【摘要】：樹突狀細(xì)胞(Dendritic cells,DCs)是目前已知的體內(nèi)最重要的專職性APC,能攝取、加工及提呈抗原,刺激初始型T細(xì)胞的活化和增殖,是啟動、調(diào)控并維持特異性免疫應(yīng)答的中心環(huán)節(jié)。DCs介導(dǎo)的T細(xì)胞免疫應(yīng)答在機(jī)體抗腫瘤免疫中發(fā)揮主導(dǎo)作用,包括對抗原特異性T細(xì)胞的誘導(dǎo)、激發(fā)、擴(kuò)增和功能介導(dǎo)等。業(yè)已表明,DCs和Th細(xì)胞的極化誘導(dǎo)密切相關(guān),不同的抗原致敏和致DCs成熟信號可能會賦予DCs不同的介導(dǎo)T細(xì)胞極化能力。凋亡腫瘤細(xì)胞可以提供DCs豐富的腫瘤抗原,能夠提供多個MHC-Ⅰ和MHC-Ⅱ兩類途徑的抗原表位,因而采用凋亡腫瘤細(xì)胞作為抗原可以有效獲得腫瘤特異性樹突狀細(xì)胞。CD40/CD40L信號被認(rèn)為是DCs發(fā)育成熟至關(guān)重要的信號,CD4~+T細(xì)胞與DCs表面CD40L-CD40的相互作用對T細(xì)胞和DCs的功能均產(chǎn)生重要影響。利用CD40信號激發(fā)在體外可望獲得表型和功能上成熟的樹突狀細(xì)胞。 本研究第一部分利用共聚焦顯微鏡觀察了未成熟樹突狀細(xì)胞對凋亡腫瘤細(xì)胞的攝取,采用流式細(xì)胞術(shù)和~3H-TdR摻入實(shí)驗(yàn)研究了CD40和TNFR信號對凋亡腫瘤細(xì)胞負(fù)載的樹突狀細(xì)胞表型的促成熟作用和促T細(xì)胞增殖效應(yīng),采用胞內(nèi)染色、流式細(xì)胞術(shù)和ELISA探討了CD40配基化的腫瘤特異性樹突狀細(xì)胞對Th細(xì)胞的極化作用,發(fā)現(xiàn)CD40較TNFR信號更能增強(qiáng)樹突狀細(xì)胞介導(dǎo)Th細(xì)胞向Th1細(xì)胞極化的能力。 論文第二部分試圖從共刺激分子的激發(fā)和調(diào)節(jié)性表達(dá)角度探討DCs對Th細(xì)胞極化的作用。首先采用RT-PCR和流式細(xì)胞術(shù)分析了CD40信號對樹突狀細(xì)胞表面B7-H3分子表達(dá)的調(diào)節(jié)作用,發(fā)現(xiàn)了CD40信號能上調(diào)樹突狀細(xì)胞上B7-H3分子的表達(dá),并進(jìn)一步采用特異性抗B7-H3抗體阻斷實(shí)驗(yàn)、~3H-TdR摻入實(shí)驗(yàn)和ELISA發(fā)現(xiàn)了B7-H3分子的上調(diào)性表達(dá)有利于樹突狀細(xì)胞介導(dǎo)Th1型免疫應(yīng)答。同時還發(fā)現(xiàn)CD40信號促進(jìn)凋亡腫瘤細(xì)胞負(fù)載的樹突狀細(xì)胞IFN-γ的分泌,推測CD40信號上調(diào)樹突狀細(xì)胞上B7-H3分子的表達(dá)可能和其介導(dǎo)IFN-γ
[Abstract]:Dendritic cells (Dendritic cells,DCs) are the most important specialized APC, known to ingest, process and present antigens, stimulate the activation and proliferation of initial T cells. The central link of regulating and maintaining specific immune response. DCS mediated T cell immune response plays a leading role in antitumor immunity, including induction, stimulation, amplification and function mediated by antigenic specific T cells. It has been shown that the polarization induction of DCs and Th cells is closely related, and different antigen sensitized and DCs mature signals may endows DCs with different polarization ability of T cells. Apoptotic tumor cells can provide DCs rich tumor antigens and provide multiple epitopes of MHC- 鈪，

本文編號：2493275