接种卡介苗对热休克蛋白65-MUC1抗原肽融合蛋白抑瘤作用的影响

目的：探讨接种卡介苗对热休克蛋白65-MUC1抗原肽融合蛋白（HSP65-MUC1）所激发的抑瘤作用的影响。方法：给经卡介苗免疫后产生HSP65抗体的小鼠注射HSP65-MUC1融合蛋白3次，然后给小鼠接种MUC1阳性的B16肿瘤细胞，观察HSP65-MUC1融合蛋白对MUC1阳性的B16肿瘤细胞在已产生HSP65抗体的小鼠体内生长的抑制作用。结果：HSP65-MUC1能够显著抑制MUC1阳性的B16肿瘤细胞在已产生HSP65抗体小鼠体内的生长，HSP65-MUC1组小鼠的肿瘤重量和体积显著地低于PBS组。结论：接种卡介苗并不影响HSP65-MUC1所激发的对MUC1阳性B16肿瘤细胞生长的抑制作用。     

C型CpG单链寡核苷酸对肿瘤疫苗抑瘤效果的增强作用

目的：研究C型CpG单链寡脱氧核苷酸（CpG ODN）对肿瘤疫苗抑瘤效果的增强作用.方法：利用体外淋巴细胞增生实验和病毒保护实验确定新C型CpG ODN, 采用小鼠体内抑瘤实验观察CpG ODN对肿瘤疫苗HSP65-MUC1重组蛋白抑制MUC1阳性肿瘤生长的增强作用, 并对小鼠血清中抗HSP65-MUC1抗体的类型进行了初步鉴定.结果：自行设计的CpG ODN BW005能刺激人PBMC和小鼠脾细胞增生,其刺激后的培养上清具有保护Vero E6细胞免受VSV感染的作用, 属于新型C型CpG ODN.将BW005与HSP65-MUC1联合应用于C57BL/6小鼠后, MUC1阳性肿瘤的发生明显延缓（平均44.8 d）, 其终末肿瘤发生率最低（33.33%）;荷瘤小鼠的生存期明显延长（平均49.5 d）, 其终末生存率最高（66.67%）.小鼠血清中抗HSP65和抗MUC1的IgG2a抗体水平增加.结论：C型CpG ODN可以增强肿瘤疫苗HSP65-MUC1的抑瘤效果, 考虑与小鼠体内Th1环境的形成有关.     

MUC1/Y胞外段在大肠杆菌中的表达和鉴定

目的：获得MUC1／Y胞外段重组蛋白，研究其生物学功能，为肿瘤治疗提供实验依据。方法：利用RT—PCR从MCF7细胞中获得MUC1／Y胞外段编码基因，将其克隆到原核表达载体pET-32a中，并在BL21（DE3）大肠杆菌中进行表达；以亲和层析法对MUC1／Y重组蛋白进行纯化；利用纯化的MUC1／Y蛋白免疫家兔制备MUC1／Y多克隆抗体，然后对乳腺癌组织进行组化染色。结果：在大肠杆菌BL21（DE3）中成功表达了分子量为30000的Trx—MUC1／Y融合蛋白，经镍亲和层析一步纯化所获得的蛋白质纯度〉90％，用Trx-MUC1／Y融合蛋白免疫家兔获得的抗血清对乳腺癌组织的初步组化检测证明MUC1／Y融合蛋白具有很好的生物学活性。结论：成功表达并纯化了具有生物学活性的MUC1／Y胞外段重组蛋白。     

