优化核酸疫苗对慢性MPTP帕金森病小鼠的免疫作用

Immunological effects of optimized nucleic acid vaccines on chronic MPTP Parkinson's disease mice

目的评价优化核酸疫苗(pVAX1-IL-4/SYN-B)预防接种对小鼠MPTP损害的免疫保护作用。方法将C57BL/6小鼠随机分为正常对照组、PBS模型组、空质粒模型组、优化核酸疫苗模型组4组,分别在小鼠双后肢胫前肌注射PBS、PBS、空质粒、pVAX1-IL-4/SYN-B各100μl,共3次。末次注射3周后,后3组注射MPTP构建慢性帕金森病小鼠模型,正常对照组注射同体积的PBS。末次给药后观察小鼠行为学变化;免疫组织化学、Western blot检测小鼠黑质部酪氨酸羟化酶(tyrosine hydroxylase,TH)表达情况;RT-PCR检测小鼠黑质TNF-α、IL-1β的mRNA水平。结果与PBS模型组、空质粒模型组相比,优化核酸疫苗模型组小鼠运动症状明显改善;TH丢失减少;TNF-α、IL-1β的mRNA水平表达降低;差异有统计学意义。结论优化核酸疫苗预防接种对小鼠的慢性MPTP损害有一定的神经保护及抗炎作用。

This study aimed to evaluate the protective effects of optimized nucleic acid vaccine（pVAX1-IL-4/SYN-B） on the immune function of model mice of Parkinson’s disease damaged by MPTP.C57BL/6 mice were randomly divided into four groups： normal control group,PBS model group,empty plasmid model group,optimized DNA vaccine model group.Then,the anterior tibial muscles of mouse hind leg were respectively injected with 100 μl of PBS,PBS,empty plasmid,and pVAX1-IL4/SYN-B unilaterally,total for three times at two weeks interval.Three weeks after the last injection,the latter three groups were built the chronic MPTP model by injecting MPTP,while normal control group received the same volume of PBS.After the last administration of MPTP,we observed the behavior changes of mice,evaluated the tyrosine hydroxylase（TH） expression in substantia nigra of mice using immunohistochemistry and western blot methods,and detected the TNF-α and IL1-β mRNA levels in substantia nigra of mice using RT-PCR.We found that the motor symptoms of mice improved significantly,the loss of TH reduced,the TNF-α and IL1-β mRNA levels decreased obviously in optimized DNA vaccine model group which was immunized preventively with pVAX1-IL-4/SYN-B when compared with the PBS model group and/or empty plasmid model group.From these results we can conclude that optimized DNA vaccine has neuroprotective and anti-inflammatory effects in chronic Parkinson’s disease mice induced with MPTP.