Combined Treatment with Zinc Aspartate and Intravenous Immunoglobulins (IVIGs) Ameliorates Experimental Autoimmune Encephalomyelitis (EAE).

Intravenous immunoglobulins (IVIGs) are widely used in replacement therapy of primary and secondary immunodeficiency disorders and in approved autoimmune indications. In addition, IVIG application is used off-label for treatment of other autoimmune diseases, e.g., multiple sclerosis (MS), an inflammatory autoimmune disorder with a clear T cell-mediated immune pathogenesis. The trace element zinc is shown to play a regulatory role in the maintenance of immune functions. Changes of zinc homeostasis affect both the innate and the adaptive immune system. On one hand, therapeutic zinc supplementation can normalize impaired immune functions due to zinc deficiency. On the other hand, therapeutic zinc supplementation is under consideration as a possible option to treat T cell-mediated autoimmune diseases. The aim of the present study was to investigate the influence of IVIG (Octagam®), zinc aspartate (Unizink®), and the combined application of both preparations in the experimental autoimmune encephalomyelitis (EAE), the animal model of MS. Therapeutic intraperitoneal application of zinc aspartate significantly diminished clinical signs during the relapsing-remitting phase of EAE in SJL/J mice. In contrast, IVIG given in a therapeutic manner did not influence the course of EAE. Interestingly, the combined application of both, IVIG and zinc aspartate, significantly reduced the severity of the disease during the acute and the relapsing-remitting phase of the EAE. Our data suggest that the combination of IVIG and zinc aspartate may have beneficial effects in autoimmune diseases, like MS. Further studies should verify the benefit of a controlled immunosuppressive therapy with IVIG and zinc for such diseases.

Differential effects of FTY720 on the B cell compartment in a mouse model of multiple sclerosis.

BACKGROUND: MP4-induced experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis (MS), which enables targeted research on B cells, currently much discussed protagonists in MS pathogenesis. Here, we used this model to study the impact of the S1P1 receptor modulator FTY720 (fingolimod) on the autoreactive B cell and antibody response both in the periphery and the central nervous system (CNS). METHODS: MP4-immunized mice were treated orally with FTY720 for 30 days at the peak of disease or 50 days after EAE onset. The subsequent disease course was monitored and the MP4-specific B cell/antibody response was measured by ELISPOT and ELISA. RNA sequencing was performed to determine any effects on B cell-relevant gene expression. S1P1 receptor expression by peripheral T and B cells, B cell subset distribution in the spleen and B cell infiltration into the CNS were studied by flow cytometry. The formation of B cell aggregates and of tertiary lymphoid organs (TLOs) was evaluated by histology and immunohistochemistry. Potential direct effects of FTY720 on B cell aggregation were studied in vitro. RESULTS: FTY720 significantly attenuated clinical EAE when treatment was initiated at the peak of EAE. While there was a significant reduction in the number of T cells in the blood after FTY720 treatment, B cells were only slightly diminished. Yet, there was evidence for the modulation of B cell receptor-mediated signaling upon FTY720 treatment. In addition, we detected a significant increase in the percentage of B220+ B cells in the spleen both in acute and chronic EAE. Whereas acute treatment completely abrogated B cell aggregate formation in the CNS, the numbers of infiltrating B cells and plasma cells were comparable between vehicle- and FTY720-treated mice. In addition, there was no effect on already developed aggregates in chronic EAE. In vitro B cell aggregation assays suggested the absence of a direct effect of FTY720 on B cell aggregation. However, FTY720 impacted the evolution of B cell aggregates into TLOs. CONCLUSIONS: The data suggest differential effects of FTY720 on the B cell compartment in MP4-induced EAE.

Sodium Benzoate, a Food Additive and a Metabolite of Cinnamon, Enriches Regulatory T Cells via STAT6-Mediated Upregulation of TGF-ß.

Upregulation and/or maintenance of regulatory T cells (Tregs) during autoimmune insults may have therapeutic efficacy in autoimmune diseases. Earlier we have reported that sodium benzoate (NaB), a metabolite of cinnamon and a Food and Drug Administration-approved drug against urea cycle disorders, upregulates Tregs and protects mice from experimental allergic encephalomyelitis, an animal model of multiple sclerosis. However, mechanisms by which NaB increases Tregs are poorly understood. Because TGF-ß is an important inducer of Tregs, we examined the effect of NaB on the status of TGF-ß. In this study, we demonstrated that NaB induced the expression of TGF-ß mRNA and protein in normal as well as proteolipid protein-primed splenocytes. The presence of a consensus STAT6 binding site in the promoter of the TGF-ß gene, activation of STAT6 in splenocytes by NaB, recruitment of STAT6 to the TGF-ß promoter by NaB, and abrogation of NaB-induced expression of TGF-ß in splenocytes by small interfering RNA knockdown of STAT6 suggest that NaB induces the expression of TGF-ß via activation of STAT6. Furthermore, we demonstrated that blocking of TGF-ß by neutralizing Abs abrogated NaB-mediated protection of Tregs and experimental allergic encephalomyelitis. These studies identify a new function of NaB in upregulating TGF-ß via activation of STAT6, which may be beneficial in MS patients.

Upregulation of astrocytic leptin receptor in mice with experimental autoimmune encephalomyelitis.

The detrimental role of leptin in experimental autoimmune encephalomyelitis (EAE) is opposite to its neuroprotective role in other neuropathologies. We hypothesize that a shifted cellular distribution of leptin receptors underlies the differential effects of leptin. A robust increase of ObR immunoreactivity was seen along glial fibrillary acidic protein (GFAP)(+) intermediate filaments in reactive astrocytes in the hippocampus and hypothalamus of mice with EAE. Although astrocyte-specific GFAP mRNA and protein were both increased, ObRa mRNA was elevated only after resolution of EAE symptoms, and ObRb mRNA was even decreased at the peak time of symptoms of EAE. A cell type-specific action of leptin may underlie its differential effects.

