人树突状细胞融合肝癌细胞体外诱导特异性抗肿瘤免疫

目的 探讨人树突状细胞(DC)融合肝癌细胞(HCC)体外诱导T淋巴细胞产生特异性抗肝癌免疫的作用.方法 应用人重组粒细胞/巨噬细胞集落刺激因子(rhGM-CSF)和重组人白细胞介素4(rhIL-4)对人外周血单个核细胞进行体外诱导产生树突状细胞,流式细胞仪检测DC表面标志物表达水平,聚乙二醇融合DC与肝癌细胞HerG2,MTT法测定融合细胞(HerG2/DC)刺激T淋巴细胞增生、分化能力,细胞毒性实验检测HerG2/DC诱导的细胞毒T淋巴细胞(CTL)对HerG2的特异性杀伤作用.结果 融合细胞HerG2/DC刺激T淋巴细胞增值能力明显提高,HerG2/DC活化的CTL对HerG2具有明显的特异性杀伤作用.结论 人树突状细胞融合肝癌细胞可有效诱导T淋巴细胞产生特异性的抗肝癌肿瘤免疫.     

胎儿来源的树突状细胞诱导抗膀胱癌效应的研究

目的：研究胎儿来源的树突状细胞（DC）体外诱导抗膀胱癌的特异性细胞免疫的效果.方法：从胎儿骨髓获得单个核细胞,经粒细胞-单核细胞集落刺激因子（GM-CSF）、IL-4和TNF-α诱导产生DC.利用50%～70%硫酸铵饱和沉淀法获取膀胱癌细胞系EJ含热休克蛋白（HSP）成分的细胞溶解物,以该抗原负载DC,激活胎脾细胞产生肿瘤特异性的细胞杀伤性T淋巴细胞（CTL）.利用IL-2刺激胎脾细胞产生LAK细胞.应用MTF法分别检测CTL和LAK细胞对EJ细胞的杀伤效应.结果：胎儿骨髓可诱导出功能成熟的DC,高表达CD1a、CD86、HLA-DR和CD83.负载EJ抗原的DC可诱导产生CD8＋CTL.其对EJ细胞的杀伤作用明显强于LAK细胞.结论：含HSP成分的肿瘤细胞溶解物负载胎儿来源的DC,体外可诱导出更强的特异性抗肿瘤免疫应答.     

脐带血与外周血来源树突细胞体外刺激特异抗白血病T细胞免疫应答

目的：比较脐血（CB）及外周血（PB）单个核细胞（MNC）体外诱导生成树突状细胞（DC）的产量;并将此DC负载白血病抗原,检测两者诱导的特异性细胞毒T细胞（CTL）对白血病细胞的杀伤活性。方法：取CB及健康成人PB各8份,以淋巴细胞分离液分离获得MNCs,培养体系中加入重组人粒单核细胞集落刺激因子（rhGM-CSF）,重组人白细胞介素4（rhIL-4）和肿瘤坏死因子α（TNF-α）,并在培养第5天,加入HL-60细胞经反复冻融提取的抗原,致敏DC。培养过程中,观察树突状细胞形态,流式细胞仪（FCM）检测表型。培养第12天收获成熟DC,CB组分别与8例PB来源T淋巴细胞共培养;PB组与自体T淋巴细胞共培养,诱导产生白血病特异性CTL,乳酸脱氢酶法（LDH法）测定溶靶细胞活性。结果：（1）CB与PB来源DC均表现出成熟DC典型形态和免疫表型特征,2组DC相关分化抗原CD1a、CD83、CD86、CD80和人类白细胞相关抗原DR（HLA-DR）的表达较培养前增高,2组比较差异无统计学意义（P〉0.05）。（2）CB组DC产量高于PB组,差异有统计学意义（P〈0.01）。（3）以白血病抗原冲击的DC所刺激的T淋巴细胞对白血病靶细胞显示出明显的杀伤活性,按照各效靶比进行两者的比较,差异无统计学意义（P〉0.05）。结论：利用细胞因子体外诱导CB及PB来源MNCs均能产生大量成熟DC,且功能相同;前者DC产量更高,来源丰富,可能成为急性白血病免疫治疗中DC的丰富来源。     

