本文選題：髓源性抑制細胞 + FcγRⅡb　； 參考：《揚州大學(xué)》2017年碩士論文

【摘要】：髓源性抑制細胞(myeloid-derived suppressor cell,MDSC)是一群具有很強免疫抑制功能的異質(zhì)性細胞,與多種腫瘤的預(yù)后呈負相關(guān),并降低腫瘤免疫治療的效果。新近的研究指出:MDSC具有可塑性,可以在免疫刺激與免疫抑制表型,抗腫瘤與促腫瘤之間相互轉(zhuǎn)換。如抗磷脂酰絲氨酸抗體能夠誘導(dǎo)腫瘤組織中MDSC向免疫刺激表型極化;使用SHP-1抑制劑,腫瘤組織和脾臟中M-MDSC均能極化為免疫刺激型巨噬細胞,發(fā)揮抗腫瘤效應(yīng)。因此,改變MDSC的極化狀態(tài),使其向免疫刺激表型極化是腫瘤免疫治療的新思路。IgG的Fc段受體(FcγR)由活化性和抑制性兩種功能相反的家族所組成�；罨訤cγR種類很多,而抑制性FcγR在人和小鼠均只有一種,即FcγRⅡb,廣泛表達于B細胞和髓系細胞表面。FcγRⅡb可調(diào)控多種免疫細胞的功能,如B細胞的FcγRⅡb可抑制由BCR引起的鈣流、細胞增殖和抗體分泌;巨噬細胞表面的FcγRⅡb交聯(lián)能夠降低巨噬細胞吞噬能力和細胞因子分泌;FcγRⅡb能夠抑制樹突狀細胞中活化型FcγR依賴的抗原內(nèi)化和提呈功能�？傊�,FcγRⅡb能調(diào)控多種免疫細胞功能,但是FcγRⅡb能否調(diào)控腫瘤中的MDSC功能,到目前為止,國內(nèi)外均未見相關(guān)報道。因此,在本研究中我們圍繞FcγRⅡb對MDSC的調(diào)控作用進行了探討。一、FcγRⅡb缺陷誘導(dǎo)MDSC向免疫刺激表型極化為了研究FcγRⅡb對MDSC功能有無影響,我們首先檢測了肺癌細胞株3LL移植瘤小鼠體內(nèi)MDSC表達FcγRⅡb的情況。結(jié)果發(fā)現(xiàn),荷瘤小鼠骨髓、外周血、脾臟、腫瘤組織中CD11b+Gr-1+ MDSC均表達FcγRⅡb。既然MDSC表達FcγRⅡb,那么FcγRⅡb對MDSC的擴增和功能有無影響呢?我們利用WT(wild type,WT)和FcγRⅡb缺陷(FcγRⅡb-/-)小鼠制備了兩種移植瘤模型(3LL和B16F10),在這兩種模型中均發(fā)現(xiàn):與WT相比,FcγRⅡb-/-小鼠脾臟中CD11b+Gr-1+MDSC比例明顯增高。此外,我們比較了 WT和FcγRⅡb-/-移植瘤小鼠脾臟MDSC在細胞因子分泌、表面分子表達、酶活性及對T細胞功能影響上的差別。結(jié)果發(fā)現(xiàn),與WT相比,FcγRⅡb-/-荷瘤小鼠脾臟MDSC中Ⅰ型精氨酸酶(arginase-1,ARG-1)活性、IL-10和CD206的表達明顯下降,誘導(dǎo)型一氧化氮合成酶(inducible nitricoxide synthase,iNOS)活性、TNF-α、CCR7 和 IFN-γ受體的表達顯著上調(diào),CD11c、CD86和MHC Ⅱ類分子的表達沒有明顯變化。此外,與WT相比,FcγRⅡb-/-荷瘤小鼠脾臟MDSC對活化T細胞增殖的抑制作用以及對CD4+CD25+Foxp3++調(diào)節(jié)性T細胞的誘導(dǎo)作用明顯下降。以上結(jié)果提示:FcγRⅡb缺陷誘導(dǎo)MDSC向免疫刺激表型極化。二、FcγRⅡb調(diào)控MDSC極化對腫瘤進展的影響為了研究FcγRⅡb-/-MDSC是否具有抗腫瘤效應(yīng),我們將WT MDSC和FcγRⅡb-/-MDSC分別過繼回輸給3LL荷瘤小鼠,檢測荷瘤小鼠腫瘤的生長情況。結(jié)果發(fā)現(xiàn):過繼回輸WT MDSC可促進腫瘤生長,而過繼回輸FcγRⅡb-/-MDSC則延緩腫瘤的生長,提示FcγRⅡb-/-使MDSC由促腫瘤向抗腫瘤效應(yīng)轉(zhuǎn)變。為了研究FcγRⅡb是否影響腫瘤的進展,我們分別給WT小鼠和FcγRⅡb-/-小鼠皮下成瘤(3LL或B16F10細胞),檢測腫瘤的生長情況及小鼠的死亡率。結(jié)果在兩種荷瘤模型中均發(fā)現(xiàn):與WT小鼠相比,FcγRⅡb-/-小鼠體內(nèi)的腫瘤生長緩慢且小鼠的死亡率明顯下降,提示FcγRⅡb-/-抑制了小鼠腫瘤的進展。但這一現(xiàn)象是否與FcγRⅡb調(diào)控MDSC向免疫刺激表型極化有關(guān),尚需通過抗體清除體內(nèi)MDSC實驗進一步證實�？傊�,本研究首次發(fā)現(xiàn)FcγRⅡb-/-調(diào)控MDSC向免疫刺激表型極化并使之向抗腫瘤效應(yīng)轉(zhuǎn)變。所得的結(jié)果不僅可揭示FcγRⅡb參與腫瘤發(fā)生發(fā)展的新機制,豐富對MDSC可塑性的認識,更可為研制以MDSC為靶標(biāo)的新型防治策略提供理論基礎(chǔ)。
