半抗原DNP修饰自体肿瘤疫苗治疗恶性黑素瘤

目的:探讨半抗原二硝基氟苯(dinitrophenyl,DNP)修饰自体肿瘤疫苗治疗恶性黑色素瘤的疗效。方法:32例Ⅲ期恶性黑素瘤(恶黑)患者,肿瘤或淋巴结切除后,分别采用半抗原DNP修饰的自体瘤苗和未修饰自体瘤苗联合生物化疗进行治疗,观察两组患者淋巴细胞亚群变化、迟发型超敏反应(delayed-type hypersensitivity,DTH)和临床随访。结果:①两组比较,半抗原修饰瘤苗组较未修饰疫苗组CD8~ -IFN-PE明显升高(P<0.05);半抗原修饰瘤疫苗组治疗后CD8~ -IFN-PE细胞比例较治疗前明显升高(P<0.05),然而,半抗原未修饰瘤苗组治疗前后变化不大(P>0.05)。②半抗原修饰瘤苗组患者治疗后DTH明显增强,硬结由(5.4±1.2)mm增大到(23.5±4.2)mm(P<0.05),半抗原未修饰瘤苗组硬结由(6.3±1.4) mm增大到(11.2±3.2)mm(P<0.05),然而,两组DTH达到阳性结果(≥5mm)的百分比分别为95%和36%(P<0.01)。③随访2年,半抗原修饰瘤苗组13例患者生存时间超过24个月,其中仅2例DTH阴性;半抗原未修饰瘤苗组8例患者生存时间超过24个月,6例DTH阳性。结论:半抗原DNP修饰的自体肿瘤疫苗可增强恶性黑素瘤患者特异性细胞介导的免疫反应,从而延长患者生存时间。     

树突状细胞体外高效诱导白血病特异性细胞毒性T淋巴细胞生成

[目的]研究体外诱导产生的细胞毒性T淋巴细胞(CTL)及其抗白血病反应.[方法]应用mGM-CSF及mIL-4细胞因子从小鼠骨髓细胞扩增出成熟树突状细胞(DC),使其负载冻融法制备的白血病细胞相关抗原(TAA),通过观察DC诱导的白血病特异性CTL的免疫表型,MTT分析其对于L7212细胞的抑制率,利用ELISA评价IL-2和IL-4水平.[结果]骨髓单个核细胞经mGM-CSF、mIL-4的联合作用7天后光镜及扫描电镜下观察到大量成熟DC生成.经负载TAA的DC活化后T细胞中CD3 、CD8 、CD25 细胞明显增多.FCM显示CD3 、CD8 、CD25 T细胞显著增多,CD8 细胞多于CD4 细胞.活化后T细胞对L7212细胞有特异性杀伤活性,在效靶比为50:1培养72 h后杀伤率达90.1%±2.7%.DC与T细胞共培养上清中IL-2的分泌水平为4.656±0.62pg/ml,明显高于普通T细胞培养组的1.436±0.11pg/ml(P=0.011),IL-4水平则无明显变化(P＞0.05).[结论] mGM-CSF及mIL-4配伍诱导生成的DCs经L7212冻融抗原负载后可在体外高效诱导白血病特异性CTL生成.     

癌胚抗原重组痘苗病毒转染树突状细胞诱导CEA特异性T细胞免疫

 目的　研究人癌胚抗原重组痘苗病毒 (rV CEA)转染树突状细胞 (DC)在体外诱导CEA特异性的T细胞免疫。方法　将rV CEA转染外周血单个核细胞来源的DC后用于激发自体的T细胞 ,通过对T细胞的增殖及杀伤功能的检测 ,与野生型痘苗病毒 (V 76 1)转染的DC激发的T细胞进行比较。结果　经rV CEA转染的DC激活的T细胞增殖力强 ,对CEA分泌性肿瘤细胞具特异性杀伤作用。结论　rV CEA转染的DC可以诱导CEA特异性T细胞活性。     

