B-CLL患者瘤细胞膜表面Id-ScFv和人Hsp70的制备及其抗瘤效应

背景与目的:恶性B型淋巴细胞表面免疫球蛋白(surface membrane immunoglobulin,SmIg)表达的独特型决定簇(Idiotypic determinant,Id)不仅是该类肿瘤特异性标记,也是该类肿瘤的特异性抗原,可诱导机体对其产生特异性免疫应答,但由于Id是自体成分,分子量小,免疫原性较弱。人热休克蛋白70(heat shock protein,Hsp70)是一类重要的抗原提呈分子,能有效加强抗原肽的免疫原性。本研究通过制备慢性B型淋巴细胞性白血病(B-cell chronic lymphatic leukemia,B-CLL)患者瘤细胞膜表面独特型单链抗体(Idiotypic determinant single-chain antibody,Id-ScFv)和Hsp70两种蛋白,在体外研究两者联合抗瘤作用并初步探讨其机制。方法:分别在大肠杆菌中表达Id-ScFv和Hsp70两种蛋白,表达产物经SDS-PAGE电泳(sodium dodecyl sulfate polyacrylamide gel electropheresis)及ELISA(enzyme-linked immunosorbentassay)检测鉴定后,分别用金属螯合层析和离子交换层析纯化并在体外将这两种蛋白结合成复合物(Hsp70-Id)。用MTT法及检测Id-ScFv组、人Hsp70组及Hsp70-Id组刺激外周血单个核细胞(peripheral blood mononuclear cell,PBMC)的增殖作用,以ELISA法检测各组培养上清中IL-12和TNF-α水平,并用流式细胞术检测各组PBMC亚群的变化。用活细胞计数法检测各组被激活的PBMC对慢性B细胞白血病细胞株Daudi、慢性髓性白血病细胞株K562和肝癌细胞株HepG2的杀伤作用。结果:经SDS-PAGE电泳分析纯化后表达产物的分子量大约为30ku(Id-ScFv蛋白)和70ku(Hsp70蛋白),分别与其理论预期值相符。PBMC的增殖作用、培养上清中IL-12和TNF-琢水平,Hsp70-Id组明显强于Id-ScFv组和人Hsp70组(P<0.05),而Id-ScFv组和人Hsp70组明显强于阴性对照组(P<0.05)。流式细胞术检测显示在Hsp70-Id组、Id-ScFv组和人Hsp70组PBMC中CD8 T细胞亚群的百分率均有增加,其中Hsp70-Id组最明显。在Id-ScFv组和Hsp70-Id组激活的PBMC对Daudi细胞的杀伤作用较K562、HepG2细胞强(P<0.05),且Hsp70-Id组激活的PBMC对Daudi细胞的杀伤作用明显强于Id-ScFv组(P<0.001)。结论:成功获取B-CLL患者瘤细胞膜表面Id-ScFv和人Hsp70两种纯化蛋白;Hsp70-Id在体外可增强PBMC的特异性杀瘤作用,其机制可能与促进PBMC的增殖、活化CD8 T细胞并诱导具有抗肿瘤作用的Th1型细胞因子的分泌有关。     

