發(fā)布時(shí)間：2018-03-13 14:17

  本文選題：NK細(xì)胞　切入點(diǎn)：CTLA4Ig　出處：《第三軍醫(yī)大學(xué)》2009年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】： 大面積燒傷后,患者免疫應(yīng)答低下(1, 2),容易發(fā)生感染,另一方面機(jī)體卻對(duì)皮膚移植物產(chǎn)生強(qiáng)有力的排斥反應(yīng),因此在不增加患者感染幾率的前提下提高異體皮的存活時(shí)間(即所謂免疫耐受的誘導(dǎo)),是大面積燒傷治療的核心問(wèn)題。 NK細(xì)胞作為天然免疫系統(tǒng)最重要的細(xì)胞在機(jī)體殺傷腫瘤細(xì)胞和抵抗病原體(病毒、細(xì)菌等)感染中發(fā)揮著重要作用。NK細(xì)胞的活化與否受控于NK細(xì)胞表面表達(dá)的抑制性受體(如NKG2A)和激活性受體(如NKG2D)的狀態(tài)。然而,在大面積燒傷后,患者NK細(xì)胞毒性功能顯著下降(26, 27),是機(jī)體容易發(fā)生感染的重要原因之一。研究發(fā)現(xiàn),院內(nèi)獲得性綠膿桿菌感染是燒傷感染和敗血癥發(fā)生的重要原因(3)。綠膿桿菌分泌的外毒素可抑制NK細(xì)胞毒性和IFN-γ的分泌(4),且對(duì)現(xiàn)在臨床使用的大部分抗生素均耐藥(5)。激活性受體NKG2D在NK細(xì)胞清除肺綠膿桿菌感染中起了關(guān)鍵作用(6, 7),那么NK細(xì)胞功能的增強(qiáng)是否會(huì)降低機(jī)體播散性感染發(fā)生的幾率呢? 在免疫耐受誘導(dǎo)的研究中,20年前發(fā)現(xiàn)的CTLA4以及在此基礎(chǔ)上制備的重組融合蛋白CTLA4Ig最令人矚目。由于CTLA4Ig能高親和力地結(jié)合抗原遞呈細(xì)胞上的CD80/CD86,阻斷了共刺激信號(hào),使T細(xì)胞不能接受第二信號(hào),從而導(dǎo)致T細(xì)胞不應(yīng)答,所以CTLA4Ig是T細(xì)胞活化中重要的負(fù)調(diào)節(jié)分子(8)。目前,CTLA4Ig的衍生物-Abatacept和Belatacept分別被用于治療自身免疫性疾病和控制器官移植免疫排斥反應(yīng)(9-12)。我們的前期研究結(jié)果(13)和文獻(xiàn)報(bào)道(14)也證實(shí)注射CTLA4Ig或創(chuàng)面局部應(yīng)用CTLA4Ig重組腺病毒均可延長(zhǎng)異體皮移植存活期,因此,CTLA4Ig如果可以應(yīng)用于燒傷患者將會(huì)抑制移植物排斥反應(yīng),延長(zhǎng)移植物的存活時(shí)間。那么,在燒傷情況下使用CTLA4Ig會(huì)加重?zé)齻蟮牟∏楹驮黾硬l(fā)癥及死亡率嗎? Abatacept是被美國(guó)FDA批準(zhǔn)用于臨床治療類(lèi)風(fēng)濕關(guān)節(jié)炎的藥物,由人CTLA4分子胞外區(qū)和突變的IgG1 Fc段融合而成。奇怪的是,這一T細(xì)胞強(qiáng)有力的抑制劑應(yīng)用于人體后,其腫瘤形成、病毒及細(xì)菌感染等副作用的發(fā)生率卻比預(yù)期大大降低(15-17)。亦有研究證實(shí),小鼠全身應(yīng)用兩倍劑量于人的藥物濃度時(shí),并不影響其抵抗肺結(jié)核感染的能力,但這一有悖于常理的現(xiàn)象的機(jī)制和意義還是未知數(shù)(18)。Ursula Grohmann發(fā)現(xiàn),CTLA4Ig與DCs表面B7分子結(jié)合后,向DCs胞內(nèi)傳遞激活信號(hào)(19)。該研究說(shuō)明,CTLA4Ig對(duì)表達(dá)CD80/CD86分子的細(xì)胞有調(diào)節(jié)作用。另有報(bào)道,天然免疫系統(tǒng)中最重要的細(xì)胞-NK細(xì)胞表面也表達(dá)CD86分子,且在某些條件下可表達(dá)CD80分子(20, 21)。Beissert S發(fā)現(xiàn),長(zhǎng)期暴露于紫外線中的CTLA4Ig轉(zhuǎn)基因小鼠,其皮膚腫瘤結(jié)節(jié)數(shù)量明顯少于野生型小鼠(22),事實(shí)上,NK細(xì)胞在皮膚癌細(xì)胞殺傷中發(fā)揮中重要作用(23)。綜上所述,CTLA4Ig可通過(guò)阻斷T細(xì)胞激活的共刺激信號(hào)通路抑制皮膚移植免疫排斥反應(yīng).其全身應(yīng)用并不會(huì)顯著增加機(jī)體感染和腫瘤形成的風(fēng)險(xiǎn).同時(shí),CTLA4Ig可能對(duì)表面表達(dá)CD80/CD86分子且在控制感染和腫瘤形成的其重要作用的細(xì)胞(如NK細(xì)胞)有調(diào)節(jié)作用(23).因此,我們提出如下科學(xué)問(wèn)題:CTLA4Ig是否因?yàn)榕cNK細(xì)胞表面B7分子結(jié)合增強(qiáng)NK細(xì)胞毒性而造成機(jī)體清除皮膚癌細(xì)胞(或其他腫瘤細(xì)胞)能力的增強(qiáng)?其機(jī)制如何?這些作用可否解釋CTLA4Ig在活體內(nèi)使用后并不顯著降低整體抵抗力的現(xiàn)象? 本實(shí)驗(yàn)通過(guò)體內(nèi)、體外試驗(yàn)驗(yàn)證CTLA4Ig對(duì)NK細(xì)胞功能是否具有調(diào)節(jié)功能,通過(guò)小鼠感染、燙傷和腫瘤模型驗(yàn)證上述調(diào)節(jié)作用,并初步探討其分子機(jī)制。從而深化對(duì)CTLA4Ig免疫調(diào)節(jié)作用的認(rèn)識(shí),并為CTLA4Ig應(yīng)用于大面積燒傷治療提供理論基礎(chǔ)。我們將本研究獲得的主要結(jié)果和結(jié)論歸納如下: 一、CTLA4Ig及其衍生物Abatacept是NK細(xì)胞強(qiáng)有力的激活劑: 1、CTLA4Ig在體外可明顯增強(qiáng)人PBMC和NK細(xì)胞功能: 為了研究CTLA4Ig體外對(duì)人PBMC和NK細(xì)胞功能有無(wú)調(diào)節(jié)作用,我們利用流式細(xì)胞技術(shù)檢測(cè)加入不同濃度的CTLA4Ig后的人PBMC和NK細(xì)胞毒性。