[Abstract]:Myeloid derived suppressor cells (myeloid-derived suppressor cell, MDSC) is a group of heterogeneous cell has strong immunosuppressive function, and negatively related to the prognosis of many tumors, and reduce the effects of tumor immunotherapy. Recent studies suggest that MDSC has plasticity, can inhibit the phenotype in immune stimulation and immune, anti-tumor and the mutual conversion between cancer. Such as anti phosphatidylserine antibody can be induced by MDSC in tumor tissue to stimulate immune phenotype polarization; the use of SHP-1 inhibitors, M-MDSC tumor tissue and spleen were polarized into immune stimulation of macrophages, play the anti-tumor effect. Therefore, the change of polarization state of MDSC, which leads to immune phenotype polarization new ideas of tumor immunotherapy.IgG Fc receptor (Fc - R) consists of the activation and inhibition of the two functions of the opposite family. Activated Fc gamma R species is very much, and inhibition of Fc gamma R in human and mouse are only one, namely Fc gamma R II B, widely expressed in B cells and myeloid cell surface.Fc gamma R II B can regulate immune cell functions, such as B Fc gamma R II B cells could be inhibited by BCR induced calcium influx, cell proliferation and antibody secretion; the macrophage surface Fc gamma R II B crosslinking can reduce the phagocytosis of macrophage and cytokine secretion; Fc gamma R II B can activate Fc R gamma dependent antigen presenting function of internalization and inhibition of dendritic cells. In short, Fc gamma R II B can regulate immune cell function, but Fc gamma R II can b the regulation of tumor MDSC function, so far, both at home and abroad has not been reported. Therefore, the regulation role in this study we focus on Fc gamma R II B of MDSC was studied. A Fc gamma R II B defects induced by MDSC to immune phenotype polarization in order to study the Fc gamma R B on MDSC the function has no effect, we first examined 浜嗚偤鐧岀粏鑳?yōu)鏍?LL縐繪鐦ゅ皬榧犱綋鍐匨DSC琛ㄨ揪Fc緯R鈪鐨勬儏鍐，

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