树突状细胞疫苗对人肺腺癌GLC-82细胞体外杀伤作用的实验观察

目的 通过建立负载人肺腺癌细胞株GLC-82可溶性抗原的树突状细胞(DC)疫苗,探讨应用DC疫苗的致敏特异性杀伤性T细胞(CTL)体外杀瘤细胞的可行性和实验条件,为后期l临床应用提供实验依据.方法 通过用定量摩尔氯化钾提取法获得人肺腺癌细胞GLC-82的可溶性抗原多肽(TSA),从人外周血单核细胞(PBMC)中用GM-CSF、白细胞介素-4和肿瘤坏死因子-α体外诱导扩增并鉴定获取DC,构建DC疫苗;利用DC疫苗刺激同种异体外周血T淋巴细胞活化增殖,诱导产生具有识别肺癌细胞抗原的特异性CTL的可行性及MTT法检测该CTL对GLC-82、肺癌CALU-6和人红白血病K 562细胞的体外杀伤效应.结果 人PBMC体外经7d诱导出的DC,经形态学、免疫组化证实具有典型的树突状细胞特性;负载GLC-82抗原的DC疫苗能有效诱导同种异体T淋巴细胞活化增殖产生CTL,最适浓度为1:10;诱导活化的CTL对靶细胞的杀伤活性明显高于未经肿瘤抗原致敏的组.结论 诱导培养人外周血PBMC中的Mo可获取大量DC,诱导出的DC功能较强,适宜临床应用;DC疫苗能强烈刺激初始型同种异体T淋巴细胞增殖产生CD 8+表达增加的CTL;激活的CTL对肺癌靶细胞发挥高效而特异的细胞毒效应,对非肺组织瘤靶细胞也具有非特异性杀伤效应.     

冻融人外周血树突状细胞基因疫苗体外抗肿瘤活性研究

目的观察EB病毒潜伏膜蛋白重组腺病毒(rAd-EBV-LMP2)转染的冻融人外周血树突状细胞(DC)诱导的特异性细胞毒性T淋巴细胞(CTL)抗肿瘤活性。方法人外周血来源的单核细胞经细胞因子扩增培养为成熟DC,液氮冻存;rAd-LMP2重组腺病毒转染冻融DC制备疫苗。动态观察细胞形态学特征,四甲基偶氮唑蓝(MTT)法检测DC疫苗刺激同种T淋巴细胞增殖活性,以及诱导的CTL对肿瘤细胞的杀伤活性。结果rAd-LMP2转染的冻融DC疫苗具有形态迥异、多突起的典型形态学特征,其刺激同种T淋巴细胞的增殖能力明显高于对照组(P<0.01),能诱导高效的CTL活性(P<0.01),与新鲜DC疫苗差异无统计学意义(P>0.05)。结论rAd-LMP2转染冻融DC疫苗在体外能激发较强的EBV-LMP2特异性的功能性CTL,为EBV相关的鼻咽癌(NPC)的免疫治疗提供策略。     

K562白血病株树突状细胞诱导及其抗肿瘤功能的体外研究

目的将K562细胞诱导分化为树状突细胞(DC),并以K562-DC作为刺激细胞诱导细胞毒T淋巴细胞(CTL)反应,观察其体外特异性抗肿瘤效应,对白血病细胞来源DC用于白血病免疫治疗进行初步探讨。方法(1)低浓度丙戊酸钠将K562细胞诱导分化为DC(K562-DC)。(2)DC的鉴定:①形态学:倒置显微镜(Olympus)下观察细胞形态并摄相。②免疫表型:PE结合的鼠抗人CD1a、HLADR、CD83、CD80及CD86单抗用流式细胞仪分析检测细胞表面标志。③功能鉴定:采用同种异体混合淋巴细胞反应。(3)MTT杀伤实验检测DC诱导特异性细胞毒性T淋巴细胞的杀伤活性。结果(1)丙戊酸钠(VPA)培养第7天时,细胞均匀分散,变形,体积增大,数量增多,细胞表面可见多个突起,且具有刺状突起的细胞数量较前增多。(2)通过流式细胞术检测诱导的K562DC表面分子的表达,结果发现丙戊酸钠(VPA)诱导的K562DC各表面标志的表达,与K562细胞相比均明显上调(P<0.05)。(3)丙戊酸钠(VPA)诱导的K562DC具有较强的诱导CTL杀伤肿瘤细胞的能力且随效靶比例增高而增强,并显著高于未负载肿瘤可溶性抗原的DC及单纯T细胞组(P<0.05)。结论以K562细胞为靶细胞,观察VPA对K562细胞诱导向树突状细胞分化作用。进一步的实验证实,VPA可以诱导K562细胞向树突状细胞分化,而且诱导的树突状细胞具有较强的抗原呈递功能和诱导特异性细胞毒性T淋巴细杀伤活性作用。     

