致敏树突细胞及exosome对胃癌的免疫治疗作用研究

目的 :了解胃癌组织中树突细胞 (DC)的功能状态 ,探讨DC及其分泌的亚细胞成分exosomes用于防治胃癌的可能性 ,旨在为胃癌的防治探索新的途径。方法 :利用致敏DC及其所分泌的亚细胞成分exosomes对荷胃癌小鼠进行免疫治疗 ,观察其免疫治疗效果。结果 :荷胃癌小鼠经胃癌细胞RNA致敏的DC及其分泌的亚细胞成分exosomes治疗后 ,小鼠腹水产生率、肿瘤转移率、动物存活率、瘤体平均重量等指标均明显优于对照组 (P <0 0 1) ,局部组织中IL 12、IFN γ和IL 18的基因表达水平都明显升高 (P <0 0 1) ,肿瘤局部CD4 + 、CD8+ 细胞数量增加 (P <0 0 5 ) ,TIL细胞毒活性明显增强。结论 :胃癌RNA致敏的DC及其所分泌的亚细胞成分exosomes,能促进胃癌抗原的提呈 ,并启动和增强机体的抗瘤免疫功能 ,改善临床症状和生存质量 ,对荷胃癌小鼠具有一定的免疫治疗效果。     

多发性骨髓瘤患者树突状细胞介导的特异性抗瘤活性的体外诱导

目的 :观察U2 6 6 细胞及其可溶性抗原激发的多发性骨髓瘤 (MM)患者树突状细胞 (DC)体外诱导U2 6 6 特异性CTL的作用。方法 :将MM患者外周血来源的单核细胞在rhGM CSF 80 0U ml与IFNα 6 0 0U ml条件下利用无血清技术培养生成DC ,应用丝裂霉素C处理的U2 6 6 细胞及用U2 6 6 细胞制备的可溶性抗原预刺激DC ,然后与自体淋巴细胞共同孵育 5～ 7d以诱生特异性CTL ,采用MTT法检测对U2 6 6 细胞的特异性杀伤效果。结果 :MM患者外周血单核细胞在GM CSF IFNα条件下培养 8d后生成具有典型特征的DC ,高度表达CD86、CD5 4及MHCII类分子HLA DR。应用MTT法检测U2 6 6 细胞及其可溶性抗原激发的DC诱导特异性CTL对靶细胞U2 6 6 的杀伤率分别为 2 1 2 %± 5 4 %和 2 8 0 %± 7 6 % ,对照组未用抗原刺激组都为 11 7%±4 3%。而以抗原直接刺激自体淋巴细胞组为 15 6 %± 4 8%和 13 1%± 5 5 % (P <0 0 1)。结论 :U2 6 6 细胞及其可溶性抗原激发的DC与自体淋巴细胞孵育能诱导抗U2 6 6 特异性CTL。     

树突细胞对Lewis肺癌抗瘤作用的研究

目的：研究经体外骨髓细胞衍生的DC在Lewis肺癌中的抗瘤作用。方法：将肿瘤抗原MUT－1加载的DC（DC－MUT－1）经尾静脉免疫C57BL／6小鼠后,随后将肿瘤细胞接于小鼠皮下,观察DC能否诱发机体的免疫保护。同时检测DC－MUT－1免疫后小鼠脾脏T细胞的CTL活性。结果：经DC－MUT－1免疫后能诱发机体产生对相应肿瘤细胞的持久和特异性的免疫保护作用,体外检测CTL活性显示,免疫小鼠脾脏T细胞对相应肿瘤具有 特异性杀伤。结论：经DC－MUT－1免疫小鼠能诱发机体产生特异性抗肿瘤细胞免疫从而使宿主对随后的肿瘤细胞攻击产生特异性的免疫保护作用。     

