HIV—1CN与IL—2基因共表达核酸疫苗诱导产生CTL的观察

目的 观察HIV－1CN gp120基因与IL－2基因共表达核酸疫苗质粒pGPIL-2诱导产生CTL。方法 脂质体介导共表达中国流行株HIV－1 Gag-gp120基因与IL－2基因的核酸疫苗质粒pGPIL-2转染BHK－21细胞,以间接免疫荧光法鉴定其表达,取pGPIL-2免疫鼠脾细胞,检测pGPIL-2诱导的细胞毒性T细胞杀伤活性。结果 pGPIL-2可有效地诱导CTL的产生,并可杀伤HIV－1CN嵌合基因转染的靶细胞,结论 为进一步设计中国流行株HIV－1核酸疫苗提供了重要实验依据。     

CD1d融合蛋白的表达及其在自然杀伤T细胞原代培养中的作用

目的 构建重组真核表达质粒pcDNA3.1(-)-CD1d-hIgG1-BriAtag,建立稳定表达CD1d融合蛋白的细胞系,并检测该蛋白对体外培养人原代自然杀伤T(natural killing T,NKT)细胞的活化刺激功能,为肿瘤过继性免疫治疗提供新方法.方法 从健康人外周血提取CD1d全长基因作为目的DNA片段...     

EHV-1_(CN)与IL-2基因共表达核酸疫苗诱导产生CTL的观察

目的 观察ＨＩＶ－１ＣＮ　ｇｐ１２０基因与ＩＬ－２基因共表达核酸疫苗质粒ｐＧＰＩＬ－２诱导产生ＣＴＬ。方法 脂质体介导共表达中国流行株ＨＩＶ－１Ｇａｇ－ｇｐ１２０基因与ＩＬ－２基因的核酸疫苗质粒ｐＧＩＬ－２转染ＢＨＫ－２１细 胞,以间接免疫光法鉴定其表达。取ｐＧＰＩＬ－２免疫鼠脾细胞,检测ｐＧＰＩＬ－２诱导的细胞毒性Ｔ细胞杀伤活性。 结果ｐＧＰＩＬ－２可有效地诱导ＣＩＬ的产生,并可杀伤ＨＩＶ－１ＣＮ嵌合基因转染的靶细胞。结论 为进一步设计中国流行株ＨＩＶ－１核酸疫苗提供了重要实验依据。     

禽流感病毒NS1A蛋白诱导人肺癌细胞SPC-A1的凋亡

目的研究禽流感病毒NS1A蛋白对人肺癌细胞SPC-A1增殖的影响。方法将含有NS1A基因的重组质粒pVAX1-NS1A经脂质体介导转染人肺癌细胞SPC-A1,用MTT检测其对细胞增殖的抑制作用;Annexin VFITC-PI结合流式细胞仪检测细胞凋亡率;PI结合流式细胞仪检测细胞周期的变化;对转染细胞的表达产物进行Western blot分析。结果NS1A蛋白能抑制人肺癌细胞SPC-A1增殖且呈时间依赖性。随着作用时间延长,重组质粒转染组细胞凋亡率可达38.17%,细胞周期中G0/G1比例升高,G1期阻滞。Western blot分析显示,重组质粒转染组细胞在相对分子质量约30000处可见特异性反应条带,与NS1A蛋白产物大小相符。结论禽流感病毒NS1A蛋白能够抑制SPC-A1细胞增殖,并诱导SPC-A1细胞凋亡。     