树突状细胞/肿瘤细胞融合诱导的抗肺癌CTL作用的初步究

目的探讨人源树突状细胞/肿瘤细胞融合诱导的抗肺癌CTL作用。方法培养体系中加入rhGM-CSFrhIL-4rhTNF-α等细胞因子诱导人骨髓来源树突状细胞,并与原代培养的人肺癌细胞融合;以融合细胞诱导外周血产生CTL并测定其细胞毒性。结果骨髓单个核细胞在rhGM-CSFrhIL-4rhTNF-α等细胞因子存在下培养10～12d,出现典型的成熟树突状细胞。体外诱导的人骨髓来源树突状细胞（DC）表达较高水平HLA-DR、CD86。对照DC和肿瘤细胞表达相应检测的单种抗原,而融合细胞两种抗原的表达水平均较高。DC/肺癌细胞融合在体外能有效诱导CTL产生,后者对靶细胞产生较强的细胞毒作用。结论通过本课题的研究证实DC与肿瘤细胞融合技术制备的肿瘤疫苗代表一类更为有效的抗肿瘤免疫策略。     

慢性乙型肝炎患者外周血树突状细胞状况的初步研究

目的 研究慢性乙型肝炎(慢性乙肝)患者外周血树突状细胞(DCs)的状况。方法 外周血单个核细胞，在含重组人白细胞介素4(rhIL-4)(500U／m1)和重组人粒细胞巨噬细胞集落刺激因子(rhGM-CSF)(100ng／m1)完全培养基中培养诱导出DCs。在显微镜下观察DCs生长状况，并采用直接计数法以了解DCs的增殖速度。采用LDH法检测DCs诱导的细胞毒性T细胞(CTL)杀伤能力。以MTT法检测DCs刺激同种异体混合淋巴细胞反应的能力。结果 慢性乙肝患者外周血单个核细胞中通过诱导培养所产生的DCs的细胞数量明显少于正常人群；慢性乙肝患者的DCs的增殖速度与正常人DCs无显著性差异，但细胞发育不良。慢性乙肝患者的DCs诱导CTL杀伤作用的能力明显弱于正常人；并且在经过体外培养3、6、9天后，慢性乙肝患者的DCs刺激同种异体混合淋巴细胞反应的能力均显著低于同培养时段的正常人DCs。结论 慢性乙肝患者体内的DCs不仅细胞数量明显少于正常人，而且发育不良、功能低下。这可能是导致慢性乙肝患者抗HBV特异性免疫功能低下的重要原因之一。     

致敏树突状细胞疫苗抗小鼠乳腺癌的实验研究

目的研究以EMT6乳腺癌细胞致敏的树突状细胞(DC)疫苗的抗肿瘤作用。方法无菌取小鼠骨髓细胞,在体外培养条件下经细胞因子诱导为DC,用EMT6肿瘤细胞冻融抗原冲击致敏DC,检测经DC免疫产生的细胞毒T淋巴细胞(CTL)体外杀伤肿瘤细胞的活性。建立EMT6荷瘤小鼠模型,随机分为实验组、实验对照组和空白对照组,于肿瘤接种后第7、14天给予相应DC疫苗治疗,观察致敏DC免疫对小鼠乳腺肿瘤模型的治疗作用。结果致敏DC诱导生成的特异性CTL在体外对肿瘤细胞可产生杀伤作用,与PBS对照组比较,差异有显著性(P<0.05);经致敏DC注射免疫后,小鼠移植瘤得到抑制,与PBS对照组比较,差异有显著性(P<0.05)。结论以EMT6乳腺癌细胞致敏的树突状细胞(DC)疫苗在体外和小鼠体内均显示了抗肿瘤作用。     