脐血来源树突状细胞体外诱导抗卵巢癌免疫特异性

[目的]研究脐血来源树突状细胞(DC)体外诱导特异性抗卵巢癌细胞的免疫效应.[方法]①从脐血中分离单个核细胞(MNCs)后,获得单核细胞(Mo).粒单集落刺激因子(GM-CSF)和白介素4(IL-4)诱导分化,培养7天后应用流式细胞仪进行细胞表型分析.②诱导单核细胞分化的第3天加入人卵巢癌细胞株3AO的冻融抗原,共培养4天后获得负载肿瘤抗原的成熟DC;将致敏DC与从脐血中分离的同种异体T淋巴细胞共培养3天,获得细胞毒T淋巴细胞(CTL);四甲基偶氮唑蓝(MTT)法检测CTL及上清对人卵巢癌细胞株3AO、人胚肾细胞株293T(对照细胞)、人肝癌细胞株HCCC-9810的细胞毒作用.[结果]①脐血来源单核细胞(Mo)在GM-CSF和IL-4作用下,7天后可分化生成成熟的DC,高表达DC特异性抗原CDla、CD80(B7-1)、CD86(B7-2)、HLA-DR、CD83.②DC可负载并递呈肿瘤抗原,激活同种异体T淋巴细胞,诱导肿瘤特异性CTL产生.不同浓度CTL及上清对卵巢癌细胞3AO有特异性杀伤、抑制作用(P＜0.05).[结论]脐血中单核细胞可体外分化扩增为成熟的功能性DC,并诱导出特异性杀伤卵巢癌细胞的免疫效应.     

半抗原DNP修饰自体肿瘤疫苗治疗晚期恶性黑色素瘤的临床研究

目的 探讨半抗原二硝基氟苯（dinitrophenyl,DNP）修饰自体肿瘤疫苗在晚期恶性黑色素瘤治疗中的作用。方法 84例Ⅲ期或Ⅳ期可切除恶性黑色素瘤患者随机分为半抗原DNP修饰瘤苗组和半抗原DNP未修饰瘤苗组,每组42例,分别采用半抗原DNP修饰的自体肿瘤疫苗和半抗原DNP未修饰的自体瘤苗联合化疗进行治疗,采用流式细胞技术检测两组患者外周血CD4＋CD25＋调节性T细胞（regulatory T cell,Treg）数量及淋巴细胞亚群的变化,观察迟发型超敏反应（delayed type hypersensitivity,DTH）及随访生存情况。结果 治疗后半抗原DNP修饰瘤苗组患者CD4＋-IFN-γPE、CD8＋-IFN-γPE淋巴细胞亚群较治疗前及半抗原DNP未修饰瘤苗组明显升高（P均〈0.05）,而CD4＋CD25＋Treg数量减少（P〈0.05）,半抗原DNP未修饰瘤苗组治疗前后无明显变化（P〉0.05）;半抗原DNP修饰瘤苗组患者较半抗原DNP未修饰瘤苗组DTH明显增强,硬结明显增大,两组DTH达到阳性结果（≥5 mm）的百分比分别为94.6%和45.0%（P〈0.05）。半抗原DNP修饰瘤苗组患者1年、2年和3年生存率分别为95.0%、73.0%和65.5%,总生存率（overall survival,OS）为79.3%,无疾病生存率（disease free survival,DFS）为81.1%;半抗原DNP未修饰瘤苗组患者1年、2年和3年生存率分别为90.1%、59.0%和43.5%,OS为64.2%,DFS为74.0%,两组患者生存时间差异有统计学意义（P〈0.05）。结论 半抗原DNP修饰的自体瘤苗可增强恶性黑色素瘤患者特异性细胞介导的免疫反应,抑制机体免疫耐受,从而延长患者生存时间。     

CB6F1小鼠树突状细胞诱导细胞毒性T淋巴细胞的杀伤作用

[目的]探讨CB6F1小鼠脾树突状细胞(DC)的培养及其诱导针对小鼠路易斯肺癌(LLC)的细胞毒性T淋巴细胞(CTL)对肿瘤的杀伤效应.[方法]应用CB6F1小鼠脾细胞在GM-CSF、IL-4等细胞因子作用下培养出DC,反复冻融法制备LLC抗原致敏DC,与淋巴细胞及IL-2混合培养诱导出肿瘤特异性CTL,利用乳酸脱氢酶法检测CTL的杀伤活性.[结果]用GM-CSF、IL4联合培养小鼠脾细胞第4d,可见细胞形态发生改变,培养第8d,可见典型的刺突样DC,通过流式细胞术检测了DC表型高表达CD80占76.5％,CD86占60.0％,MHCⅡ占67.4％,CD11C占80.6％.[结论]应用GM-CSF、IL-4、LPS等细胞因子培养CB6F1小鼠脾细胞经过肿瘤抗原冲击,可以培养出成熟DC,并且DC可以诱导出具有杀伤活性的肿瘤特异性CTL.     

