Experimental allergic neuritis in the SJL/J mouse: dysfunction of peripheral nerve without clinical signs

Histological and Immunohistological Changes of the Skeletal Muscles in Older SJL/J Mice

SJL/J mice have been studied as the model animals for autoimmunological diseases. Recently it was clarified that SJL/J mice have a defect of dysferlin. Human limb girdle muscular dystrophy 2B and Miyoshi myopathy also have a defect of dysferlin. In this study we present the histological and immunohistological changes in the natural course. Histological study revealed that SJL/J mice had inflammatory, degenerative changes, and neurogenic changes in later ages. As for interstitial inflammatory cells, the macrophages were dominant in any age, and in the T cell subset, the CD4+ T cells were more abundant than the CD8+ T cells, and few B cells were seen. The laboratory data showed a high level of creatine kinase in all ages. It is suspected that the inflammatory changes were induced by the primary immunological abnormality or by the defect of dysferlin in SJL/J mice.

Advances in understanding and treatment of immune-mediated disorders of the peripheral nervous system

During recent years, novel insights in basic immunology and advances in biotechnology have contributed to an increased understanding of the pathogenetic mechanisms of immune-mediated disorders of the peripheral nervous system. This increased knowledge has an impact on the management of patients with this class of disorders. Current advances are outlined and their implication for therapeutic approaches addressed. As a prototypic immune-mediated neuropathy, special emphasis is placed on the pathogenesis and treatment of the Guillain-Barré syndrome and its variants. Moreover, neuropathies of the chronic inflammatory demyelinating, multifocal motor, and nonsystemic vasculitic types are discussed. This review summarizes recent progress with currently available therapies and--on the basis of present immunopathogenetic concepts--outlines future treatment strategies.

Animal models of immune-mediated neuropathies

PURPOSE OF REVIEW

This article gives an overview on animal models for immune-mediated demyelinating disorders of the peripheral nervous system. As insight into human disease is mainly based on biopsy material and ex-vivo analysis, an understanding of the pathogenetic mechanism of these complex and heterogeneous disorders is mainly based on animal models.

RECENT FINDINGS

Besides experimental autoimmune neuritis in rats, recent efforts to establish this model in mice are discussed. In addition, models for spontaneous autoimmune neuropathies and secondary immune reactions in degenerative disorders of the peripheral nervous system are reviewed.

SUMMARY

Recently described animal models offer the possibility to analyse the complex interaction of genetic and immunological factors. The entire panel of animal models for immune-mediated disorders of the peripheral nervous system provides a rational basis for studying the mechanisms of pathogenesis and new immunotherapeutic strategies for human autoimmune demyelinating neuropathies.

Experimental allergic neuritis in the SJL/J mouse: induction of severe and reproducible disease with bovine peripheral nerve myelin and pertussis toxin with or without interleukin-12

We report a reproducible model of experimental allergic neuritis (EAN) with severe clinical signs and consistent pathological features in mice. Pertussis toxin (PT) in the presence or absence of murine recombinant interleukin-12 (mrIL-12) was used as an adjuvant with bovine peripheral nerve myelin (BPNM) to induce clinical EAN in SJL/J mice. After immunization with a combination of BPNM in complete Freund's adjuvant (CFA) and PT, mice developed severe consistent signs of EAN. The additional treatment of immunized mice with mrIL-12 prolonged the course of EAN characterized by earlier clinical signs of the disease and delayed the recovery stage. Mice injected with BPNM and CFA without PT developed mild clinical signs. Histological examination of the caudae equinae and the sciatic nerves taken from mice with clinical signs of EAN during the recovery stage revealed severe demyelination, remyelination and remnants of mononuclear cell infiltration. Moderate to severe EAN can be induced in SJL/J mice by the injection of a combination of BPNM in CFA and PT. This model can provide a better understanding of mechanism of demyelination in infiltrating peripheral neuropathy.

Pathogenesis of neuroimmunologic diseases. Experimental models

Animal models of autoimmune diseases have greatly improved our current understanding of the pathogenesis of human autoimmunity and have provided the potential for therapies based on manipulation of the immune system. In our laboratory, we have investigated the immunopathogenesis of autoimmune diseases of the nervous system and muscle. We have developed immune-based approaches for the suppression of experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis (MS), and experimental autoimmune neuritis (EAN), a model for the Guillain-Barré syndrome (GBS). These approaches included induction of peripheral tolerance, immunotoxin targeting of activated T cells, and cytokine manipulations. In addition, we identified the antigen and characterized immunopathologically an autoimmune inflammatory disease of skeletal muscle, experimental autoimmune myositis (EAM), a model for the human inflammatory muscle disease polymyositis.

Features of the Guillain-Barré syndrome in mice following intraperitoneal injection of patient serum

Intraperitoneal injection of serum from a patient with the Guillain-Barré syndrome (GBS) produced GBS-like signs in mice: inadequate respiration and weakness in the legs. We studied the clinical, electrophysiological and pathological features of these mice. Three groups of three mice were injected with patient serum from days 6, 10 and 15 after onset of neurological symptoms. GBS-like signs in mice were observed only with serum from day 6 and improved within 48 h. When serum was frozen and thawed more than once no signs were seen. Electrophysiological measurements of the sciatic nerves of injected and control mice were done before and after serum injection. Five days after injection of patient serum of day 6, the mice showed a significant decrease in the ratio between CMAP amplitude from proximal and distal stimulation and increase in H-M interval from proximal stimulation. These electrophysiological changes returned to normal within 12 days. The sciatic nerve showed no morphological abnormalities. Our results indicate that the observed GBS-like signs in mice are caused by peripheral nerve dysfunction.

The beta 2-adrenergic agonist terbutaline suppresses experimental allergic neuritis in Lewis rats

Treatment of rats with experimental allergic neuritis with the beta 2-adrenergic agonist terbutaline suppresses clinical symptoms, decreases demyelination and Wallerian degeneration in peripheral nerves and improves electrophysiological parameters. Treatment is highly effective when given from the time of immunization through the acute phase of illness, when given for the first 12 days after immunization and also when given after the onset of the disease.