糖基化修饰的树突状细胞疫苗激发的骨髓瘤特异性T细胞免疫反应

探讨经糖基化修饰的肿瘤相关糖抗原冲击树突状细胞(DC)后,所得DC疫苗对骨髓瘤患者自身T细胞的刺激作用。采用化学方法及细胞生物工程法,使骨髓瘤细胞表达新肿瘤相关抗原N-丙酰多聚唾液酸(NPrPSA);在无血清培养条件下用GM-CSF/IFN-α及TNF-α诱导培养多发性骨髓瘤(MM)患者外周血单核细胞DC,继用表达新抗原的肿瘤细胞冲击制备DC疫苗,并与MM患者自身T细胞共同温育,流式细胞仪分析CD4+CD29+、CD8+CD28+及CD69+T细胞。结果显示糖基化修饰的骨髓瘤DC疫苗与正常细胞相比,可明显诱导CD4+及CD8+T细胞的活化。糖基化修饰的DC疫苗可激发骨髓瘤特异性T细胞免疫反应,将为靶向性杀伤骨髓瘤细胞奠定基础。     

CD40分子在树突状细胞抗人多发性骨髓瘤免疫应答中的作用及其机理

目的为研究CD40分子在人树突状细胞(DC)抗多发性骨髓瘤(MM)中的作用及其机制。方法采用CD40配体(CD40L)转基因细胞及抗CD40的激发型单克隆抗体在体外激发DC,并通过DC细胞计数、形态学和细胞表型分析、IL-12定量检测、DC对MM抗原的摄取及混合淋巴细胞反应等手段对其进行研究。结果CD40分子配基化可促进DC的体外增殖和分化,使DC增加分泌IL-12,并下调DC摄取抗原的能力,促进DC的成熟,同时赋予DC激发自体CD8+细胞增殖的作用,使后者对MM细胞产生特异性的杀伤作用。结论CD40分子激发不仅有利于DC的增殖、分化和增强激发T细胞增殖,而且Th细胞表达的CD40L是DC获得直接激发抗MM抗原特异性CD8+T细胞的关键分子。     

TIGIT信号途径介导多发性骨髓瘤免疫逃逸的研究进展

肿瘤微环境免疫抑制是多发性骨髓瘤(multiple myeloma,MM)重要的病理特征之一.T细胞免疫球蛋白和ITIM结构域(T-cell immunoglobulin and ITIM domain,TIGIT)是近年新兴的免疫检查点蛋白,多表达于Treg、活化型T细胞和NK细胞.目前研究证实TIGIT/CD155...     

负载U937细胞冻融抗原的DC诱导CTL的特异性杀伤

树突状细胞 (DC)作为重要的专职抗原提呈细胞 ,其抗原提呈能力远强于巨噬细胞和B细胞等抗原提呈细胞。因而 ,以DC为中心的免疫治疗是肿瘤生物学治疗的主要方向之一。我们应用当前普遍采用的rhGM CSF、rhIL 4培养体系 ,自骨髓单个核细胞诱导产生CD14 - CD1a 的前体DC ,使其负载     

骨髓瘤细胞裂解物致敏的DC-CIK细胞抗骨髓瘤细胞作用

目的:研究负载骨髓瘤细胞裂解物的健康供者树突状细胞(Dendritic cells,DCs)联合细胞因子诱导杀伤细胞(Cytokine induced kil1er cells,CIK)体外对骨髓瘤U266细胞杀伤作用的影响。方法:通过血细胞分离机采集健康供者单个核细胞100 ml用于体外培养,选取贴壁细胞进行DC细胞培养,悬浮细胞用于CIK细胞培养,DC细胞培养7日后用骨髓瘤U266细胞裂解物致敏,然后与CIK细胞共培养7日,用倒置显微镜、扫描电镜观察细胞形态,流式细胞仪检测细胞表型,乳酸脱氢酶释放法检测共培养细胞对U266细胞杀伤作用。结果:CIK细胞大部分形态为圆形,少数梭形,DC细胞有典型细胞突起,流式细胞仪分析培养的CIK细胞高表达CD3,培养后CD3和CD56共表达细胞明显升高,在致敏后DC细胞表达CD86、CD80,共培养细胞对U266细胞杀伤作用强于单独CIK细胞作用。结论:瘤细胞裂解物致敏的健康供者DC-CIK细胞能显著提高对瘤细胞的杀伤性,在患者干细胞移植后是否可应用以清除残留病变,值得进一步研究应用。     