抗人整合素β3亚基单克隆抗体的制备及其抗肿瘤活性的研究

目的制备抗人整合素β3亚基的单克隆抗体(mAb),研究其对肿瘤治疗的作用。方法用RT-PCR方法扩增人β3胞膜外基因,将其克隆至原核表达载体pQE30中,获得含β3胞膜外基因的高效表达载体pQE30-β3,将其转化大肠杆菌M15,通过诱导表达及纯化,获得β3蛋白。将此蛋白免疫BALB/c小鼠,应用B淋巴细胞杂交瘤技术制备抗β3亚基mAb,Western blot鉴定mAb的特异性。通过小鼠体内抑制黑色素瘤生长实验筛选出具有抑制肿瘤生长作用的mAb。进一步用MTT法及流式细胞术观察该mAb体外抑制人脐静脉内皮细胞(HUVEC)增殖及诱导其凋亡的作用。结果扩增获得了β3胞膜外基因,构建了β3蛋白的原核表达载体,表达纯化了β3蛋白,成功制备了8株mAb,Western blot证明了其特异性。经过体内抑瘤实验筛选出一株具有显著抑制肿瘤生长的mAb4F12。该mAb可抑制HUVEC细胞增殖并诱导其凋亡。结论成功表达了β3蛋白,并制备了有活性的mAb,抗体具有抑制肿瘤生长的作用,这可能是通过抑制血管内皮细胞的增殖和诱发凋亡实现的。     

PCGF1蛋白的表达、纯化及其单克隆抗体的制备与鉴定

目的:原核表达人表观抑制因子Polycomb家族成员PCGF1蛋白片段,并制备其鼠源单克隆抗体(mAb)。方法:应用PCR技术扩增人PCGF1基因编码区部分序列(CDS区第382～567bp的DNA片段)并插入到pET-32a(+)质粒中,在大肠杆菌BL21中进行His-PCGF1-128/189融合蛋白(简写为His-N128/189)的原核表达。利用所表达的融合蛋白中含有的6×His标签进行亲和层析纯化。用所获得的纯化蛋白免疫BALB/c小鼠,利用杂交瘤技术,分别通过ELISA和Western blot法筛选稳定分泌抗体的杂交瘤细胞株,用免疫双向扩散法鉴定mAb的Ig亚类。取1株杂交瘤细胞按照常规方法制备腹水,利用Millipore公司的mAb纯化试剂盒纯化mAb,用Western blot法检测mAb的效价。结果:表达纯化了重组人His-N128/189蛋白;筛选出2株可稳定分泌特异性抗人PCGF1 mAb的杂交瘤细胞株,其免疫球蛋白类型均为IgG1类;通过腹水制备和纯化获得高效价(1∶6000)、高特异性的鼠抗人PCGF1 mAb。结论:原核表达的PCGF1片段融合蛋白可以被纯化,并具有足够的蛋白免疫原性,所制备的相应mAb可特异识别内源性和外源性PCGF1蛋白,可以运用于PCGF1基因功能的研究。     

人睾丸特异性新基因hT279单克隆抗体制备及其应用

目的构建人睾丸特异性新基因hT279(GenBank登录号BC016750)的原核表达载体,纯化融合蛋白并以其为抗原免疫Balb/c小鼠制备抗人睾丸特异性hT279蛋白单克隆抗体(mAb)并进行特性鉴定。方法用PCR方法得到睾丸特异性新基因hT279并克隆至pET32a原核表达载体中,转化大肠杆菌BL21诱导融合蛋白表达;获得的可溶性蛋白经亲和层析纯化、SDS-PAGE鉴定后,免疫Balb/c小鼠,应用淋巴细胞杂交瘤技术制备抗hT279 mAb,并通过间接ELISA、Western blot和免疫组织化学法对mAb进行特性鉴定。结果实现了hT279的原核表达,获得了1株稳定分泌抗hT279 mAb的杂交瘤细胞株4B2,抗体亚型为IgG2b(κ),效价达到1×104。Western blot鉴定表明,该mAb在人正常睾丸蛋白中相对分子质量约为22 000处检测到特异条带。免疫组织化学显示hT279蛋白主要在正常人睾丸的精母细胞及圆形精子细胞中表达,而在男性不育患者睾丸组织中表达消失。结论成功制备出1株抗hT279的mAb 4B2,为进一步研究hT279在人类精子发生中的功能和男性不育症的诊断提供了特异的检测工具。     