树突状细胞在食管癌T细胞抗肿瘤免疫中的作用

目的：研究食管癌组织中树突状细胞（ＤＣｓ）在肿瘤浸润性Ｔ淋巴细胞激活中的作用,方法：用免疫组化和ＲＴ－ＰＣＲ的方法,检测４６例食管癌手术标本中ＤＣｓ（ＣＤ１ａ）、Ｔ细胞亚群（ＣＤ３、ＣＤ４、Ｃ人刺激因子Ｂ７。结果：癌组织中的ＤＣｓ与ＣＤ３（＋）、ＣＤ４（＋）Ｔ细胞有相关性,与ＣＤ８（＋）、ＣＤ２５（＋）Ｔ细胞无明显关系,且Ｂ７ｍＲＮＡ表达均为阴性,结论：食管癌中ＤＣｓ不一定能有效地激活Ｔ细胞,其中Ｂ７基因表达受抑制,可能是不能有效激活Ｔ淋巴细胞产生免疫耐受的重要原因之一。     

HBsAg基因修饰的树突状细胞体外诱导抗 HepG2.2.15特异性细胞毒作用

背景与目的:目前缺少一种针对乙型肝炎病毒感染相关肝癌的有效免疫治疗手段.以树突状细胞( dendritic cell, DC)为基础的肿瘤特异性免疫治疗方法,为免疫治疗乙型肝炎病毒感染相关的肝癌提供了新方法 .本实验通过体外负载乙型肝炎表面抗原基因( HBsAg)的重组质粒转染 DC,制备 HBsAg-DC瘤苗,评价 HBsAg-DC瘤苗体外诱导抗 HepG2.2.15的细胞毒性 T淋巴细胞反应.方法:将已构建含 HBsAg基因的重组质粒 pCR3.1-S转染培养第 5天的 DC; Western blot和免疫荧光法鉴定转染基因表达;以 MTT法测定 DC诱导的抗 HepG2.2.15特异性细胞毒作用.结果:细胞表型鉴定结果显示诱导 5天的 DC CD1a、 CD11c、 CD86、 CD80和 HLA-DR表达量分别为 55.0%、 98.6%、 86.1%、 66.1% 和 88.9%;采用免疫荧光和 Western blot法研究表明 HBsAg基因能在转染的 DC中表达; MTT法检测特异性细胞毒作用结果显示:不同效靶比, pCR3.1-S转染 DC组均显示对 HepG2.2.15肝癌细胞高效特异的杀伤活性,杀伤率分别为:( 52.3± 2.8)%( E∶ T为 5∶ 1)、( 64.6± 2.4)%( 10∶ 1)、( 78.8± 2.6)%( 20∶ 1)、( 82.1± 2.4)%( 40∶ 1),显著高于 pCR3.1-DC 组和 DC组 (P< 0.05, n=4).结论:重组质粒转染的 DC能够有效表达 HBsAg;并在体外诱导出特异性 CTL反应.     