不同大鼠胶质瘤抗原致敏的DC体外诱导CTL活性的研究

目的: 比较大鼠骨髓来源的树突状细胞(dendritic cells, DC)体外经由大鼠C6胶质瘤细胞由不同方式制备的不同抗原致敏后,对特异性细胞毒性T淋巴细胞(cytotoxic T lymphocyte, CTL)的诱导作用。方法: 自大鼠骨髓分离DC前体细胞,经重组大鼠粒细胞巨噬细胞集落刺激因子(rrGM-CSF)+白细胞介素4(rrIL-4)诱导培养、扩增;由C6胶质瘤细胞经由反复冻融、煮沸灭活及超声破碎细胞抽提其总蛋白的方法制备各种不同抗原致敏DC,致敏的DC与T淋巴细胞进行共培养诱导CTL;以ELISA法检测CTL诱导过程中淋巴细胞趋化因子(lymphocyte chemoattractant factor)及细胞因子IFN-γ分泌水平:以 -TdR掺入法检测DC诱导T细胞增殖及其特异性CTL杀伤活性。 结果: 体外应用煮沸灭活瘤细胞制备的肿瘤抗原致敏DC,能诱导更强的刺激T细胞增殖的能力、并且可以诱导杀伤活性更强的CTL。结论: 应用煮沸灭活的瘤细胞制备瘤抗原负载DC获得瘤苗可获得更强的抗肿瘤保护作用。     

多发性骨髓瘤的免疫学研究

多发性骨髓瘤 (ｍｕｌｔｉｐｌｅｍｙｅｌｏｍａ ,ＭＭ )是发生在Ｂ细胞系统的恶性肿瘤。其特征是骨髓中浆细胞克隆性增殖并积聚 ,分泌单克隆的免疫球蛋白或其片段 (Ｍ蛋白 ) ,同时伴有广泛的溶骨病变或骨质疏松。作为一种代表性的免疫增殖性疾病 ,ＭＭ的免疫学研究一直受到血液学和免疫学工作者的关注 ,近年来该领域更是成果斐然 ,引人瞩目。1　骨髓瘤细胞的起源[1 ]Ｂ细胞发育、分化过程中的哪一个阶段发生恶变 ,继而进一步分化为恶性细胞 ,是ＭＭ临床和科研人员一直关注的焦点之一 ,概括起来有以下几种假设。1 1　造血干细胞　依据主要有…     

Determining control parameters for dendritic cell-cytotoxic T lymphocyte interaction

Dendritic cells (DC) are potent immunostimulatory cells facilitating antigen transport to lymphoid tissues and providing efficient stimulation of T cells. A series of experimental studies in mice demonstrated that cytotoxic T lymphocytes (CTL) can be efficiently induced by adoptive transfer of antigen-presenting DC. However, the success of DC-based immunotherapeutic treatment of human cancer, for example, is still limited because the details of the regulation and kinetics of the DC-CTL interaction are not yet completely understood. Using a combination of experimental mouse studies, mathematical modeling, and nonlinear parameter estimation, we analyzed the population dynamics of DC-induced CTL responses. The model integrates a predator-prey-type interaction of DC and CTL with the non-linear compartmental dynamics of T cells. We found that T cell receptor avidity, the half-life of DC, and the rate of CTL-mediated DC-elimination are the major control parameters for optimal DC-induced CTL responses. For induction of high avidity CTL, the number of adoptively transferred DC was of minor importance once a minimal threshold of approximately 200 cells per spleen had been reached. Taken together, our study indicates that the availability of high avidity T cells in the recipient in combination with the optimal application regimen is of prime importance for successful DC-based immunotherapy.     

