https://scholars.lib.ntu.edu.tw/handle/123456789/163762
標題: | 伏馬鐮孢毒素B1 (FUMONISIN B1) 對豬的免疫毒害: 肺泡巨噬細胞與週邊血液單核細胞的致害及其作用機制(3/3) | 作者: | 龐飛 | 關鍵字: | 伏馬鐮孢毒素B1;免疫毒性;細胞素;抱合脂質;週邊血液單核細胞;肺泡巨噬細胞;豬;Fumonisin B1;Immunotoxicity;Sphingolipid;Peripheral blood mononuclear cells;Alveolar macrophages;Swine | 公開日期: | 2002 | 出版社: | 臺北市:國立臺灣大學獸醫學系暨研究所 | 摘要: | 伏馬鐮孢毒素(fumonisins)是由多種鐮孢菌屬 黴菌( Fusarium spp.)所產生之二次性代謝物, 其中以fumonisin B1 (FB1)為最常見的玉米、玉 米製品及飼料污染物。研究顯示FB1 會對禽 類、大小鼠造成免疫系統的影響,為探討FB1 對豬隻免疫系統的可能影響,選擇豬肺泡巨噬 細胞(SAM)與週邊血液單核細胞(SPBMC),在 活體外與不同濃度FB1 共同培養不等時間,以 評估該等細胞的viability 與功能是否會受到 影響。同時,另以LPS 與Con A 兩種致裂原 分別刺激SAM 與SPBMC,使其成為活化狀 態,藉以瞭解不同活化狀態下的細胞,對於 FB1 的感受性是否相同。在SPBMC,分別測 定其viability、DNA、RNA 及protein 合成能 力、IL-1b, IL-2, IL-8, IL-10, IL-12 及IFN-g等 細胞素mRNA 表現能力以及IL-2 產生能力。 在SAM,則分別測其viability、吞菌與殺菌能 力,自由基(O2 -和H2O2)產生能力、IL-1b, IL-8 及TNF-a等細胞素mRNA 表現能力以及 TNF-a與PGE2 產生能力。同時也進一步分析 FB1 是否具干擾SPBMC 與SAM 抱合脂質 sphinganine (Sa)及sphingosine (So)之代謝。實 驗結果顯示,於所測試之劑量及培養時間條件 下,無論是經Con A 活化及未經Con A 活化 的SPBMC,FB1 均會造成其細胞存活率、 DNA、RNA 及蛋白質合成能力與IL-2 產生能 力的下降;在細胞素mRNA 表現上,在未經 Con A 活化之細胞,其IL-1b、IL-2、IL-8、IL-10 及IFN-g mRNA 之表現於早期多呈下降,但後 期則大致上升;而IL-12 及TNF-a於攻毒36 小時前,其mRNA 之表現大致呈現上升,但 之後則下降。經Con A 活化之SPBMC 細胞素 mRNA 表現則較不一致,其中IL-1b於各攻毒 時間多呈現上升;IL-2、IL-8、IL-12 及IFN-g 則不一致;TNF-a mRNA 之表現多呈下降之 趨勢。大體而言,經Con A 活化之對照組細 胞,其細胞素mRNA之表現能力皆較未經Con A活化之對照組為差。在FB1對SPBMC 抱合 脂質代謝之影響方面,與對照組相較下,於攻 毒後24 小時在20 及50 mg/ml FB1 處理組,其 Sa 與So 含量以及Sa/So 的比例均有提升的趨 勢,其中Sa 的提升在兩處理組均達統計上極 顯著性(P < 0.01)。在SAM 方面,其viability 呈早期提升而晚期抑制的情形,且此趨勢以 LPS 活化的SAM 反應較早;在自由基O2 -和 H2O2 的產生能力上亦均受到抑制,其中以O2 – 較為明顯;FB1 攻毒組對Candida albicans的 吞菌能力較差,且隨攻毒時間的延長而下降程 度越大,其中以LPS 活化之SAM 受抑制的情 形較非活化SAM 來得明顯;在SAM 的C. albicans殺菌能力上亦受到抑制,且以LPS 活 化之SAM 較明顯,而此抑制程度與FB1 濃度 成正相關;就IL-1b mRNA 的表現,在經LPS 或未經LPS 活化的SAM 中,均呈先下降後提 昇的現象;就IL-8 mRNA 的表現,在經LPS 活化的SAM,呈早期輕微上升,其後持平的 現象,而在未經LPS 活化的SAM,則呈早期 下降,而後期微升的趨勢;就TNF-a mRNA 的表現,經LPS 活化與否之表現則不一致; FB1 會造成LPS 活化SAM TNF-a產生能力的 下降,而非活化SAM 之TNF-a產生能力在早 期呈抑制,但後期則呈上升的趨勢;FB1 對於 經LPS 活化與非活化SAM 之PGE2 產生能力 影響不盡相同,活化狀態SAM 的PGE2 產生 是呈上昇的現象,而非活化SAM 在攻毒早期 呈增加的趨勢,但後期則呈抑制;在FB1 對 SAM 抱合脂質代謝之影響方面,經LPS 活化 的SAM 經FB1 處理後,其抱合脂質的代謝情 形亦出現Sa 和So 濃度及Sa/So 比率上升的現 象,且隨攻毒時間的延長,更趨明顯。根據上 述結果顯示,FB1 的確會造成SPBMC 及SAM 的死亡、多重功能的受損及其抱合脂質代謝異 常。因此推測長期攝食受到FB1 污染的飼料, 可能會造成豬隻免疫調節功能的干擾,進而影 響豬隻對疾病的抵抗力。而此免疫功能的干擾 可能與抱合脂質代謝異常有關。 by Fusarium species in which Fumonisin B1 (FB1) is the most common corn, corn product, and feedstuff contaminant. It has been shown that it may cause immunological effects in poultry, mice, and rats. To evaluate the potential effect of FB1 on swine immune functions, swine peripheral blood mononuclear cells (SPBMC) and alveolar macrophages (SAM) were incubated with FB1 in vitro at various concentrations for different time periods. The cell viability and various functions of both cells were examined. Additionally, the SAM and SPBMC were activated by LPS and Con A, respectively, to compare the susceptibility of resting and activated cells to FB1 toxicity. For SPBMC, the parameters examined included cell viability; DNA, RNA, and protein synthesis; mRNA expression of IL-1b, IL-2, IL-8, IL-10, IL-12, and IFN-g; and IL-2 production. For SAM,the parameters examined included cell viability; phagocytic and microbicidal activities; O2 - and H2O2 production; mRNA expression of IL-1b, IL-8, and TNF-a; and TNF-a and PGE2 production. In