6Ckine修饰的树突状细胞促进T淋巴细胞增殖和分化的作用

目的研究次级淋巴组织趋化因子(6Ckine)修饰的树突状细胞(DC)对T淋巴细胞增殖和分化的影响。方法用携带人6Ckine基因的重组复制缺陷型腺病毒(Ad-6Ckine)感染人外周血单个核细胞来源的DC,检测Ad-6Ckine-DC对6Ckine的表达及细胞因子分泌的影响,并观察其吞噬功能和表型的变化及对自身T淋巴细胞的趋化作用。用结肠癌LoVo细胞抗原致敏Ad-6Ckine-DC,将该DC与自身T淋巴细胞共同培养,分别用3H掺入法、RT-PCR和ELISA检测Ad-6Ckine-DC对T淋巴细胞增殖和分化的影响。结果在Ad-6Ckine转染后24h内,DC的吞噬功能几乎不受影响。转染的6Ckine基因能在DC中表达,表达的6Ckine能促进其表达CD83和CCR7,上调RANTES的表达。Ad-6Ckine-DC对自身T淋巴细胞有明显的趋化作用,抗原致敏的Ad-6Ckine-DC能显著促进T淋巴细胞的增殖,并增强其表达T-bet和IL-2的能力。结论6Ckine基因的修饰能在一定程度上促进DC的成熟,并募集T淋巴细胞于DC周围,有利于DC向T淋巴细胞传递抗原和第二信息,增强DC促进T淋巴细胞增殖的作用并使其向Th1分化,诱导细胞免疫,将成为制备肿瘤疫苗的一种良好选择。     

人Makorin环指蛋白1基因沉默对HEK293细胞的影响

目的探讨特异性抑制人Makorin环指蛋白1(MKRN1)基因的表达对HEK293细胞的影响。方法用脂质体将前期筛选出的含最有效干扰序列的人MKRN1基因shRNA真核表达质粒,转染至HEK293细胞中,观察其对人端粒酶逆转录酶(hTERT)基因mRNA转录水平、蛋白表达水平及细胞增殖的影响。结果人MKRN1基因shRNA真核表达质粒转染HEK293细胞后,在mRNA和蛋白水平均能明显上调细胞hTERT基因的表达,且细胞明显增殖。结论抑制HEK293细胞中人MKRN1基因的表达,可导致hTERT基因mRNA转录水平和蛋白表达水平上调,并促进细胞增殖。     

JTV1基因真核表达质粒的构建及其在K562细胞中的表达

目的 构建JTV1基因真核表达质粒并稳定转染人白血病细胞系K562,检测转染细胞中JTV1基因mRNA和蛋白的表达水平及其对K562细胞增殖的影响。方法从人外周血单个核细胞中克隆JTV1基因,并将其插入pcDNA3.1表达载体中,构建真核重组表达质粒pcDNA3.1-JTV1,经脂质体介导转染K562细胞,采用RT-PCR和Western blot法鉴定转染细胞中JTV1基因mRNA和蛋白的表达水平;MTT法检测JTV1稳定表达对K562细胞增殖的影响。结果重组表达质粒pcDNA3.1-JTV1经双酶切及测序证实,目的基因已插入质粒中;人JTV1基因能在K562细胞中稳定表达;JTV1具有抑制K562细胞增殖的作用。结论已成功构建了JTV1基因真核表达质粒,并获得了稳定表达人JTV1基因的K562细胞克隆,为进一步研究人JTV1基因的功能及其与白血病细胞增殖及凋亡的相关性提供了细胞模型。     

慢性粒细胞白血病树突状细胞对T细胞增殖作用的研究

目的　体外诱导慢性粒细胞白血病 (CML)患者外周血单个核细胞 (PBMCs)为树突状细胞 (DCs) ,并对其形态、表型及对T细胞刺激增殖作用进行研究。方法　利用GM CSF、IL 4、TNF α体外定向诱导生成树突状细胞 ,对所诱生的细胞进行细胞表型及形态检测 ,用D FISH方法检测所诱生DCs的白血病源性 ,应用MTT法检测所诱生的DCs刺激T细胞增殖的能力。结果　CML患者PBMCs在体外可诱导生成bcr/abl融合基因阳性的DCs(CMLDCs)。CMLDCs对自体T细胞有明显刺激增殖作用 ,而CML细胞无此作用。CMLDCs刺激同一异体T细胞增殖能力弱于正常DCs,但当培养体系中加入 30 0U/ml干扰素 α(IFN α)时可使其刺激能力接近正常DCs。结论　CMLDCs具有刺激自体及异体T细胞增殖的能力 ,但对异体T细胞的刺激作用弱于正常DCs,IFN α可提高CMLDCs刺激T细胞增殖能力     

