Effect of muscular exercise on chronic relapsing experimental autoimmune encephalomyelitis

We examined whether physical exercise affected the development of an autoimmune response, experimental autoimmune encephalomyelitis (EAE), which is a demyelinating disease leading to paralysis. EAE was inducted on day 0, in rats of both sexes, by injecting them with spinal cord tissue in adjuvant. From days 1 to 10 after injection, exercised rats (n = 55) ran on a treadmill (60-120 min/day) before the onset of the paralytic disease. Clinical signs of the disease (ataxia, paralysis, and body mass loss) were examined in exercised and control rats (n = 54). Three types of EAE were induced: monophasic, acute, and chronic relapsing (CR)-EAE (3 bouts of disease, CR-EAE 1, 2, and 3, separated by remissions). Exercise significantly delayed the onset of CR-EAE 1 (P = 0.001) and the 1st day of maximum severity of CR-EAE 1 (P = 0.001) and CR-EAE 2 (P = 0.002). Moreover, the duration of CR-EAE 1 was significantly decreased in exercised rats compared with control rats (P = 0.004). The peak severity of the different types of EAE was not modified by exercise. The present study indicates that endurance exercise during the phase of induction of EAE diminished lightly only one type of EAE (CR-EAE) and therefore did not exacerbate the autoimmune disease.     

Risk factors for sudden unexpected cardiac death in Tasmanian men

Cerebral expression of the injury response cytokine transforming growth factor-beta 1 (TGF-beta 1) has been found to be increased in several neurological diseases but it remains unclear whether its function is primarily beneficial or detrimental. Here we show that transgenic (tg) mice that overexpress bioactive (TGF-beta 1 in the central nervous system (CNS) and show no overt phenotype in the unmanipulated state, are more susceptible to the immune-mediated CNS disease experimental autoimmune encephalomyelitis (EAE). TGF-beta 1 tg mice with EAE showed an earlier onset of clinical symptoms, more severe disease and increased mononuclear cell infiltration in their spinal cords compared with non-tg littermate controls with EAE. Whereas previous observations indicated that increased peripheral levels of TGF-beta 1 can suppress EAE, our findings demonstrate that local expression of TGF-beta 1 within the CNS parenchyma can enhance immune cell infiltration and intensify the CNS impairment resulting from peripherally triggered autoimmune responses.     

Treatment of murine experimental autoimmune encephalomyelitis with a myelin basic protein peptide analog alters the cellular composition of leukocytes infiltrating the cerebrospinal fluid

Experimental autoimmune encephalomyelitis (EAE) can be effectively treated during disease exacerbation by administration of a peptide corresponding to the major T cell epitope of myelin basic protein (MBP), but the mechanism by which T cell tolerance leads to clinical improvement is not well-defined. Acute exacerbations of EAE are accompanied by an infiltration of blood-borne leukocytes into the brain and spinal cord, where they mediate inflammation and demyelination. To investigate peptide effects on infiltrating cells, we collected cerebrospinal fluid (CSF) from (PL/JxSJL)F1 mice with MBP-induced EAE. Pleiocytosis by lymphocytes, neutrophils, and macrophages was seen throughout the course of relapsing-remitting disease. A single administration of the MBP peptide analog, Ac1-11[4Y], reduced disease severity, accompanied by a dramatic and selective loss of neutrophil pleiocytosis. A longer course of peptide therapy resulted in complete recovery from clinical signs of disease, and decreased pleiocytosis by all cell types. Clinical severity throughout the course of disease and therapy was directly related to the degree of infiltration by neutrophils and macrophages, and the clinical improvement following peptide therapy was accompanied by decreased central nervous system (CNS) expression of chemoattractants for these cell types. These observations support a model of disease exacerbation mediated by phagocytic cellular infiltration under the ultimate control of T cell-derived factors, amenable to treatment by down-regulation of the T cell activation state.     

Suppression of experimental autoimmune encephalomyelitis with a TNF binding protein (TNFbp) correlates with down-regulation of VCAM-1/VLA-4

The effect of a novel TNF binding protein (TNFbp), a polyethylene glycol-linked form of the type I soluble receptor of TNF, on the expression of adhesion molecules has been investigated with a passive transfer model of experimental autoimmune encephalomyelitis (EAE) in SJL/J mice. The expression of L-selectin, VLA-4 and LFA-1 on spleen cells of EAE animals treated with TNFbp or saline was examined by FACS analysis. The expression of VCAM-1 and ICAM-1 was investigated by immunochemistry in spinal cord tissue of SJL/J mice with EAE. In animals sensitized for EAE and treated with TNFbp, the expression of VCAM-1 in the central nervous system as well as VLA-4 on spleen cells was clearly diminished. Reduction in VCAM-1 staining and VLA-4 expression corresponded to inhibition of inflammation in the spinal cord and to prevention of clinical signs of EAE. The results have also shown that myelin basic protein responses as well as non-antigen-specific responses were not diminished in animals treated with TNFbp. The findings suggest that TNFbp might prevent EAE development by modulating the expression of VCAM-1 and VLA-4.     

