Treatment of experimental allergic encephalomyelitis by selective removal of CD4+ T cells

Cytapheresis with a filter for selective removal of CD4+ T cells in experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a major animal model of human multiple sclerosis (MS). CD4+ T cells are thought to play a pivotal role in the patho genesis of EAE and MS. In order to investigate the depletio n of CD4+ T cells from the systemic circulation as an effective strategy for the treatment of MS, we performed extracorporeal CD4+ T cell adsorption, using a filter to which anti-CD4+ antibody is immobilized as a ligand, in adoptively transferred EAE. Rats treated with CD4+ T cell removal filter (C D4RF) exhibited milder clinical signs of EAE and earlier recovery than those receiving sham treatment. Moreover, the thymic cells from EAE rats treated with C D4RF exhibited a suppressed proliferative response and IFN-g production to myelin basic protein. These results suggest that depletion of CD4+ T cells from the systemic circulation by extracorporeal treatment is a potentially useful strategy for treatment of acute phase and relapsing MS.

Novel immunosuppressive therapy by M2000 in experimental multiple sclerosis

The therapeutic potency of M2000 (beta-D-mannuronic acid), a novel designed nonsteroidal anti-inflammatory drug with immunosuppressive property in T-cell-mediated autoimmune disease, was tested. The influence of M2000 on myelin basic protein (MBP)-induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, was assessed. M2000 at two doses, 40 and 80 mg/kg/day, was administered intraperitoneally (i.p.) to prevention and treatment groups, respectively. Onset of i.p. injections of M2000 to prophylactic and therapeutic groups was day-1 and day-7 postimmunization. The WEHI-164 cell line was used for assaying the tolerability against M2000. The results of this experiment showed that the treatment of EAE with M2000 could significantly suppress disease development both prophylactically and therapeutically; the onset and symptoms of EAE in Lewis rats could be suppressed following the administration of M2000. Clinical improvement was accompanied by a marked decrease in mean numbers of vessels with perivascular cellular infiltration in M2000-treated rats compared with nontreated control. Disease suppression was associated with a marked suppression of MBP-specific T-cell reactivity in vitro, without any evidence for a generalized impairment of T-cell activity. Moreover, M2000 also showed a very high tolerability compared with certain steroidal and nonsteroidal anti-inflammatory drugs. Collectively, our data suggest that M2000 may provide a novel therapeutic option for T-cell-mediated autoimmune diseases in animal models and possibly in humans.

Development of a device for selective removal of CD4+ T cells

To control antigen (Ag)-specific immune cells is important in the treatment of autoimmune diseases. In particular, controlling the immune response of autoimmune T cells is effective in the treatment of these diseases. The development of a device that can remove CD4+ T cells specifically by extracorporeal circulation is now in progress, with the aim to deplete autoimmune T cells. We developed a removal material made of polypropylene non-woven fabrics with anti human CD4 monoclonal antibody immobilized on the surface. Using a column packed with the removal material, we succeeded in removing CD4+ T cells specifically from peripheral whole blood by direct perfusion. Moreover, CD4+ T cells can be specifically removed even from blood with lower surface antigen density by in vitro activation.

A new device for selective removal of CD4+ T cells

To control antigen (Ag)-specific immune cells is important in the treatment of autoimmune diseases. In particular, a direct solution may be obtained by controlling the CD4+ cell function that controls the immune response of autoimmune T cells. Thus, a technique to selectively remove CD4+ cells has been developed, based on the consideration that the immune system may possibly be modified by selectively removing the CD4+ cells by means of extracorporeal circulation. The currently developed device to selectively remove CD4+ cells uses a material made of nonwoven fabric with monoclonal antibodies immobilized on the surface. With this device, removal of only CD4+ cells from human mononuclear cells suspension can be accomplished. Moreover, CD4+ cells can be specifically removed from peripheral whole blood by direct perfusion. This review outlines a series of procedures for selective cell removal and the results of our research.