Anti-Glycolipid Antibody Examination in Five EAE Models and Theiler's Virus Model of Multiple Sclerosis: Detection of Anti-GM1, GM3, GM4, and Sulfatide Antibodies in Relapsing-Remitting EAE.

Anti-glycolipid antibodies have been reported to play pathogenic roles in peripheral inflammatory neuropathies, such as Guillain-Barré syndrome. On the other hand, the role in multiple sclerosis (MS), inflammatory demyelinating disease in the central nervous system (CNS), is largely unknown, although the presence of anti-glycolipid antibodies was reported to differ among MS patients with relapsing-remitting (RR), primary progressive (PP), and secondary progressive (SP) disease courses. We investigated whether the induction of anti-glycolipid antibodies could differ among experimental MS models with distinct clinical courses, depending on induction methods. Using three mouse strains, SJL/J, C57BL/6, and A.SW mice, we induced five distinct experimental autoimmune encephalomyelitis (EAE) models with myelin oligodendrocyte glycoprotein (MOG)35-55, MOG92-106, or myelin proteolipid protein (PLP)139-151, with or without an additional adjuvant curdlan injection. We also induced a viral model of MS, using Theiler's murine encephalomyelitis virus (TMEV). Each MS model had an RR, SP, PP, hyperacute, or chronic clinical course. Using the sera from the MS models, we quantified antibodies against 11 glycolipids: GM1, GM2, GM3, GM4, GD3, galactocerebroside, GD1a, GD1b, GT1b, GQ1b, and sulfatide. Among the MS models, we detected significant increases in four anti-glycolipid antibodies, GM1, GM3, GM4, and sulfatide, in PLP139-151-induced EAE with an RR disease course. We also tested cellular immune responses to the glycolipids and found CD1d-independent lymphoproliferative responses only to sulfatide with decreased interleukin (IL)-10 production. Although these results implied that anti-glycolipid antibodies might play a role in remissions or relapses in RR-EAE, their functional roles need to be determined by mechanistic experiments, such as injections of monoclonal anti-glycolipid antibodies.

Change in light-dark cycle affects experimental autoimmune encephalomyelitis.

The prevalence of multiple sclerosis is associated with geographic latitude. Low sun exposure or reduced daylight hours are considered possible causes. We examined whether a change in the number of daylight hours affects the course of experimental autoimmune encephalomyelitis (EAE) disease. Housing mice in a 24-h dark or light cycle upregulated internal corticosterone secretion and ameliorated the EAE disease course relative to that in mice housed in a conventional 12/12-h cycle environment. After EAE induction, the rhythmic pattern of corticosterone secretion was disrupted. Upregulation of internal steroid secretion might act as an immunosuppressive and ameliorate EAE.

Chondroitin sulfate N-acetylgalactosyltransferase-1 knockout shows milder phenotype in experimental autoimmune encephalomyelitis than in wild type.

Proteoglycans (PGs) are one of the main components in the extracellular matrix of the central nervous system. Chondroitin sulfate (CS) is a glycosaminoglycan (GAG), which is composed of major PGs. Similar to keratin sulfate (KS), another GAG, CS inhibits axon regeneration. However, the influence of these GAGs on the pathogenicity of neuroimmunological diseases is unclear. Here, we induced experimental autoimmune encephalomyelitis (EAE) in mice lacking CS N-acetylgalactosaminyltransferase-1 (CSGalNAcT1-KO), an important enzyme for CS synthesis. In our study, CSGalNAcT1-KO mice showed milder EAE symptoms than those in wild-type (WT) mice. The recall response of antigen-specific lymphocytes showed that CSGalNAcT1-KO-derived lymphocytes had a milder cell proliferation response than that in WT-derived lymphocytes. These results suggest that CS contributes toward the induction phase of EAE. We previously performed EAE experiments in GlcNAc-6-O-sulfotransferase KO (GlcNAc6ST-KO) and C6ST1-KO mice, which had reduced KS and reduced CS-C, respectively. EAE in CSGalNAcT1-KO mice was more similar to that in GlcNAc6ST-KO mice than in C6ST1-KO mice. In conclusion, the distinct GAG sugar chains are associated with severe or mild phenotypes of EAE and are therefore potential new therapeutic targets for neuroimmunological diseases, including multiple sclerosis.

Oryeongsan (Goreisan) Ameliorates Experimental Autoimmune Encephalomyelitis.

