约氏疟MIF对小鼠BM-DC细胞作用的探索

 摘要：目的 探索约氏疟原虫来源巨噬细胞迁移抑制因子（PyMIF）对小鼠髓系树突状细胞（BM-DC）表型和功能的影响。方法分离小鼠骨髓细胞并经GM-CSF和IL-4诱导培养得到BM-DC：经PyMIF刺激后，通过流式细胞术检测其TLR2、TLR4、CD80、CD86、CD40、MHCII分子表达，通过ELISA方法检测IL-12、IL-10分泌；经PyMIF刺激的BM-DC与CD4+T或CD8+T细胞共培养，同样方法检测T细胞CD69表达、IL-2分泌情况，并检测CD8+T细胞对靶细胞杀伤能力。结果PyMIF可以下调小鼠骨髓来源树突状细胞TLR-4的表达；但不能影响BM-DC细胞表面分子TLR2、CD80、CD86、CD40、MHCII的表达，也不改变BM-DC分泌IL-12、IL-10。PyMIF可通过BM-DC下调CD8+T的CD69表达，但不能通过BM-DC改变CD4+T细胞CD69表达、IL-2分泌，及CD8+T细胞IL-2分泌。结论PyMIF可能是通过下调BM-DC细胞TLR4表达来抑制免疫细胞对疟原虫的识别，使之逃逸机体的攻击而存活。

Influence of P.yoelii derived recombinant MIF on phenotype and function of mouse BM-DC

Objective To detect the role of P.yoelii plasmodium derived macrophage migration inhibitory factor(PyMIF) recombination protein on the phenotype and function of bone marrow dendritic cells(BM-DC).MethodsBM-DCs induced from bone marrow precursors by GM-CSF and IL-4 were treated with PyMIF,then cell surface molecules including TLR2,TLR4,CD80,CD86,CD40 and MHCⅡ were detected by flow cytometry,IL-12 and IL-10 were analyzed by ELISA.PyMIF treated BM-DC were first stimulated by LPS,then co-cultured with CD4+T or CD8+T cells,CD69 was detected by flow cytometry and IL-2 was detected by ELISA.The cytotoxictity of CD8+T was also measured.Results PyMIF decreased the TLR4 expression of BM-DC(fluorescence intensity decrease from 1±0.001 to 0.81±0.02,normalized to control group),but had no effect on TLR2,CD80,CD86,CD40 and MHCⅡ expression,nor on IL-12 and IL-10 secreting.After co-coluturing with PyMIF treated BM-DC,the CD69 expression of CD8+T decreased,but CD69 expression and IL-2 secrecting of CD4+T and CD8+T cells did not change.Conclusions PyMIF may down-regulate TLR4 expression of BM-DC to block plasmodium being recognized and attacked by immune system,so as to survive in the organism.