全细胞性肿瘤抗原以不同方式负载树突状细胞诱导肝癌特异性T细胞反应

[目的]研究肝癌3种不同全细胞抗原负载方式（肿瘤细胞裂解物、融合以及肿瘤细胞总RNA）制备DC瘤苗的体外抗肿瘤活性,分析其体外诱导T细胞反应的异同．以期选择更好的DC瘤苗。[方法]分离肝癌患者外周血单核细胞,体外诱导DC;以上述3种抗原负载方式制备DC瘤苗（Lys—DC、Fus—DC、RNA—DC）．刺激肝癌患者淋巴细胞作为效应细胞．肝癌细胞株HepG2为靶细胞,MTT法测定效应细胞对各肿瘤细胞的杀伤作用;分离CD8^＋和CD4^＋ t细胞,瘤苗刺激后,应用IFN-γ ELISA检测试剂盒检测CD8^＋T 细胞IFN-γ分泌．MTT法检测各种瘤苗刺激自体CD4^＋T细胞增殖的能力。[结果]三种瘤苗刺激的淋巴细胞均显示对HepG2高效特异的杀伤活性,但Fus-DC-L、RNA-DC—L对HepG2的杀伤率明显高于Lys—DC—L组：Lys—DC、Fus—DC、RNA—DC刺激的CD8^＋ T细胞组IFN—γ分泌显著高于DC刺激的CD8^＋ T细胞组和单纯CD8^＋ T细胞组;但Fus—DC、RNA—DC刺激组IFN-γ分泌显著高于Lys—DC刺激组：Lys—DC、Fus—DC、RNA—DC组刺激自体CD4^＋ T细胞增殖功能显著高于DC组;但Lys—DC、Fus—DC、RNA—DC刺激自体CD4^＋ T细胞增殖功能无明显差异。[结论]肿瘤总RNA转染的DC以及融合瘤苗能更有效地诱导肿瘤特异性细胞毒性T淋巴细胞反应．是更为有效的DC免疫治疗方式。     

Hep-2细胞总RNA转染树突状细胞诱发抗喉癌特异性免疫效应的研究

目的:研究转染喉鳞状细胞癌总RNA对树突状细胞(DC)免疫功能的影响,观察肿瘤总RNA修饰后的DC在体外诱导高效而特异的抗喉癌免疫效应.方法:采用分离脐血单核细胞体外诱导DC,Trizol法提取喉鳞状细胞癌细胞株Hep-2总RNA后转染入DC,流式细胞仪分析DC表面分子CD40、CD80、CD83、CD86的表达,LDH法评估转染肿瘤总RNA的DC瘤苗的细胞毒性T淋巴细胞反应.结果:转染后的DC表面分子表达CD40(60.6±0.15)%,CD80(60.2±0.21)%,CD83(85.1±0.06)%,和CD86(91.9%±0.09)%,而在未转染的未成熟DC中低表达;转染RNA的DC瘤苗对于Hep-2细胞株有特异性杀伤效应,在E/T为40:1时,杀伤效率达45.6%,而对对照组靶细胞杀伤效率较低.结论: 喉鳞状细胞癌总RNA转染修饰的DC能特异性诱导细胞毒性T淋巴细胞,显著提高DC的抗原提呈功能,在体外能诱导高效而特异的抗喉癌免疫效应.     

