大黄素-BSA包被膜片人工抗原制备及其免疫原性与特异性检测

目的:通过大黄素-BSA包被膜片的免疫原性及特异性研究,探讨半抗原-载体包被膜片人工抗原制备法的可行性。方法:先将BSA包被于PVDF膜片,再与大黄素-偶联剂衍生物偶联,制备大黄素-BSA包被膜片,经膜片皮下包埋法免疫大鼠,用大黄素或大黄酚、大黄素甲醚包被CA膜片免疫分析法检测免疫原性和特异性。结果:大黄素-BSA包被膜片的免疫原性高于或等于液相抗原;其抗血清对三种蒽醌类化合物反应的特异性基本一致(P0.05)。结论:大黄素-BSA包被膜片抗原,具有良好免疫原性和特异性,提示用半抗原-载体包被膜片法制备人工抗原可行。     

罗汉果甜苷V人工抗原免疫原性检测法的建立与评价

目的制备罗汉果甜苷V(mogroside V,MogV)-载体蛋白复合物人工抗原及抗血清,建立抗血清与MogV特异性反应的检测方法,为进一步制备MogV的单克隆抗体、建立快速检测MogV的ELISA法提供技术基础。方法将MogV与丁二酸酐、载体蛋白牛血清蛋白(BSA)和人血清蛋白(HSA)反应偶联,制得半抗原-载体蛋白复合物后,通过紫外扫描光谱计算出结合的半抗原数目;以此抗原免疫Balb/c小鼠,制备抗血清,并通过ELISA法检测效价和特异性。结果合成的人工抗原MogV-HS-BSA结合比约为44∶1,MogV-HS-HSA结合比约为64∶1;通过免疫小鼠得到特异性针对MogV的抗血清,血清效价较高。结论 MogV人工抗原有较好的免疫原性,建立的免疫原性检测方法简便可行。     

BPI N端优势抗原表位的模拟合成及其抗血清的制备

目的通过生物信息学模拟合成杀菌/渗透增强蛋白氨基端(BPIN端)优势抗原表位肽,免疫动物获得相应抗血清。方法利用生物信息学分析BPIN端(1-199)氨基酸序列的抗原性、亲水性、可塑性、表面可及性和二级结构等理化特性,据此设计合成TA/IK两条多肽,将其与钥孔戚血蓝素(KLH)偶联后,免疫家兔获得相应抗血清;采用间接ELISA法鉴定多肽的抗原性、测定血清抗体效价,Westernblot鉴定抗血清特异性。结果人工合成BPIN端TA/IK两个B细胞表位肽;ELISA检测证实TA/IK抗原肽能与商品化兔抗人BPI55多克隆抗体结合;所获TA/IK抗血清效价分别为1∶51200和1∶25600;Westernblot证实TA/IK抗血清能与BPI55标准品特异性结合。结论模拟合成的TA/IK抗原肽确为BPIN端优势抗原表位,相应抗血清可用于BPIN端功能性片段的检测鉴定。     

去氢甲睾酮抗体的制备与鉴定

目的:制备兔抗去氢甲睾酮(DMT)抗体,为采用免疫法分析食品中该激素的残留提供基础。方法:采用碳二亚胺法将肟化后的DMT分别偶联到钥孔血蓝蛋白、鸡卵清蛋白和牛血清白蛋白蛋白载体上,制备完全抗原,并利用薄层层析法、红外和紫外光谱法对其进行确证后,免疫新西兰大白兔;通过间接ELISA法测定和比较2种兔抗血清的效价、IC50及交叉反应率。结果:成功制备了DMT的完全抗原,其抗体效价分别为1∶64000(KLH-DMT)和1∶256000(OVA-DMT),IC50值分别为0.24μg/L和5.29μg/L;抗血清与丙酸睾酮酯、群勃龙的IC50值均大于781.25μg/L。结论:制备的DMT完全抗原具有较高的免疫原性,抗体与类似物丙酸睾酮酯、群勃龙无明显的交叉反应,可用于ELISA实验。     

多聚抗原肽免疫磁珠在制备单表位抗体中的应用

目的： 建立用多聚抗原肽（multiple antigen peptides, MAP）包被磁珠制备单表位抗体的方法.方法： 通过Fmoc法固相化学合成UreB的8分支单表位MAP, 将其作为免疫原免疫小鼠, 获得多克隆抗血清.将MAP以共价偶联的方式包被磁珠制备免疫磁珠（immunomagnetic beads, IB）, 通过IB从多克隆抗血清中纯化单表位抗体, 荧光偏振（fluorescence polarization, FP）法鉴定抗体的特异性, SDS-PAGE鉴定抗体纯度, 紫外分光光度法测定其回收率.结果： 合成的MAP具有较强的免疫原性, 免疫小鼠后得到的抗体滴度高达1∶ 12 800.MAP制备免疫磁珠的最佳包被浓度为100 mg/L, 包被效率最高可达79%.应用MAP免疫磁珠从抗血清中纯化得到的单表位抗体, 经鉴定与其他抗原表位无反应性, 其纯度为95%, 抗体的回收率为5.8%.结论： MAP包被的磁珠可快速分离纯化出针对某一抗原表位的特异性抗体, 其性质类似单克隆抗体.这一方案在快速制备少量高特异性抗体中具有广阔的应用前景.     