在本實(shí)驗(yàn)系統(tǒng)中,我們發(fā)現(xiàn):1)濃度大于1μg/ml的CTLA4Ig作用于人PBMC和NK細(xì)胞后,其殺傷K562細(xì)胞的能力(即NK細(xì)胞毒性)明顯增強(qiáng);2)加入CTLA4Ig與加入IL-2后對(duì)人PBMC和NK細(xì)胞毒性調(diào)節(jié)無(wú)明顯差異;3)在本實(shí)驗(yàn)濃度范圍內(nèi),人PBMC和NK細(xì)胞毒性并沒(méi)有隨CTLA4Ig濃度增加而發(fā)生明顯變化。上述結(jié)果說(shuō)明CTLA4Ig在體外可明顯增強(qiáng)人PBMC和NK細(xì)胞毒性,CTLA4Ig與IL-2激活NK細(xì)胞毒性的能力相當(dāng),且在我們的實(shí)驗(yàn)體系中CTLA4Ig對(duì)NK細(xì)胞毒性調(diào)節(jié)作用與其濃度無(wú)關(guān)。 2、CTLA4Ig(Abatacept)在體內(nèi)可顯著增強(qiáng)小鼠NK細(xì)胞毒性: 為了研究Abatacept在抑制T細(xì)胞活化的同時(shí)卻并未顯著增加腫瘤或感染發(fā)生的幾率的現(xiàn)象是否與Abatacept對(duì)NK細(xì)胞功能調(diào)節(jié)有關(guān),我們將高于臨床治療類(lèi)風(fēng)濕關(guān)節(jié)炎劑量的Abatacept經(jīng)小鼠尾靜脈注射入小鼠體內(nèi),比較其脾臟NK細(xì)胞毒性與未注射小鼠是否有差異。結(jié)果顯示注射Abatacept 24h和48h后小鼠脾臟NK細(xì)胞毒性較未注射小鼠脾臟NK細(xì)胞毒性明顯上升。這一結(jié)果說(shuō)明,Abatacept注射小鼠體內(nèi)后,CTLA4分子可顯著增強(qiáng)小鼠NK細(xì)胞的毒性。這可能是Abatacept應(yīng)用并未顯著增加腫瘤或感染發(fā)生的幾率的重要原因。 3、CTLA4Ig增強(qiáng)人NK細(xì)胞毒性的作用是CTLA4分子依賴(lài)的: 為了明確CTLA4Ig對(duì)NK細(xì)胞毒性增強(qiáng)的效應(yīng)是否全部由ADCC引起,我們進(jìn)行如下實(shí)驗(yàn):首先在體外實(shí)驗(yàn)系統(tǒng)中引入可溶性hIgG1或模擬膜表達(dá)的hIgG1作為對(duì)照,通過(guò)比較加入CTLA4Ig與引入FcR信號(hào)后的NK細(xì)胞毒性,明確ADCC作用在CTLA4Ig對(duì)NK細(xì)胞調(diào)節(jié)中的作用。結(jié)果顯示加入CTLA4Ig后NK細(xì)胞毒性增加的比率遠(yuǎn)高于引入FcR。因此,CTLA4Ig對(duì)NK細(xì)胞毒性的增強(qiáng)效應(yīng)主要是由CTLA4分子介導(dǎo)的;為了進(jìn)一步說(shuō)明上述問(wèn)題,我們選用表面僅表達(dá)少量低親和力FcR-CD16,且無(wú)CD32和CD64的表達(dá)(25)的NK92細(xì)胞株作為效應(yīng)細(xì)胞。在NK92細(xì)胞和K562共培養(yǎng)體系中加入CTLA4Ig后,NK92細(xì)胞的毒性仍然明顯增強(qiáng),證實(shí)CTLA4分子在增強(qiáng)NK細(xì)胞毒性作用中起絕對(duì)的主導(dǎo)作用。因此我們認(rèn)為體外實(shí)驗(yàn)中CTLA4Ig增強(qiáng)人NK細(xì)胞毒性的作用是CTLA4分子依賴(lài)的。 二、CTLA4Ig(Abatacept)可增強(qiáng)機(jī)體抗腫瘤的能力: NK細(xì)胞在機(jī)體抗腫瘤形成中起著至關(guān)重要的作用,因此本實(shí)驗(yàn)探討CTLA4Ig對(duì)NK細(xì)胞毒性增強(qiáng)作用是否有利于機(jī)體控制腫瘤形成。我們的實(shí)驗(yàn)發(fā)現(xiàn)注射超過(guò)臨床劑量的Abatacept不僅沒(méi)有因?yàn)橐种芓細(xì)胞激活促進(jìn)腫瘤形成和生長(zhǎng),相反地,極大地減少了B16細(xì)胞肺轉(zhuǎn)移。不僅如此,荷瘤小鼠的生存時(shí)間亦明顯延長(zhǎng)。提示Abatacept可增強(qiáng)機(jī)體抗腫瘤(B16)的能力。 三、我們對(duì)CTLA4Ig(Abatacept)在大面積燒傷治療中的新認(rèn)識(shí): 我們的前期研究結(jié)果(13)和文獻(xiàn)報(bào)道(14)都證實(shí)注射CTLA4Ig或創(chuàng)面局部應(yīng)用CTLA4Ig重組腺病毒均可延長(zhǎng)異體皮移植存活期,這就意味著CTLA4Ig如果可以應(yīng)用于燒傷患者將會(huì)抑制移植物排斥反應(yīng),延長(zhǎng)移植物的存活時(shí)間。因此,我們利用綠膿桿菌感染模型和燙傷模型評(píng)價(jià)CTLA4Ig用于燒傷患者治療皮膚移植排斥反應(yīng)的安全性,我們的研究首次發(fā)現(xiàn)使用Abatacept不僅可以顯著提高Balb/c小鼠清除綠膿桿菌的能力而且還能增強(qiáng)燙傷小鼠脾臟細(xì)胞的毒性,與體外的實(shí)驗(yàn)結(jié)果一致。這一研究發(fā)現(xiàn)提示CTLA4Ig未來(lái)可用于大面積嚴(yán)重?zé)齻颊咭哉T導(dǎo)對(duì)皮膚移植物的免疫耐受,增強(qiáng)機(jī)體天然免疫力。這將是嚴(yán)重?zé)齻膊≈委煹闹卮笸黄啤?四、CTLA4Ig通過(guò)與NK細(xì)胞表面CD80/CD86分子結(jié)合上調(diào)激活性受體NKG2D和NKp44表達(dá),增強(qiáng)NK細(xì)胞毒性功能: 1,CTLA4Ig通過(guò)與NK細(xì)胞表面CD80/CD86分子的結(jié)合促進(jìn)NK細(xì)胞的毒性功能:本實(shí)驗(yàn)研究抗CD80抗體和抗CD86抗體對(duì)NK細(xì)胞有無(wú)調(diào)節(jié)作用。