肝癌树突状细胞瘤苗诱导抗肿瘤作用的研究

目的：研究负载肝癌抗原的肝癌树突状细胞（dendritic cell,DC）瘤苗诱导的抗肿瘤作用。方法：于体外用rhGM-CSF和rhIL-4从肝癌患者外周血诱导DC,并用肝癌细胞抗原冲击致敏,制成负载肝癌抗原的肝癌DC瘤苗。肝癌DC瘤苗活化自体T淋巴细胞分化为细胞毒性T淋巴细胞（cytotoxic of T-lymphocytes,CTL）,采用流式细胞术检测CTL分型;乳酸脱氢酸（LDH）4 h释放法检测CTL对肝癌细胞的特异性杀伤作用。MTT法检测肝癌DC瘤苗及其活化CTL培养上清对肿瘤细胞的抑制作用;ELISA法检测肝癌DC瘤苗活化的CTL培养上清中IL-12、IFN-γ和TNF-α水平。结果：经肝癌DC瘤苗活化后的T淋巴细胞群中,CD56^＋细胞数量显著减少,CD4^＋T和CD8^＋T细胞数量增加,其中以CD8^＋T细胞增加较明显;细胞毒实验显示,该CTL对自体肝癌细胞具有较强的杀伤作用,而对与致敏DC的肝癌抗原无关的CT26结肠腺癌细胞无明显杀伤作用;单纯肝癌DC瘤苗或其激活的CTL培养上清也表现出较强的抑瘤作用,而且这种抑瘤作用具有广谱性,可抑制多种肿瘤细胞的生长;在CTL培养上清中可检测到IL-12、TNF-α和IFN-γ的含量。结论：肝癌DC瘤苗不仅诱导了对肝癌细胞的特异性CTL杀伤作用,而且可激活CD4^＋T和CD8^＋T细胞分泌IL-12、TNF-α和IFN-γ等细胞因子,以非杀伤方式直接或间接地抑制肿瘤细胞生长,发挥非特异性的抗肿瘤作用。     

递呈乳腺癌细胞MCF-7肿瘤抗原的树突状细胞对T细胞的激活

目的：在体外利用细胞因子的诱导获取树突状细胞（DC）,并观察递呈肿瘤抗原后的成熟DC对T细胞的激活作用。方法：健康人外周血单个核细胞（PBMC）在体外用细胞因子诱导获取DC,并经乳腺癌细胞MCF-7肿瘤细胞裂解物体外冲击,再以1：5的比例将致敏DC与T细胞共同孵育5d并共同作为效应细胞,通过FACS分析T细胞激活前后的表型变化以及MTT试验观察体外特异性肿瘤杀伤效果。结果：DC在细胞因子的诱导下7d后,形态学表现为伸出许多伪足样突起,在摄取抗原后可见内吞样小泡。FACS检测呈现成熟DC的标志,CD40、CD83、CD80、CD86和HL-DR等高表达。另外,未经成熟DC激活的T淋巴细胞以辅助性T细胞（Th）为主,CD4^＋ 52．1％,CD8^＋ 仅22．1％;而经成熟DC激活的T淋巴细胞以杀伤性T细胞（Tc）为主,CD4^＋ 32．6％,CD8^＋ 64．2％。同时,MTT试验证实经递呈MCF-7肿瘤抗原的DC激活了细胞毒性T淋巴细胞（CTL）,并对MCF-7具有特异性肿瘤杀伤作用。结论：体外递呈肿瘤抗原MCF-7的成熟DC对T细胞具有激活作用,并产生肿瘤特异性CTL。     

HSP70-Id复合物修饰的树突状细胞体外诱导特异性抗肿瘤作用

目的观察人慢性B淋巴细胞性白血病（B-CLL）细胞的独特型抗原Id-ScFv与热休克蛋白70（HSP70）形成复合物修饰的树突状细胞（DC）体外诱导特异性抗肿瘤作用,并初步探讨其机制。方法将HSP70与Id-ScFv体外结合形成复合物HSP70-Id,修饰自人外周血单核细胞获取的DC。倒置相差显微镜观察DC的形态特征;流式细胞仪检测修饰前后DC的表型变化,酶联免疫吸咐试验（ELISA）检测DC分泌的白细胞介素12（IL-12）和肿瘤坏死因子-α（TNF-α）,四甲基偶氮唑蓝（MTT）法检测修饰的DC对自身淋巴细胞的激活和增殖作用,流式细胞仪检测激活的自身淋巴细胞T细胞亚群的变化,台盼蓝染色法检测其对Daudi、K562和HepG2等细胞的杀伤作用。结果DC体外诱导培养成功,HSP70-Id复合物可使DC成熟,镜下可见典型的DC形态,其CD1a表达率为20％-30％,CD83表达率〉72％,CD86和HLA-DR表达显著增加（P〈0．05）,上清中IL-12、TNF-α亦显著高于DC对照组（P〈0．01）。HSP70-Id复合物修饰的DC激活自身淋巴细胞,对Daudi细胞的杀伤率为71．24％,而对K562细胞杀伤作用较弱,对HepG2细胞无明显作用。其淋巴细胞亚群中,CD4^＋T细胞、CD8^＋T细胞的比例均显著增加,分别为56．51％和70．21％,CD4^＋T细胞／CD8^＋T细胞比值由空白对照组的1．49倒置为0．81。结论HSP70-Id复合物修饰的DC生物学活性增强,经其刺激后,传代培养的淋巴细胞可产生高效而特异性的抗肿瘤免疫效应,可能是CD4^＋T细胞、CD8^＋T细胞及DC协同作用的结果。     

