檳榔子萃取物誘發卵白蛋白免疫小鼠發炎反應及促進骨髓衍生抑制細胞之生成

嚼食檳榔為導致口腔癌及口腔癌前病變最主要的病因之一。臨床研究指出長時間的口腔組織發炎以及病人免疫功能的惡化和嚼食檳榔所造成相關疾病有顯著的關聯性。近年來許多離體實驗指出檳榔子萃取物(areca nut extract; ANE)會影響淋巴球及噬中性球的功能，但ANE在活體中對免疫功能的作用仍有待釐清。本實驗利用卵白蛋白(ovalbumin; OVA)免疫小鼠的模式探討ANE對抗原專一性免疫反應的影響。於第1-5天及第8-12天每天1次以腹腔注射ANE (5-50 mg/kg)或經胃管投與ANE (50-200 mg/kg)，小鼠以鋁膠(alum)吸附之OVA於第3天給予免疫，第13天於後肢足墊皮下注射OVA (10 microgram 溶於20 micorliter 生理食鹽水)以誘發遲發型過敏反應。實驗結果顯示腹腔注射ANE以劑量相關性的方式增加脾臟指數及脾臟中CD11b+Gr-1+骨髓衍生抑制細胞(myeloid-derived suppressor cells; MDSC)的比例。CD11b+細胞由顆粒球性及單核球性兩種型態的細胞所組成，其經由lipopolysaccharide (LPS)刺激後IL-10的產量在ANE處理的組別中顯著增加。此細胞的吞噬作用和表現TNF-alpha的細胞族群在ANE的作用下亦顯著上升。ANE也促進脾臟細胞分泌OVA專一性IFN-gamma以及LPS刺激之iNOS mRNA的表現。腹腔注射ANE (5和25 mg/kg)顯著抑制小鼠血清中OVA專一性IgM及IgG1的生成，而IgG2a的產量則在高劑量(50 mg/kg)有顯著上升。局部經由OVA刺激所引起的足墊腫脹、CD3+ 和F4/80+炎症細胞的浸潤，以及IFN-gamma陽性細胞的數量，在腹腔注射ANE組皆有明顯的增加。綜合上述，腹腔注射ANE具有促進抗原專一性IFN-gamma表現、引起發炎反應，以及促進CD11b+Gr-1+骨髓衍生抑制細胞生成的作用。此發炎反應可能促使具有分泌IL-10能力的骨髓衍生抑制細胞族群增加。這些細胞抑制免疫功能的特性仍有待後續實驗進一步釐清。

關鍵字

檳榔子萃取物；骨髓衍生抑制細胞；珈瑪干擾素；發炎反應

並列摘要

Areca nut chewing is an etiological factor for oral cancer and pre-cancer lesions. Clinical studies suggest that prolonged tissue inflammation and immune deterioration are closely associated with the pathophysiology of areca-related oral diseases. Although recent in vitro studies demonstrated that areca nut extract (ANE) influenced the functionality of lymphocytes and neutrophils, the in vivo immunomodulatory effect of areca nut ingredients remains mostly unclear. The present studies investigated the effect of ANE on antigen-specific immune responses in ovalbumin (OVA)-sensitized mice. BALB/c mice were daily administered with ANE by intraperitoneal (IP; 5-50 mg/kg) injection or oral gavage (50-200 mg/kg) from day 1-5 and 8-12. The mice were IP sensitized with ovalbumin (OVA) absorbed to alum on day 3 and their footpads were subcutaneously challenged with OVA (10 microgram in 20 microliter saline) on day 13 to induce delayed-type hypersensitivity (DTH) reactions. IP administration of ANE dose-dependently increased the spleen index and the number of CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC) in the spleen. Morphologic examination revealed that the CD11b+ cells included granulocytic and monocytic cells. Lipopolysaccharide (LPS)-induced IL-10 production by CD11b+ cells of IP ANE-treated mice was significantly increased. The phagocytic activity and TNF-alpha expression by the splenic CD11b+ cells were elevated in ANE-treated groups. IP ANE also enhanced OVA-specific IFN-gamma production and LPS-induced iNOS mRNA expression by splenocytes. The serum levels of OVA-specific IgM and IgG1 was significantly attenuated in mice treated with IP ANE (5 and 25 mg/kg), whereas OVA-specific IgG2a were enhanced in mice treated with the high dose of ANE (50 mg/kg). In addition, an increase in OVA challenge-induced footpad swelling, and a greater infiltration of inflammatory cells, including CD3+ and F4/80+ cells was observed in ANE-treated mice. The number of IFN-gamma secreting cells in the footpads was also increased. Taken together, these results demonstrated that IP administration of ANE enhanced the production of antigen-specific IFN-gamma, produced a pro-inflammatory effect, and induced the development of CD11b+Gr-1+ MDSC. The inflammation may induce the accumulation of CD11b+Gr-1+ MDSC which have the ability to secret IL-10. Further studies were needed to clarify the suppressive nature of the MDSC.

並列關鍵字

areca nut extract ； myeloid-derived suppressor cell ； IFN-gamma ； inflammation

參考文獻

Aderem, A. (2003) Phagocytosis and the inflammatory response. J Infect Dis 187 Suppl 2, S340-5.

Akiyama, H., Sato, Y., Watanabe, T., Nagaoka, M.H., Yoshioka, Y., Shoji, T., Kanda, T., Yamada, K., Totsuka, M., Teshima, R., Sawada, J., Goda, Y. and Maitani, T. (2005) Dietary unripe apple polyphenol inhibits the development of food allergies in murine models. FEBS Lett 579, 4485-91.

Ali, S. and Mann, D.A. (2004) Signal transduction via the NF-kappaB pathway: a targeted treatment modality for infection, inflammation and repair. Cell Biochem Funct 22, 67-79.

Almand, B., Clark, J.I., Nikitina, E., van Beynen, J., English, N.R., Knight, S.C., Carbone, D.P. and Gabrilovich, D.I. (2001) Increased production of immature myeloid cells in cancer patients: a mechanism of immunosuppression in cancer. J Immunol 166, 678-89.

Auffray, C., Sieweke, M.H. and Geissmann, F. (2009) Blood monocytes: development, heterogeneity, and relationship with dendritic cells. Annu Rev Immunol 27, 669-92.

國際替代計量

檳榔子萃取物誘發卵白蛋白免疫小鼠發炎反應及促進骨髓衍生抑制細胞之生成

全文下載

主題瀏覽