DYNAMICS OF CIRCULATING AND EXPRESSED CYTOKINES UPON INDUCTION OF EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS

Abstract. Experimental allergic encephalomyelitis (EAE) represents an inflammatory demyelinating CNS disease, thus being regarded as an experimental model of multiple sclerosis. The aim of present work was to study production of pro- and anti-inflammatory cytokines, and their expression in spinal cord of rats challenged with encephalitis-inducing mixture, in the course of EAE progression. Pathological features of EAE were characterized by meningeal, perivascular, and periventricular infiltration of brain stem, cerebellum and spinal cord. The areas of demyelinization were associated with inflammatory foci, being located at the edges of infiltrates. In sensitized animals, increased levels of serum ТNFα were detectable, being higher in diseased animals, as compared with healthy ones, both in latent phase and during advanced neurological disorder. Increase in circulating IL-10 was in parallel with initial phase of EAE, being also observed in recovering animals. Early increase of IL-10 levels predetermined mild course of the disease, accompanied by decrease in ТNFα activity, whereas low IL-10 levels were registered in severely ill rats with high ТNFα, followed by lethal outcome. ТNFα-specific mRNA was revealed in acute phase of EAE, IL-10 mRNA was detectable at the time of recovery. ТNFα expression was observed for a long time in cases of protracted disease, being, however, absent in EAE-free rats. The data demonstrate that higher levels of ТNFα in blood serum during latent period, and, especially, at later time, may promote development of damage in central nervous system. The central cytokine pool is involved into progression of neurological disorders, thus influencing duration and severity of the disease. (Med. Immunol., 2008, vol. 10, N 2-3, pp 193-202)