Experimental Studies On The Effect Of Schistosoma Japanese Egg Antigen On Experimental Autoimmune Encephalomyelitis

Objectives:1.To explore the establishment of EAE animal model by another encephalitogenic determinant of myelin proteolipid protein (residues 178-191) and its immunological characterization.2. To explore the immunomodulation potential of Schistosoma Japanese Egg Antigen for EAE and to find out the relationship between parasite infection and the onset of MS.3. To explore the change of cytokines (IL-4 and IFN-y) in the immunomodulation procedure of Schistosoma Japanese Egg Antigen for EAE and to discuss its mechanism.Methods:1. Each SJL mouse was injected s.c.over the abdominal wall with PLPns-m, Mycobacteria H37RA and CFA, and Bordetella pertussis bacilli.2. EAE was induced by PLP178-191 in SJL mouse, all mice were weighted and examined daily for neurologic signs.3 . The proliferation response of lymphoid node cells induced by different peptide concentration of PLP178-191 was detected by the method of MTT.4. The immunomodulation effect of Schistosoma Japanese Egg Antigen on EAE mice was studied by examination daily for neurologic signs and pathology examination.5. To find out the effect of Schistosoma Japanese Egg Antigen, the expression of IL-4 and IFN-y of the lymphoid node (LN) cells in EAE mice was tested by using ELISA.Results:1. Incidence of EAE in immunized female animal was 90%. Most mice received injection of PLP178-191 developed clinical EAE 9.6 2.13 days postinjection. Clinical signs were severe and different. Histologically, meningeal inflammatory infiltrates were present over the entire neuraxis of mice immunized with PLP178-191.Perivascular, predominantly perivenous, inflammation was present in cerebral periventricular, cerebellar, brain stem, and spinal cord white matter. Small foci of perivascular demyelination were present adjacent to dorsal root entry zones in the spinal cords.2. The best peptide concentration of PLP178-191 attribute to the proliferation response of lymphoid node cells was 5ug/ml, while the effective concentration was 5-25ug/ml.3. Mice received Schistosoma Japanese Egg Antigen pretreatment or synchronously immunization with PLP 178-191 had a significantly improved clinical outcome compared with control group (P<0.05). And it was also proved histologically.4. In the group with synchronously immunization of PLP178-191 and SEA, LNC expression of IL-4 induced by SEA was higher than that induced by PLP178-191only, but the expressin of IFN was opposite (P<0.05). And compared with the group immunized with PLP178-191 singly, the expression of IL-4 was hightened, while IFN was reduced (P<0.05).Conclusion:1. The animal model of EAE induced by PLP178-191 had features of stability, relapse-remitting and high incidence, which was considered a better model for the study of multiple sclerosis.2. Schistosoma Japanese Egg Antigen was effective in improving the degree ofEAE. It has some relationship between parasite infection and the onset of MS. And maybe parasite infection can alleviate the onset of MS.3. Cytokine play an important role in procedure of SEA's immodulation on EAE. Modulating the balance of Thl/Th2 and alleviating the swiftness of Thl reaction may be the mechanism.