Tumor necrosis factor blockade in actively induced experimental autoimmune encephalomyelitis prevents clinical disease despite activated T cell infiltration to the central nervous system

Recently, we demonstrated that experimental autoimmune encephalomyelitis (EAE) in the rat, passively transferred using myelin basic protein (MBP)-reactive encephalitogenic CD4+ T cells, was preventable by administration of a p55-tumor necrosis factor-IgG fusion protein (TNFR-IgG). This was despite quantitatively and qualitatively normal movement of these MBP-specific T cells to the central nervous system (CNS). To extend these findings, the effect of TNFR-IgG on EAE actively induced by injection of MBP in complete Freund's adjuvant was examined. This form of EAE in the rat typically involves an acute, self-limiting neurological deficit, substantial CNS inflammation, but minimal demyelination. Here we show that administration of TNFR-IgG prior to onset of disease signs completely prevented the neurological deficit or markedly reduced its severity. This blockade of clinical disease was dissociated from weight loss which occurred at the same tempo and magnitude as in control rats exhibiting neurological signs of disease such as paralysis. The timing of TNF blockade was critical as established clinical disease was relatively refractory to TNFR-IgG treatment. Activated CD4+ T cells expressing normal or elevated levels of VLA4, major histocompatibility complex class II, MRC OX40 and CD25 were isolated from or immunohistochemically localized in the CNS of clinically healthy rats treated before disease onset. There was a reduction of the amount of other inflammatory leukocytes in the CNS of these treated animals but, more importantly, the activation state of inflammatory leukocytes, as well as that of microglia isolated from treated animals, was reduced. Thus, TNFR-IgG, when administered before disease onset, appears to act by inhibiting an effector function of activated T cells and possibly other inflammatory leukocytes necessary to bring about the neurological deficit. However, while TNF is a critically important cytokine for the early events leading to initiation of EAE, it is not a necessary factor in the acute neurological deficit characteristic of this form of EAE, once disease onset has occurred.     

Fas- and FasL-deficient mice are resistant to induction of autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an organ-specific autoimmune disease inducible in susceptible animals by myelin Ag-specific CD4+ Th1 cells. The mechanisms by which these cells induce inflammation and demyelination in the central nervous system (CNS) are incompletely understood. To determine the roles of Fas and FasL in the involvement of CNS autoimmune injury, we determined susceptibility to EAE of Fas-or FasL-deficient mice. Compared with wild-type mice, mice expressing lpr (Fas) and gld (FasL) mutations were relatively resistant to the development of clinical EAE, and this correlated with fewer inflammatory infiltrates and cells undergoing apoptosis in the CNS of the mutant mice. The gld and lpr mice, however, developed significant T cell responses with production of Th1 cytokines in response to the encephalitogenic myelin peptide. These results suggest that the Fas/FasL pathway plays a critical role in the development of EAE probably by mediating apoptosis within the target tissue.     

A protease-resistant form of insulin-like growth factor (IGF) binding protein 4 inhibits IGF-1 actions

Smooth muscle cells (SMC) secrete a serine protease that cleaves insulin-like growth factor (IGF) binding protein (IGFBP)-4 into fragments that have low affinity for IGF-1. When IGFBP-4 is added to monolayer cultures of cell types that do not secrete this protease, IGF-1 stimulation of DNA synthesis is significantly inhibited. In contrast, if cell types that secrete this protease are used, IGFBP-4 is a much less potent inhibitor. These studies were conducted to determine whether proteolysis of IGFBP-4 accounted for its reduced capacity to inhibit IGF-1-stimulated DNA synthesis. The cleavage site in IGFBP-4 that the SMC protease uses was determined to be lysine120, histidine121. A protease-resistant mutant form of IGFBP-4 was prepared, expressed, purified, and tested for biologic activity using porcine SMC cultures. Addition of the protease-resistant mutant resulted in inhibition of DNA and cell migration responses to IGF-1. The inhibition was concentration dependent and was maximal when 500 ng/ml (20 nM) of the mutant was added with 20 ng/ml (2.8 nM) of IGF-1. When the mutant was added in the absence of IGF-1, it had no activity. The results show that cleavage of IGFBP-4 at lysine120, histidine121 results in inactivation of the ability of IGFBP-4 to bind to IGF-1. Creation of a mutant form of IGFBP-4 that was not cleaved by the protease resulted in inhibition of IGF-1-stimulated actions. The results suggest that IGFBP-4 can act as a potent inhibitor of the anabolic effects of IGF-1 and that the variables that regulate protease activity may indirectly regulate IGF-1 actions.     