CpG ODN诱导树突状细胞抗肿瘤作用的研究进展

 CpG ODN是含有CpG基序的脱氧寡核苷酸,它具有强大的免疫调节作用,能够激活自然杀伤（NK）细胞、单核／巨噬细胞、树突状细胞（DC）、B细胞和T细胞等多种免疫细胞,诱导并增强非特异性及特异性免疫应答;同时还可以诱导产生Th1型免疫反应,下调Th2型反应,调控免疫应答类型。DC是目前发现的功能最强的专职抗原提呈细胞,在抗原加工提呈、抗原识别及T细胞激活中发挥重要作用,对多种肿瘤细胞具有杀伤作用。近年来,以DC为基础的肿瘤免疫治疗日益受到人们的重视。现就近年CpG ODN与DC免疫治疗肿瘤的研究进展作一综述。     

bcr／abl基因修饰树突细胞疫苗诱导CTLs杀伤K562细胞体外实验研究

背景与目的：T细胞介导的特异性免疫效应在慢性粒细胞白血病的治疗中发挥着重要作用,而以树突细胞（dendriticcell,DC）为中心的免疫治疗是目前肿瘤生物免疫学治疗的热点之一。本研究以复制缺陷型重组腺病毒为载体,介导慢性粒细胞白血病bcr／abl基因片段转导DC制备疫苗,观察bcr／abl基因修饰DC疫苗诱导产生的特异性细胞毒性T淋巴细胞（cytotoxic T lymphocytes,CTLs）在体外对白血病K562细胞的杀伤效应。方法：应用RT—PCR法扩增慢性粒细胞白血病bcr／abl基因片段．构建复制缺陷型重组腺病毒质粒。并包装产生重组腺病毒。体外诱导培养外周血单个核细胞来源DC,观察DC分别经重组腺病毒转染及多肽负载后,诱导产生特异性的CTLs在体外对白血病K562细胞的杀伤效应。结果：成功构建了携带bcr／abl基因片段的复制缺陷型重组腺病毒表达载体,包装产生的重组腺病毒滴度高达2．0×10^10pfu／mL。体外转染DC效率达到50％～60％,成功制备了bcr／abl特异性DC疫苗。体外实验中,在40：1和20：1效靶比下,bcr／abl基因修饰DC疫苗对K562细胞的杀伤效应分别为（47．6±4．7）％和（47．5±1．6）％,多肽负载DC为（25．8±4．4）％和（24．6±6．3）％,空白DC为（5．7±1．3）％和（4．5±1．6）％,基因修饰DC疫苗诱导的杀伤效应明显高于多肽负载及空白组（P〈0．05）。结论：以重组腺病毒为载体介导bcr／abl基因片段转导DC制备的基因修饰DC疫苗,具有显著的诱导CTLs杀伤白血病K562细胞的作用。     

DC和NK细胞诱导的抗肿瘤CTL反应

细胞毒性T淋巴细胞（CTL）介导的细胞毒效应能够高效、特异性杀伤肿瘤细胞而不损伤周围组织。树突细胞（DC）是已知体内抗原提呈功能最强的抗原提呈细胞,能摄取各种抗原,体内外能激发T细胞增殖,诱导特异性CTL生成。自然杀伤（NK）细胞在由DC引起的抗肿瘤免疫中发挥重要作用。近年来NK-DC细胞的相互作用在CTL反应中的作用引起关注。现综述DC、NK细胞在诱导抗肿瘤CTL反应中作用的研究进展。     

