Abstract
Although IL-23 and downstream signal transduction play essential roles in neuroinflammation, the local impact of IL-23 in multiple sclerosis is still not fully understood. Our previous study revealed that the central nervous system (CNS)-restricted expression of IL-23 in a mouse model with astrocyte-specific expression of IL-23, called GF-IL23 mice, leads to spontaneous formation of infiltrates in the brain, especially in the cerebellum. To further investigate the impact of CNS-specific IL-23-expression on neuroinflammation, we studied the GF-IL23 model in mice expressing a myelin oligodendrocyte glycoprotein (MOG)-specific T cell receptor (GF23-2D2 mice). The GF23-2D2 mice developed a chronic progressive experimental autoimmune encephalomyelitis with myelitis and ataxia without requiring additional immunization. CNS-production of IL-23 alone induced pronounced neuroinflammation in the transgenic MOG-specific T cell receptor model. The GF23-2D2 mice spontaneously developed multilocular infiltrates with a high number of B cells, demyelination and a proinflammatory cytokine milieu indicating that the interaction of encephalitogenic T cells and B cells via co-stimulatory factors seemed to be crucial.