Insulin-like growth factor-1 (IGF-1) receptor-insulin receptor substrate complexes in the uterus. Altered signaling response to estradiol in the IGF-1(m/m) mouse

Some of the actions of estradiol occur through stimulation of growth factor pathways in target organs. Tyrosine-phosphorylated (Tyr(P)) insulin-like growth factor-1 receptor (IGF-1R) and the insulin receptor substrate (IRS)-1 are found in the uterus of mice treated with estradiol. Immunoprecipitates of uterine Tyr(P) IRS-1 contained both p85, the regulatory subunit of phosphatidylinositol (PI) 3-kinase, and PI 3-kinase catalytic activity. Estradiol also stimulated binding of IRS-1 and PI 3-kinase to the IGF-1R. Depletion of IRS-1 from uterine extracts reduced PI 3-kinase associated with the receptor, which suggests that binding of the enzyme to IGF-1R occurs primarily in a complex that also contains IRS-1. Following treatment with estradiol, formation of Tyr(P) IGF-1R, Tyr(P) IRS-1, and the p85.IRS-1 complex was very weak in the uterus of IGF-1(m/m) mice, which are severely deficient in IGF-1. This indicated that most, if not all, of the estradiol-stimulated Tyr phosphorylation of uterine IRS-1 originates from ligand activation of IGF-1R kinase. IRS-2 was also Tyr-phosphorylated in the normal uterus and bound more IGF-1R and p85 in response to estradiol; however, a marked decrease in levels of uterine IRS-2 occurred 12-24 h after treatment with estradiol. Since IRS-2 was present in IGF-1R precipitates and a recombinant form of IGF-1 (long R3 IGF-1) stimulated formation of Tyr(P) IRS-2, hormonal activation of this docking protein probably occurs through the IGF-1R. In summary, our findings show that estrogen activation of uterine IGF-1R kinase results in enhanced binding of p85 (PI 3-kinase) to IRS-1 and IRS-2. The formation of one or both of these complexes may be important for the potent mitogenic action of this steroid. That estradiol stimulated a decrease of IRS-2, but not of IRS-1, suggests that these docking proteins have different roles in hormone-induced signaling in the uterus.     

Challenging cytokine redundancy: inflammatory cell movement and clinical course of experimental autoimmune encephalomyelitis are normal in lymphotoxin-deficient, but not tumor necrosis factor-deficient, mice

Lymphotoxin (LT) is widely regarded as a proinflammatory cytokine with activities equivalent to tumor necrosis factor (TNF). The contribution of LT to experimental autoimmune encephalomyelitis (EAE) was examined using TNF/LTalpha-/- mice, TNF-/- mice, and a new LTalpha-/- line described here. All mice were generated directly in the C57BL/6 strain and used for the preparation of radiation bone marrow chimeras to reconstitute peripheral lymphoid organs and restore immunocompetence. This approach overcame the problems related to the lack of lymph nodes that results from LTalpha gene targeting. We show here that when LT is absent but TNF is present, EAE progresses normally. In contrast, when TNF is absent but LT is present, EAE is delayed in onset and inflammatory leukocytes fail to move normally into the central nervous system parenchyma, even at the peak of disease. In the absence of both cytokines, the clinical and histological picture is identical to that seen when TNF alone is deficient, including demyelination. Furthermore, the therapeutic inhibition of TNF and LTalpha with soluble TNF receptor in unmanipulated wild-type or TNF-/- mice exactly reproduces these outcomes. We conclude from these studies that TNF and LT are functionally distinct cytokines in vivo, and despite sharing common receptors, show no redundancy of function nor mutual compensation.     