抗人乳腺癌候选抑制蛋白1单克隆抗体的制备及鉴定

目的:制备抗人乳腺癌候选抑制蛋白1(BCSC-1)蛋白单克隆抗体(mAb),并对其特异性进行鉴定。方法:构建原核表达载体pET-30a-BCSC-1,在原核表达系统E.coliBL21(DE3)中表达重组人BCSC-1蛋白。超声洗涤纯化重组蛋白作为抗原免疫BALB/c小鼠,取免疫小鼠的脾细胞和同系小鼠的骨髓瘤细胞Sp2/0进行常规融合,通过有限稀释法进行克隆和间接ELISA筛选,获得分泌小鼠抗人BCSC-1蛋白mAb的杂交瘤细胞株,通过ELISA、Western blot等方法检测其特异性。将真核重组表达载体pcDNA3.1/v5-HisB-BCSC-1转染入乳腺癌MCF-7细胞,通过免疫组化确定了人BCSC-1蛋白的表达。结果:成功构建了原核表达载体pET-30a-BCSC-1,经IPTG诱导表达出了重组人BCSC-1蛋白,主要以包涵体的形式存在沉淀中。用纯化的重组BCSC-1蛋白免疫小鼠后经融合筛选得到1株稳定分泌抗BCSC-1的mAb杂交瘤细胞株。通过ELISA、Western blot、免疫组化等方法鉴定,抗BC-SC-1的mAb能与BCSC-1蛋白特异性结合。结论:成功制备了小鼠抗人BCSC-1的mAb。     

一种双抗体夹心ELISA检测热休克融合蛋白方法的建立

MUC1蛋白在乳腺癌、卵巢癌、胰腺癌等多种肿瘤细胞都呈现高水平表达。MUC1蛋白的表位肽VNTR，是诱生MUC1特异性免疫应答的靶点；采用MUC1 VNTR多肽研制出的生物制剂能刺激小鼠抑制表达MUC1肿瘤细胞的生长。     

细胞因子Midkine融合蛋白的表达及其单克隆抗体的制备与应用

目的:克隆细胞因子midkine(MK)基因,表达其融合蛋白,制备抗MK单克隆抗体(mAb)并检测MK在肿瘤细胞中的表达。方法:利用MK基因的特异性引物,通过RT-PCR从人肾癌组织mRNA中扩增人MKcDNA分子。将其定向克隆于原核表达载体中,在大肠杆菌中表达MS2-MK融合蛋白。以纯化的融合蛋白免疫BALB/c小鼠,用传统的杂交瘤技术,进行细胞融合、筛选、克隆化并制备mAb腹水。用ELISA法分析其Ig亚类,用免疫细胞化学染色法检测MK在肿瘤细胞中的表达。结果:成功地克隆出MK基因并表达了MS2-MK融合蛋白。通过免疫和筛选,获得2株分泌小鼠抗人MKmAb的杂交瘤细胞,其分泌的mAb的Ig亚类分别为IgG1和IgG2a。免疫细胞化学染色显示,2株mAb与人胃癌细胞株MGC803和胃癌组织呈强阳性反应。结论:在原核细胞中获得MS2-MK融合蛋白的表达,并制备出抗MK的mAb,为研究MK的生物学活性提供了条件。     

MAGE-1与结核杆菌HSP70融合基因的构建及原核表达

目的 构建结核杆菌HSP70与肿瘤抗原MAGE-1的融合基因，在大肠杆菌中进行表达，并通过GST纯化系统进行分离纯化。方法 利用PCR方法扩增TBHSP70基因，经测序后连入原核表达载体pGEX-4T-1，再通过PCR方法扩增MAGE-1基因片段(289～927bp)，测序后插入TBHSP70基因的5’端，构建MAGE-1与TBHSP70的N端融合基因原核表达质粒pGEX-MAGE-1-TBHSP70，含有该质粒的大肠杆菌DH5a进行诱导表达和分离纯化。结果 成功地扩增了TBHSP70基因与MAGE-1基因片段，测序结果表明与GenBank公布的序列一致；成功地构建了pGEX-MAGE-1-TBHSP70原核表达质粒，含有该质粒的大肠杆菌DH5α经IPTG诱导后表达一Mt约为125000的蛋白，经GST融合蛋白表达系统纯化，得到了MAGE-1与TBHSP70的融合蛋白。结论 成功地获得了MAGE-1与TBHSP70的融合蛋白，为研究MAGE-1-TBHSP70融合蛋白在肿瘤免疫治疗中的作用奠定了基础。     