結(jié)果發(fā)現(xiàn):抗CD80抗體和抗CD86抗體在體外可明顯增強(qiáng)人PBMC對(duì)K562細(xì)胞的毒性,且與CTLA4Ig組NK細(xì)胞毒性無(wú)明顯差異。結(jié)合上述實(shí)驗(yàn)結(jié)果我們認(rèn)為,CTLA4Ig通過(guò)與NK細(xì)胞表面CD80/CD86分子的結(jié)合促進(jìn)NK細(xì)胞的毒性功能。 2,CTLA4Ig可上調(diào)NK細(xì)胞表面激活性受體NKG2D、NKp44的表達(dá):我們采用流式細(xì)胞技術(shù)探討CTLA4Ig對(duì)NK細(xì)胞表面NKG2D和NKp44表達(dá)的調(diào)節(jié)作用。結(jié)果發(fā)現(xiàn)體外加入CTLA4Ig后,人NK細(xì)胞表面激活性受體NKG2D、NKp44表達(dá)明顯上調(diào),且程度與IL-2相似。FcR受體與NK細(xì)胞結(jié)合不會(huì)導(dǎo)致NKG2D、NKp44表達(dá)上調(diào)。這一結(jié)果說(shuō)明NK細(xì)胞表面激活性受體NKG2D、NKp44的在CTLA4Ig增強(qiáng)NK細(xì)胞毒性功能的調(diào)節(jié)作用中可能發(fā)揮了重要作用。 總結(jié): 一、CTLA4在體內(nèi)、體外均可增強(qiáng)NK細(xì)胞毒性; 二、CTLA4Ig通過(guò)與NK細(xì)胞表面CD80/CD86分子結(jié)合上調(diào)NK細(xì)胞表面NKG2D和NKp44的表達(dá),增強(qiáng)NK細(xì)胞功能; 三、CTLA4Ig及其衍生物(如Abatacept)在全身應(yīng)用,可增強(qiáng)小鼠抗腫瘤和抗感染的能力,不增加患者罹患腫瘤及感染的幾率,擴(kuò)大了其臨床應(yīng)用的適應(yīng)癥; 四、CTLA4Ig全身應(yīng)用不僅可治療皮膚移植物排斥反應(yīng),且可增加燙傷小鼠NK細(xì)胞毒性,減少播散性感染的發(fā)生,為CTLA4Ig應(yīng)用于治療燒傷患者提供了新思路; 五、我們發(fā)現(xiàn)CTLA4對(duì)于獲得性免疫系統(tǒng)(T細(xì)胞)和天然免疫系統(tǒng)(NK細(xì)胞)截然不同的作用,這對(duì)我們深入了解免疫系統(tǒng)的調(diào)節(jié)和內(nèi)環(huán)境的穩(wěn)定具有重大意義,將為臨床腫瘤生物治療和大面積燒傷救治提供全新的理論基礎(chǔ)和研究方向。
[Abstract]:Burn patients with low immune response (1, 2), prone to infection, on the other hand, the body has produced strong rejection of skin grafts, thus improving skin allograft survival time in order not to increase the probability of infection of patients with lower (i.e. so-called induced immune tolerance), is the core issue of treatment burns.
NK cell as the most important natural immune system to kill tumor cells and resistance to pathogens in the body (viruses, bacteria) play an important role in the activation of.NK cells is controlled by the NK cell surface expression of inhibitory receptors in infection (such as NKG2A) and activated receptor (NKG2D) status. However, in after large area burns, significantly decreased NK cell toxicity in patients with (26, 27), the function is one of the important reasons of the body prone to infection. The study found that hospital acquired Pseudomonas aeruginosa infection is an important cause of burn infection and septicemia (3). The secretion of Pseudomonas aeruginosa exotoxin secretion can inhibit NK cell toxicity IFN- and gamma (4), and most of the clinical use of antibiotics now were resistant (5). The activation of receptor NKG2D in NK cell clearance plays a key role in pulmonary Pseudomonas aeruginosa infection (6, 7), then whether the enhanced function of NK cells decreased What is the probability of an organism's disseminated infection?
