MBL调节白假丝酵母菌相态转化及免疫反应的初步研究
发布时间：2018-11-02 07:30
【摘要】：[背景]白假丝酵母菌(Candida albicans, C.albicans,白色念珠菌)是临床上最常见的致病性真菌,可引起各种念珠菌病。深入研究抗C.albicans感染免疫,意义重大。C.albicans可因环境条件改变由一种形态转变为另一种形态,为二态性真菌。C.albicans由酵母相(Yeast form, Y)向菌丝相(Hyphal form, H)转化是其感染性转变的关键因素。 甘露聚糖结合凝集素(mannan-binding lectin, MBL)是由肝细胞分泌的血浆蛋白,被称为“天然免疫系统中的关键分子”,目前,已经报道的有关MBL抗C.albicans作用主要是通过激活补体发挥调理吞噬作用。但是,作为天然免疫关键分子,MBL除了通过激活补体促进对C.albicans的调理吞噬外,是否还有其他作用?是否可通过调节C.albicans相态转化和其诱导免疫反应,从而发挥抗C.albicans感染的作用?至今无相关报道,但潜在研究意义重大。 [目的]1.分析不同浓度MBL对C.albicans二相性转化的影响；2.揭示MBL调节C.albicans相态转化的机制；3.初步探讨MBL对C.albicans刺激外周血单个核细胞(Peripheral blood mononuclear cell, PBMC)产生免疫反应的调节作用。 [方法]1.用亲和层析法,分离纯化人血浆MBL;2.倒置显微镜观察不同浓度的MBL对C.albicans相态转化的影响；3.用RealTime RT-PCR分析MBL对C.albicans相态转化过程中关键调控基因表达情况；4.Ficoll密度梯度离心法分离PBMC;5.ELSIA检测MBL对C.albicans刺激PBMC产生细胞因子的影响。 [结果]1.MBL能够抑制C.albicans由酵母相向菌丝相转化;2.MBL能够抑制C.albicans相态转化过程中关键调控基因HWP1的表达；3.低浓度MBL(生理浓度)对C.albicans刺激PBMC分泌IFN-γ、TNF-α及IL-6具有促进作用,高浓度MBL(超生理浓度)则对上述细胞因子的分泌有抑制作用。 [结论]1.MBL能够通过调节HWP1基因的表达抑制C.albicans由酵母相向菌丝相转化；2.MBL能够以浓度依赖方式双向调节C.albicans诱导的细胞因子分泌。提示MBL作为天然免疫的关键分子在C.albicans相态转化及其诱导的免疫反应中均具有作用。
[Abstract]:[background] Candida albicans (Candida albicans, C.albicans) is the most common pathogenic fungus in clinic, which can cause various Candida albicans. It is of great significance to study the immunity against C.albicans infection. C.albicans can be changed from one form to another form because of the change of environmental conditions. C.albicans can be transformed from yeast to hyphae from (Yeast form, Y) to (Hyphal form,. H) transformation is the key factor of its infectious transformation. Mannan-binding lectin (mannan-binding lectin, MBL), a plasma protein secreted by hepatocytes, is known as a "key molecule in the innate immune system". It has been reported that the anti-C.albicans effect of MBL is mainly by activating complement to regulate phagocytosis. However, as a key molecule of innate immunity, does MBL have other functions besides activating complement to promote the regulation and phagocytosis of C.albicans? Can the effect of C.albicans infection be played by regulating the phase transformation of C.albicans and its induction of immune response? No relevant reports have been reported so far, but the potential research is of great significance. [objective] 1. The effects of different concentrations of MBL on the two-phase transformation of C.albicans were analyzed. 2. The mechanism of MBL regulating C.albicans phase transition was revealed. 3. To investigate the effect of MBL on the immune response of peripheral blood mononuclear cells (Peripheral blood mononuclear cell, PBMC) stimulated by C.albicans. [methods] 1. Purification of human plasma MBL;2. by affinity chromatography The effects of different concentrations of MBL on the phase transition of C.albicans were observed by inverted microscope. RealTime RT-PCR was used to analyze the expression of key regulatory genes in the phase transformation of C.albicans by MBL and PBMC;5.ELSIA was separated by 4.Ficoll density gradient centrifugation to detect the effect of MBL on the cytokines produced by C.albicans stimulated PBMC. [results] 1.MBL could inhibit the transformation of C.albicans from yeast to hyphae, 2.MBL could inhibit the expression of key regulatory gene HWP1 in the process of C.albicans phase transformation. Low concentration of MBL (physiological concentration) promoted the secretion of IFN- 纬, TNF- 伪 and IL-6 by PBMC stimulated by C.albicans, and high concentration of MBL (superphysiological concentration) inhibited the secretion of these cytokines. [conclusion] 1.MBL can inhibit the transformation of C.albicans from yeast to hyphae by regulating the expression of HWP1 gene, and 2.MBL can regulate cytokine secretion induced by C.albicans in a concentration-dependent manner. It is suggested that MBL, as a key molecule of innate immunity, plays an important role in the phase transformation of C.albicans and its induced immune response.
