Objective. To establish a new murine model of polymyositis (PM) for the understanding of its pathologic mechanisms and the development of new treatment strategies.Methods. C protein-induced myositis (CIM) was induced by a single immunization of recombinant human skeletal C protein in C57BL/6 mice, as well as in CD4-depleted, CD8-depleted, and mutant mice as controls. Some mice were treated with high-dose intravenous immunoglobulin (IVIG) after disease induction. Muscle tissues were examined histologically.Results. In mice with CIM, inflammation was confined to the skeletal muscles. Polymyositis (PM) is a chronic autoimmune inflammatory myopathy affecting striated muscles (1). Damage of muscles results in varying degrees of muscle weakness. Dysphagia with choking episodes and respiratory muscle weakness can occur in acute cases of PM. Currently, the pathogenesis of PM is unknown, and patients are therefore treated with nonspecific immunosuppressants. High-dose corticosteroids are the first-line treatment but are not effective in all patients. Improvement of disease often depends on the dosage of corticosteroids, making a dosage reduction difficult and thus, in many cases, necessitating administration of methotrexate or other immunosuppressants as adjunctive treatment. Because these medications can elicit a wide variety of adverse drug reactions, new therapies to address the specific pathologic features of PM are needed.In affected muscles of patients with PM, infiltration of mononuclear cells leads to muscle fiber necrosis. These cells are found in the endomysial site, where non-necrotic muscle fibers are damaged, and also in the perimysial and perivascular sites of the muscles. Immunohistochemical studies have disclosed that CD8 T cells are most abundant in the endomysial site and invade
Cyclodextrin glucanotransferase from an alkalophilic Bacillus species produced neohesperidin monoglucoside and a series of its maltooligoglucosides by transglycosylation with neohesperidin as an acceptor and soluble starch as a donor. As the reaction using beta-CD as a donor at an alkaline pH was very effective for solubilizing neohesperidin, the amount of glycosides formed was increased. As a result, its amount with beta-CD at pH 10 was about 7 times greater than that with soluble starch at pH 5. Neohesperidin monoglucoside was purified from the reaction mixture by glucoamylase and naringinase treatments, an Amberlite XAD-16 column, a Sephadex LH20 column, and HPLC on an ODS column. The structure of the purified monoglucoside was identified as 3G-alpha-D-glucopyranosyl neohesperidin by FAB-MS, methylation analysis, and 1H- and 13C-NMR. The solubility of neohesperidin monoglucoside in water was approximately 1500 times higher than that of neohesperidin, and the bitterness of the monoglucoside was about 10 times less than that of neophesperidin. In addition, naringin was also glycosylated by the same method as neohesperidin, and its monoglucoside was identified as 3G-alpha-D-glucopyranosyl naringin. The solubility of naringin monoglucoside in water was also at least 1000 times higher than that of naringin without altering its bitterness.
A soluble tag-assisted liquid-phase peptide synthesis was successfully established based on simple hydrophobic benzyl alcohols, which can be easily prepared from naturally abundant materials. Excellent precipitation yields can be obtained at each step, combining the best properties of solid-phase and liquid-phase techniques. This approach can also be applied efficiently to fragment couplings, allowing chemical synthesis of several bioactive peptides.
SUMMARYHigh-dose intravenous immunoglobulin (IVIG) therapy has been effective in many autoimmune and systemic inflammatory diseases including polymyositis (PM) and dermatomyositis (DM). In the present study we evaluated the efficacy of IVIG using experimental models of PM and DM. An experimental autoimmune myositis (EAM) model was produced in SJL/J mice by an immunization with rabbit myosin B (MB) fraction. In this model, the plasma level of anti-MB antibody was elevated, and mouse IgG and complement C3 were deposited in the muscle fibres. Administration of IVIG dose-dependently reduced the incidences of necrotic and inflammatory changes in the skeletal muscle. IVIG treatment also decreased the elevation of anti-MB antibody level, as well as the deposition of IgG and C3. We next evaluated the effect of IVIG in adoptive EAM mice made by an intravenous injection of lymph node cells previously stimulated with MB. Adoptive EAM mice showed similar lesions in skeletal muscle as EAM mice and IVIG inhibited the lesion development. In vitro experiments demonstrated that IVIG inhibited complement-mediated lysis of human erythrocytes sensitized with anti-human erythrocyte antibodies. The binding of C1q, C4 and C3 to the same cells was also inhibited by IVIG. Taken together these findings suggest that IVIG prevents the development of myositis in EAM and adoptive EAM models by several mechanisms, such as reducing anti-myosin antibody and by blocking complement activation. Our present findings might account for the clinical efficacy of IVIG in PM and DM patients.
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