抗原负载的树突状细胞介导的抗慢性粒细胞白血病作用

目的：研究慢性粒细胞白血病（CML）细胞冻融抗原(CLA)负载的树突状细胞（DC）对特异性抗白血病T细胞的作用。方法：将健康人外周血单个核细胞来源的DC在体外用CLA负载,再与CML患者的经细胞因子诱导的杀伤细胞（CIK）共同培养,应用乳酸氢酶释放法观察其对自身CML细胞杀伤活性,与未负载的DC与CIK共培养组、CIK组分别进行比较。结果：DC经抗原负载后介导的特异性抗白血病T细胞对CML细胞杀伤活性明显增强。结论：用CLA负载可进一步提高DC介导的特异性抗白血病T细胞对CML细胞的杀伤活性。     

肺癌可溶性抗原联合超抗原诱导的DC疫苗对肺癌细胞杀伤作用的研究

背景与目的 通过经肺癌肿瘤可溶性抗原(TSA)和超抗原金黄色葡萄球菌肠毒素A(SEA)联合修饰致敏树突状细胞(DC)体外诱导对肺癌细胞杀伤作用的研究,为以DC为基础的肺癌免疫瘤苗的临床应用提供一定的实验依据.方法 3M KCI法提取人肺癌可溶性抗原;从人外周血单个核细胞(PBMC)中诱导扩增DC并鉴定;肺癌TSA和不同质量浓度的SEA联合修饰致敏DC;以联合抗原修饰后的DC、单纯肺癌抗原致敏的DC和未经抗原修饰的DC分别与同种异体T淋巴细胞共同孵育,MTT法测定混合淋巴细胞反应中DC的免疫刺激活性,诱导产生具有识别肺癌抗原的特异性CTL(作为效应细胞分别称为TSA-SEA-DCL、TSA-DCL、DCL);用流式细胞仪FCS及免疫染色法分析鉴定DC和效应细胞表型;M1T法检测各效应细胞对靶细胞体外杀伤效应.结果 诱导出表达CD1a,CD80,HLA-DR分子的DC;经肺癌TSA和SEA联合修饰致敏后,上述分子表达上调;联合修饰后的DC具有较强的免疫刺激活性,DC/T比例1:10可能为最适比例;TSA-SEA-DCL中CD3+CD8+细胞的比例大幅度增加;TSA-SEA-DCL对靶细胞GLC-82的杀伤率明显高于TSA-DCL及DCL,亦明显高于对肺癌CALU-6和人红白血病K562细胞的杀伤率.结论 经肺癌TsA和sE^联合修饰致敏的DC可诱导同种异体T淋巴细胞活化增殖产生CD8+表达增加的CTL;联合抗原诱导的DC疫苗对肺癌细胞有高效特异性的杀伤作用,肺癌TSA和超抗原SEA联合修饰的DC的活性明显强于单用肺癌TSA修饰.     

Lymphokine-activated killer (LAK) cells discriminate between Epstein-Barr virus (EBV)-positive Burkitt's lymphoma cells

We have generated in vitro lymphokine-activated killer (LAK) cells from healthy donors by stimulating their mononuclear leukocytes with recombinant interleukin-2 (rIL-2) (100 U/ml). After 6 days in culture, the lytic properties of the LAK cells were analyzed in the 51Cr-release assay by utilizing a target panel of 6 paired lines consisting of an Epstein-Barr virus (EBV)-positive Burkitt's lymphoma (BL) cell line and an EBV-transformed lymphoblastoid cell line (LCL) from the same donor, the Raji BL line and the natural killer (NK) cell-sensitive K562 line. The patterns of lysis showed that the LAK cells discriminated between two categories of BL cell lines. Group I/II BL tumor cells which expressed the common acute lymphoblastic leukemia antigen (CALLA), the BL-associated glycolipid antigen (BLA) and phenotypically resembled biopsy cells were strongly lysed whereas group III BL cells which had assumed an LCL-like phenotype during culture and lacked the CALLA and BLA surface markers were only poorly lysed. The LCL targets were generally resistant to lysis but the K562 cell line was particularly sensitive. The outcome of cell depletion and monoclonal antibody (MAb) studies indicated that the LAK cell populations were phenotypically and functionally heterogeneous and consisted of at least 2 subpopulations of effector cells; a tumor-specific component and an NK-cell-mediated component.     