负载冻融抗原的DC诱导特异性CTL杀伤胃癌细胞的实验研究

目的 研究负载肿瘤抗原的树突状细胞(DC)活化的特异性细胞毒性T淋巴细胞(CTLs)对胃癌细胞的体外杀伤作用.方法 冻融法获取胃癌细胞抗原,联合应用粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)、白细胞介素4(IL-4)和肿瘤坏死因子α(TNF-α)诱导培养外周血BC并负载肿瘤抗原,激活自体T淋巴细胞,制备特异性CTLs,MTT法检测对胃癌细胞的体外杀伤作用.ELISA法检测γ干扰素(IFNγ)分泌情况.结果 负载胃癌抗原的DC激活的CTLs表现出对胃癌细胞的特异性杀伤作用,产生高水平的IFNY(P<0.01);而对B16黑色素瘤细胞没有杀伤作用不产生高水平的IFNγ.未负载胃癌抗原DC刺激的CTLs对胃癌细胞无杀伤作用.结论 应用细胞因子从人外周血中诱导的DC负载胃癌抗原后,激活的CTLs在体外对胃癌细胞能产生高效而特异性的杀伤作用.     

奥沙利铂联合Exosome诱导的效应性T细胞抑制HepG2细胞增殖的研究

目的观察奥沙利铂(OXA)联合负载HepG2细胞裂解物的Exosome诱导的效应性T细胞对肝癌HepG2细胞系增殖的抑制作用。方法自健康人外周血中提取单个核细胞和T淋巴细胞,并以GM-CSF+IL-4的培养方案获得树突状细胞(DC)。将反复冻融后产生的HepG2细胞裂解物体外致敏DC,收集培养上清后以超高速离心法分离得到Exosome,电镜下观察其形态特征。用致敏DC及其分泌的Exosome刺激T淋巴细胞的增殖和活化。以ELISA试验检测不同刺激环境下T细胞分泌IL-1β、IL-2、IL-4、IL-6、IL-10、IFN-γ和TNF-α的能力。以细胞杀伤实验(MTT法)检测不同因素刺激后的T细胞、OXA(2.5、5.0、10.0mg.L-1)以及两者联合应用对HepG2细胞生长的抑制效应。结果与未致敏DC及其分泌的Exosome相比,HepG2细胞冻融裂解物致敏的DC及其分泌的Exosome能显著促进T细胞的增殖,并使其活化和分泌大量的IL-1β、IL-2、IL-6、IFN-γ和TFN-α等Th1型细胞因子。活化后的T细胞、OXA以及两者联合应用对HepG2细胞体外增殖均有抑制作用,而活化T细胞联合10mg.L-1OXA对HepG2细胞的杀伤率最高,但与联合5 mg.L-1OXA的效应相比,差异无统计学意义(P0.05)。结论负载肿瘤细胞抗原的DC所分泌的Exosome可在体外刺激T细胞,使其活化为具有抗肿瘤效应的细胞毒性T细胞,该细胞联合低浓度OXA能显著抑制肝癌细胞的体外增殖,并降低OXA的用量。     

肌肉免疫DC-EBV-LMP2诱导免疫应答的研究

目的探讨肌肉免疫DC-EBV-LMP2诱导的免疫效果。方法从BALB/C小鼠分离骨髓细胞,诱导培养获得小鼠DC,以100 MOI的rAd-LMP2感染获得DC-EBV-LMP2,继续培养48h,诱导DC-EBV-LMP2成熟。用免疫酶法确定LMP2在DC中表达。0,2,4周,以2×105个DC-EBV-LMP2/只免疫BALB/C小鼠,于第5,8周分别LMP2特异性水平和T细胞亚群的变化。结果结果显示,肌肉免疫DC-EBV-LMP2可诱导BALB/C鼠LMP2特异性免疫应答,且第5周强于第8周。CD8+T/CD3+T细胞亚群的比值在第5周高于对照组,而第8周低于对照组。结论 DC-EBV-LMP2肌肉免疫BALB/C鼠可诱导LMP2特异性CTL。     

树突状细胞瘤苗诱导的抗神经胶质瘤作用体外实验研究

目的 :研究负载自体神经胶质瘤抗原的树突状细胞 (DCs)瘤苗在体外诱导的特异性细胞毒性淋巴细胞 (CTL)对神经胶质瘤细胞的杀伤效应。方法 :以组合酶消化法从新鲜神经胶质瘤手术标本中获取神经胶质瘤细胞 ,冻融制备神经胶质瘤抗原。GM -CSF、IL -4体外诱导外周血单个核细胞 (PBMC)获得DCs并负载神经胶质瘤抗原 ,继而以其刺激自体T淋巴细胞制备神经胶质瘤抗原特异性CTL ;用CytoTox96TM检测CTL对患自身神经胶质瘤细胞体外杀伤效应。结果 :负载神经胶质瘤抗原DCs诱导的特异性CTL对患者自身神经胶质瘤细胞的杀伤率达88 17 % ,显著高于LAK细胞的杀伤率 (P<0 05)。且其对同种不同分化类型的神经胶质瘤细胞株 (P<0 01)。结论 :负载神经胶质瘤抗原的DCs体外可诱导出高效而特异的抗神经胶质瘤效应 ,提示以DCs为中心的肿瘤生物治疗作用可望提高神经胶质瘤综合治疗水平     