【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R379.4
本文编号：2305353
[Abstract]:[background] Candida albicans (Candida albicans, C.albicans) is the most common pathogenic fungus in clinic, which can cause various Candida albicans. It is of great significance to study the immunity against C.albicans infection. C.albicans can be changed from one form to another form because of the change of environmental conditions. C.albicans can be transformed from yeast to hyphae from (Yeast form, Y) to (Hyphal form,. H) transformation is the key factor of its infectious transformation. Mannan-binding lectin (mannan-binding lectin, MBL), a plasma protein secreted by hepatocytes, is known as a "key molecule in the innate immune system". It has been reported that the anti-C.albicans effect of MBL is mainly by activating complement to regulate phagocytosis. However, as a key molecule of innate immunity, does MBL have other functions besides activating complement to promote the regulation and phagocytosis of C.albicans? Can the effect of C.albicans infection be played by regulating the phase transformation of C.albicans and its induction of immune response? No relevant reports have been reported so far, but the potential research is of great significance. [objective] 1. The effects of different concentrations of MBL on the two-phase transformation of C.albicans were analyzed. 2. The mechanism of MBL regulating C.albicans phase transition was revealed. 3. To investigate the effect of MBL on the immune response of peripheral blood mononuclear cells (Peripheral blood mononuclear cell, PBMC) stimulated by C.albicans. [methods] 1. Purification of human plasma MBL;2. by affinity chromatography The effects of different concentrations of MBL on the phase transition of C.albicans were observed by inverted microscope. RealTime RT-PCR was used to analyze the expression of key regulatory genes in the phase transformation of C.albicans by MBL and PBMC;5.ELSIA was separated by 4.Ficoll density gradient centrifugation to detect the effect of MBL on the cytokines produced by C.albicans stimulated PBMC. [results] 1.MBL could inhibit the transformation of C.albicans from yeast to hyphae, 2.MBL could inhibit the expression of key regulatory gene HWP1 in the process of C.albicans phase transformation. Low concentration of MBL (physiological concentration) promoted the secretion of IFN- 纬, TNF- 伪 and IL-6 by PBMC stimulated by C.albicans, and high concentration of MBL (superphysiological concentration) inhibited the secretion of these cytokines. [conclusion] 1.MBL can inhibit the transformation of C.albicans from yeast to hyphae by regulating the expression of HWP1 gene, and 2.MBL can regulate cytokine secretion induced by C.albicans in a concentration-dependent manner. It is suggested that MBL, as a key molecule of innate immunity, plays an important role in the phase transformation of C.albicans and its induced immune response.
【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R379.4
【参考文献】
中国期刊全文数据库 前2条
1 郭明卫;彭文娟;;常见深部真菌感染性疾病的研究进展[J];河北医药;2009年01期
2 苏惠春;程波;;白念珠菌双形态性的分子调节机制[J];中国真菌学杂志;2006年04期
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