NY-ESO-1致敏树突状细胞诱导的CTL对肝癌细胞株的特异性杀伤作用

目的:探讨肿瘤睾丸抗原NY-ESO-1(New York-esophageal-1)致敏树突状细胞体外诱导特异性CTL对肝癌细胞株的杀伤作用.方法:重组质粒pGEX-ESO1经原核诱导表达并纯化GST-ESO1融合蛋白肽.重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)和白细胞介素4(rhIL-4)诱导培养人外周血来源的树突状细胞(dendritic cells, DCs),经GST-ESO1融合蛋白肽致敏后诱导特异性CTL增殖.以此CTL为效应细胞,分别以NY-ESO-1阳性表达的肝癌细胞株HepG2和不表达NY-ESO-1的肝癌细胞株H2P为靶细胞,MTT法检测CTL对肝癌细胞株的杀伤作用.结果:重组质粒pGEX-ESO1经IPTG诱导,在大肠杆菌中表达相对分子质量约36 000的GST-ESO1融合蛋白肽,纯化后的质量浓度为50 μg/ml;经rhGM-CSF和rhIL-4联合诱导成功培养人外周血DCs,其表型分子HLA-DR为91.4%、CD86为70.5%、CD83为71.2%、CD80为55.3%.NY-ESO-1致敏的DCs能明显诱导CTL增殖,此CTL对肝癌细胞株HepG2的杀伤率显著高于GST刺激组、未致敏DC组和无DC刺激组(均P<0.05),效靶比为50 ∶1时杀伤效应达到最高峰[(53.23±3.78)%,P<0.01];相同条件下CTL对H2P细胞无特异性杀伤作用.结论: NY-ESO-1抗原致敏的DCs在体外可诱导同种CTL产生和增殖,后者对NY-ESO-1阳性肝癌细胞株具有特异性杀伤效应,该方法为肝癌免疫治疗提供了一条新思路.     

胶质瘤细胞来源的exosome负载树突状细胞诱导肿瘤特异性杀伤的研究

背景与目的：对于各种恶性肿瘤细胞抗原致敏的树突状细胞疫苗研究目前已成为全球抗肿瘤治疗的热门话题。本研究旨在观察胶质瘤细胞来源外来体致敏的树突状细胞,诱导细胞毒性T淋巴细胞（CTL）杀伤胶质瘤细胞的活性。方法：采用差速离心法分离胶质瘤细胞分泌的外来体,制备胶质瘤冻融抗原;从胶质瘤患者外周血中获取单状核细胞和T淋巴细胞,培养并获取树突状细胞;将胶质瘤来源的外来体、胶质瘤冻融抗原分别冲击树突状细胞并与T淋巴细胞混合培养．通过MTT法检测两种方法制备的效应细胞对胶质瘤细胞的杀伤效应。结果：当效靶比分别为10：1、25：1、50：1时,冻融抗原-DC＋T细胞对恶性胶质瘤细胞杀伤率为（17．50±1．13）％、（21．18±1．36）%、（30．20±1．46）％。外来体-DC＋T细胞组对恶性胶质瘤细胞杀伤率分别是（32．25±1．36）％、I（43．04±1．22）％、（70．42±1．40）％,二者杀伤力的差异具有统计学意义（P〈0．05）。结论：胶质瘤细胞来源的外来体致敏树突状细胞,其特异性杀伤胶质瘤细胞的能力明显优于胶质瘤冷冻抗原。     

Whole-body hyperthermia maintains the secondary immune response of specific antitumour immune T cells

The effect of hyperthermia on the spleen cells of Meth A-hyperimmunized BALB/c mice (Meth A-Im-SPL) was examined. Three kinds of heating were employed: (a) a cell suspension of Meth A-Im-SPL was directly heated for 1 h at 41 degrees C; (b) the whole body of Meth A-hyperimmunized mice was heated in the same manner--the antitumour activity of Meth A-Im-SPL was examined by Winn assay after heating; (c) the whole body of BALB/c mice intradermally inoculated with a mixture of Meth A-Im-SPL and Meth A cells (Winn assay) was heated in the same manner. The results showed that the antitumour activity of Meth A-Im-SPL was not affected by heating in vivo (Experiments B and C), although it was affected in vitro (Experiment A). Furthermore, slight augmentation of the antitumour activity of Meth A-Im-SPL was observed on heating in vivo. This shows the possibility of combination therapy involving adoptive transfer and whole-body hyperthermia.     