Murine epidermal Langerhans cells and splenic dendritic cells present tumor-associated antigens to primed T cells

We examined the ability of epidermal Langerhans cells and splenic dendritic cells to present tumor-associated antigens (Ag) to immune T cells. Methylcholanthrene (MCA)-induced subcutaneous fibrosarcomas derived from C57BL/6 mice were used as tumor models. Our data demonstrate that both murine Langerhans cells and splenic dendritic cells have the capacity to present tumor-associated Ag to primed T cells. We found that variously treated tumor preparations (irradiated viable tumor cells, irradiated frozen-stored tumor cells, mitomycin C-treated viable tumor cells, and snap freeze-thawed tumor cell lysates) can be utilized for tumor Ag-pulsing. Primed CD4⁺ T cells demonstrated in vitro specificity towards their respective tumors and did not cross-react to other syngeneic MCA-induced or non-MCA-induced tumors. The T cell proliferative response critically depended on the presence of immune CD4⁺ T cells. We discuss the implications of these findings for the adoptive immunotherapy of cancer using immune CD4⁺ T cells.     

Exposure to myeloma cell lysates affects the immune competence of dendritic cells and favors the induction of Tr1-like regulatory T cells

The aim of this work was to investigate the interactions of tumor cells with dendritic cells (DC) in normal donors and patients with multiple myeloma (MM). Normal and MM DC internalized necrotic lysates derived from myeloma cell lines (MCL) with high efficiency, whereas necrotic lysates from primary myeloma cells (PMC) were internalized with significantly lower efficiency. A positive correlation was found between susceptibility to internalization and the ability to induce DC maturation. After PMC exposure, DC produced large amounts of IL-10 and measurable amounts of IL-4 but no detectable IL-12. Two rounds of exposure to PMC-treated DC generated autologous T cells with low proliferative capacity, decreased IFN-gamma production and increased IL-10 production in the absence of IL-4 production. These data indicate that myeloma cells can affect host immunity by priming DC towards a maturation state favoring the generation of T cells with a regulatory rather than an effector phenotype.     

HBV S基因修饰树突状细胞疫苗诱导特异性CTL反应的探讨

目的分析腺病毒载体介导HBVS基因修饰树突状细胞（DCs）能否诱导抗HBV特异性CTL反应。方法制备携带HBVS基因的重组腺病毒，分别转染外周血诱导培养的DCs，观察腺病毒转染DCs效率和DCs中HBV抗原的表达；混合淋巴细胞反应测定HBV抗原基因修饰DCs刺激同种异体T淋巴细胞增殖能力；乳酸脱氢酶释放法检测特异性CTL细胞对HepG2 22．1．5靶细胞的杀伤能力。结果腺病毒载体能够高效介导HBVS基因在DCs中表达，且DC细胞形态完整；HBVS基因修饰DCs具有刺激同种异体T细胞增殖能力，同时能诱导抗HBV特异性CTL反应。结论HBVS基因修饰DCs疫苗具有增强抗HBV特异性CTL效应的能力，可能发展为一种新型抗病毒疫苗。     

Effect of prolactin on carcinoembryonic antigen-specific cytotoxic T lymphocyte response induced by dendritic cells

The cytokine hormone prolactin (PRL) has been shown previously to modulate native cellular responses and maturation of antigen-presenting cells. Here we have addressed its effect on the antigen-specific response of cytotoxic T lymphocytes (CTL). CTL were generated from HLA-A2 lymphocytes after three rounds of stimulation with autologous dendritic cells loaded with HLA-A2-restricted carcinoembrionic antigen (CEA) Cap-1 (YLSGANLNL) peptide. Selected cultures were expanded on cytokine-supplemented feeder-layers, enriched for CD8+ lymphocytes and analysed for PRL-receptor (PRL-R) expression and PRL responsiveness. Resting CD8+ lymphocytes were negative for PRL-R, whereas antigen-activated CD8+ lymphocytes derived from long-term cultures were highly positive. Results of a 51Cr release assay showed CTL killing of CEA-loaded, but not unloaded, T2 cell line and the CEA-positive gastric carcinoma cell line KATO, but not of the CEA-negative T leukaemia cell line Jurkat. Interferon (IFN)-gamma release, evaluated in an ELISPOT assay against CEA-loaded T2, was enhanced (P < 0.05) by concentrations of PRL (12-25 ng/ml) very close to the physiological levels (6-20 ng/ml), but was decreased (P < 0.05) by high concentrations (200 ng/ml). Pre-incubation of the stimulators with the anti-MHC class I MoAb W6.32 induced a 40-60% decrease of the PRL-boosted IFN-gamma release, thus proving the MHC restriction of the lymphocyte response. Cytotoxicity against CEA-loaded T2 and KATO cell lines was also increased by 12-25 ng (P < 0.05) and decreased (P < 0.05) by 200 ng PRL. Pre-incubation of CTL with an antibody specific for the PRL-R almost completely abrogated this effect.     