靶向Pin1基因的shRNA干扰质粒的构建及其对大肠癌SW620细胞Pin1基因的抑制作用

目的构建靶向Pin1基因的短发夹RNA(shRNA)干扰真核表达质粒,并检测其对大肠癌SW620细胞Pin1基因的抑制作用。方法设计合成特异性针对人Pin1基因的寡核苷酸序列,退火后与pGenesil-1载体连接,构建靶向Pin1基因的shRNA真核表达质粒pGenesil-1-Pin1(+),利用脂质体转染大肠癌SW620细胞,以质粒pGenesil-1-Pin(-)转染细胞和未转染细胞为对照。利用荧光显微镜观察转染后细胞表达的绿色荧光蛋白,估算转染效率;应用实时荧光定量PCR和Western blot检测其对SW620细胞Pin1基因mRNA转录及蛋白表达的影响。结果所构建的特异Pin1shRNA真核表达质粒经酶切及测序证明构建正确,转染SW620细胞的转染效率为64%。shRNA对SW620细胞Pin1基因mRNA的抑制率在转染后72h最高,为70.2%,蛋白抑制率为60%。结论已成功构建了靶向Pin1基因的shRNA干扰真核表达质粒,可抑制SW620细胞Pin1基因mRNA的转录及蛋白的表达。     

抗体阻断表面黏附分子DNAM-1和LFA-1对人自然杀伤细胞肿瘤杀伤活性的抑制作用

目的探讨抗体阻断表面黏附分子DNAM-1和LFA-1对体外扩增的人自然杀伤(Natural killer,NK)细胞的肿瘤杀伤活性的影响。方法体外活化人外周血单个核细胞来源的NK细胞,并检测其表面黏附分子DNAM-1和LFA-1的表达水平;通过Trans-well阻隔试验,阻断NK细胞与靶细胞接触,考察细胞-细胞直接接触对NK细胞杀伤活性的影响;通过NK细胞毒性试验,引入抗DNAM-1单克隆抗体和抗LFA-1单克隆抗体,阻断相应信号途径,考察相关黏附分子在NK细胞肿瘤杀伤过程中的作用。结果体外活化的NK细胞高表达表面黏附分子DNAM-1和LFA-1。阻断NK细胞与靶细胞接触,NK细胞的肿瘤杀伤效应大大降低。应用单克隆抗体阻断DNAM-1或LFA-1信号途径,可显著降低NK细胞肿瘤的杀伤效应;联合阻断DNAM-1和LFA-1信号途径,可进一步降低NK的细胞杀伤效应。结论细胞-细胞间直接接触是NK细胞发挥肿瘤杀伤效应的重要机制,表面黏附分子DNAM-1和LFA-1介导的信号途径对维持NK细胞肿瘤杀伤活性具有重要意义。     

前列腺特异性抗原体外诱导结肠癌特异性CTLs

目的检测前列腺特异性抗原(PSA)在结肠癌中的表达水平,探讨PSA作为结肠癌主动免疫治疗新靶点的可能性。方法用RT-PCR方法检测结肠癌细胞系中PSAmRNA的表达水平;免疫组织化学方法检测结肠癌细胞中PSA蛋白的表达水平。利用PAP表位肽对结肠癌患者的PBMCs进行体外诱导,ELISA法检测PSA特异性IFN-γ分泌水平;51Cr释放法检测PSA多肽特异性CTLs对结肠癌细胞的细胞毒性。结果4种结肠癌细胞(colo201,colo205,SW480和SW620)表达PSA mRNA和PSA蛋白。HLA-A+24结肠癌患者的PBMCs经体外诱导产生的CTLs可特异性杀伤HLA-A24+/PSA+的结肠癌细胞,CTLs的细胞毒活性依赖于CD8+的T淋巴细胞。结论结肠癌患者的外周血中存在PSA特异性CTLs前体细胞,PSA有可能成为结肠癌特异性免疫治疗的靶点。     