Whole-body hyperthermia maintains the secondary immune response of specific antitumour immune T cells

The effect of hyperthermia on the spleen cells of Meth A-hyperimmunized BALB/c mice (Meth A-Im-SPL) was examined. Three kinds of heating were employed: (a) a cell suspension of Meth A-Im-SPL was directly heated for 1 h at 41°C; (b) the whole body of Meth A-hyperimmunized mice was heated in the same manner—the antitumour activity of Meth A-Im-SPL was examined by Winn assay after heating; (c) the whole body of BALB/c mice intradermally inoculated with a mixture of Meth A-Im-SPL and Meth A cells (Winn assay) was heated in the same manner. The results showed that the antitumour activity of Meth A-Im-SPL was not affected by heating in vivo (Experiments B and C), although it was affected in vitro (Experiment A). Furthermore, slight augmentation of the antitumour activity of Meth A-Im-SPL was observed on heating in vivo. This shows the possibility of combination therapy involving adoptive transfer and whole-body hyperthermia.     

Humoral immune response against melanoma antigens induced by vaccination with cytokine gene-modified autologous tumor cells

Although the existence of a humoral response against tumor-associated antigens is well appreciated, a systematic analysis of its possible induction by the tumor remains missing. We compared the specific IgG response of Stage IV melanoma patients during vaccination. Patients had been treated within 2 clinical trials with autologous tumor cells gene-modified for IL-7 or IL-12. A panel of 27 tumor-associated antigens (HD-MM-01 to HD-MM-27) was isolated by a SEREX screening of a testis cDNA library using a pool of 5 sera from patients after vaccination. All antigens were retested with individual sera of 12 patients both pre- and post-vaccination. A serological response was induced during vaccination against 18 antigens. Remarkably, induction was detected only in patients included in the screening pool. The low overlap between sero-reactivity of the 12 patients suggested a very individualized immunological reaction. Two of 5 sera included in the screening pool exhibited a high frequency of induced humoral responses. The same patients had been shown to have a high Karnovsky index and had generated lytic cytotoxic T cells against the tumor. Besides 2 known cancer-germline genes (SCP-1 and PLU-1), the other isolated antigens were expressed in a non-tumor-specific fashion as analyzed by virtual Northern blot or RT-PCR. The properties of homologues to several of the identified tumor-antigens, especially PLU-1, SCP-1, DNEL2, CLOCK, and PIASx-alpha, suggest further investigation of their possible function in malignant melanoma. We conclude that a strong humoral response against tumor-associated antigens is inducible by tumor cells and that this response is very individual.     

Dendritic cells containing apoptotic melanoma cells prime human CD8+ T cells for efficient tumor cell lysis

Dendritic cells (DCs) phagocytose apoptotic influenza-infected monocytes and cross-present influenza antigen to CD8+ T cells, generating a specific CTL response. We investigated whether apoptotic melanoma cells, presented by this mechanism, can lead to CTL responses to tumor-associated antigens and melanoma cells. Apoptotic HLA-A2- MEL-397 melanoma cells were internalized by HLA-A2+ immature monocyte-derived DCs but failed to induce maturation of DCs. When exposed to interleukin 6, interleukin 1beta, tumor necrosis factor alpha, and prostaglandin E2, DCs containing apoptotic MEL-397 cell material matured normally [cross-presenting DCs (cp-DCs)]. Autologous CD8+ CTL lines generated with cp-DCs produced tumor necrosis factor when stimulated with HLA-A2-binding immunodominant peptides from MelanA/MART1 and MAGE-3 (expressed by MEL-397 cells) but not tyrosinase (absent in MEL-397). T2 target cells loaded with the respective peptides were lysed by these cell lines, although to a lesser extent than by CTL lines generated in the presence of mature DCs and peptides from melanoma-associated h antigens. In contrast, lines generated with cp-DCs lysed HLA-A2+ MEL-526 melanoma cells or allogenic HLA-A2+ cp-DCs efficiently, whereas the CTL generated with DCs and peptides had little lytic activity. Mature DCs containing apoptotic tumor cells may thus represent an alternative approach for the therapy of malignant tumors.     

