approach in suppressing severe and aggressive MS.

Huperzine A ameliorates experimental autoimmune encephalomyelitis via the suppression of T cell-mediated neuronal inflammation in mice

Huperzine A (HupA), a sesquiterpene alkaloid and a potent and reversible inhibitor of acetylcholinesterase, possesses potential anti-inflammatory properties and is used for the treatment of certain neurodegenerative diseases such as Alzheimer's disease. However, it is still unknown whether this chemical is beneficial in the treatment of multiple sclerosis, a progressive inflammatory disease of the central nervous system. In this study, we examined the immunomodulatory properties of HupA in experimental autoimmune encephalomyelitis (EAE), a T-cell mediated murine model of multiple sclerosis. The following results were obtained: (1) intraperitoneal injections of HupA significantly attenuate the neurological severity of EAE in mice. (2) HupA decreases the accumulation of inflammatory cells, autoimmune-related demyelination and axonal injury in the spinal cords of EAE mice. (3) HupA down-regulates mRNA levels of the pro-inflammatory cytokines (IFN-γ and IL-17) and chemokines (MCP-1, RANTES, and TWEAK) while enhancing levels of anti-inflammatory cytokines (IL-4 and IL-10) in the spinal cords of EAE mice. (4) HupA inhibits MOG35–55 stimulation-induced T-cell proliferation and IFN-γ and IL-17 secretion in cultured splenocytes. (5) HupA inhibition of T-cell proliferation is reversed by the nicotinic acetylcholinergic receptor antagonist mecamylamine. We conclude that HupA can ameliorate EAE by suppressing autoimmune responses, inflammatory reactions, subsequent demyelination and axonal injury in the spinal cord. Therefore, HupA may have a potential therapeutic value for the treatment of multiple sclerosis and as a neuroimmunomodulatory drug to control human CNS pathology.

Platelets Contribute to the Pathogenesis of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE), are inflammatory disorders of the central nervous system (CNS). The function of platelets in inflammatory and autoimmune pathologies is thus far poorly defined. We addressed the role of platelets in mediating CNS inflammation in EAE. We found that platelets were present in human MS lesions as well as in the CNS of mice subjected to EAE but not in the CNS from control nondiseased mice. Platelet depletion at the effector-inflammatory phase of EAE in mice resulted in significantly ameliorated disease development and progression. EAE suppression on platelet depletion was associated with reduced recruitment of leukocytes to the inflamed CNS, as assessed by intravital microscopy, and with a blunted inflammatory response. The platelet-specific receptor glycoprotein Ibα (GPIbα) promotes both platelet adhesion and inflammatory actions of platelets and targeting of GPIbα attenuated EAE in mice. Moreover, targeting another platelet adhesion receptor, glycoprotein IIb/IIIa (GPIIb/IIIa), also reduced EAE severity in mice. Platelets contribute to the pathogenesis of EAE by promoting CNS inflammation. Targeting platelets may therefore represent an important new therapeutic approach for MS treatment.

Depletion of CD4+CD25+ T cells exacerbates experimental autoimmune encephalomyelitis induced by mouse, but not rat, antigens

A key question in the field of autoimmunity concerns the fact that experimental disease is generally induced more easily with closely related, but not completely identical, tissue-restricted antigens. Here, the possibility that naturally occurring regulatory T cells (Tregs) for self-antigens are more potent than those for related antigens was investigated. The self-antigen specificity of naturally occurring Tregs was tested in experimental autoimmune encephalomyelitis (EAE) induced with mouse (self) or closely related (rat) myelin oligodendrocyte glycoproteins (MOGs). Surprisingly, Treg depletion increased EAE severity in mice immunized with mouse, but not rat, MOG. This increase was associated with increased T-cell activation and infiltration of the central nervous system, as well as increased interleukin (IL)-17 production and a higher ratio of interferon-gamma- to IL-10-producing cells. These data suggest that Tregs are specific for self-antigen and do not "cross-protect" against autoimmunity even when disease is induced with closely related foreign antigens.