Cirsii Herba glycoprotein regulates immune function of dendritic cells through Toll-like receptor 4-mediated signaling pathway(小蓟糖蛋白通过Toll样受体4介导的信号通路调节树突状细胞免疫功能)

The present study aimed to investigate the immunomodulatory effect and mechanism of Cirsii Herba glycoproteins (CHPs) on dendritic cells. The flow cytometry, Griess method, enzyme-linked immunosorbent assay (ELISA), real time fluorescent quantitative polymerase chain reaction (qRT-PCR) and confocal microscopy were employed to investigate the effects of CHPs on phagocytic activity, NO production, the expression and secretion of inflammatory factors and chemokines, and surface molecule expression as well as the roles of mitogen-activated protein kinase (MAPK), nuclear factor kappa-B (NF-κB), and Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathways and the functional receptor of CHPs. The results showed that CHPs significantly inhibited the phagocytic activity of dendritic cells and promoted NO production and the secretion of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and CXC chemokine ligand 10 (CXCL10). Moreover, CHPs upregulated the mRNA expression of inflammatory factors, including IL-1β, IL-6, TNF-α, prostaglandin-endoperoxide synthase 2 (PTGS2) and CXCL10, and elevated the expression of surface molecules, including CD40, CD80, CD86, MHC Ⅰ, and MHC Ⅱ. Significantly decreased contents of NO were observed in the presence of specific pathway inhibitors or Toll-like receptor 4 (TLR4) inhibitor. Additionally, the stable binding between CHPs and dendritic cells and the co-localization of CHPs and TLR4 were observed. In conclusion, these results indicated that CHPs might activate dendritic cells through TLR4-mediated MAPK, NF-κB, and JAK-STAT pathways, promoting their maturation and activating immune functions. The present study provides a theoretical foundation for pharmacodynamic material basis and clinical application of Cirsii Herba.(为探究小蓟糖蛋白（Cirsii Herba glycoproteins, CHPs）对树突状细胞的免疫调节作用及其分子机制，采用流式细胞术、格里斯（Griess）法、酶联免疫吸附试验（enzyme-linked immunosorbent assay, ELISA）、实时荧光定量聚合酶链反应（real time fluorescent quantitative polymerase chain reaction, qRT-PCR）和激光共聚焦显微镜等分别研究CHPs对树突状细胞的吞噬活性、一氧化氮（NO）产生、炎症因子和趋化因子的表达和分泌、表面分子表达的影响，并分析丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）、核因子κB（nuclear factor kappa-B, NF-κB）和Janus激酶-信号转导及转录激活因子（Janus kinase-signal transducer and activator of transcription, JAK-STAT）信号转导通路在其中的作用及CHPs可能的功能受体。结果表明，CHPs能显著抑制树突状细胞的吞噬活性，促进NO、白细胞介素-1β（interleukin-1β, IL-1β）、白细胞介素-6（IL-6）、肿瘤坏死因子α（tumor necrosis factor-α, TNF-α）、CXC趋化因子配体10（CXC chemokine ligand 10, CXCL10）的分泌，提高炎症因子IL-1β、IL-6、TNF-α、前列腺素内过氧化物合酶2（prostaglandin-endoperoxide synthase 2, PTGS2）和CXCL10 mRNA的表达量，上调表面分子CD40、CD80、CD86、MHC Ⅰ和MHC Ⅱ的表达。在特异性通路抑制剂或Toll样受体4（Toll-like receptor 4, TLR4）抑制剂的作用下，CHPs刺激的NO分泌被显著抑制。此外，CHPs能与树突状细胞受体稳定结合，并观察到其与TLR4共定位。综上所述，CHPs可能是通过TLR4介导的MAPK、NF-κB和JAK-STAT通路激活树突状细胞，促进其成熟和发挥免疫功能。本研究为丰富中药小蓟的药效物质基础、拓宽其临床应用范围提供了理论依据。)