Study On The Treating Effect Of Schistosoma Japanese Egg Antigen On Experimental Allergic Encephalomyelitis

Objectives:1. To prove the value of experimental allergic encephalomyelitis (EAE) model for dynamic studding on multiple sclerosis (MS) by magnetic resonance imaging (MRI) scanning.2. To explore the potentially clinical value of Schistosoma Japanese Egg Antigen (SEA) treating EAE by observing both the therapeutic effect and the histopathological change.3. To find out its mechanism by analyzing the quantitative of cytokines IL-4 and IFN-γ and the proliferation responses of spleen lymphoid cell culture after addingimmunomodulation, such as SEA, conA, dexamethasone and proteolipid protein (PLP) 139-151 polypeptide.Methods:1. EAE mice were anesthetized with chloral hydrate by i.p., injected contrast medium Gd-DTPA at tail vein and then separately scanned by routine MRI and Gd-DTPA enhanced MRI in relapse period and remission. The MRI pictures get in both relapse and remission of EAE were compared one another.2. All EAE mice were randomly distributed into three groups. Negative control group was injected with saline at tail vein, the treat group with SEA and the positive control group with Dex. All EAE mice were weighted and examined daily for neurological signs. Some were killed at the peak of relapsing to gain their brains and spinal cords. The grade of inflammation and demyelination was examined with hematoxylin-erosin and Fuxol Fast blue respectively.3. The positive control group, negative control group and the treat group were thesame as above. The mice spleen lymphocytes of three groups were get at fifteen days stimulated by different reagent, such as saline, SEA and Dex, cultured in RPMI1640 and then counted. The proliferation responses of spleen lymphocytes stimulated by different reagent were detected by 3H-thymidine incorporation. The cytokine IL-4 and IFN- γ were measured in the culture supernatants with ELISA method. Results:1. The relative signal intensity of Gd-DTPA enhanced MRI on focus of EAE mice was much higher during relapse period than that in remission. Each of EAE groups was higher than that of negative control group.2. Compared with control group, the EAE mice received SEA treatment had a significantly improve clinical outcome. The same results were also get with histopathological examing and MRI scanning. The inflammation reaction and demyelination in cerebral periventricular, cerebellar, brain stem, and spinal cord white matter were all ameliorated.3. The proliferation response of spleen lymphocytes in SEA-treated group was suppressed when compared with merely PLP 139.151 stimulated group and control group(P<0.05). SEA could delay and even prevent EAE relapse and suppress inflammatory infiltration. In SEA-treated group, the IL-4 of the mice spleen lymphocytes induced by SEA was higher than that induced by PLP 139.) 51 only, but the IFN- Y was opposite. That is the SEA-treated made the lymphocytes secret IL-4 hightened and IFN- Y reduced(P<0.05).Conclusion:1. It was proved there were more similar in the EAE model and human MS on MRI scan, and both the animal model and MRI scan were much more useful for the study of MS.2. SEA can effectively treat EAE and improvd the degree of EAE clinically and histopathologically. Maybe there is some relationship between parasite infectionand the onset of MS.3. Cytokine play an important role in EAE onset t relapse and remittence. Our study implied that SEA can modulate the balance of Thl/Th2 on EAE and alleviate the accentuation of Thl reaction.