Hsp70-H22肿瘤抗原肽复合物激活树突状细胞诱导抗肿瘤免疫的研究

目的　探讨通过树突状细胞 (DC)提呈途径降低肿瘤抗原肽用量的可行性 ,了解热休克蛋白 70 (Hsp70 )和抗原肽修饰DC作用的特点。方法　以Hsp70于体外结合抗原肽 ,并于体外修饰DC ,检测修饰后DC的代谢活性及分泌的细胞因子 ;比较修饰后DC和Hsp70 H2 2肽对淋巴细胞的激活作用 ;检测激活的淋巴细胞对H2 2瘤细胞的细胞毒作用以及注射DC和Hsp70 H2 2肽对小鼠肿瘤的抑制作用。结果　Hsp70结合 0 .15 μgH2 2肽可使 2× 10 5DC成熟 ,4× 10 3 成熟DC可激活 2× 10 6淋巴细胞 ;Hsp70结合 0 .0 0 3μg肽修饰的DC或Hsp70结合 0 .15 μg肽直接刺激 ,可激活相同数量的淋巴细胞 ,产生同样的杀瘤效果。激活DC后再回输的治疗方式与直接注射Hsp70 肽复合物的治疗方式相比 ,抗原肽的用量可以降低 5 0倍。正常肝组织来源的混合肽结合Hsp70后 ,不能使DC成熟 ,亦不能通过DC途径活化脾淋巴细胞。结论　DC提呈抗原肽激活淋巴细胞的途径能够有效降低Hsp70 肿瘤抗原肽复合物使用剂量。正常细胞的混合肽不能通过Hsp70和DC提呈激活淋巴细胞 ,其诱发自身免疫应答的可能性极低     

塞来昔布促进T细胞淋巴瘤对化疗药物的敏感性

目的:研究塞来昔布对T细胞淋巴瘤细胞化疗敏感性的影响,并探讨其作用机制.方法:MTF法检测不同浓度塞来昔布分别作用24、48和72 h,对T细胞淋巴瘤细胞株Jurkat和Hut78增殖活性的影响;MTT法检测化疗药物[顺铂(cis-platinum,DDP)、表柔比星(epirubicin,EPI)及长春新碱(vincristine,VCR)]联合塞来昔布对Jurkat和Hut78细胞增殖活性的影响;并计算IC50值;流式细胞术检测塞来昔布联合化疗药对Jurkat和Hut78细胞凋亡水平的影响;Real-time PCR及Westernblotting技术分别从mRNA及蛋白水平检测塞来昔布对Jurkat和Hut78细胞表达MDR1、MRP1、LRP及TopoⅡ的影响.结果:塞来昔布对T细胞淋巴瘤细胞株Jurkat和Hut78增殖活性具有一定抑制作用,且可明显增强化疗药物对Jurkat和Hut78细胞的杀伤作用;在塞来昔布作用下Jurkat和Hut78细胞的凋亡水平明显增加(P＜0.01);与塞来昔布共培养的Jurkat和Hut78细胞,TopoⅡmRNA和蛋白的表达水平均明显增加,而MDR1、MRP1、LRP mRNA及蛋白的表达水平均明显下降(P＜0.05).结论:塞来昔布可通过调控耐药相关基因的表达而增强T淋巴瘤细胞对化疗药物的敏感性,因此在T细胞淋巴瘤的临床治疗中具有良好应用前景.     

Hsp70-肿瘤抗原肽复合物防治小鼠黑色素瘤B16肺转移的作用

目的:探讨热休克蛋白70-肿瘤抗原肽复合物(Hsp70-antigen peptide complexes)对小鼠黑色素瘤B16转移的防治作用.方法:分别从小鼠腿部接种的B16实体瘤及小鼠肺B16转移灶提取混合抗原肽,体外与Hsp70结合制得复合物,此复合物免疫小鼠后用于预防或治疗经尾静脉接种转移至肺的B16黑色素瘤,观察其对肿瘤转移的防治作用.结果:Hsp70-肿瘤抗原肽复合物免疫后肺转移灶节结数显著减少(P＜0.01),体外脾细胞表现出对B16较高的杀伤率(P＜0.01);并对肺转移灶有显著的治疗作用(P＜0.01),而从B16实体瘤提取的混合抗原肽制得的复合物比从肺转移灶提取的混合抗原肽制得复合物有更好的治疗效果(P＜0.01),表现出体外脾细胞对B16更高的杀伤率(0.01＜P＜0.05).结论:Hsp70-肿瘤抗原肽复合物对肿瘤的转移有明显的防治作用,而从实体瘤提取的混合抗原肽比从转移灶提取的混合抗原肽更为有效.     

