秋葵萃取物對大鼠樹突狀細胞免疫調節作用之探討

Evaluation on the immune responses induced by extracts from Abelmoschus esculentus L. in rat dendritic cells

賴美惠(Mei-Huei Lai)

指導教授 ： 許祥純

國立屏東科技大學/農學院/食品科學系所/碩士(2009年)

摘要

β-glucan可以有效調控免疫功能，抑制腫瘤成長，為大家熟知的人體免疫系統調節物質，而負責防禦人體健康的免疫細胞，彼此之間也是靠這些結合在蛋白質表面的醣來傳達免疫訊息。在免疫系統中，樹突狀細胞 (dendritic cell, DC) 是重要的抗原呈獻細胞 (antigen presenting cell, APC)，可刺激原始T細胞和啟動初級免疫反應。本研究目的為利用誘導單核球分化成樹突狀細胞模式，評估秋葵多醣 (Abelmoschus esculentus L. polysaccharides, AE-PS) 水解產物對大鼠DCs分化之功效。由5-8週齡大鼠分離骨髓造血幹細胞 (bone marrow hematopoietic cell, BMHC)，以含20 ng/mL rGM-CSF及20 ng/mL rIL-4之完全培養基RPMI-1640共同培養7天後，細胞型態擴大且有典型樹突狀突起之未成熟樹突狀細胞 (BMHC-derived immature dendritc cells, BMHC-imDCs) 產生，添加不同濃度之AE-PS (0、25、50、100、200、400、800 μg/mL) 與1 μg/mL之陽性控制組LPS，處理BMHC-imDCs並於體外培養48小時後，進行細胞型態、細胞表面抗原、吞噬作用與細胞激素含量之分析。結果顯示，經由AE-PS不同濃度處理細胞後，以AE-PS 100 μg/mL為最適刺激濃度，在細胞表面型態方面相較於控制組有更明顯的樹突狀突起，並且可以增加細胞表面協同刺激分子CD80/86和MHC class II的表現；而在胞飲能力方面，相較於未添加刺激物之控制組，其胞飲FITC-dextran能力也有顯著性降低；另外利用酵素免疫分析法分別測定細胞培養液中IL-12、IFN-γ、IL-10含量，結果IL-12、IFN-γ含量顯著高於控制組，而IL-10含量則顯著降低。由上述結果可知，AE-PS 100 μg/mL不僅能刺激大鼠BMHC-imDCs分化趨向BMHC-mDCs之活性，且可增加IL-12、IFN-γ之分泌，促進DCs活化T細胞趨向Th1細胞之途徑。

關鍵字

秋葵 ； 多醣體 ； 樹突狀細胞 ； 抗原呈獻細胞 ； 流式細胞儀 ； 細胞激素

並列摘要

β-glucan is well known for its modulating effect on host immune system and inhibitory effect of tumor growth. It plays a key role in enhancing immune function and facilitating cellular communication. In immune system, dendritic cells (DCs) are efficient and professional antigen presenting cells (APCs) to initiate primary immune response. The aim of this study is to investigate the effect of Abelmoschus esculentus L. polysaccharides (AE-PS) on the maturation and function of DCs from rat bone marrow in vitro. Bone marrow hematopoietic cells (BMHC) were derived from 5-8 week-old rats and cultivated in complete RPMI 1640 media containing rGM-CSF and rIL-4. After cultivation for 7 days, the short cytoplasmic protrusions were displayed on DCs. Following the stimulation with a serial concentrations of AE-PS (0, 25, 50, 100, 200, 400, 800 μg/mL) and 1 μg/mL LPS (positive control) for 48 h, BMHC-imDCs were analyzed for morphology, cell surface marker, phagocytosis and cytokine concentration. The results revealed that different concentrations of AE-PS could increase the expression of co-stimulator CD80/86 and MHC class II molecules on the surface of DCs, and the most optimal dose of stimulation was 100 μg/mL. The ability of unstimulated DC to uptake FITC-dextran was higher than that of AE-PS-treated DC. In addition, BMHC-imDCs stimulated with AE-PS secreted higher level of IL-12 and IFN-γ but lower level of IL-10 than control ELISA study. The results showed that AE-PS could promote both the maturation of cultured rat bone marrow derived DCs in vitro and the secretion of IL-12 and IFN-γ. It is also associated with the downstream differentiation of DCs to Th1 cells.

並列關鍵字

Abelmoschus esculentus L. ； polysaccharide ； dendritic cell ； antigen-presenting cells (APC) ； flow cytometer ； cytokine

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