【摘要】： CD200是近年來新發(fā)現(xiàn)的免疫球蛋白超家族成員,研究證明CD200與其受體相互作用,可以下調(diào)髓樣細(xì)胞的活性、減輕自身免疫性疾病的癥狀、誘導(dǎo)免疫耐受等作用。1995年,Sakaguchi等發(fā)現(xiàn)了CD4~+CD25~+調(diào)節(jié)性T細(xì)胞(Tr),調(diào)節(jié)性T細(xì)胞可能是機(jī)體以“主動”方式來維持自身穩(wěn)定的主要途徑。Tr對免疫反應(yīng)具有抑制效應(yīng),在體外增殖能力低,在免疫病理、移植物耐受、阻止自身免疫反應(yīng)和維持機(jī)體免疫平衡方面都有一定作用。 本研究用脂質(zhì)體轉(zhuǎn)染的方法,將pcDNA3-CD200重組質(zhì)粒轉(zhuǎn)染到外周血分離的未成熟樹突狀細(xì)胞(imDC)內(nèi),用熒光標(biāo)記的抗人CD200抗體作用后,經(jīng)流式細(xì)胞儀監(jiān)測CD200的表達(dá)情況。再用經(jīng)轉(zhuǎn)染CD200基因的未成熟DC誘導(dǎo)臍血淋巴細(xì)胞產(chǎn)生CD4~+CD25~+調(diào)節(jié)性T細(xì)胞(Tr),經(jīng)流式細(xì)胞儀檢測調(diào)節(jié)性T細(xì)胞的表型,為進(jìn)一步探討CD200基因誘導(dǎo)機(jī)體免疫耐受機(jī)制的研究奠定基礎(chǔ)。 結(jié)果表明:pcDNA3-CD200重組質(zhì)粒轉(zhuǎn)染到未成熟DC后,CD200分子在DC表面大量表達(dá),轉(zhuǎn)染CD200基因的未成熟DC誘導(dǎo)的產(chǎn)生CD4~+CD25~+調(diào)節(jié)性T細(xì)胞(Tr)明顯高于對照組;同時證明調(diào)節(jié)性T細(xì)胞(Tr)表面CD4~+CD25~+分子的表達(dá)與其表面FOXP3分子的表達(dá)在統(tǒng)計學(xué)上沒有顯著性差異。 本研究的意義在于:建立穩(wěn)定表達(dá)CD200分子的未成熟DC體系,轉(zhuǎn)染CD200基因的未成熟DC可以誘導(dǎo)產(chǎn)生更多的Tr,提示誘生Tr是CD200誘導(dǎo)免疫耐受的途徑之一;同時,在調(diào)節(jié)性T細(xì)胞中FOXP3的表達(dá)與CD4~+CD25~+分子的表達(dá)在統(tǒng)計學(xué)上差異沒有顯著性,且CD200分子可以誘生更多的Tr,從而推斷CD200基因具有誘導(dǎo)FOXP3分子表達(dá)的作用,為CD200誘導(dǎo)免疫耐受機(jī)制的進(jìn)一步研究奠定了基礎(chǔ)。
[Abstract]:CD200 is a newly discovered member of immunoglobulin superfamily in recent years. It has been proved that the interaction between CD200 and its receptors can down-regulate the activity of myeloid cells, relieve the symptoms of autoimmune diseases, induce immune tolerance and so on. Sakaguchi et al found that CD4~ CD25~ regulatory T cell (Tr), regulatory T cell may be the main way for the body to maintain its own stability in an "active" manner. Tr has inhibitory effect on immune response, low proliferative ability in vitro and immunopathology. Graft tolerance, blocking autoimmune responses and maintaining immune balance play a role. In this study, pcDNA3-CD200 recombinant plasmid was transfected into (imDC) of immature dendritic cells isolated from peripheral blood by liposome transfection, and the expression of CD200 was monitored by flow cytometry after using fluorescent labeled anti-human CD200 antibody. Immature DC transfected with CD200 gene was used to induce CD4~ CD25~ regulatory T cell (Tr), in cord blood lymphocytes. Flow cytometry was used to detect the phenotype of regulatory T cells. It lays a foundation for further study on the mechanism of immune tolerance induced by CD200 gene. The results showed that after transfection of pcDNA3-CD200 recombinant plasmid into immature DC, CD200 molecules were expressed on the surface of DC. (Tr) of CD4~ CD25~ regulatory T cells induced by immature DC transfected with CD200 gene was significantly higher than that of control group. At the same time, there was no statistical difference between the expression of CD4~ CD25~ molecule on regulatory T cell (Tr) surface and that of FOXP3 molecule on regulatory T cell surface. The significance of this study lies in the establishment of immature DC system expressing CD200 molecules stably. Immature DC transfected with CD200 gene can induce more Tr, to induce Tr as one of the pathways of CD200 induced immune tolerance. At the same time, there was no statistically significant difference between the expression of FOXP3 and CD4~ CD25~ in regulatory T cells, and CD200 could induce more Tr, thus inferred that CD200 gene could induce the expression of FOXP3. It lays a foundation for the further study of the mechanism of immune tolerance induced by CD200.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2007
【分類號】：R392

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相關(guān)期刊論文 前2條

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本文編號：2362074