Heat shock fusion protein induces both specific and nonspecific anti-tumor immunity

Mucin 1 (MUC1) is a tumor antigen, and the most important epitopes that can induce cytotoxic T lymphocytes (CTL) reside in the variable-number tandem repeats (VNTR). Heat shock protein (HSP) complexes isolated from tumors have been shown to induce specific anti-tumor immunity. HSP alone can also induce nonspecific immunity. To explore the possibility to utilize the specific anti-tumor immunity induced by MUC1 VNTR and the nonspecific immunity induced by HSP, we constructed a recombinant protein (HSP65-MUC1) by fusing Bacillus Calmette-Guérin-derived HSP65 with the MUC1 VNTR peptide and tested its ability to induce anti-tumor activities in a tumor challenge model. The growth of MUC1-expressing tumors was significantly inhibited in mice immunized with HSP65-MUC1, both before and after tumor challenge. A much larger percentage of immunized mice survived the tumor challenge than non-immunized mice. Correlating with the anti-tumor activity, HSP65-MUC1 was shown to induce MUC1-specific CTL as well as nonspecific anti-tumor immunity. In the human system, HSP65-MUC1-loaded human DC induced the generation of autologous MUC1-specific CTL in vitro. These results suggest that exogenously applied HSP65-MUC1 may be used to treat MUC1 tumors by inducing the epitope-specific CTL as well as nonspecific anti-tumor responses mediated by the HSP part of the fusion protein.     

肝癌抗原肽(EPVTKAEML)与人HSP70融合基因的构建及原核表达

目的:构建及原核表达肝癌抗原肽(EPVTKAEML)与人热休克蛋白70(HSP70)的融合基因.方法:采用加端PCR方法,将EPVTKAEML的基因序列融合到人HSP70基因的3′端;将融合基因克隆入原核表达载体pET-28a( )中,构建重组质粒pET-28a( )/EPVTKAEML-HSP70.经限制性内切酶BamH I、Xho I双酶切鉴定及序列测定后,转化E.coli BL21(DE3),经IPTG诱导表达融合蛋白,SDS-PAGE检测表达结果.结果:应用加端PCR方法扩增出约2.0 kb的目的片段,序列测定结果证实,EPVTKAEML的基因序列成功地融合到人HSP70基因的3′端.经BamH I、Xho I酶切鉴定证实,融合基因成功地克隆到原核表达载体pET-28a( )上;转入重组质粒的E.coli BL21(DE3)经IPTG诱导后,SDS-PAGE分析发现在相对分子质量(Mr)约72 000处有表达量明显增多的蛋白条带.结论:成功地构建并表达了肝癌抗原肽(EPVTKAEML)与人HSP70的融合基因.     

Influence of organ site and tumor cell type on MUC1-specific tumor immunity

We investigated the influence of organ-specific parameters on tolerance and immunity to human MUC1. C57Bl/6 mice (wild-type) and C57Bl/6 transgenic for MUC1 (MUC1.Tg) were challenged in the pancreas with Panc02-MUC1, a C57Bl/6-syngeneic pancreatic cancer cell line expressing human MUC1. Wild-type mice produced immune responses to MUC1 when presented on tumor cells growing in the pancreas; however, the responses to tumors in the pancreas were less effective than responses produced by tumor challenge at the s.c. site. Tumor immunity specific for MUC1 was produced in wild-type mice by two different procedures: (i) s.c. immunization of wild-type mice with a low dose of Panc02-MUC1 or (ii) adoptive transfer of spleen and lymph node cells harvested from wild-type mice previously immunized s.c. with Panc02-MUC1. This demonstrates that immune responses to MUC1 presented at the s.c. site can be detected and adoptively transferred. MUC1.Tg mice were immunologically tolerant to MUC1; however, some immunological protection against orthotopic challenge with Panc02-MUC1 was conferred by adoptive transfer of CD4+ and CD8+ T cells from wild-type mice. These results show that it is more difficult to produce immune responses to tumors growing at the pancreatic site than the s.c. site. Panc02-MUC1 cells growing in the pancreas were accessible to the immune system, and immune responses evoked by s.c. presentation of this molecule in wild-type mice were effective in rejecting tumor cells in the pancreas of both wild-type and MUC1.Tg mice. No effective anti-tumor immune responses against MUC1 were produced in MUC1.Tg mice.     