In the study of immune tolerance, found 20 years ago CTLA4 and on the basis of preparation of the recombinant fusion protein CTLA4Ig is the most remarkable. Because the CTLA4Ig high affinity binding antigen presenting cells on CD80/CD86, blocking the costimulatory signal to T cells can not accept the second signal, which causes the T cells response. So CTLA4Ig is an important negative regulator of T cell activation (8). At present, the derivatives of CTLA4Ig -Abatacept and Belatacept were used for the treatment of autoimmune disease and organ transplantation rejection (9-12). The results of a previous study we have reported in the literature (13) and (14) also confirmed that the injection of CTLA4Ig or wound local application of CTLA4Ig recombinant adenovirus can prolong allograft survival, therefore, if CTLA4Ig can be applied to burn patients will inhibit graft rejection, prolong the survival time of the graft. So, in the case of burn, can the use of CTLA4Ig aggravate the condition after the burn and increase the complications and mortality?
Abatacept is approved by the FDA for the clinical treatment of rheumatoid arthritis, the extracellular domain of human CTLA4 gene and mutation of IgG1 Fc fused together. Strangely, this powerful T cell inhibitor used in the human body, the formation of tumors, the incidence of viral and bacterial infections and other side effects were less than expected greatly reduced (15-17). Some studies have confirmed that the drug concentration in systemic application of two times the dose to the human, does not affect its ability to resist TB infection, but this abnormal phenomenon of the mechanism and significance is still unknown (18).Ursula Grohmann and DCs CTLA4Ig found that the surface of B7 molecules, to intracellular delivery of DCs activation signal (19). The study shows that the regulatory role of CTLA4Ig on the expression of CD80/CD86 molecules in cells. Another report, the most important cell surface of -NK cells in the innate immune system is the expression of CD86, and in a The expression of CD80 may be some conditions (20, 21).Beissert S found that CTLA4Ig transgenic mice chronically exposed to ultraviolet radiation, the skin tumor nodule number was significantly less than the wild-type mice (22), in fact, NK cells play an important role in the destruction of skin cancer cells (23). In summary, by CTLA4Ig blocking the activation of T cell costimulatory signal pathway and inhibition of skin allograft rejection. The systemic application does not significantly increase the risk of infection and tumor formation. At the same time, CTLA4Ig may affect the surface expression of CD80/CD86 molecules and in the control of infection and tumor formation in the role cells (such as NK cells (23) Regulation). Therefore, we put forward the following scientific questions: whether CTLA4Ig and NK because of the combination of cell surface B7 molecules with enhanced NK cell cytotoxicity caused by scavenging of skin cancer cells (or other tumor cells) to enhance the ability of? What is the mechanism? Can these effects explain the fact that CTLA4Ig does not significantly reduce the overall resistance after use in living bodies?
Through the experiments in vivo, in vitro experiments of CTLA4Ig on NK cell function has the function of regulation, the infected mice, verify the regulation effect of scald and tumor model, and to explore its molecular mechanism. In order to deepen the understanding of immune regulation of CTLA4Ig, and provide a theoretical basis for the application of CTLA4Ig in large area burn treatment. We will mainly the results and conclusions of this study are summarized as follows:
First, CTLA4Ig and its derivative, Abatacept, are powerful activators in NK cells.
1, CTLA4Ig can significantly enhance the function of human PBMC and NK cells in vitro.
In order to study the CTLA4Ig in vitro has no moderating effect on human PBMC and NK cell function, we use PBMC and NK cells by flow cytometry with different concentrations of CTLA4Ig. In the experiment system, we found that: 1) the concentration of CTLA4Ig is greater than 1 g/ml in PBMC and NK cells. The ability to kill K562 cells (NK cells toxicity) significantly enhanced; 2) CTLA4Ig and entering IL-2 on PBMC and NK cells regulate no significant difference; 3) in the experimental concentration range, PBMC and NK cell toxicity did not change significantly with the increase of CTLA4Ig concentration. The results show that CTLA4Ig PBMC and NK can significantly enhance the cytotoxicity in vitro, the ability of CTLA4Ig and activation of IL-2 NK cell toxicity, and in the CTLA4Ig experimental system in our independent regulation of its concentration on NK cells.
2, CTLA4Ig (Abatacept) can significantly enhance the toxicity of NK cells in mice in vivo.
In order to study the probability of Abatacept in inhibition of T cell activation but did not significantly increase the tumor or infection phenomenon with Abatacept on NK cell function regulation, we will be higher than the treatment of rheumatoid arthritis clinical dose of Abatacept mice through caudal vein injection into mice, the spleen NK cell toxicity and no injection in mice there are differences. The results showed that the injection of Abatacept 24h and 48h NK cells of spleen toxicity in mice were injected mouse spleen NK cells increased significantly. This result shows that the injection of Abatacept mice after CTLA4 can significantly enhanced NK cell toxicity in mice. This may be an important reason for the application of Abatacept did not significantly increase the risk of tumor or infection happen.