Improved efficacy of therapeutic vaccination with dendritic cells pulsed with tumor cell lysate against hepatocellular carcinoma by introduction of 2 tandem repeats of microbial HSP70 peptide epitope 407-426 and OK-432

Therapeutic vaccination with dendritic cells (DCs) pulsed with tumor cell lysate vaccine (H-D) represents an attractive approach for hepatocellular carcinoma (HCC) treatment. However, the efficacy of this approach is not most satisfactory for the low levels of T helper 1 (Th1)-type cytokines secretion and weak T cell responses. In this study, in order to increase the potency of H-D, two tandem repeats of microbial HSP70 peptide epitope 407–426 (2mHSP70_407-426, M2) which has been demonstrated to be effective in enhancing DC maturation were applied. The DC vaccine (HM-D) which was HCC tumor cell lysate pulsed with M2 was developed. Nevertheless, the immunotherapeutic effect was still not satisfactory enough even some promotion was obtained. Therefore, OK-432 (OK), which is a useful anti-cancer agent and effectively in stimulating DC maturation, was introduced to HM-D. Our results demonstrated that treatment with the improved DC vaccine which was tumor cell lysate pulsed with M2 and OK (HMO-D), compared with H-D and HM-D, significantly increased cell surface markers (MHC-I and II, CD40, CD80, CD86 and CD11c) expression on DCs, enhanced Th1-type cytokines (IL-12, TNF-α and IFN-γ) production but not Th2-type cytokine (IL-5) production, induced remarkable high levels of lymphocytes proliferation and CD8⁺ cytotoxic T-lymphocyte (CTL). Furthermore, immunization with HMO-D effectively reduced tumor progression and enhanced the survival of mice with H22 tumors. Besides, we also found that the capability of M2 in inducing the Th1 cytokines was stronger than OK. In view of these results, HMO-D vaccination provided a novel immunotherapeutic approach for the treatment of HCC.     

Blocking drug-induced autophagy with chloroquine in HCT-116 colon cancer cells enhances DC maturation and T cell responses induced by tumor cell lysate

Autophagy is an important mechanism for tumor escape, allowing tumor cells to recover from the damage induced by chemotherapy, radiation therapy, and immunotherapy and contributing to the development of resistance. The pharmacological inhibition of autophagy contributes to increase the efficacy of antineoplastic agents. Exposing tumor cells to low concentrations of select autophagy-inducing antineoplastic agents increases their immunogenicity and enhances their ability to stimulate dendritic cell (DC) maturation. We tested whether the application of an autophagy-inhibiting agent, chloroquine (CQ), in combination with low concentrations of 5-fluorouracil (5-FU) increases the ability of tumor cells to induce DC maturation. DCs sensitized with the lysate of HCT-116 cells previously exposed to such a combination enhanced the DC maturation/activation ability. These matured DCs also increased the allogeneic responsiveness of both CD4+ and CD8+ T cells, which showed a greater proliferative response than those from DCs sensitized with control lysates. The T cells expanded in such cocultures were CD69+ and PD-1- and produced higher levels of IFN-γ and lower levels of IL-10, consistent with the preferential activation of Th1 cells. Cocultures of autologous DCs and lymphocytes improved the generation of cytotoxic T lymphocytes, as assessed by the expression of CD107a, perforin, and granzyme B. The drug combination increased the expression of genes related to the CEACAM family (BECN1, ATGs, MAPLC3B, ULK1, SQSTM1) and tumor suppressors (PCBP1). Furthermore, the decreased expression of genes related to metastasis and tumor progression (BNIP3, BNIP3L, FOSL2, HES1, LAMB3, LOXL2, NDRG1, P4HA1, PIK3R2) was noted. The combination of 5-FU and CQ increases the ability of tumor cells to drive DC maturation and enhances the ability of DCs to stimulate T cell responses.     