新基因MAGE-n表位肽与人HSP70融合基因的构建及表达纯化

目的构建MAGE-n159-167(QLVFGIEVV)表位肽与人热休克蛋白70(HSP70)的融合基因并表达纯化。方法应用PCR方法,将QLVFGIEVV的cDNA序列融合到人HSP70基因的3'端,将融合基因克隆入原核表达载体pET-28a(+)中,构建重组质粒pET-28a(+)QLVFGIEVV-HSP70;采用双酶切(Sac Ⅰ、Hind Ⅲ)及PCR鉴定后测序;转化大肠杆菌E.coli BL21(DE3),用IPTG诱导表达,Ni Sepharose6FF亲和填料进行分离纯化,SDS-PAGE检测表达及纯化结果。结果经PCR扩增成功获得约2.0kb的目的片段,重组体经Sac Ⅰ、Hind Ⅲ双酶切分析及PCR结果与预期结果一致,测序正确。转入重组质粒的E.coli BL21(DE3)经IPTG诱导、SDS-PAGE分析得到71kD左右的目的蛋白条带。用Ni Sepharose6FF亲和填料分离纯化,获得了纯化的融合蛋白。结论成功构建原核表达载体pET-28a(+)QLVFGIEVV-HSP70,并获得纯化的融合蛋白,为基于MAGE-n的肿瘤疫苗研制提供良好的抗原奠定了实验基础。     

Induction of immune response and anti-tumor activities in mice with a DNA vaccine encoding human mucin 1 variable-number tandem repeats

Mucin 1 (MUC1) is a tumor-associated antigen that carries the important variable-number tandem repeat (VNTR) epitopes for inducing cytotoxic T lymphocytes. Such a property makes MUC1 VNTR potentially attractive for immunotherapy. This study explored the possibility of developing an efficient anti-tumor vaccine strategy using the specific antitumor immunity induced by the MUC1 VNTR DNA vaccine combined with the adjuvant effect of a plasmid expressing murine interleukin-2 (IL-2). The results showed that the MUC1 VNTR DNA vaccine successfully induced both humoral and cellular immune responses against MUC1 VNTR in mice. The effect could be obviously enhanced by increasing the number of tandem repeats, the number of immunizations, and by co-administration of the cytokine plasmid. The growth of MUC1-expressing (MUC1(+)) tumors was significantly inhibited in mice immunized with the MUC1 VNTR DNA vaccine combined with the IL-2 plasmid, both before and after tumor challenge. A much larger percentage of the immunized mice survived tumor challenge than the non-immunized mice. The combination of the MUC1 VNTR DNA vaccine and the IL-2 adjuvant plasmid provides an attractive alternative for prophylactic and therapeutic vaccinations against MUC1(+) tumors.     

人MUC1与GM-CSF基因融合真核表达质粒的构建与表达

目的：构建人MUC1重复序列串联体基因与GM-CSF基因重组的真核共表达质粒pcDNA3.1（＋）-MUC1-GM-CSF,并观察重组质粒在COS-7细胞中的表达。方法：将信号肽及编码MUC1基因片段合成、合成的片段经退火等方法获得MUC1基因重复序列串联体,酶切鉴定及序列分析后,与GM-CSF基因克隆入pcDNA3.1（＋）真核表达载体中,构建真核共表达质粒pcDNA3.1（＋）-MUC1-GM-CSF。以重组质粒转染COS-7细胞,通过间接免疫荧光法及ELISA检测目的基因的表达。结果：酶切鉴定及序列分析表明,重组质粒含有人MUC1重复序列串联体与GM-CSF的融合基因,在COS-7细胞中可检测到MUC1表达,重组质粒免疫小鼠可诱导产生抗GM-CSF抗体。结论：人MUC1重复序列串联体与GM-CSF基因重组的真核共表达质粒的成功构建,为对其免疫原性、生物学特性及免疫治疗的进一步研究奠定了基础。     