An important role for the chemokine macrophage inflammatory protein-1 alpha in the pathogenesis of the T cell-mediated autoimmune disease, experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a CD4+ T cell-mediated, inflammatory demyelinating disease of the central nervous system (CNS) that serves as a model for the human demyelinating disease, multiple sclerosis. A critical event in the pathogenesis of EAE is the entry of both Ag-specific T lymphocytes and Ag-nonspecific mononuclear cells into the CNS. In the present report we investigated the role of two C-C chemokines (macrophage inflammatory protein-1 alpha (MIP-1 alpha) and monocyte chemotactic protein-1) and a C-x-C chemokine (MIP-2) in the pathogenesis of EAE. Production in the CNS of MIP-1 alpha, but not that of MIP-2, a rodent homologue of IL-8, or monocyte chemotactic protein-1, correlated with development of severe clinical disease. Administration of anti-MIP-1 alpha, but not that of anti-monocyte chemotactic protein-1, prevented the development of both acute and relapsing paralytic disease as well as infiltration of mononuclear cells into the CNS initiated by the transfer of neuroantigen peptide-activated T cells. Ab therapy could also be used to ameliorate the severity of ongoing clinical disease. Anti-MIP-1 alpha did not affect the activation of encepahlitogenic T cells as measured by cytokine secretion, surface marker expression, and ability to adoptively transfer EAE. These results demonstrate that MIP-1 alpha plays an important role in directing the chemoattraction of mononuclear inflammatory cells in the T cell-mediated autoimmune disease, EAE.     

Persistent expression of experimental autoimmune encephalomyelitis (EAE)-specific Vbeta8.2 TCR spectratype in the central nervous system of rats with chronic relapsing EAE

Monitoring the TCR repertoire is indispensable for the assessment of T cell-associated autoimmune diseases and subsequent TCR-based immunotherapy. In the present study, we examined the TCR repertoire of spinal cord T cells of Lewis rats by CDR3 spectratyping during chronic relapsing experimental autoimmune encephalomyelitis (EAE) induced by immunization with spinal cord homogenate. It was found that Vbeta8.2 spectratype with the shortest CDR3 expanded oligoclonally throughout the course of the disease. In addition, Vbeta12 spectratype expansion was observed at the first and second attacks of EAE. Sequence analysis revealed that clones with the DSSYEQYF sequence, which is a representative sequence of myelin basic protein (MBP)-reactive T cell clones, constituted the predominant population in the Vbeta8.2 family. Surprisingly, Vbeta12 also used the identical amino acid sequence in the CDR3 region. These findings indicate that although infiltrating T cells in the central nervous system are activated polyclonally, the TCR repertoire remains unchanged throughout the course. Moreover, the finding that the predominant CDR3 amino acid sequence of Vbeta8.2 and Vbeta12 spectratypes is identical with that of MBP-induced EAE suggests that a single Ag in spinal cord homogenate, possibly MBP, is involved in disease development.     

Central nervous system delivery of interleukin 4 by a nonreplicative herpes simplex type 1 viral vector ameliorates autoimmune demyelination

Multiple sclerosis (MS) is a T cell-mediated organ-specific inflammatory disease leading to central nervous system (CNS) demyelination. On the basis of results obtained in experimental autoimmune encephalomyelitis (EAE) models, MS treatment by administration of antiinflammatory cytokines such as interleukin 4 (IL-4) is promising but is hampered by the limited access of the cytokines to the CNS and by the pleiotropic effects of systemically administered cytokines. We established a cytokine delivery system within the CNS using non-replicative herpes simplex type 1 (HSV-1) viral vectors engineered with cytokine genes. These vectors injected into the cisterna magna (i.c.) of mice diffuse in all ventricular and subarachnoid spaces and infect with high efficiency the ependymal and leptomeningeal cell layers surrounding these areas, without obvious toxic effects. Heterologous genes contained in the vectors are efficiently transcribed in infected ependymal cells, leading to the production of high amounts of the coded proteins. For example, 4.5 ng of interferon gamma (IFN-gamma) per milliliter is secreted into the cerebrospinal fluid (CSF) up to day 28 postinjection (p.i.) and reaches the CNS parenchyma in bioactive form, as demonstrated by upregulation of MHC class I expression on CNS-resident cells. We then exploited the therapeutic potential of the vectors in EAE mice. An HSV-1-derived vector containing the IL-4 gene was injected i.c. in Biozzi AB/H mice at the time of EAE induction. We found the following in treated mice: (1) delayed EAE onset, (2) a significant decrease in clinical score, (3) a significant decrease in perivascular inflammatory infiltrates and in the number of macrophages infiltrating the CNS parenchyma and the submeningeal spaces, and (4) a reduction in demyelinated areas and axonal loss. Peripheral T cells from IL-4-treated mice were not affected either in their antigen-specific proliferative response or in cytokine secretion pattern. Our results indicate that CNS cytokine delivery with HSV-1 vectors is feasible and might represent an approach for the treatment of demyelinating diseases. Advantages of this approach over systemic cytokine administration are the high cytokine level reached in the CNS, the absence of effects on the peripheral immune system, and the long-lasting cytokine production in the CNS after a single vector administration.     

