肥大细胞对重组口蹄疫病毒VP1-VP4蛋白的模式识别效应

The Effectiveness of Mast Cell Pattern Recognition of Recombinant VP1-VP4 of Foot-and-mouth Disease Virus

为研究肥大细胞对重组口蹄疫病毒VP1-VP4蛋白的模式识别作用,将VP1-VP4蛋白负载经TLR2/TLR4抑制剂、甘露糖受体抑制剂或清道夫受体抑制剂预处理的小鼠肥大细胞系P815,在不同时间点观察其脱颗粒现象,并用ELISA检测细胞上清液中TNF-α的含量。结果显示,清道夫受体抑制剂处理组在负载VP1-VP4蛋白15和30min时P815细胞脱颗粒数目均极显著低于重组VP1-VP4蛋白组(P<0.001)。在负载VP1-VP4蛋白24h时,各抑制剂处理组的TNF-α含量均极显著低于VP1-VP4蛋白组(P<0.001),其中以甘露糖受体抑制剂处理组含量最低。这表明小鼠肥大细胞系P815主要通过清道夫受体识别FMDV VP1-VP4并引起脱颗粒现象的发生,而甘露糖受体和TLR2/TLR4识别FMDV VP1-VP4则是引起P815细胞分泌TNF-α的主要模式识别机制,其中以甘露糖受体的作用最强。

The objective of this study was designed to investigate the effectiveness of mast cell pattern recognition of recombinant VP1-VP4 of foot-and-mouth disease virus(FMDV).To this end,murine mast cell line P815 were pulsed with the recombinant VP1-VP4 of FMDV after inhibitors of Toll-like receptor 2/4(OxPAPC),mannose receptors(Mannan),and scavenger receptors(Sennoside B)were administered to murine mast cell line,respectively.Degranulation of P815 mast cells stained with toluidine blue was observed at the given time.And the levels of TNF-αin P815 mast cell culture supernatants were determined by ELISA at different timepoints.It was showed that the number of degranulated P815 mast cells with administration of scavenger receptor inhibitor was significantly lower than that of cells pulsed with recombinant VP1-VP4 protein at 15 min and 30min(P<0.001).Intriguingly,the TNF-αrelease from the mast cell line activated by recombinant VP1-VP4 at 24hwas significantly blocked with three inhibitors(P<0.01),of which,mannan,a mannose receptor inhibitor,showed the strongest inhibition on TNF-αrelease.Our data indicate that murine mast cell line P815 degranulation triggered by recombinant VP1-VP4 was predominantly mediated via the recognition of scavenger receptors,while the TNF-αre-lease from the activated mast cells was constitutively initiated with the recognition of mannose receptors,TLR2,and TLR4.Of note,recognition of recombinant VP1-VP4 through mannose receptors plays a predominant role in triggering TNF-αrelease from P815 mast cells activated by recombinant VP1-VP4.