ABSTRACT
Objective To study effect of nasal tolerance with rat-derived 97-116 peptide of AChR α-subunit(Rα97-116(V108A))on the manifestation of muscle weakness and the immunity function of experimental autoimmune myasthenia gravis(EAMG).Methods Twenty-two EAMG model Lewis rats immunized thrice with Rα97-116(V108A)were divided randomly into tolerance group and control group.They were respectively immunized with Rα97-116(V108A)and PBS buffer solution for 10 days via nasal mucous.Then the body weight and Lennon score of two group Lewis rats were measured.Their serum anti-AChR antibodies were tested by ELISA,the expression levels of CD28,CTLA4,B7-1 and B7-2 were determined by flow cytometry.Results Compared with control group at different time points.the body weight of tolerance group rats(tolerance group(228.1±5.8)g,control group(215.0±16.2)g,t=2.395,P＜0.05)increased,the mean clinical score of rats(tolerance group 1.55±0.44.control group 2.10±0.66,t=-2.20,P＜0.05)decreased and the amount of serum anti-AChR antibody(tolerance group 0.97±0.20,control group 1.27±0.26,t=-2.857,P＜0.05)decreased obviously.the amount of CD28,B7-1,B7-2,CTLA4(%)expressed on the surface of peripheral blood cells(tolerance group:27.35±7.05,4.73±0.58,2.71±0.35,1.72±0.44,control group:40.02±8.81,9.52±1.25,5.88±1.09,2.64±0.47)down-regulated markedly(t=3.479,10.861,8.755,4.403,all P＜0.01).Conclusion Nasal mucous tolerance with Rα97-116(V108A)could ameliorate muscular weakness of EAMG rats while activates T cell and inhibits B cellular immunity.