Expression of chemokines RANTES, MIP-1alpha and GRO-alpha correlates with inflammation in acute experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an investigator-initiated disorder that serves as an animal model for the common human demyelinating disease multiple sclerosis. Both diseases are typified by disseminated perivascular and submeningeal cuffs in the central nervous system (CNS). It was shown recently that chemokines are integral to the pathogenesis of EAE. In the present study we analyzed the gene expression of three chemokines, RANTES, MIP-1alpha and GRO-alpha, at the onset of acute EAE, and correlated that expression with the intensity of inflammatory changes in the CNS. We showed that all three chemokines are upregulated simultaneously with symptom onset of acute EAE, and that chemokine expression correlates with the intensity of inflammation in the CNS. This consistent relationship supports the hypothesis that chemokines are relevant to leukocyte accumulation in CNS parenchyma.     

ICAM-1-dependent pathway is not critically involved in the inflammatory process of autoimmune encephalomyelitis or in cytokine-induced inflammation of the central nervous system

To determine whether the rat homolog of intercellular adhesion molecule 1 (ICAM-1) plays an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) we examined the effect of anti-ICAM-1 mAb, 1A29, on both active and passive EAE. We also examined its effect on a model of cytokine-induced inflammation in the central nervous system. Treatment of recipients of EAE effector cells with anti-ICAM-1 had no inhibitory activity, and in fact at high doses, treatment enhanced disease as evidenced by an earlier onset of symptoms. Treatment of active EAE with anti-ICAM-1 beginning on the day of sensitization did protect a proportion of animals from development of disease as well as reduce the severity of clinical signs in those which developed symptoms. Lymphocytes from both the draining lymph nodes and spleens of myelin basic protein (MBP)-immunized rats treated with anti-ICAM-1 failed to proliferate in response to MBP in vitro, suggesting that the antibody had prevented the animals from becoming sensitized to the antigen. Microinjection of tumor necrosis factor (TNF)-alpha into the spinal cords of rats led to the expression of ICAM-1 on vascular endothelium, and to the accumulation of leukocytes at sites of injection. The peak expression of ICAM-1 by endothelium and the peak accumulation of leukocytes following TNF alpha injection were not positively correlated. Furthermore, treatment of TNF alpha injected rats with anti-ICAM-1 did not inhibit the accumulation of leukocytes at the site of cytokine injection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neutralizing antibodies to IFN-gamma-inducing factor prevent experimental autoimmune encephalomyelitis

Specific oligonucleotide primers were used to identify and isolate IFN-gamma-inducing factor (IGIF) from the brain of rats with developing experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune disease of the central nervous system that serves as a model for multiple sclerosis. IGIF was highly transcribed in the brain at the onset and during the course of active EAE. PCR products encoding rat IGIF were used to generate the recombinant protein that was used to induce anti-IGIF neutralizing Abs. These Abs significantly reduced the production of IFN-gamma by primed T cells proliferating in response to their target myelin basic protein epitope and by Con A-activated T cells from naive donors. When administered to rats during the development of either active or transferred EAE, these Abs significantly blocked the development of disease. Splenic T cells from protected rats were cultured with the encephalitogenic myelin basic protein epitope and evaluated for production of IL-4 and IFN-gamma. These cells, which proliferated, exhibited a profound increase in IL-4 production that was accompanied by a significant decrease in IFN-gamma and TNF-alpha production. Thus, we suggest that perturbation of the Th1/Th2 balance toward Th2 cells is the mechanism underlying EAE blockade by anti-IGIF immunotherapy.     