3, the role of CTLA4Ig in enhancing the cytotoxicity of NK cells is dependent on CTLA4 molecules:
In order to clarify whether the effect of CTLA4Ig on NK cells enhanced all caused by ADCC, we performed the following experiments: firstly, soluble hIgG1 or analog film is introduced in vitro expression of hIgG1 by NK cells as control, toxicity CTLA4Ig and introduction of FcR signal, clear the role of ADCC in the regulation of CTLA4Ig on NK cells effect of ratio. The results showed that after adding CTLA4Ig NK increased cytotoxicity is far higher than the introduction of FcR. so the enhancement effects of CTLA4Ig on NK cells is mainly mediated by CTLA4 molecules; in order to further explain the above questions, we select the surface expressed low affinity FcR-CD16, and no expression of CD32 and CD64 (25). NK92 cells were used as effector cells. Co cultured in NK92 cells and K562 into CTLA4Ig system, NK92 cell toxicity still significantly enhanced, confirmed that CTLA4 molecules in enhanced NK cytotoxicity Sex plays an absolute leading role. Therefore, we believe that the effect of CTLA4Ig on enhancing the toxicity of human NK cells in vitro is dependent on CTLA4 molecules.
Two, CTLA4Ig (Abatacept) can enhance the body's ability to antitumor:
NK cells in tumor formation plays an important role, so the experiment of CTLA4Ig on NK cell toxicity enhancement effect is beneficial to the body control. Tumor formation were found than the clinical dose of Abatacept injection did not inhibit T cell activation because promote tumor formation and growth, on the contrary, greatly reduced B16 cells of lung metastasis. Moreover, the survival time of tumor bearing mice was prolonged. Abatacept can enhance the anti-tumor ability (B16).
Three, we have a new understanding of CTLA4Ig (Abatacept) in the treatment of large area burns:
The results of our previous study (13) and (14) reported in the literature have confirmed that prolonged injection CTLA4Ig or wounds CTLA4Ig recombinant adenovirus can be allograft survival, this means that if CTLA4Ig can be applied to burn patients will inhibit graft rejection, prolong the survival time of the graft. Therefore, we use the green aeruginosa infection model and scald model evaluation of CTLA4Ig for the safety of the treatment of burn patients with skin graft rejection, our study is the first to find that Abatacept not only can significantly improve the clearance of Pseudomonas aeruginosa in Balb/c mice but also enhance the ability of scalded mice spleen cell toxicity in vitro, consistent with the experimental results. The research findings suggest that CTLA4Ig in the future can be used for patients with severe burns to the skin to induce graft immune tolerance, enhance the body's natural immunity. It will be strictly A major breakthrough in the treatment of severe burn diseases.