Suppressor T cells in BCG-treated mice interfere with an in vivo specific antitumoral immune response

The interference by BCG in the induction and expression of a specific antitumoral immune reaction was studied in B6 mice, using the in vivo Winn assay and also active immunization. T cells immunized against MCA-induced fibrosarcoma (MC B6-1) transferred together with the tumour cells protected the syngeneic host against tumour take. Pretreatment of normal B6 mice with moderate or high doses of BCG prevented the development of a protective immune response after immunization. Moreover, a single dose of 1 mg, or 2 doses of 0.01 mg BCG, completely eliminated an established antitumour immunity. Suppressor cells are involved in the BCG-induced inhibitory effect; they interfered (1) with the expression of the antitumour response, since their addition to immune T cells in the Winn test resulted in decreased protection and (2) with the induction of the antitumour response, since injection of spleen cells from BCG-treated mice (BCG SpC) into normal mice before immunization inhibited the development of immunity. Treatment of BCG SpC with anti Thy 1.2 and anti Lyt 1.2 antibodies plus complement before injection into normal mice significantly decreased the suppressive activity, showing that the suppressor cells induced by BCG are T cells expressing the Lyt 1+ phenotype. The partial increase in protection obtained after IL-2 administration to BCG-treated mice suggests that the suppressive action of BCG SpC on the IL-2 producing capacity of helper T cells is only one of a number of possible mechanisms of T-cell-mediated suppression.     

肝癌细胞对重组人HSP70联合肝癌组织冻融抗原修饰树突状细胞的免疫应答

目的:研究重组人热休克蛋白70(rhHSP70)联合肝癌组织冻融抗原修饰的树突状细胞(dendritic cell,DC)诱导对肝癌细胞的免疫杀伤效应.方法:外周血单个核细胞经粒-巨噬细胞集落刺激因子(GM-CSF)、白细胞介素4 (IL-4)诱导生成DC,负载冻融抗原的同时加入rhHSP70,不同分组致敏的DC激活淋巴细胞生成肿瘤抗原特异性细胞毒性T淋巴细胞(cytotoxic T cells,CTL),四甲基偶氮唑蓝(MTT)法及3H-TdR法检测DC刺激淋巴细胞增殖能力, MTT法检测CTL对肝癌细胞的体外杀伤活性,酶联免疫吸附试验(ELISA)测定细胞因子的分泌,流式细胞术(FCM)检测DC表型变化.结果:冻融抗原致敏的DC可明显促进淋巴细胞增殖,能有效呈递肝癌冻融抗原,诱导产生抗原特异性CTL,联合rhHSP70能进一步增强CTL对肝癌细胞的杀伤作用.结论:肝癌冻融抗原联合rhHSP70修饰的DC诱导CTL对肝癌细胞能产生高效杀伤作用.     

Dendritic cells transfected with hepatocellular carcinoma (HCC) total RNA induce specific immune responses against HCC in vitro and in vivo

Background

Immunotherapy is an effective method for preventing metastasis and recurrence of carcinoma. Hepatocellular carcinoma (HCC) is a common malignancy with a high rate of recurrence, and has not successfully been introduced to immunotherapy.

Methods

Peripheral blood mononuclear cells were isolated from whole blood of HCC patients and stimulated to transform into dendritic cells (DCs). These DCs were then transfected with RNA extracted from HepG-2 hepatoma cells to induce expression of specific antigens.

Results

The transfected DCs stimulated T lymphocytes to produce cytotoxic T lymphocytes, which specifically attacked HepG-2 cells. Injection of T lymphocytes from HCC patients and transfected DCs into severe combined immunodeficiency mice limited the growth of HepG-2 tumors.

Conclusion

A specific immune response against hepatoma can be generated in vivo by administering DCs transfected with RNA from a specific tumor. This method may have therapeutic application in humans to reduce recurrence of HCC.     

Regulation of melanoma epitope-specific cytolytic T lymphocyte response by immature and activated dendritic cells, in vitro

Dendritic cell (DC)-based immunization in cancer has proven to be a promising approach. However, just as DCs are crucial accessory cells in generating immune responses, they also seem to participate in tolerance induction, especially against peripheral "self" antigens. The bulk of the evidence that DCs present peripheral self antigens to induce tolerance has, however, come mostly from studies in transgenic animal models. A tolerogenic function of DCs for peripheral self antigens in a human model has not been critically examined. In this study using the Melan-A/MART-1(27-35) peptide as a model for self but melanoma-associated antigen-against which human hosts often harbor CD8(+) CTL precursors with high frequencies-we confirm that although immature dendritic cells (iDCs) are inefficient antigen presenting cells (APCs), fully activated DCs efficiently activate melanoma epitope-specific CD8(+) CTL precursors, in vitro. We, however, show that in a direct epitope presentation schema, iDCs neither delete nor anergize epitope-specific CD8(+) T cells in primary or secondary stimulation. Interestingly, iDCs and activated DCs can delete a large fraction of the epitope-specific CTLs on tertiary stimulation. The deletion is induced in an epitope-specific manner and through apoptosis. These observations, therefore, have implications on the DC-based cancer vaccine designs and are relevant in the inquiry into the role of DCs on tolerance induction.     