趋化因子受体CCR7在T细胞淋巴瘤播散中的作用

目的:探讨趋化因子受体CCR7在T细胞淋巴瘤播散中的作用;旨在为T细胞淋巴瘤靶点治疗的新方向提供一定的实验基础及理论依据.方法:皮肤T细胞淋巴瘤Hut78和成人T淋巴细胞白血病/淋巴瘤Jurkat细胞株培养,通过Transwell小室检测了细胞体外侵袭能力并进行比较;通过RT-PCR和Western-blot技术对两种细胞株的CCR7和PI3K/Akt信号转导通路的表达进行了检测.结果:1)Hut78细胞体外侵袭能力较强;两种T细胞淋巴瘤细胞经过CCL21共培养后,侵袭能力均有所增强,且均呈现与CCL21浓度的正相关趋势;2)Hut78细胞中CCR7mRNA,PI3KmRNA、AktmRNA均高于Jurkat细胞,差异均有显著性(P＜0.001);CCR7、pAkt蛋白在Hut78细胞中的表达也明显高于Jurkat细胞(P＜0.05).结论:T细胞淋巴瘤中高表达的CCR7与肿瘤的侵袭性有关,可能通过PI3K/Akt信号通路促进肿瘤的侵袭和播散.     

肝癌热休克蛋白—抗原肽复合物的构建及诱导CTL反应的初步研究

目的：研究体外构建热休克蛋白-抗原肽复合的方法,观察其在体外的抗肿瘤作用。方法：用经43℃热处理1小时的人肝细胞悬液,经过裂解液裂解,60%-80%饱和硫酸铵沉淀,用SephadexG-100柱制备,取分子量为70KD组份,Westen blot进行性质鉴定。应用多肽解离液处理该组份,SephadexG-25柱过滤获得未结合多肽的蛋白分子,使其在体外与肝癌抗原肽SLIVHLNEV结合,构建成热休克蛋白-抗原肽复合物。应用此复合物树突状细胞,激活同源外周血T淋巴细胞产生肿瘤特异性杀伤T淋巴细胞（CTL）,应用MTT法检测其对T2细胞及肿瘤细胞的杀伤活性。结果：所得蛋白经电泳及Western blot进行蛋白分子量及性质鉴定为热休克蛋白70。SephadexG-25柱双分离法证实应用上述方法成功构建了肝癌热休克蛋白70-抗原肽复合物,用该复合物负荷树突状细胞在体外可以诱导出较强的肝癌抗原肽物特异性CTL,可以杀伤负荷有该肽的T2细胞及递呈该肽的肿瘤细胞系。结论：体外构建的热休克蛋白-抗原肽复合物可以增强抗原肽诱导CTL反应能力,热休克蛋白是良好的T细胞免疫佐剂,有可能在肿瘤疫苗治疗中发挥重要作用。     

自体宫颈癌-树突细胞疫苗激活的CTL杀伤效应

背景与目的:树突细胞(dendriticcells,DC)是目前已知的功能最强的抗原递呈细胞(antigen-presentingcell,APC),它可以在体内、外向T淋巴细胞递呈抗原,并诱发细胞毒T淋巴细胞(cytotoxicTlymphocyte,CTL)反应。本研究旨在探讨负载自体宫颈癌抗原的DC体外激发的CTL对自体宫颈癌细胞的杀伤效应。方法:先冻融宫颈癌细胞制备抗原,然后以GM-CSF、IL-4诱导自体外周血单个核细胞(peripheralbloodmononuclearcell,PBMC)获得DC并负载抗原,刺激自体T淋巴细胞制备宫颈癌抗原特异性CTL,观察CTL对宫颈癌细胞的杀伤活性。结果:负载自体宫颈癌抗原DC诱导的特异性CTL对自体宫颈癌细胞的体外杀伤率高达79.32%～89.27%,显著高于淋巴因子激活的杀伤细胞(lymphokine-activatedkillingcells,LAK)的杀伤率(t≥2.89,P<0.05);且对宫颈癌HeLa细胞株具有一定杀伤效应(40.35%～58.09%),但低于自体癌细胞组(t≥2.97,P<0.05);特异性CTL对HepG2、MCF7、A549、MGC803细胞无明显杀伤效应。结论:自体宫颈癌-树突细胞疫苗体外诱导的CTL具有高效而特异的抗自体宫颈癌细胞免疫活性,可望成为宫颈癌生物治疗的一个有力手段。     