VM26影响人肺腺癌细胞放射效应的机制探讨

目的：体外实验显示，ＶＭＤ６能提高人肺腺癌（ＳＰＣ）细胞放射效应。本文探讨其可能的作用机制。材料与方法：通过分段放射后克隆形成实验来研究ＶＭ２６对ＳＰＣ细胞放射损伤的修复；利用流式细胞技术（ＦＣＭ）观察不同作用时间及浓度下ＶＭ２６对ＳＰＣ细胞周期的影响。细胞存活曲线用单击多靶模式拟合。结果：ＶＭ２６（０．０６２５Ｍ）作用于细胞６小时，能使２Ｇｙ照射后，间隔６小时再组第二次剂量照射，得到的细胞存活曲线出现的“肩区”再现完全消失。当浓度升高到０．１２５Ｍ，放射引起的细胞杀灭明显增加。对ＳＰＣ细胞周期的影响，０．１２５Ｍ的ＶＭ２５作用２小时后，Ｇｏ／Ｇ１，期细胞比例升高，其阻滞率为４．２５％／小时。伴Ｇ２＋Ｍ期比例降低，ｓ期在作用１小时升高，然后恢复。在０．１２５－２．５Ｍ浓度范围内，ＶＭ２６作用于细胞１小时，细胞周期变化无明显差异。结论：ＶＭ２６能显著抑制ＳＰＣ细胞亚致死性损伤修复而对其细胞周期的影响未见５期和Ｇ２＋Ｍ期阻滞。     

Endothelial cells (EC) and endothelial precursor cells (EPC) kinetics in hematological patients undergoing chemotherapy or autologous stem cell transplantation (ASCT)

Our objective was to study the kinetics of circulating endothelial cells (EC) and endothelial precursor cells (EPC) in hematological patients during chemotherapy and autologous stem cell transplantion (ASCT). Eighteen newly diagnosed patients and 17 patients undergoing ASCT were studied and compared to healthy controls. ECs were evaluated as CD146+CD31+Lin- cells, while EPCs were evaluated as CD34+CD133+Lin-, or CD34+VEGFR2+Lin- cells, or CFU-En colony forming units. Numbers of these cells were evaluated before and after treatment, and, in patients treated with ASCT, during mobilization of hematopoietic progenitors. Both newly diagnosed patients and patients before ASCT had significantly higher number of CD146+CD31+Lin- cells and significantly lower number of CFU-En colonies than healthy controls. These parameters did not return to normal for at least 3 months after chemotherapy or ASCT. Numbers of CFU-En did not correlate either with numbers of CD34+CD133+Lin- cells or with numbers of CD34+VEGFR2+Lin- cells but they did correlate with numbers of CD4+ lymphocytes and NK cells. In conclusion, we have found that hematological patients have higher number of EC and lower numbers of CFU-En than healthy controls and that these parameters do not return to normal after short-term follow-up. Furthermore, our observations support emerging data that CFU-En represent cell population different from flowcytometrically defined EC and endothelial precursors and that their development requires cooperation of monocytes and CD4+ lymphocytes. However, cells forming CFU-En express endothelial surface markers and can contribute to proper endothelial function by NO production.     

Foetal haemoglobin-blood cells (F-cells) as a feature of embryonic tumours (blastomas)

Tumour markers are important in the diagnosis and monitoring of many tumours. This study tested the hypothesis that an oncofoetal protein, foetal haemoglobin (HbF) is a potential tumour marker in embryonic tumours, useful for management. An immunohistochemical investigation of HbF blood cell (Fc) distribution was carried out in tumours and in bone marrow samples from 83 children and 13 adults with various embryonic tumours (blastomas), and in bone marrow samples of 24 leukaemia patients. In the three, main blastoma types, nephroblastoma (Wilms' tumour), neuroblastoma and retinoblastoma, where all the patients, except two, were children, around 80% of the tumour samples had Fc within proliferating blood vessels and spaces between tumour cells. In parallel, clusters of Fc, mostly F-erythroblasts (Feb), were distributed in the bone marrow of some of those patients and in the bone marrow of 79% of the leukaemia patients. Foetal haemoglobin, as well as being a potential prognostic cancer marker, is a potential indicator of DNA hypomethylation implicated in the development of these tumours, as well as in others previously noted for the presence of HbF.     