MUC1模拟表位肽治疗表达人MUC1 T739荷瘤小鼠的实验研究

目的观察MUC1的模拟表位肽对表达人MUC1 T739荷瘤小鼠的治疗作用。方法建立稳定表达人MUC1 T739荷瘤小鼠,培养T739小鼠成熟树突状细胞,荷瘤小鼠随机分为4组,用负载模拟表位肽成熟DC免疫表达人MUC1 T739荷瘤小鼠,第1组皮下注射等渗盐水,第2组注射空DC,第3组注射负载1号肽的DC,第4组注射负载2号肽的DC,测量肿瘤大小,计算肿瘤体积,称瘤重,并观察小鼠存活期。结果两组DC+肽免疫的小鼠瘤体积减小明显,与1、2组相比差异非常显著(P<0.01)。平均瘤重1、2组与3、4组相比差异非常显著(P<0.01)。第1～4组荷瘤鼠的生存期分别为(34.6±3.507)d,(35.2±3.564)d,(58.4±5.595)d,(59±6.819)d,3、4两组荷瘤小鼠生存期较1、2组明显延长,差异有显著性意义(P<0.01)。结论 MUC1模拟表位肽能明显抑制表达人MUC1 T739荷瘤小鼠肿瘤生长,显著延长T739荷瘤小鼠生存时间。     

Dendritic cells fused with human cancer cells: morphology, antigen expression, and T cell stimulation

Fusion of human dendritic cells (DC) with tumor cells is an effective approach for delivering tumor antigens to DC, and DC/tumor fusion cells are potent stimulators of autologous T cells. However, the integration and morphology of DC/tumor fusion cells has not been examined. In the present study, we fused patient-derived DC to autologous breast or ovarian carcinoma cells. The fusion cells possessed the properties of both parent cells. After fusion, the cytoplasm of the two cells was integrated, whereas their nuclei remained separate entities. Colocalization of MUC1 peptide and HLA-DR molecules was observed on fusion cells under the immunoelectron microscope. Coculture of patient-derived peripheral blood mononuclear cells (PBMC) with DC/tumor fusion cells resulted in activation of CD4 and CD8 T cells as assessed by IFN-gamma secretion, HLA-A*0201-MUC1 tetramer, and standard cytotoxic T lymphocyte (CTL) assays. The present study provides first evidence of integration of human DC and tumor cells and links their properties to T cell activation.     

Epitope mapping of anti-breast and anti-ovarian mucin monoclonal antibodies.

Anti-breast cancer antibodies (BC2, HMPV and 4B6) and an anti-ovarian cancer antibody (OM1) were found to react with mucins--indeed with the protein core encoded by the MUC1 gene. This gene contains a VNTR (variable number of tandem repeats) encoding a 60 bp (= 20 amino acids) repeat sequence and within this amino acid sequence SAPDTRPAP was predicted, by hydrophilicity analysis, to be the immunogenic peptide sequence. The four antibodies were shown to react with MUC1 VNTR encoded peptides in direct binding and inhibition studies. The precise reactivity of the 4 mAbs was mapped using ELISA in both solid and liquid phase, and demonstrated the epitopes to be: APDTR (BC2 and HMPV), PDTR (4B6) and DTRPA (OM1). By using the pepscan method, the epitopes were shorter (PDTR, DTR and DTRP). However when these short peptides (except DTR) were synthesized they did not react; flanking amino acids are needed for the epitopes. Clearly several different methods should be used to define the reactive epitope. Within (S)APDTR, major amino acid substitutions could be made--even of three to four amino acids without altering antibody binding, provided that P and R were not substituted. It was of interest that an anti-ovarian cancer antibody gave similar anti-peptide reactions to the anti-breast cancer antibodies; apparently MUC1 peptides in ovarian cancer are the same as in breast cancer.