Human CD4+ T-Cell Clone Expansion Leads to the Expression of the Cysteine Peptidase Inhibitor Cystatin F

The existence of CD4+ cytotoxic T cells (CTLs) at relatively high levels under different pathological conditions in vivo suggests their role in protective and/or pathogenic immune functions. CD4+ CTLs utilize the fundamental cytotoxic effector mechanisms also utilized by CD8+ CTLs and natural killer cells. During long-term cultivation, CD4+ T cells were also shown to acquire cytotoxic functions. In this study, CD4+ human T-cell clones derived from activated peripheral blood lymphocytes of healthy young adults were examined for the expression of cytotoxic machinery components. Cystatin F is a protein inhibitor of cysteine cathepsins, synthesized by CD8+ CTLs and natural killer cells. Cystatin F affects the cytotoxic efficacy of these cells by inhibiting the major progranzyme convertases cathepsins C and H as well as cathepsin L, which is involved in perforin activation. Here, we show that human CD4+ T-cell clones express the cysteine cathepsins that are involved in the activation of granzymes and perforin. CD4+ T-cell clones contained both the inactive, dimeric form as well as the active, monomeric form of cystatin F. As in CD8+ CTLs, cysteine cathepsins C and H were the major targets of cystatin F in CD4+ T-cell clones. Furthermore, CD4+ T-cell clones expressed the active forms of perforin and granzymes A and B. The levels of the cystatin F decreased with time in culture concomitantly with an increase in the activities of granzymes A and B. Therefore, our results suggest that cystatin F plays a role in regulating CD4+ T cell cytotoxicity. Since cystatin F can be secreted and taken up by bystander cells, our results suggest that CD4+ CTLs may also be involved in regulating immune responses through cystatin F secretion.     

WT1蛋白CTL表位肽基因载体的构建与鉴定

目的构建WT1(Wilms’tumor gene 1)蛋白CTL表位肽基因载体,并检测其在293T细胞中的转录。方法设计分别含WT1-126肽、WT1-235肽以及这两种肽的基因载体,并加入Th通用表位Pan-DR-Th(PADRE),应用蛋白酶体切割软件PAProC和NetChop优化各表位和间隔序列,DNA疫苗在线预测工具DyNAVacS优化真核密码子后,人工合成核苷酸序列,分别插入pUC57载体,构建pUC57-WT1质粒,测序鉴定后,酶切回收各目的片段,亚克隆至真核表达载体pcDNA3.1(+)中,构建重组真核表达质粒,转染293T细胞,RT-PCR检测各目的基因在293T细胞中的转录。采用无内毒素质粒大量提取试剂盒提取各重组质粒,采用紫外分光光度计测定质粒的纯度和浓度。结果各重组真核表达质粒经双酶切及测序鉴定证实构建正确;重组质粒携带的目的基因可在293T细胞中成功转录;各重组质粒DNA的纯度均合格,浓度在864.6～883.9μg/ml之间。结论成功构建了WT1蛋白CTL表位肽基因载体,并能在真核细胞中正常转录,为下一步在小鼠体内探讨特异性不同的CTLs群发挥抗肿瘤作用的机制奠定了基础。     

前列腺酸性磷酸酶在胃癌中的表达及其体外诱导抗胃癌免疫应答

目的检测前列腺酸性磷酸酶(PAP)在胃癌中的表达水平,探讨PAP作为胃癌主动免疫治疗新靶点的可能性。方法分别用RT-PCR和Western blot方法检测胃癌细胞系中PAP mRNA和PAP蛋白的表达;用免疫组织化学方法检测胃癌组织中PAP的表达。利用PAP表位肽对胃癌患者的PBMCs进行体外诱导,ELISA法检测PAP特异性IFN-γ分泌水平;51Cr释放法检测CTLs的细胞毒活性。结果3种胃癌细胞(MKN-7、MKN-28和MKN-45)表达PAP mRNA,其中MKN-28和MKN-45表达PAP蛋白,胃癌组织中PAP呈阳性表达。从2/4胃癌患者PBMCs中诱导出的PAP多肽特异性CTLs可特异性杀伤HLA-A24+/PAP+的胃癌细胞MKN-45,CTLs的细胞毒活性依赖于CD8+T淋巴细胞。结论PAP有可能成为胃癌特异性免疫治疗的新靶点。     