Dendritic cells incubated with irradiated tumor cells effectively stimulate T lymphocyte activation and induce enhanced expression of CD69, CD25 as well as production of IFNgamma and IL4

Understanding of immunological processes at the molecular level in the cancer-bearing organism is the prerequisite for development of specific tumor vaccines. Most of these vaccines are aimed at enhancing the immunogenicity of the antigens presented by the tumor cells. Since dendritic cells (DC) are potent antigen presenting cells (APC) in the organism, they are considered as a powerful tool to deliver the signals essential for the activation of immune system. In an attempt to clarify the functional importance of DC in the process of anti-tumor vaccination, we characterized the effect of DC activated with a classical tumor vaccine (mixture of irradiated B16F1 tumor cells and MVE-2) on the activation of T lymphocytes. The T lymphocyte activation was assessed by determination of expression of CD25, CD69, and intracellular IFNgamma and IL4 production. Activated DC significantly increased the proportion of CD25+ and CD69+ cells as well as IFNgamma+ and IL4+ cells among CD3+ T lymphocytes. On the other hand, the direct effect of the tumor vaccine on T lymphocytes was just an increment in the proportion of IL4+ T lymphocytes. With the results of in vivo experiments, the phagocytic cells (including DC) were proved to be essential for establishing an active protection against tumor cells (tumor development), but more importantly, also for formation of the memory cell pool. These data indicate that DC loaded with tumor antigens are required for effective stimulation of T lymphocytes, and that the phagocytic cells (including DC) are essential for the anti-tumor immunity triggered by this kind of vaccine.     

OM197-MP-AC induces the maturation of human dendritic cells and promotes a primary T cell response

Dendritic cell (DC) maturation is critical for the induction of antigen-specific T lymphocyte responses and may be essential for the development of human vaccines relying on T cell immunity. We investigated the effects on human DC of OM-197, a synthetic pseudodipeptide derived from amino acids, linked to three fatty acid chains and devoid of endotoxin properties. OM-197 upregulated the expression of HLA-DR, CD80, CD86, CD83, CD40 and CD54 at the surface of myeloid DC naturally present in blood as well as of DC generated in vitro from monocytes using IL-4 and GM-CSF. OM-197 also induced the release of IL-12 and TNF-alpha from DC. Finally, DC incubated with OM-197 after pulsing with hepatitis B surface antigen (HBs Ag) induced in vitro expansion of IFN-gamma-secreting HBs Ag-specific CD4(+) T lymphocytes from naive individuals. Taken together, these data identify OM-197 as a potential vaccine adjuvant for the induction of Th1-type responses.     

In vitro human T cell sensitization to haptens by monocyte-derived dendritic cells

We previously reported that in vitro primary sensitization of hapten-specific T cells by cultured human epidermal Langerhans cells (LC) provides an alternative approach to discriminate strong contact sensitizers from irritants (Krasteva et al., 1996; Moulon et al., 1993). However, this LC-based immunoassay was limited by the availability of human skin samples. In the present study, we used monocyte-derived dendritic cells (DC) to analyse the autologous proliferative T cell response to several allergens. Monocytes were purified from the peripheral blood of healthy donors and cultured for 6–8 days in the presence of GM/CSF and IL-4 and then for 2 days in the presence of GM/CSF and TNF. The resulting cells exhibited the phenotype of mature DC, as assessed by the strong expression of HLA-DR, CD80, CD83 and CD86 antigens. We showed that trinitrophenyl (TNP)-treated mature DC induced a significant T cell proliferative response in all experiments, while fluorescein isothiocyanate (FITC) gave positive results in about half of them. The prohaptens eugenol and isoeugenol induced significant proliferation in one out of eight and in four out of 12 experiments, respectively. Interestingly, in 16 assays T cells never proliferated in the presence of sodium lauryl sulfate (SLS)-treated DC. Thus, this in vitro model allows discrimination between strong contact sensitizers and irritants. It might be very useful, therefore, for restriction of animal experimentation.     

基因修饰的树突状细胞体外免疫功能的初步研究

目的 制备转染乙型肝炎病毒核心抗原(HBcAg)基因、人外周血单个核细胞(PBMC)来源的树突状细胞(DC)疫苗,观察HBcAg的表达效率,检测其在体外诱导的细胞毒性T淋巴细胞(cytotoxic T lymphocytes,CTL)对HepG2.2.15细胞的杀伤效应.方法 体外诱导并培养DC;将HBcAg基因导入...