Induction of tolerance to self-antigens using genetically modified bone marrow cells

Methylprednisolone induces reversible clinical and pathological remission and loss of lymphocyte reactivity to myelin oligodendrocyte glycoprotein in experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model of human multiple sclerosis (MS). EAE, induced by immunisation with myelin-associated autoantigens, is characterised by an inflammatory infiltrate in the central nervous system (CNS) associated with axonal degeneration, demyelination and damage. We have recently shown in an experimental mouse model of autoimmune gastritis that methylprednisolone treatment induces a reversible remission of gastritis with regeneration of the gastric mucosa. Here, we examined the effect of oral methylprednisolone on the mouse EAE model of human MS induced by immunisation with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)). We examined the clinical scores, CNS pathology and lymphocyte reactivity to MOG(35-55) following treatment and withdrawal of the steroid. Methylprednisolone remitted the clinical signs of EAE and the inflammatory infiltrate in the CNS, accompanied by loss of lymphocyte reactivity to MOG(35-55) peptide. Methylprednisolone withdrawal initiated relapse of the clinical features, a return of the CNS inflammatory infiltrate and lymphocyte reactivity to MOG(35-55) peptide. This is the first study to show that methylprednisolone induced a reversible remission in the clinical and pathological features of EAE in mice accompanied by loss of lymphocyte reactivity to the encephalitogen. This model will be useful for studies directed at a better understanding of mechanisms associated with steroid-induced disease remission, relapse and remyelination and also as an essential adjunct to an overall curative strategy.

Prednisolone promotes remission and gastric mucosal regeneration in experimental autoimmune gastritis

A cardinal feature of organ-specific autoimmunity is destructive pathology in the target organ. In human and experimental models of autoimmune gastritis, mononuclear cell infiltration and cellular destruction in the gastric mucosa are disease hallmarks. Strategies to cure autoimmune disease must not only establish immunological tolerance to autoantigen, but also rid the organ of pathogenic autoreactive cells. The present study has assessed the effect of prednisolone treatment in clearing the inflammatory infiltrate in experimental autoimmune gastritis and in preventing disease relapse in athymic compared with euthymic mice. Experimental autoimmune gastritis was induced by neonatal thymectomy or by transgenic expression of GM-CSF (PC-GMCSF mice). Groups of mice were treated with prednisolone (10 mg/kg per day) for 10 weeks or with prednisolone for 10 weeks followed by 10 weeks without prednisolone. Stomachs were examined for gross morphological changes, and by histology and immunohistochemistry for composition of inflammatory infiltrate and gastric mucosal integrity. Autoantibody to gastric H+/K+ ATPase was determined by ELISA. Prednisolone promoted remission of gastritis in both mouse models of experimental autoimmune gastritis, evident by reduction in stomach size, clearing of gastric inflammatory infiltrate, and regeneration of the gastric mucosa. Prednisolone withdrawal resulted in disease relapse in all PC-GMCSF mice, whereas approximately 40% of neonatal thymectomy mice retained normal stomach morphology and remained free of gastric pathology. It is concluded that prednisolone promotes remission and gastric mucosal regeneration in experimental autoimmune gastritis. Prolonged remission of autoimmune gastritis in some athymic mice suggests a role for the thymus in disease relapse.