拟步甲科昆虫不同抗冻蛋白的免疫交叉性分析

目的 利用甲虫小胸鳖甲的抗冻蛋白MpAFP698制备抗血清,分析拟步甲科不同种类昆虫抗冻蛋白的免疫同源性.方法 通过DNA疫苗初次免疫-蛋白质加强的策略免疫新西兰大白兔,先以重组质粒pcDNA3-Mpafp698作为DNA疫苗免疫接种2次,再以融合蛋白His-MpAFP698进行蛋白质加强免疫2次.采用ELISA检测MpAFP698抗体的效价,Western blot法检测抗体的特异性及不同昆虫抗冻蛋白与MpAFP698抗体的免疫交叉反应.结果 兔抗血清的效价可达1∶40万,Western blot结果显示抗血清分别与His-MpAFP698及GST-MpAFP698蛋白有特异性结合,与小胸鳖甲抗冻蛋白MpAFP149、MpAFPS77以及来自不同昆虫的抗冻蛋白ApAPAFP914、OcAFP4有特异性结合.结论 荒漠地区不同甲虫的抗冻蛋白具有相同的抗原表位,可以发生免疫交叉反应.     

百草枯人工抗原的合成及抗体的制备

目的: 制备百草枯人工抗原和抗血清, 为建立酶联免疫吸附法提供技术储备.方法: 以4, 4'-联吡啶和碘甲烷为起始原料, 于暗处通氮气保护下合成了百草枯半抗原; 混合酸酐法偶联大分子蛋白载体牛血清白蛋白(BSA)和卵清蛋白(OVA)制备免疫抗原和包被抗原; 免疫新西兰大白兔, 制备多抗.结果: 合成的半抗原经HPLC-MS、 1HNMR和IR鉴定, 初步确定合成成功; 百草枯半抗原与BSA和OVA的结合比分别为19∶ 1和14∶ 1; 抗血清经间接ELISA法检测, 效价达1∶ 2.56×104, 经饱和硫酸铵沉淀法纯化后抗体的效价达1∶ 5.12×104.结论: 合成的百草枯人工抗原具有较好的免疫原性, 为百草枯酶联免疫检测(ELISA)试剂盒的研制提供了基础.     

人肌纤生成调节因子-1抗体的制备、鉴定及其在乳鼠心肌细胞中的应用

目的:制备抗人肌纤生成调节因子-1(hMR-1)的多肽抗体,并对其纯度、特异性、效价及适用性进行检测和鉴定。方法:TMHMM、DNAstar等软件分析hMR-1蛋白序列,选取2段优势抗原序列合成多肽并与钥孔戚血蓝素(KLH)偶联,混合后免疫家兔。抗血清经过免疫亲和层析法纯化得到多克隆抗体。用ELISA法检测效价,Western blotting和细胞免疫荧光(immunocytofluorescent,ICF)法鉴定其特异性和适用范围,并观察其在乳鼠心肌细胞中的应用情况。结果:(1)抗体效价达1∶105,Western blotting检测到与预测分子量17kD相符的条带,ICF图像背景低,阳性结构清晰。(2)乳大鼠心肌细胞实验发现荧光信号浓集于核周,过表达hMR-1后荧光强度明显高于空载对照和正常对照。结论:制备的抗hMR-1多肽抗体效价及特异性可用于Western blotting及ICF实验,可识别人源性和大鼠源性抗原表位,该工作将为进一步深入研究新基因hMR-1的功能奠定基础。     

基于不同载体制备黄芪甲苷人工抗原的研究

目的:比较牛血清白蛋白(BSA)和匙孔型血蓝蛋白(KLH)两种蛋白载体合成黄芪甲苷人工抗原的免疫原性。方法:用高碘酸钠法将黄芪甲苷(AST)分别与蛋白载体BSA和KLH偶联成AST-BSA及AST-KLH免疫6~8周龄的BALB/c雌性小鼠,测定其血清抗体效价;以卵清白蛋白(OVA)为载体蛋白同样以高碘酸钠法合成AST-OVA作为包被抗原。多抗血清经间接酶联免疫吸附法(indirect enzyme-linked immunosorbent assay,iELISA)和间接竞争酶联免疫吸附法(indirect competitive enzyme-linked immunosorbent assay,icELISA)检测其抗体效价及特异性。结果:经AST-KLH免疫的多抗血清较之AST-BSA免疫的特异性要高,与AST进行竞争酶联免疫检测,其IC50值约为5μg/ml。两种人工抗原免疫所得血清抗体效价均为1∶51 200左右。结论:AST-KLH具有更好的免疫原性,本次实验为进一步建立黄芪甲苷的免疫学检测方法奠定了研究基础。     