HIFU治疗后肿瘤抗原对树突状细胞的活化及其抗肿瘤效应

目的：探讨HIFU治疗小鼠H22抑制性肝癌后产生的肿瘤抗原对机体抗肿瘤免疫功能增强的机制。方法：正常小鼠骨髓中提取骨髓细胞,在rmIL-4、rmGM-CSF奈件下培养7d,制备小鼠骨髓树突状细胞,用HIFU治疗小鼠移植性肝癌后产生的肿瘤抗原活化树突状细胞,再用活化后的树突状细胞激活T淋巴细胞为细胞毒性T细胞,用MTT法检测CTL在体外特异性杀伤肿瘤靶细胞的能力。结果：B16肿瘤HSP70-肽复合物组和H22肿瘤HSP70-肽复合物组的脾淋巴细胞的增殖率均高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组,P〈0．001;但两组之间差异无统计学意义,P〉0．05。H22肿瘤HSP70-肽复合物组CTL对H22肿瘤细胞的杀伤率为70．0％,明显高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组（P〈0．001）,但对非靶细胞B16肿瘤的杀伤率与上述各组的差异无统计学意义;B16肿瘤HSP70-肽复合物组CTL对B16肿瘤细胞的杀伤率为78．5％,对H22细胞的杀伤率为21．4％,表明CTL对肿瘤细胞的杀伤作用具有特异性。结论：HIFU治疗后坏死肿瘤组织中的HSP70-肽复合物作为肿瘤疫苗,通过活化DC和刺激T淋巴细胞增殖为CTL,发挥特异性抗肿瘤免疫功能。     

RNA干扰下调bcl11b基因表达对Molt-4细胞增殖和凋亡的影响

目的分析下调bcl11b基因表达对人T淋巴细胞白血病细胞株Molt-4细胞增殖和凋亡的影响。方法通过核转技术将bcl11b-siRNA转染Molt-4细胞;在不同时间点分别采用荧光实时定量PCR观察其对bcl11b基因表达的影响;MTT法观察对Molt-4细胞体外增殖的抑制作用;流式细胞术及刘氏染色检测siRNA的诱导凋亡作用。结果转染后24小时开始细胞生存率均显著降低(P<0.01),细胞发生凋亡,bcl11b基因表达下调。结论bcl11b-siRNA可抑制Molt-4细胞中bcl11b基因表达,使肿瘤细胞增殖抑制和发生凋亡。     

癌相关抗原粘蛋白前体诱导人肿瘤引流区淋巴结的细胞毒作用

人肿瘤相关抗原可诱导宿主的细胞免疫反应已被证实。一些肿瘤粘蛋白也证实可诱发T细胞细胞毒作用。本研究是观察从胰腺癌细胞株提取的粘蛋白核芯肽诱导人肿瘤引流区淋巴结细胞的抗肿瘤免疫作用。4例乳腺癌、3例胃癌、3例结肠癌的肿瘤引流区淋巴结手术切除后立即在体外培养于含50μg/ml胰癌核芯肽及50单位IL-2的培养基中,观察其对多种癌细胞的杀伤效应(MMT法)。结果表明体外经胰癌核芯肽刺激后增殖的淋巴结细胞对多种肿瘤细胞有杀伤作用,如结肠癌、胃癌、胰腺癌及白血病细胞K562。本研究结果为以肿瘤粘蛋白核芯肽制备疫苗用于主动特异性免疫治疗或过继免疫治疗打下基础。     

Investigation of inducing effect of specific cytotoxicity of CTLS by antigen peptides from T lymphocytic leukemia cells

