Effect of leflunomide on peripheral blood CD28/CTLA-4 costimulatory molecules expression in guinea pig with EAE / 中国生化药物杂志

ABSTRACT

Objective To investigate immunological mechanism underlying leflunomide ( LEF ) against experimental allergic encephalomyelitis ( EAE) by studying the effects of LEF on peripheral blood CD28/CTLA-4 costimulatory molecules expression in guinea pig with EAE.Methods 50 adult female guinea pigs were randomly divided into normal control group,low dose group,EAE control group,middle dose group,and high dose group, 10 guinea pigs in each group respectively.Low, medium and high dose group were treated with LEF 10 mg/kg· D, 20 mg/kg· D and 40 mg/kg· D orally, 1 times/day, to the termination of the experiment.The expression of CD28, CTLA-4 were detected by flow cytometry, incidence was recorded at the same time.Results Compared with EAE control group,high dose and middle dose group incubation period were prolonged, progress period were shorten and neurological dysfunction score decreased(P<0.05).Compared with normal control group, the expression of CD28 of EAE control group increased and the decreased expression of CTLA-4 (P<0.05).High, middle dose treatment group compared with EAE control group CD28 down regulated expression (P<0.05), but the expression of CTLA-4 increased(P<0.05).Among the treatment groups, of CD28 molecules with high dose group decreased significantly(P<0.05), the expression of CTLA-4 molecules with high dose treatment groups upregulated significantly (P<0.05).Correlation analysis showed that the EAE control group, the treatment group the CD28/CTLA-4 ratio in peripheral blood and nerve dysfunction score is proportional ( r=0.85, P=0.002; r=0.77, P=0.000).Conclusion LEF can reduce EAE guinea pig neurological symptoms, the better and the higher dose effect.Its mechanism may be through down-regulation of CD28 molecules in peripheral blood, upregulation of the expression of CTLA-4 molecule.so as to reduce the inflammatory response, relieve the clinical symptoms.