摘要
β-葡聚醣 (β-glucans) 廣泛存在於植物、真菌和細菌之細胞壁中，為一種病原相關分子型態結構 (pathogen-associated molecular patterns; PAMPs)，宿主細胞之先天性免疫力中具有對其專一性結合的受體Dectin-1；β-葡聚醣可單獨結合 Dectin-1 或協同 Toll-like receptors (TLRs) 以共同辨識其結構，進而誘發免疫反應。β-葡聚醣與 Dectin-1 結合後，可刺激巨噬細胞之吞噬能力、產生活性氧中間產物及促進細胞激素分泌，具有免疫調節之功效。本實驗以 30 隻 ICR 小鼠分別飼予顆粒性酵母多醣 (P-β-glucan)、Zymosan、Laminarin、Pullulan 及 Saline 連續 7 天後，取其脾臟及小腸細胞檢測細胞表面抗原 CD16/32 及 Dectin-1 之表現及脾臟細胞激素生成量，並分析其細胞內相關訊息路徑 Syk 及 MyD88 之表現。實驗結果顯示 P-β-glucan 及 Zymosan 可活化 Syk 及 MyD88 蛋白之磷酸化，並增加 NF-κB 之轉錄作用，同時顯著增加脾臟細胞中 CD16/32 陽性細胞之 Dectin-1 表現，且增加脾臟細胞 Dectin-1 及 TLR-2 之基因表現。因此，P-β-glucan 具有調節免疫細胞 Dectin-1 之表現，活化細胞內訊息傳遞路徑相關蛋白磷酸化，可能因此而促進免疫細胞功能之作用。
並列摘要
β-glucans are abundant in the cell wall of plants, fungi and bacteria, and have been defined as one of the pathogen-associated molecular patterns (PAMPs). Dectin-1 has been known to be the major receptor, alone or cooperating with Toll-like receptors (TLRs) for recognition of β-glucans. The binding between β-glucan and its receptor induces the signal transduction and then affects the immune function. β-glucans binding with dectin-1 can stimulate the activation of phagocytosis, reactive oxygen species (ROS) production, and induction of inflammatory cytokines. In this study, SPF mice were used for evaluating the immunomodulatory activities of a particulate β-Glucan (P-β-glucan). The commercial P-β-glucan, Zymosan and Laminarin, were used as positive controls, whereas Pullulan was used as a negative control. Spleen cells and intestinal epithelial cells taken from the animals 7 days after treatment were used for assessment of the expressions of CD16/32 and Dectin-1. The intracellular signaling associated proteins of Syk and MyD88 were analysized using Western blotting. The results show that both P-β-glucan and Zymosan can induce activation of NF-κB by phosphorylating Syk and MyD88, enhance expressions of Dectin-1 in CD16/32 positive cells, increase the mRNA expressions of Dectin-1 and TLR-2 in spleen cells. Thus, P-β-glucan may modulate the functions of immune cells.