Synthesis and Immunological Evaluation of a Multicomponent Cancer Vaccine Candidate Containing a Long MUC1 Glycopeptide

A fully synthetic MUC1‐based cancer vaccine was designed and chemically synthesized containing an endogenous helper T‐epitope (MHC class II epitope). The vaccine elicited robust IgG titers that could neutralize cancer cells by antibody‐dependent cell‐mediated cytotoxicity (ADCC). It also activated cytotoxic T‐lymphocytes. Collectively, the immunological data demonstrate engagement of helper T‐cells in immune activation. A synthetic methodology was developed for a penta‐glycosylated MUC1 glycopeptide, and antisera of mice immunized by the new vaccine recognized such a structure. Previously reported fully synthetic MUC1‐based cancer vaccines that elicited potent immune responses employed exogenous helper T‐epitopes derived from microbes. It is the expectation that the use of the newly identified endogenous helper T‐epitope will be more attractive, because it will activate cognate CD4⁺ T‐cells that will provide critical tumor‐specific help intratumorally during the effector stage of tumor rejection and will aid in the generation of sustained immunological memory.     

Immune and Anticancer Responses Elicited by Fully Synthetic Aberrantly Glycosylated MUC1 Tripartite Vaccines Modified by a TLR2 or TLR9 Agonist

The mucin MUC1 is overexpressed and aberrantly glycosylated by many epithelial cancer cells manifested by truncated O‐linked saccharides. Although tumor‐associated MUC1 has generated considerable attention because of its potential for the development of a therapeutic cancer vaccine, it has been difficult to design constructs that consistently induce cytotoxic T‐lymphocytes (CTLs) and ADCC‐mediating antibodies specific for the tumor form of MUC1. We have designed, chemically synthesized, and immunologically examined vaccine candidates each composed of a glycopeptide derived from MUC1, a promiscuous T_helper peptide, and a TLR2 (Pam₃CysSK₄) or TLR9 (CpG‐ODN 1826) agonist. It was found that the Pam₃CysSK₄‐containing compound elicits more potent antigenic and cellular immune responses, resulting in a therapeutic effect in a mouse model of mammary cancer. It is thus shown, for the first time, that the nature of an inbuilt adjuvant of a tripartite vaccine can significantly impact the quality of immune responses elicited against a tumor‐associated glycopeptide. The unique adjuvant properties of Pam₃CysSK₄, which can reduce the suppressive function of regulatory T cells and enhance the cytotoxicity of tumor‐specific CTLs, are likely responsible for the superior properties of the vaccine candidate 1 .     

口蹄疫病毒多价DNA疫苗的构建及其免疫原性

目的构建口蹄疫病毒(FMDV)多价DNA疫苗,并检测其免疫原性。方法以复合多表位表达盒OAAT及AsiaⅠ型FMDV的P1-2A-3C基因为基础,构建FMDV多价DNA疫苗pIRES-OAAT-P1-2A-3C,并用间接免疫荧光(IFA)方法检测目的蛋白在HeLa细胞中的表达。进一步进行小鼠免疫试验,并应用ELISA法检测小鼠血清抗体,ELISPOT检测小鼠脾淋巴单细胞IFN-γ的分泌水平,流式细胞术检测脾T淋巴细胞亚群数量,淋巴细胞转化试验检测特异性淋巴细胞增殖水平。结果所构建的FMDV多价DNA疫苗在HeLa细胞中获得了正确表达。免疫小鼠后,血清特异性抗体水平、脾淋巴单细胞IFN-γ的分泌、脾T淋巴细胞亚群CD4+和CD8+的数量及特异性淋巴细胞增殖水平均显著提高。结论已成功构建了FMDV多价DNA疫苗,并诱导小鼠产生了特异性的细胞免疫和体液免疫应答。     

