以初代免疫細胞培養評估不同食材之免疫調節傾向並探討桑椹多醣對卵白蛋白致敏小鼠之免疫調節功能

Abstract

摘要 過敏疾病發生的機率有逐年上升的趨勢，故如何避免由食物引起之過敏和如何增強免疫力為大家所關心的焦點，推測蕈類及水果多醣對免疫具有活化及調節作用，因此本研究選取樟芝、雲芝、靈芝、桑椹及草莓等食材，以免疫細胞體外培養評估不同食品成份之免疫調節傾向，並探討桑椹多醣對特異性免疫調節功能。 第一部分體外細胞培養實驗結果顯示，不同樣品與小鼠小腸培耶氏斑細胞共同培養後，培耶氏斑細胞不論是在細胞增生、細胞激素分泌或淋巴細胞亞群分佈，與對照組比較，均無顯著改變，培耶氏斑之培養結果與脾臟細胞比較，顯示脾臟細胞對外來物質之作用較為顯著，培耶氏斑細胞與不同食材共同培養，則產生類似腸道免疫反應之口服耐受性的現象，故無法僅以培耶氏斑細胞體外培養模式評估食品之免疫調節功能。體外脾臟細胞培養結果顯示，桑椹多醣具有調節Th1免疫傾向之潛力，且對脾臟淋巴球組成變化具有影響，因此以桑椹多醣進行後續之動物體內實驗。 第二部分動物體內實驗探討餵食桑椹多醣對小鼠卵白蛋白 (OVA) 特異性免疫反應之影響，結果顯示培耶氏斑細胞不論是在細胞增生、細胞激素分泌或淋巴細胞亞群變化，均不如脾臟細胞顯著，結果與體外實驗結果一致。桑椹多醣餵食組，使脾臟細胞所分泌之Th2細胞激素顯著下降，中、高劑量時顯著抑制血清IgG1之生成，降低腹腔細胞TNF-α分泌，具有抗發炎效果，整體而言，桑椹多醣對OVA-特異性免疫模式的影響，推測是經由同時調控Th1及Th2細胞的反應以及脾臟細胞分群的變化，而減緩整個過敏免疫反應。

ABSTRACT The incidence of allergic diseases is increasing year by year. Thus, how to prevent allergic diseases and enhance immunity is concerned by people. We hypothesized that polysaccharides might exert immunomodulatory effects. Therefore, polysaccharides from three species of fungi including Antrodia camphorate, Coriolus versicolor and Ganoderma lucidum, and two species of fruits including mulberry and strawberry were selected to test their immunomodulatory effects in vitro and in vivo. In the in vitro test, the selected samples were respectively cultured with primary immune cells, including Peyer,s patches (PPs) cells and splenocytes, to evaluate their effects. In the in vivo test, polysaccharide extracts from mulberry (PEM) was chosen and conducted to an ovalbumin (OVA)-sensitized murine model. The results from the in vitro study showed that the selected samples used in this study could not significantly affect the responses of Peyer,s patches cells, such as cell proliferation, cytokine secretions, and lymphocyte subpopulation. However, most selected samples easily stimulated splenocytes to respond. Especially, PEM administration significantly increased the cell proliferation and Th1 cytokine secretion by splenocytes. The results suggest that the administration of food components to Peyer's patches cells seem not easily to stimulate Peyer's patches cells in vitro due to the property of oral tolerance in the intestine. The cell culture model of Peyer,s patches cells in vitro could not reach the purpose of evaluating immunomodulatory food components. The results from the in vivo study showed that supplementation with PEM for 8 weeks significantly decreased the Th2 cytokine production of splenocytes from OVA-sensitized female BALB/c mice. Furthermore, PEM administration significantly decreased serum OVA-specific IgG1 production and inhibited the secretion of tumor necrosis factor (TNF)-α by LPS-stimulated peritoneal macrophages from OVA-sensitized mice. The results suggest that PEM administration might alleviate the inflammation and hypersensitivity in allergic diseases via modulating the Th1/Th2 balance and lymphocyte subpopulation.