Distinct subsets of human invariant NKT cells differentially regulate T helper responses via dendritic cells

Invariant natural killer T (iNKT) cells regulate the T helper (Th) 1/2 balance and elicit either enhancement or suppression of the immune responses. However, the exact mechanism by which iNKT cells exert these contrasting functions has remained elusive. We demonstrate herein that two major distinct subsets of human iNKT cells, CD4+CD8beta(-) (CD4+) and CD4(-)CD8beta(-) (double negative; DN) cells, express functional CD40 ligand (CD40L), but they differentially regulate the dendritic cell (DC) function by reciprocal NKT-DC interactions, thereby influencing the subsequent Th response. The CD4 subset stimulated by alpha-galactosylceramide (alpha-GalCer)-loaded DC immediately produced massive amounts of IL-4 and IL-13, which together with IFN-gamma enhanced CD40L-induced IL-12 production by DC. In contrast, the DN subset eliminated the DC by cytolysis and changed the living DC into a default subtype, in turn markedly down-regulating the levels of IL-12. Therefore, the DC stimulated by the CD4 subset preferentially induced Th1 responses, whereas the DC reacted with the DN subset induced a shift toward Th2 responses. These findings may provide an important insight into better understanding the contribution of iNKT-DC cross-talk governing the Th1/2 balance and the diverse influences of iNKT cells in various diseases.     

人树突状细胞体外直接抑瘤作用研究

目的：诱导获得人外周血树突状细胞(DCs)，研究其体外直接抑瘤作用及机制。方法：自正常人外周血分离获得单核细胞，体外rhGM-CSF和rhIL-4联合诱导培养，观察细胞形态并检测其相关表型；利用MTT法检测所诱导DCs及其培养上清对不同肿瘤细胞系的体外直接抑瘤效应。结果：诱导5—7天后的悬浮细胞具有典型的DCs形态，流式分析显示HLA-DR表达率为64．02％，CD14表达率为2．34％；抑瘤实验显示：DCs对HT29、Hela及HepG2．2．15三种肿瘤细胞系的生长具有明显抑制，其抑制率分别为20．16％，25．44％，75．41％，而对Lovo和HepG2两种肿瘤细胞系，则无明显的抑制作用。DCs培养上清均未见明显的抑瘤效应。结论：人类DCs可对某些肿瘤细胞的生长产生直接抑制作用，但对不同的肿瘤细胞其作用不同。此作用可能由DCs与肿瘤细胞的直接接触而触发，而与DCs分泌的细胞因子关系不大。     

The production of secretory leukocyte protease inhibitor by dendritic cells

Secretory leukocyte protease inhibitor (SLPI) is produced at mucosal sites where it plays an important role in the homeostatic control of local inflammation. In addition to its anti-protease activity SLPI is able to reduce LPS activity by interfering with the transfer of LPS to CD14. In addition SLPI can be taken up by cells where it can prevent signaling via the NF-κB route.It is preferentially expressed in dendritic cells from mucosal sites, suggesting a role in the maintenance of a tolerogenic environment, but it is unclear how this differential expression is regulated.Here we analyzed the regulation of SLPI expression in dendritic cells and found that activation by TLR ligands but not via antiCD40 leads to its expression, which is predominantly dependent on p38 activation. This induced expression is late compared to the induction of cytokines and co-stimulatory molecules, is not dependent on factors that are secreted by the cell itself and may be related to cellular feedback mechanisms involved in inflammation and immunity. In correlation with the differential expression by TLR ligands and antiCD40, SLPI deficient mice show enhanced specific immunity when antigen is co-injected with LPS, but not with antiCD40. The results underscore the importance of SLPI as a modulator of specific immunity that can also function at peripheral sites under pathogenic pressure.