High-density sub-100-nm peptide-gold nanoparticle complexes improve vaccine presentation by dendritic cells in vitro

Nanocarriers have been explored to improve the delivery of tumor antigens to dendritic cells (DCs). Gold nanoparticles are attractive nanocarriers because they are inert, non-toxic, and can be readily endocytosed by DCs. Here, we designed novel gold-based nanovaccines (AuNVs) using a simple self-assembling bottom-up conjugation method to generate high-peptide density delivery and effective immune responses with limited toxicity. AuNVs were synthesized using a self-assembling conjugation method and optimized using DC-to-splenocyte interferon-γ enzyme-linked immunosorbent spot assays. The AuNV design has shown successful peptide conjugation with approximately 90% yield while remaining smaller than 80 nm in diameter. DCs uptake AuNVs with minimal toxicity and are able to process the vaccine peptides on the particles to stimulate cytotoxic T lymphocytes (CTLs). These high-peptide density AuNVs can stimulate CTLs better than free peptides and have great potential as carriers for various vaccine types.     

HIV-2型gp105、gag核酸疫苗构建与免疫学研究

目的 构建含 HIV－2 gp 105和 gag基因的核酸疫苗，并评价其免疫效果。方法 将 HIV－2 gp 105型和gag 基因克隆到核酸疫苗载体 pcDNA3．l（＋）中，构建重组核酸疫苗质粒。通过间接免疫荧光试验在细胞水平上检测gp105和ggg基因的表达产物。重组核酸疫苗免疫小鼠后，用流式细胞仪测定CD4+、CD8+淋巴细胞亚类数，用HIV－2抗体ELISA检测试剂盒检测免疫鼠血清中抗HIV－2抗体。结果 构建了3种重组核酸疫苗质粒pcgag、pcgp105和pcgag-gp105-gp105，转染BHK细胞后都能表达外源蛋白，免疫小鼠后可有效地刺激淋巴细胞增殖，并诱导产生抗HIV-2特异性抗体，其中pcgag-gp105的免疫效果较pcgag和pcgp105显著。结论 构建的重组核酸疫苗质粒均能诱导机体产生免疫反应，含有融合基因的pcgag-gp105免疫效果最显著。     

Engineering a CD123xCD3 bispecific scFv immunofusion for the treatment of leukemia and elimination of leukemia stem cells

Engineered bispecific antibodies that recruit cytotoxic lymphocytes to kill specific tumor cells have been showing promising clinical results. Here, we describe a bispecific single-chain Fv (scFv) immunofusion or BIf to target CD123(+) leukemia, that contains an anti-CD123 scFv fused at the N-terminus of human IgG1 hinge-C(H)2-C(H)3, and an anti-CD3 scFv fused at C-terminus. When expressed from transfected CHO-S cells, CD123xCD3 BIf forms a homodimer that provides a structure of N-terminal tumor-targeting domain that closely resembles natural antibody. The CD123xCD3 dimeric structure also provides binding affinity to CD123(+) tumor cells with a Kd of 10(-10) M, one to two orders of magnitude stronger than traditional bispecific antibody constructs. The location of the anti-CD3 scFv at C-terminus of BIf reduces the binding affinity to CD3(+) T cells by two orders, which could help to prevent non-specific T-cell activation. CD123xCD3 BIf is able to achieve T-cell-mediated target cell killing activities at low pM levels with E/T ratios as low as 2. Overall, the inclusion of human IgG1 constant region in BIf construct increases target cell-binding affinity; potentially increases serum half-life by its larger size and FcRn-mediated salvage system; and includes the abilities to activate the additional antibody-mediated cellular cytotoxicities.