Objective Oryeongsan (Goreisan), a formula composed of five herbal medicines, has long been used to treat impairments of the regulation of body fluid homeostasis. Goreisan has been revealed to have anti-inflammatory actions and inhibit a water channel, the aquaporin (AQP). We herein report the therapeutic effect of Goreisan on experimental autoimmune encephalomyelitis (EAE in, an animal model of inflammatory demyelinating diseases. Materials and Methods EAE mice immunized with MOG35-55 peptide were divided into Goreisan- and sham-treated groups. The clinical EAE score and histopathological finding of the central nervous system (CNS) were analyzed. For the proliferation assay, prepared spleen cells from immunized mice were cultured and analyzed for the [3H]-thymidine uptake and cytokine concentrations of the culture supernatant. The relative quantification of AQP4 mRNA in the CNS of EAE mice was analyzed quantitatively. Results The EAE score of the Goreisan-treated mice was significantly lower than that of the sham-treated mice. The CD4-positive cell number in the CNS of Goreisan-treated mice was lower than that of sham-treated mice. In the recall response to MOG35-55 peptide, the cell proliferation did not differ markedly between the spleen cells from Goreisan- and sham-treated mice. Furthermore, Goreisan decreased the mRNA level of AQP4 in the spinal cord during EAE. Conclusion Goreisan prevented the disease activity of EAE by inhibiting the migration of pathogenic cells into the CNS by suppressing the AQP4 expression in the CNS. Goreisan may have a therapeutic effect on inflammatory demyelinating diseases.

4-Aminopyridine ameliorates relapsing remitting experimental autoimmune encephalomyelitis in SJL/J mice.

We evaluated the effects of a non-specific potassium channel blocker, 4-aminopyridine (4-AP), on chronic experimental autoimmune encephalomyelitis (chEAE) and relapsing remitting EAE (rrEAE) in mice. 4-AP did not affect chEAE, but ameliorated rrEAE, particularly in the relapsing phase. Disease amelioration was confirmed pathologically, and glial fibrillary acidic protein expression was observed to be downregulated in 4-AP-treated mice. In the recall response, a T-cell proliferative response was not inhibited; however, Th1/Th17 polarization was attenuated. 4-AP is currently accepted as an anti-symptomatic drug only in the chronic phase of multiple sclerosis (MS); however, its use in the active phase of MS should be considered.

4-Aminopyridine ameliorates experimental autoimmune neuritis in Lewis rats.

We investigated the effect of 4-aminopyridine (4-AP) on experimental autoimmune neuritis (EAN) using a 4-AP-treated group in which 4-AP was administered in the diet, and a control group (n=10 per group). Electrophysiological and pathological assessment was performed in the sciatic nerve. The EAN clinical scores were significantly lower in the 4-AP-treated group than in the control group (p<0.05). The motor conductance velocity two weeks post-immunization was significantly higher in the 4-AP-treated group (p<0.05). Finally, 4-AP did not lead to pathological changes. Thus, 4-AP might be a potential therapeutic agent in demyelinating neuropathy.

IgG4 anti-neurofascin155 antibodies in chronic inflammatory demyelinating polyradiculoneuropathy: Clinical significance and diagnostic utility of a conventional assay.

We aimed to validate the diagnostic utility of enzyme-linked immunosorbent assay (ELISA) for the detection of anti-neurofascin (NF) 155 antibody in 191 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Human NF155-based ELISA clearly distinguished between anti-NF155 antibody-positive and -negative sera. Fifteen CIDP patients (8%) were IgG4 anti-human NF155 antibody-positive, which were confirmed by western blot, cell-based assay and immunohistochemical study. None of disease controls or healthy subjects had positive results. Clinical presentation of IgG4 anti-NF155 antibody-positive patients was consistent with those in previous reports. This ELISA combined with determination of the IgG4 subclass is useful in screening for anti-NF155 antibodies.

C-C chemokine receptor type 4 antagonist Compound 22 ameliorates experimental autoimmune encephalomyelitis.

Chemokines and chemokine receptors play important roles in the immune response. We previously reported the pathogenic role of C-C chemokine receptor type 4 (CCR4) in experimental autoimmune encephalomyelitis (EAE). Here, we examined whether CCR4 antagonism modulates the disease course of EAE. Wild-type and CCR4-knockout mice were induced EAE and were administered Compound 22, an antagonist of CCR4. Compound 22 significantly ameliorated the severity of EAE in wild-type mice, but not in the CCR4-knockout mice. Compound 22 inhibited Th1 and Th17 polarization of antigen-induced T-cell responses. Therefore, CCR4 antagonists might be potential therapeutic agents for multiple sclerosis.

Keratan sulfate exacerbates experimental autoimmune encephalomyelitis.