Circulating cerebriform lymphoid cells (Sezary-type cells) in a B-cell malignant lymphoma

Circulating cerebriform lymphoid cells (Sezary cells) are considered to be highly predictive of cutaneous T-cell Lymphoma (CTCL). A leukemic peripheral blood (leukocyte count 24.5 x 10(9)/l) composed predominantly of cerebriform cells was found in a 75-year-old man presenting with weight loss and generalized lymphadenopathy but without skin lesions. Cell suspensions studies and immunohistochemistry of peripheral blood revealed that the cerebriform cells were B-cells (IgM+ Kappa+, HLA DR+, Leu 1+, CALLA-, B1+, and OKT 10+). A variety of T-cell markers (other than Leu1) was negative. Computer-assisted morphometry confirmed a nuclear profile typical of CTCL (mean nuclear contour index, 7.47). A lymph node that underwent subsequent biopsy revealed a follicular malignant lymphoma of small to intermediate cells with similar morphologic and immunologic characteristics to the circulating cerebriform cells. The findings of a leukemic presentation of a cerebriform B-cell lymphoma extends the recent observation of nodal B-cell lymphomas composed of cerebriform cells and indicates that circulating cerebriform cells should not be considered to be exclusively of T-cell origin.     

Tumor cells suppress cytokine-induced nitric-oxide (no) production in cerebral endothelial cells

Nitric oxide (NO) produced by endothelial cells (EC) has been shown to exert cytotoxic activity on tumor cells. In order to analyze events involved in brain metastasis, the modulation of NO production in rat-brain-derived EC was investigated. NO release was increased by tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β, lipopolysaccharide or forskolin in EC2I9 cells, a rat-brain-microvessel-derived EC line. Dexamethasone decreased NO release by cytokine-activated EC219 cells. Tumor cells (DHD/K12/PROb, a rat coloncarcinoma cell line) were highly adherent to EC2I9 cells, and adhesion was not modified by TNF-α plus IFN-γ, or by dexamethasone. Addition of tumor cells or tumor-cell-conditioned medium significantly inhibited NO release induced by any of the stimuli examined, but only if added during the initial phase of endothelial-cell activation. Tumor-derived suppression of NO release was also observed in primary cultures of cerebral EC. NO synthase (NOS) activity in cytosol extracts of the cerebral EC line was Ca²⁺-independent and required both NADPH and tetrahydrobiopterin. NOS activity was increased by TNF-α and IFN-γ, and significantly reduced by tumor-cell-conditioned medium. These results suggest that rat colon-carcinoma cells may have developed a protective mechanism involving the release of (a) soluble factor(s) which inhibit(s) NO production by cerebral EC.     

Intracellular accumulation and cytotoxic effect of (8-thiotheophyllinate) (triphenylphosphine) gold(I) in Friend leukemia cells

Following continuous exposure to tTAuP in medium containing 10% fetal calf serum (FCS), cells resistant to doxorubicin (DOX-RFLC) were 3 fold more resistant to tTAuP than its sensitive counterpart (FLC). Moreover, FLC were 100 fold more sensitive to tTAuP when the cells were grown in the absence of FCS but in the presence of synthetic medium (BMS). When the cytotoxic effect was measured after short-term exposure (60 min) followed by 72 hr incubation in drug-free medium, unexpectedly, DOX-RFLC were 8 fold more sensitive [ID50 = 1.5 microM] than FLC [ID50 = 12 microM] to tTAuP. When FLC were exposed 60 min at different temperatures (4, 25 or 37 degrees C) to tTAuP prior to 72 hr incubation in drug free medium, the ID50 was achieved at 20, 13 and 3 microM respectively). In contrast, when DOX-RFLC were treated in similar conditions, the cytotoxic activity of tTAuP did not vary following exposure at 4, 25 or 37 degrees C. Although the mechanism of action of gold compounds is still unknown we have assumed that tTAuP cytotoxicity is related to the ease with which it is accumulated. This assumption was supported by the analysis of tTAuP incorporation by SXRF. The results reported here show that tTAuP accumulates rapidly in the cell and is distributed in the cytoplasmic and the nuclear fractions. It is suggested that accumulation is mediated by passive diffusion. However, the detection of gold binding to DNA in complexes resistant to solvent treatments suggests that interaction with macromolecules can be mediated by the formation of covalently bound complexes.