热激胃癌细胞外泌体致敏DC诱导显著的抗肿瘤免疫反应

目的:探讨热激胃癌细胞来源外泌体致敏树突状细胞(dendritic cells,DCs)诱导的肿瘤特异性细胞毒T细胞(cytotoxic T lymphocyte,CTL)反应.方法:制备小鼠前胃癌细胞(murine foregastric cancer cells,MFC)来源外泌体(Exo)、热激MFC细胞来源外泌体(Exo/HS)及MFC细胞冻融抗原(lysates,Lys),通过电镜观察外泌体的形态,Western blotting检测外泌体的成分.培养小鼠骨髓来源的DCs,将Exo/HS、Exo和Lys冲击致敏DCs,制备的DCs瘤苗分别命名为DC-Exo/HS、DC-Exo和DC-Lys.HSP70小干扰RNA(small interference RNA,siRNA)转染MFC细胞,热激后分离上清,用制备外泌体致敏DCs,流式术检测DCs的表型.以DC-Exo/HS、DC-Exo、DC-Lys、DC和PBS免疫小鼠,3H-TdR法检测脾脏T细胞的增殖,LDH法检测脾细胞CTL活性.建立MFC细胞荷瘤小鼠模型,观察各组DCs瘤苗的免疫治疗效应.结果:电镜确认外泌体为膜性小囊泡.Western blotting检测表明,Exo/HS含有高水平的HSP70,流式术发现热激MFC细胞来源外泌体能显著上调DCs表面MHC-Ⅱ、CD80、CD86和CD40分子的表达,HSP70 siRNA干扰能下调热激MFC细胞来源外泌体刺激的DCs表面MHC-Ⅱ、CD80、CD86和CD40分子的表达.3H-TdR检测结果显示DC-Exo/HS刺激T细胞增殖的能力显著强于DC-Exo、DC-Lys、DC和PBS组(均P＜0.01),LDH检测结果表明DC-Exo/HS诱导的CTL活性显著高于DC-Exo、DC-Lys、DC和PBS组(均P＜0.01),HSP70 siRNA组诱导的CTL活性显著低于对照siRNA组(P＜0.01).免疫治疗结果显示,DC-Exo/HS对荷瘤小鼠的肿瘤抑制效应显著优于其他各组(P＜0.01).结论:热激胃癌细胞来源外泌体致敏的DCs能诱导显著的抗肿瘤免疫反应.     

Cellular immune response induced by the radiation leukemia virus (RadLV)

Studies on the cellular basis involved in the build up of immunity in C57BL/6 mice inoculated intrathymically with the radiation leukemia virus (RadLV) have been carried out. The virus inoculated C57BL/6 mice were resistant to isotransplantation of leukemic cells for two months after immunization. Lymphoid cells from immune mice present in the thymus, lymph nodes, spleen and peritoneal exudate were found to cause tumor growth retardation. RadLV inoculated C57BL/6 mice performed transplantation resistance only to leukemic cells induced by RadLV (127 LC), but not to radiation induced leukemias (XRL-1, XRL-2, XRL-3), to EL₄ or to any other syngeneic tumors tested. The immunological specificity of the lymphoid cells taken from immunized mice (with RadLV) was tested in vivo and in vitro against leukemic cells induced in C57BL/6 mice by various agents (RadLV, chemical carcinogens and X-rays) and were found to be highly specific for the presence of RadLV associated antigen(s) on their cell surface. A cytostatic effect rather than a cytolytic effect was demonstrated, when effector:leukemic cell interaction was tested in vitro. The cytostasis assay was performed on syngeneic leukemic cells (induced by RadLV) in suspension at various leukemic: effector cell ratios. A specific reaction occurred mainly at the ratio of 1:80.