addition, the effects of FB1 on the metabolism of sphinganine (Sa) and sphingosine (So) of SPBMC and SAM were also evaluated. The results showed that under the selected doses and incubation periods FB1 could cause significant reduction in the cell viability; DNA, RNA, and protein synthesis; and IL-2 production in either Con A-activated SPBMC or non-Con A-activated SPBMC. For the mRNA expression in non-Con A-activated SPBMC, it was reduced at the early stage but then increased in IL-1b, IL-2, IL-8, IL-10, and IFN-g, but it was increased before 36 hours of incubation (HOI) and reduced thereafter in IL-12 and TNF-a. The cytokine mRNA expression in Con A-activated SPBMC was inconsistent, among which IL-1b was constantly increased in most of the time points; significant variations were present in IL-2, IL-8, IL-12, and IFN-g; and it was decreased in TNF-a. For the medium control, the level of cytokine mRNA expression in Con A-activated SPBMC was lower than that in non-Con A-activated SPBMC. For the sphingolipid metabolism, the content of Sa and So and the Sa/So ratio were elevated following 24 HOI in both 20 and 50 mg/ml FB1-treated SPBMC. As for the SAM, the cell viability was increased at the early stage but reduced later in both LPS-activated and non-LPS-activated groups with the former occurring earlier. The potential of O2 - and H2O2 production were all reduced in both groups with O2 - more prominent. The ability of SAM to engulf Candida albicans was reduced in both LPS and Fumonisins are secondary metabolites produced non-LPS-activated FB1-treated groups in a time-dependent manner with the former more evident. The ability of SAM to kill the engulfed C. albicans was also reduced in both groups in a dose-dependent manner with the LPS-activated FB1-treated group more apparent. As for the IL-1b mRNA expression, it was reduced initially followed by increase in both groups; for IL-8, it was slightly increased initially and then became plateau in the LPS-activated FB1-treated group, but it was slightly decreased initially and then became increased in the non-LPS-activated FB1-treated group; for TNF-a, no consistent results were revealed in both groups. FB1 treatment caused the reduction in the level of TNF-a production in the LPS-activated SAM but caused initial reduction followed by elevation in the non-LPS-activated SAM. FB1 treatment induced the increase in the level of PGE2 production in the LPS-activated SAM but caused initial increase followed by decrease in the non-LPS-activated SAM. For the sphingolipid metabolism, the content of Sa and So and the Sa/So ratio were elevated in a time-dependent manner in the LPS-activated FB1-treated SAM. The results indicate that FB1 could indeed cause cell death, multiple functional alterations, and disturbance in the sphingolipid metabolism of SPBMC and SAM. It is anticipated that long-term consumption of FB1-contaminated feed has the potential to interfere with the immune regulation in pigs with subsequent reduction in disease resistance. The immune deregulation is possibly related to the changes in sphingolipid metabolism. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/28701 | 其他識別: | 902313B002297 | Rights: | 國立臺灣大學獸醫學系暨研究所 |
顯示於: | 獸醫學系 |
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