Proteoglycans (PGs) are the components of extracellular matrices in the central nervous system (CNS). Keratan sulfate (KS) is a glycosaminoglycan that is included in the KSPG that acts as an inhibitory factor in nerve regeneration after CNS injury. To investigate the role of KS in immune diseases, we induced experimental autoimmune encephalomyelitis (EAE) in mice that were deficient in the N-acetylglucosamine (GlcNAc)-6-O-sulfotransferase 1 (GlcNAc6ST1) gene (KS-KO). KS-KO mice developed less severe EAE and showed repressed recall response in the induction phase. Furthermore, GlcNAc6ST1 might have roles in the passage of the pathogenic lymphocytes through the blood-brain barrier via adhesion molecules. Thus, modulation of KS may become a treatment for neuroimmunological diseases.

Human herpes virus-8-associated multicentric Castleman's disease in an HIV-positive patient presenting with relapsing and remitting hyponatraemia.

We report a case of human herpes virus-8-associated multicentric Castleman's disease in an HIV-positive patient with hyponatraemia. A 65-year-old man was admitted with relapsing and remitting fever, scattered skin eruptions and hepatosplenomegaly following combination antiretroviral therapy for his HIV infection. Based on histopathological findings, he was diagnosed as having human herpes virus-8-associated multicentric Castleman's disease and was treated with four-weekly infusions of rituximab. Prior to receiving chemotherapy, we observed several suspected biomarkers of disease activity, positive correlations between plasma human herpes virus-8 viral load and the levels of plasma interleukin-6, C-reactive protein and soluble interleukin-2 receptor, and negative correlations between platelet count, albumin levels and especially serum sodium levels. We hypothesize that non-osmotic release of plasma antidiuretic hormone is a cause of hyponatraemia in human herpes virus-8-associated multicentric Castleman's disease and that relapsing and remitting hyponatraemia could be correlated with plasma human herpes virus-8 viral load.

Chondroitin 6-O-sulfate ameliorates experimental autoimmune encephalomyelitis.

Chondroitin sulfate proteoglycans (CSPGs) are the main component of the extracellular matrix in the central nervous system (CNS) and influence neuroplasticity. Although CSPG is considered an inhibitory factor for nerve repair in spinal cord injury, it is unclear whether CSPG influences the pathogenetic mechanisms of neuroimmunological diseases. We induced experimental autoimmune encephalomyelitis (EAE) in chondroitin 6-O-sulfate transferase 1-deficient (C6st1(-/-)) mice. C6ST1 is the enzyme that transfers sulfate residues to position 6 of N-acetylgalactosamine in the sugar chain of CSPG. The phenotypes of EAE in C6st1(-/-) mice were more severe than those in wild-type (WT) mice were. In adoptive-transfer EAE, in which antigen-reactive T cells from WT mice were transferred to C6st1(-/-) and WT mice, phenotypes were significantly more severe in C6st1(-/-) than in WT mice. The recall response of antigen-reactive T cells was not significantly different among the groups. Furthermore, the number of pathogenic T cells within the CNS was also not considerably different. When EAE was induced in C6ST1 transgenic mice with C6ST1 overexpression, the mice showed considerably milder symptoms compared with those in WT mice. In conclusion, the presence of sulfate at position 6 of N-acetylgalactosamine of CSPG may influence the effecter phase of EAE to prevent the progression of pathogenesis. Thus, modification of the carbohydrate residue of CSPG may be a novel therapeutic strategy for neuroimmunological diseases such as multiple sclerosis.

The importance of CCR4 and CCR6 in experimental autoimmune encephalomyelitis.

Chemokine receptors (CCRs) play important roles in the pathogenesis of immune-mediated diseases, as well as in normal immune response. We examined the role of CCR6 and CCR4 in experimental autoimmune encephalomyelitis (EAE) by using CCR6(-/-)CCR4(-/-) double knockout (DKO) and single knockout mice. DKO mice developed less severe EAE and presented repressed recall response in the induction phase, especially in the activity of T helper 17 (Th17) cells. CCR6 expression in central nervous system (CNS)-infiltrated cells was diminished in DKO. Our results suggest that CCR6 and CCR4 were involved in a more rapid progression of EAE and that their regulation might be a therapeutic target of human inflammatory demyelinating diseases.

Four cases of anti-ganglioside antibody-positive neuralgic amyotrophy with good response to intravenous immunoglobulin infusion therapy.

Neuralgic amyotrophy (NA), which is an idiopathic disorder in the peripheral nerves, is characterized by an acute onset of unilateral pain in the proximal limbs followed by muscular weakness and wasting. Some cases of NA are thought to be related to immune pathogenic disorders such as Guillain-Barré syndrome (GBS). We report the case of four patients with NA who were positive for anti-N-acetylgalactosaminyl GD1a (anti-GalNAc-GD1a) antibodies, had a preceding infection, and showed a good response to intravenous immunoglobulin infusion therapy. Anti-ganglioside antibodies, especially the anti-GalNAc-GD1a antibody, may be a useful marker for predicting response to immune therapy.