α-黑素细胞刺激素对EAE豚鼠外周血CD4＋CD25＋FoxP3＋Treg细胞比例的影响

目的探讨α-MSH对EAE发病保护作用及免疫学机制。方法 40只雌性豚鼠随机分为正常对照组、EAE对照组和EAE高、低剂量治疗组。采用粗制髓鞘碱性蛋白（cMBP）诱发急性EAE,EAE高、低剂量治疗组自造模前7d始分别按1mg/（kg.d）及0.25mg/（kg.d）予腹腔注射注射α-MSH直至试验结束。观察豚鼠神经功能障碍评分变化,并用流式细胞方法测定CD4＋CD25＋FoxP3＋Treg细胞比例。结果 EAE高、低剂量治疗组神经功能障碍评分较EAE对照组显著降低（P〈0.01,P〈0.05）,高剂量治疗组降低更明显（P〈0.05）。EAE对照组豚鼠发病高峰期外周血CD4＋CD25＋FoxP3＋Treg细胞比例较正常对照组下降（P〈0.01）,高、低剂量治疗组CD4＋CD25＋FoxP3＋Treg细胞比例较EAE对照组升高（P〈0.01,P〈0.05）以高剂量治疗组升高最显著（P〈0.05）。EAE各组豚鼠发病高峰期外周血CD4＋CD25＋FoxP3＋Treg细胞比例与高峰期神经功能障碍评分呈负相关（r=-0.83,P〈0.05）。结论α-MSH对EAE豚鼠发病具有保护作用,其作用机制可能是通过增加外周血CD4＋CD25＋FoxP3＋Treg比例,增强对活化的自身反应性T细胞的抑制,发挥调节作用的。

Effect of alpha-melanocyte-stimulating hormone on the proportion of CD4 + CD25 + FOXP3 + T lymphocyte in guinea pig with experimental allergic encephalomyelitis

Objective To investigate the immunological mechanism underlying alpha-melanocyte-stimulating hormone（alpha-MSH） against experimental allergic encephalomyelitis（EAE）.Methods Forty female Guinea pigs were assigned randomly to four groups： the normal group,the EAE control group,the low dose treated EAE group and the high dose treated EAE group.intervention have been done from the mould to fastigium seven days to the end.The neurological disorder change of each groups were compared;the proportion of CD4＋CD25＋ FOXP3＋T lymphocyte were detected by flow cytometry（FCM） method.Results The level of neurological disorder in two treated EAE groups were lower than that of the EAE control group.the high dose treated EAE group was the lowest.The proportion of CD4＋CD25＋FoxP3＋Treg of EAE control group obvious drop than the normal control group.The proportion of CD4＋CD25＋FoxP3＋Treg of two dose treated EAE group were much higher than the EAE control group,Difference exists between the high dose treated group and low dose treated group.The proportion of peripheral CD4＋CD25＋FoxP3＋Treg cells was negatively correlated with neurological disorder score in all EAE groups.Conclusion Alpha-MSH had protective effect over guinea pigs with EAE,which is positively correlated with the dose of alpha-MSH.The mechanism may be produced by increase proportion of CD4＋CD25＋FoxP3＋Treg.