Combination treatment of mice with CRx-153 (nortriptyline and desloratadine) decreases the severity of experimental autoimmune encephalomyelitis.

Pro-inflammatory CD4(+) T cell-mediated autoimmune diseases, such as multiple sclerosis, are hypothesized to be initiated and maintained by self-reactive interferon-gamma (IFN-γ) and interleukin-17 (IL-17) producing CD4(+) T cells. Previous studies have shown moderate to significant alterations in inflammatory T cell responses and potentially treatment of autoimmune disease by administration of antihistamine or tricyclic antidepressants alone. The goal of the present study was to determine if treatment of PLP(139-151)-induced relapsing-remitting experimental autoimmune encephalomyelitis (R-EAE) in SJL/J mice with a combination of two FDA approved drugs for other indications could decrease R-EAE disease. The findings show that combination treatment with desloratadine and nortriptyline decreases the mean clinical score, disease relapse frequency, and number of CD4(+) T cells infiltrating into the CNS. In addition, combination treatment of PLP(139-151) primed mice decreases the level of IFN-γ and IL-17 secreted via a decrease in both the number of cells secreting and the amount of cytokine secreted per cell following PLP(139-151) reactivation ex vivo. This is in contrast to an increase in the level of IL-4 produced and the number of IL-4 secreting cells. The data also show that combination treatment with desloratadine and nortriptyline inhibits the production of IFN-γ and IL-17 produced by naive CD4(+) T cells activated in the presence of Th1 cell- and Th17 cell-promoting conditions, while increasing the level of IL-4 produced by naive CD4(+) T cells activated in the presence of Th2 cell-promoting conditions. The present findings suggest a novel method for the development of a putative autoimmune therapy.

Prevention of clinical and histological signs of proteolipid protein (PLP)-induced experimental allergic encephalomyelitis (EAE) in mice by the water-soluble carbon monoxide-releasing molecule (CORM)-A1.

We have evaluated the effects of the carbon monoxide-releasing molecule CORM-A1 [Na(2) (BH(3) CO(2) ); ALF421] on the development of relapsing-remitting experimental allergic encephalomyelitis (EAE) in SJL mice, an established model of multiple sclerosis (MS). The data show that the prolonged prophylactic administration of CORM-A1 improves the clinical and histopathological signs of EAE, as shown by a reduced cumulative score, shorter duration and a lower cumulative incidence of the disease as well as milder inflammatory infiltrations of the spinal cords. This study suggests that the use of CORM-A1 might represent a novel therapeutic strategy for the treatment of multiple sclerosis.

Tovaxin, radiation-attenuated, patient-specific T-cells for the therapeutic vaccination of multiple sclerosis.

Opexa Pharmaceuticals Inc is developing Tovaxin, a trivalent formulation of attenuated myelin-peptide-reactive T-cells, for the potential treatment of multiple sclerosis. Tovaxin is being evaluated in phase II clinical trials. Opexa was previously investigating Tovaxin for the potential treatment of rheumatoid arthritis; however, no development has been reported for this indication since December 2002.

Tolerance induction by acylated peptides: suppression of EAE in the mouse with palmitoylated PLP peptides.

Treatment of SJL mice either before or after challenge with palmitoylated PLP139-151 (PAL139-151) completely suppressed or considerably reduced both acute and relapsing stages of EAE induced with PLP139-151. In the presence of Pertussis toxin, treatment with PAL139-151 was less effective, but treatment with a mixture of PAL139-151 and PAL178-191, the palmitoylated PLP epitope to which T cell recognition spreads, resulted in almost complete protection. Proliferation of lymphocytes from treated mice were sharply reduced, and adoptive transfer of lymph node lymphocytes from treated mice to naive recipients resulted in the reduction of the acute phase of EAE and in delayed relapses following challenge. The results suggest that treatment with PAL139-151 leads to both anergy and the generation of regulatory cells.

Prevention of murine EAE by oral hydrolytic enzyme treatment.

Clinical trials that test the efficacy of Phlogenzym (consisting of the hydrolytic enzymes bromelain and trypsin and the anti-oxidant rutosid) as a treatment for T cell-mediated autoimmune diseases including multiple sclerosis (MS), type 1 diabetes and rheumatoid arthritis are presently ongoing. We tested the effects of Phlogenzym treatment in the murine model for MS, experimental allergic encephalomyelitis (EAE), a disease induced in SJL mice by immunization with proteolipid protein (PLP) peptide 139-151. Oral administration of Phlogenzym resulted in complete protection from EAE. In Phlogenzym-treated mice, the dose response curve of the PLP:139-151-specific T cell response was shifted to the right, that is, the primed T cells required higher peptide concentrations to become activated. Additionally, the T cell response to this peptide was shifted towards the T helper 2 cytokine profile. Both effects are consistent with an increased T cell activation threshold. In support of this interpretation, we found that the accessory molecules CD4, CD44, and B7-1 (all of which are involved in T cell co-stimulation) were cleaved by Phlogenzym, while CD3 and MHC class II molecules (which are involved in the recognition of antigens by T cells) and LFA-1 were unaffected. These data show the efficacy of oral Phlogenzym treatment in an animal model of T cell-mediated autoimmune disease and suggest that the protective effect might be the result of an increase in the activation threshold of the autoreactive T lymphocytes brought about by the cleavage of accessory molecules involved in the interaction of T cells and antigen presenting cells.