Four, CTLA4Ig increases the expression of activator NKG2D and NKp44 by binding to CD80/CD86 molecules on the surface of NK cells to enhance the toxic function of NK cells:
1, CTLA4Ig promotes the toxicity function of NK cells by binding to cell surface NK CD80/CD86 molecule: the experimental study of anti CD80 antibody and anti CD86 antibody on NK cells have no effect. The results showed that the anti CD80 antibody and anti CD86 antibody can significantly enhance the toxicity of PBMC on K562 cells in vitro, and no obvious difference group CTLA4Ig and NK cell toxicity. It indicated that CTLA4Ig promoted the toxic function of NK cells by binding to cell surface NK CD80/CD86 molecules.
In 2, CTLA4Ig in NK cells was up-regulated by activating receptor NKG2D, NKp44 expression: We used to study the role of CTLA4Ig expression on NK cell surface NKG2D and NKp44 flow cytometry. Results showed that in vitro after joining CTLA4Ig, the surface of human NK cell activating receptor NKG2D, NKp44 achieve a significant increase, and the degree of similarity and IL-2.FcR receptor and NK cell binding does not lead to NKG2D, the expression level of NKp44 increased. These results show that the surface of NK cell activating receptor NKG2D, NKp44 in CTLA4Ig enhancement may play an important role in regulating cellular toxicity of NK function.
Summary:
1. In vivo, CTLA4 can enhance the toxicity of NK cells in vitro.
Two, CTLA4Ig enhanced the function of NK cells by binding up the expression of NKG2D and NKp44 on the surface of NK cells by binding to the surface CD80/CD86 molecules on the surface of NK cells.
Three, CTLA4Ig and its derivatives (such as Abatacept) can enhance the ability of anti-tumor and anti infection in mice, do not increase the risk of tumor and infection, and expand their indications for clinical application.
Four, CTLA4Ig can not only treat skin graft rejection, but also increase NK cytotoxicity and reduce the incidence of disseminated infection, which provides a new idea for CTLA4Ig in the treatment of burn patients.
Five, we found that CTLA4 for the acquired immune system (T cells) and natural immune system (NK cells) from the role of our in-depth understanding of regulation and internal environment of the immune system stability is of great significance, will burn for clinical tumor therapy and treatment of large area provides new theoretical basis and research direction.