The key point in immunotherapy of tumor is the inducement of tumor specific CTL response in vivo, which is based on the specific recognition of TCR to tumor antigen peptides. It has been known that tumor antigen peptides are the products from the degradation of the products of some mutated genes in tumor cells[1]. During the malignant proliferation of tumor cells, mutations occur at a high frequency[2] so to result in the difference between the tumor antigen peptides of a given tumor in diff…     

Upregulation of thioredoxin reductase 1 in human oral squamous cell carcinoma

Lymphoma is not a common focus for viral therapy as many researchers do not consider lymphoma as a suitable target for viral vectors. In the present study, the infection, replication and cytotoxicity of herpes simplex virus (HSV) and adenovirus vectors were screened and evaluated in different lymphoma cell lines. Three recombinant viruses, BAC-HSV-1-eGFP, Adv-eGFP and an NV1020-like oncolytic HSV-1 virus strain named BAC-HSV-1-eGFP-delIRs, inserted with green fluorescent protein (GFP) as a reporter, were applied to evaluate the efficiency of viral infection and replication and cytotoxicity to lymphoma cells. Four types of lymphoma cell lines (SNK-6, Jurkat, Raji and Hut 78) were examined. We found that the HSV-1 vector, BAC-HSV-1-eGFP, was able to infect and replicate in the three lymphoma cell lines (Jurkat, Raji and Hut 78) and inhibit the growth of these cells more efficiently than adenovirus vector Adv-eGFP. The sensitivity of the four types of lymphoma cell lines to the viral vectors was different. The human cutaneous TL cell line Hut 78 was more sensitive to the viral vectors than the other cell lines. However, the human NK/T lymphoma cell line SNK-6 was not infected by any of the viral vectors and did not allow replication of the viruses. In conclusion, lymphoma may be a potential target for HSV-1 vector-mediated viral therapy.     

INDUCEMENT OF ANTITUMOR－IMMUNITY BY DC ACTIVATED BY HSP70－H22 TUMOR ANTIGEN PEPTIDE

Antigen peptides from tumor cells, bound with heat shock protein 70 (Hsp70), can induce specific antitumor immunity in vivo[1]. On the surface of dentritic cells (DC), the most powerful antigen-presenting cells in vivo, there is CD91[2] which is high-affinity receptor of Hsp70. Hsp70 from tumor cells can induce the maturation of DC[3]. After capturing tumor antigen, DC can be used as specific vaccine for immunotherapy of tumor[4]. Through DC-presenting pathway, limited amount of antig…     

Expression of a leukemia-associated antigen (CAMAL) in four myeloid leukemia cell lines

We have previously described the detection and partial characterization of a common myelogenous leukemia-associated antigen (CAMAL), in CGL and ANLL patients. Both polyclonal and monoclonal (CAMAL-1) antibodies have been raised to p70 (CAMAL) and have been shown to react with both p70 and myeloid leukemia cell preparations. p70 (CAMAL) has been shown to be a monomeric protein of Mr 70,000 and pI 7.2 and was also detectable in the myeloid leukemia cell lines HL60, KG1, K562 and U937, but not in the lymphocytic cell lines Molt-4, Hut-78 and CEM by immunoprecipitation from iodinated cell samples. Using [35S] methionine-labeled cell lines and immunoprecipitation, we have demonstrated the constitutive expression of p70 as well as a major component at p58 and a number at lower molecular weights in the myeloid leukemia cell lines HL60, KG1, K562 and U937, but not in the lymphocytic leukemia cell lines Molt-4, Hut-78 and CEM. The implications of these observations are discussed.     