Blocking OX-40/OX-40 ligand interaction in vitro and in vivo leads to decreased T cell function and amelioration of experimental allergic encephalomyelitis

The OX-40R is a member of the TNF receptor family and is expressed primarily on activated CD4+ T cells. When the OX-40R is engaged by the OX-40 ligand (OX-40L), a potent costimulatory signal occurs. We have identified a population of CD11b+ cells, isolated from the central nervous system (CNS) of mice with actively induced experimental allergic encephalomyelitis (EAE), that expresses OX-40L. Moreover, the expression of OX-40L was found to be associated with paralytic episodes of EAE and was reduced or absent at disease recovery. These CD11b+ cells also coexpressed B7 and MHC class II. Therefore, to address the relative contributions of OX-40R/OX-40L and CD28/B7 to the costimulation of myelin-specific T cells, blocking studies were performed using soluble OX-40R and/or soluble CTLA-4. CD11b+ cells isolated from the CNS of mice with actively induced EAE were able to present Ag to proteolipid protein 139-151-specific T cell lines in vitro. The addition of soluble OX-40R:Ig to CD11b+ brain microglia/macrophages inhibited T cell proliferation by 50-70%. The addition of CTLA-4:Ig inhibited T cell proliferation by 20-30%, and the combination inhibited T cell proliferation by 95%. In vivo administration of soluble OX-40R at the onset of actively induced or adoptively transferred EAE reduced ongoing signs of disease, and the mice recovered more quickly from acute disease. The data imply that OX-40L, expressed by CNS-derived APC, acts to provide an important costimulatory signal to EAE effector T cells found within the inflammatory lesions. Furthermore, the data suggest that agents designed to inhibit the OX-40L/OX-40R complex may be useful for treating autoimmune disease.     

The epidermal growth factor receptor tyrosine kinase phosphorylates connexin32

To elucidate the role of excessive nitric oxide (NO) via the inducible nitric oxide synthase (iNOS) in experimental allergic encephalomyelitis (EAE), the effect of a selective iNOS inhibitor, aminoguanidine, was investigated using mice with actively induced EAE. Administration of aminoguanidine by intraperitoneal or intracisternal injection from day 2 to day 12 after immunization produced a significant delay in the onset of EAE. On the other hand, administration of aminoguanidine by intraperitoneal or intracisternal injection for 10 days after the onset of EAE enhanced the clinical severity and mortality rate and hastened the onset of relapse significantly. The histological study at day 11 after the onset revealed that more inflammatory cells were present in the central nervous system of mice treated with aminoguanidine as compared with mice without aminoguanidine treatment. These results suggested that NO via iNOS was a pathogenetic factor in the induction phase of EAE, but had an inhibitory role in the progression phase of EAE. Although the effect of NO synthase inhibitors on EAE has been controversial, the present study suggested that the timing of administration might be an important consideration and might explain the previous contradictory reports.     

Combined treatment of acute EAE in Lewis rats with TNF-binding protein and interleukin-1 receptor antagonist

Experimental autoimmune encephalomyelitis (EAE) is a term given to describe a collection of animal models representing the human disease multiple sclerosis (MS). Although not fully understood, the involvement of cytokines and the immune system in either EAE or human MS is well established. Past efforts have shown that inhibition of proinflammatory cytokines tumor necrosis factor (TNF-alpha) or interleukin-1 (IL-1) result in amelioration of acute EAE in Lewis rats. The present study examined this model for the effect of concomitant inhibition of both TNF-alpha and IL-1, which resulted in a modest but significant therapeutic effect that was superior to inhibition of either single agent alone with respect to four of the five variables used to follow the progression of disease in this model, i.e., clinical severity, frequency of disease, loss of body weight, and day of onset. These results are in accordance with the idea that combination treatments are likely to prove superior to single agent therapy in the treatment of autoimmune inflammatory disease.     

Vaccination with DNA encoding an immunodominant myelin basic protein peptide targeted to Fc of immunoglobulin G suppresses experimental autoimmune encephalomyelitis

We explore here if vaccination with DNA encoding an autoantigenic peptide can suppress autoimmune disease. For this purpose we used experimental autoimmune encephalomyelitis (EAE), which is an autoaggressive disease in the central nervous system and an animal model for multiple sclerosis. Lewis rats were vaccinated with DNA encoding an encephalitogenic T cell epitope, guinea pig myelin basic protein peptide 68-85 (MBP68-85), before induction of EAE with MBP68-85 in complete Freund's adjuvant. Compared to vaccination with a control DNA construct, the vaccination suppressed clinical and histopathological signs of EAE, and reduced the interferon gamma production after challenge with MBP68-85. Targeting of the gene product to Fc of IgG was essential for this effect. There were no signs of a Th2 cytokine bias. Our data suggest that DNA vaccines encoding autoantigenic peptides may be useful tools in controlling autoimmune disease.