【學(xué)位授予單位】：第三軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2009
【分類(lèi)號(hào)】：R392;R644

【共引文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ;BTLA,a New Inhibitory B7 Family Receptor with a TNFR Family Ligand[J];Cellular & Molecular Immunology;2005年06期

2 黃曉環(huán);吳京;于健;熊柯;馬明;;B7-H1對(duì)同種異體小鼠角膜移植免疫反應(yīng)的影響[J];南方醫(yī)科大學(xué)學(xué)報(bào);2012年06期

3 施浩強(qiáng);于德新;;干擾素在腎癌細(xì)胞中的生物學(xué)效應(yīng)[J];國(guó)際泌尿系統(tǒng)雜志;2006年03期

4 黃鋼;姜曼;白云;;LPS調(diào)節(jié)U937細(xì)胞上B7-H1表達(dá)的初步研究[J];免疫學(xué)雜志;2006年05期

5 朱德勝;朱紹興;黃世勇;陳劍暉;方榮金;賴(lài)智雙;;腎透明細(xì)胞癌組織中B7-H1的表達(dá)及其與預(yù)后的關(guān)系[J];現(xiàn)代泌尿生殖腫瘤雜志;2010年03期

6 周蕓;焦志軍;辛利軍;汪四七;路麗明;丁慶;周曉榮;楊能;周光炎;;自體角朊細(xì)胞通過(guò)B7-H1介導(dǎo)對(duì)異種混合淋巴細(xì)胞增殖的抑制作用[J];現(xiàn)代免疫學(xué);2009年06期

7 陳霖;李晶;侯建偉;舒震;張偉;張英起;;重組人B7-H1IgV發(fā)酵純化工藝的建立及其抑瘤活性[J];中國(guó)生物制品學(xué)雜志;2010年06期

8 王貴強(qiáng);周業(yè)江;;腫瘤免疫耐受機(jī)制的研究進(jìn)展[J];實(shí)用醫(yī)學(xué)雜志;2008年18期

9 趙琳;李志英;劉朝奇;魯選文;;人子宮頸癌組織PD-L1表達(dá)及其與HPV16E6/E7的相關(guān)性[J];山東醫(yī)藥;2012年39期

10 吳清松;黃東勝;劉軍偉;金洪傳;沈國(guó)梁;;B7H1在胰腺癌panc-1細(xì)胞的表達(dá)及其功能研究[J];中國(guó)病理生理雜志;2010年12期

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1 陳延斌;PD-L1/PD-1在非小細(xì)胞肺癌中的臨床應(yīng)用研究[D];蘇州大學(xué);2011年

2 徐躍華;共刺激分子B7-H3在肺癌中的表達(dá)及其臨床意義[D];蘇州大學(xué);2011年

3 李寧;阻斷共抑制信號(hào)途徑聯(lián)合趨化抗原基因修飾瘤苗治療腫瘤的研究[D];中國(guó)協(xié)和醫(yī)科大學(xué);2007年

4 于曉偉;CD4~+CD25~+調(diào)節(jié)性T細(xì)胞及PD-L1與卵巢癌的相關(guān)性研究[D];吉林大學(xué);2008年

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1 吳清松;B7H1在胰腺癌panc-1細(xì)胞的表達(dá)及其功能研究[D];浙江大學(xué);2011年

2 熊辛睿;慢性乙型肝炎患者PD-1的檢測(cè)及意義[D];中南大學(xué);2011年

3 方云;免疫抑制劑他克莫司對(duì)髓源性樹(shù)突狀細(xì)胞的影響[D];浙江大學(xué);2006年

4 張莉;α-黑素細(xì)胞剌激素基因原位轉(zhuǎn)染及B7-H1基因修飾的樹(shù)突狀細(xì)胞對(duì)小鼠同種異體心臟移植排斥反應(yīng)的影響[D];第二軍醫(yī)大學(xué);2006年

5 陳永井;人B7-H1基因的克隆、表達(dá)及其生物學(xué)功能的初步研究[D];蘇州大學(xué);2005年

6 孫靜;鼠抗人PD-L1單克隆抗體的研制及其生物學(xué)功能的研究[D];蘇州大學(xué);2006年

7 朱云霞;人PD-L1轉(zhuǎn)基因細(xì)胞的構(gòu)建及其對(duì)肺癌惡性胸水中CD8~+T細(xì)胞功能的調(diào)節(jié)作用[D];蘇州大學(xué);2009年

8 陳穎;共刺激分子PD-L1在非小細(xì)胞肺癌組織及浸潤(rùn)性樹(shù)突狀細(xì)胞中的表達(dá)和意義[D];蘇州大學(xué);2009年

9 張玉霞;人惡性胸水來(lái)源樹(shù)突狀細(xì)胞PD-L1的表達(dá)及其對(duì)惡性胸水中T細(xì)胞功能的調(diào)節(jié)作用[D];蘇州大學(xué);2010年

10 包紅菊;抗PD-L1單抗聯(lián)合CTL對(duì)肺癌免疫治療的實(shí)驗(yàn)研究[D];蘇州大學(xué);2010年

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