Cell-free entry of human T-cell leukemia virus type 1 to mouse cells.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia and HTLV-1-associated myelopathy / tropical spastic paraparesis. Recently we infected newborn mice by inoculating HTLV-1-producing human cells, and found that T-cells, B-cells and granulocytes were infected in vivo. To understand the mechanism of viral-cell interaction and the pathogenesis of HTLV-1 using the mouse model, it is important to clarify the cellular tropism using a cell-free HTLV-1 transmission system. We employed a highly transmissible cell-free HTLV-1 produced by a feline kidney cell line, c77, and studied the susceptibility of 9 kinds of mouse cell lines, EL4, RLm1, CTLL-2, J774.1, DA-1, Ba / F3, WEHI-3, NIH3T3 and B1, and two kinds of human cell lines, Molt-4 and Hut78. HTLV-1 proviral sequence was found by PCR in all 9 mouse cell lines as well as in 2 human cell lines and viral entry was blocked with sera from an HTLV-1 carrier and an adult T-cell leukemia patient. Unexpectedly, mouse cell lines EL4 and RLm1 and human cell lines Molt-4 and Hut78 showed similar efficiency for viral entry. These results suggest a wide distribution of HTLV-1 receptor in mouse cells.     

Cell-free Entry of Human T-Cell Leukemia Virus Type 1 to Mouse Cells

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Recently we infected newborn mice by inoculating HTLV-1-producing human cells, and found that T-cells, B-cells and granulocytes were infected in vivo. To understand the mechanism of viral-cell interaction and the pathogenesis of HTLV-1 using the mouse model, it is important to clarify the cellular tropism using a cell-free HTLV-1 transmission system. We employed a highly transmissible cell-free HTLV-1 produced by a feline kidney cell line, c77, and studied the susceptibility of 9 kinds of mouse cell lines, EL4, RLml, CTLL-2, J774.1, DA-1, Ba/F3, WEHI-3, NIH3T3 and Bl, and two kinds of human cell lines, Molt-4 and Hut78. HTLV-1 proviral sequence was found by PCR in all 9 mouse cell lines as well as in 2 human cell lines and viral entry was blocked with sera from an HTLV-1 carrier and an adult T-cell leukemia patient. Unexpectedly, mouse cell lines EL4 and RLml and human cell lines Molt-4 and Hut78 showed similar efficiency for viral entry. These results suggest a wide distribution of HTLV-1 receptor in mouse cells.     

Ex vivo purging of leukemia cells using tumor-necrosis-factor-related apoptosis-inducing ligand in hematopoietic stem cell transplantation.

The aim of this study was to evaluate the potential of tumor-necrosis-factor-related apoptosis-inducing ligand TRAIL to eradicate leukemia cell lines, while sparing normal hematopoietic stem cells. Human Jurkat and Molt-4 cell lines were used to optimize the purging process in umbilical cord blood (UCB) mononuclear cells. The Jurkat cell line was TRAIL sensitive and TRAIL-resistant Molt-4 cell line became sensitive after being treated with TRAIL and a low dose of doxorubicin (0.1 micro M), but UCB mononuclear cells remained resistant. DR4 expression was increased when Jurkat cells were treated with TRAIL, and DR5 expression increased after exposing Molt-4 cells to TRAIL plus a low dose of doxorubicin for 24 h. The expression of DR4 and DR5 in UCB mononuclear cells was unchanged after treatment with TRAIL, a low-dose doxorubicin, or TRAIL plus a low dose of doxorubicin. In TRAIL-sensitive Jurkat cells, caspases 8, 9, 3, and 7 were activated by TRAIL treatment and activation of caspases was augmented by TRAIL plus a low dose of doxorubicin than TRAIL or a low dose of doxorubicin alone in Molt-4 cells. Experiments involving mixture of UCB mononuclear cells and Jurkat or Molt-4 cells showed a marked eradication of leukemia cells and the limiting dilution assay demonstrated an eradication rate of more than 4 logs after 24 h incubation with 100 ng/ml of TRAIL in Jurkat cells. In the case of Molt-4 cells, the eradication rate was about 3 logs when TRAIL was used in combination with a low dose of doxorubicin. No significant decrease in the number of granulocyte-macrophage colony-forming unit) (CFU-GM) colonies was detected when UCB mononuclear cells were treated with TRAIL in combination with a low dose of doxorubicin. These results suggest that TRAIL offers the possibility of being used as an ex vivo purging agent for autologous transplantation in hematologic malignancies.