双烯雌酚人工抗原的合成及特异性抗体的制备

目的制备抗双烯雌酚(DIEN)特异性抗体,为进一步研制DIEN免疫检测试剂盒打基础。方法采用4-溴丁酸乙酯对DIEN进行活化,以活泼酯法与BSA偶联制备免疫原(DIEN-CP-BSA);经紫外扫描和飞行时间质谱扫描鉴定偶联情况;以DIEN-CP-BSA免疫Balb/c小鼠制备特异性抗体,间接(竞争)ELISA评价抗血清效价及特异性。结果本试验获得较高效价的DIEN抗血清,其效价达1∶64 000,双烯雌酚半抑制浓度(IC50)为62 ng/ml;抗血清与结构类似物己烷雌酚的交叉反应率仅为0.34%,与己烯雌酚和17-β雌二醇无交叉反应;利用该抗体建立的间接竞争ELISA检测法,双烯雌酚在10～300 ng/ml呈线性关系。结论本研究制备了抗双烯雌酚(DIEN)特异性抗体,为研究畜产品中DIEN残留及开发DIEN免疫检测试剂盒奠定了基础。     

TIMP-1B细胞表位的预测和鉴定

目的: 预测并鉴定金属蛋白酶组织抑制物-1(TIMP-1)蛋白B细胞表位。方法: 采用DNAStar和BcePred分析软件联合预测TIMP-1的B细胞表位,以此合成8分支多抗原肽结构的表位肽(MAP),并与通用型T辅助表位肽(VQGEESNDK,氨基酸163~171)联合免疫家兔,检测免疫血清效价,用Western blotting和间接酶联免疫吸附测定等方法鉴定其特异性和抗体亲和力。结果: 软件预测显示,TIMP-1的第27~41 位(MAP1)、第57~71 位(MAP2)、第95~109 位(MAP3)和第193~207 位(MAP4)氨基酸序列最可能为其优势B细胞表位。抗体滴度动态检测表明,MAP2、MAP3和MAP4均能诱导产生特异性抗体,其中MAP2和MAP4诱导的抗体水平最高;免疫印迹证实MAP2、MAP3和MAP4诱导产生特异性的TIMP-1抗体;间接ELISA证实MAP4与商品化TIMP-1抗体具有最高的亲和力。结论: TIMP-1的第27~41位和第193~207位氨基酸为其优势B细胞表位,其中第193~207位氨基酸的免疫原性最强,这为TIMP-1多肽抗体和B细胞优势短肽疫苗研制提供了理论依据。     

Characterization of new antigenic determinants introduced into homologous serum albumin by dinitrophenylation and sulphanylation

Studies on the immune response against hapten-autologous protein carriers in mice, guinea-pigs and rabbits have shown that the new antigenic determinants introduced in the carrier molecule by the hapten coupling reaction play an important role in the induction of both immunity and tolerance to these conjugates. The present experiments were designed to elucidate the specificity of the new antigenic determinants induced (1) by different haptens through the same coupling procedure and (2) by the same hapten coupled by different procedures. The results showed that both the nature of the hapten and the coupling procedure played a role in the serological specificity of the new antigenic determinants.     

高灵敏免疫磁性微球的制备及评价

目的 制备一种高灵敏、高特异的免疫磁性微球(IMMS),为其在肿瘤早期诊断方面的应用提供借鉴.方法分别采用N-羟基琥珀酰亚胺3-(2-吡啶二硫代基丙酸酯)(SPDP)和1-乙基-3-(3-二甲基胺基丙基)碳化二亚胺盐酸盐(EDC)作为交联剂,将鼠抗人免疫球蛋白G(IgG)偶联于磁性微球上.采用激光共聚焦检测和125Ⅰ标记抗体考察偶联效果.比较交联剂、磁球微球上功能团、间隔臂、偶联条件及抗体用量等因素对偶联效果的影响.分别对不同浓度人源IgG进行吸附,确定最低检测值.结果 实验结果表明间隔臂对偶联效果影响不大.两种交联剂均可将抗体联接于磁性微球上,EDC为交联剂,工艺更为简便,室温条件下抗体结合效果优于4℃条件下.本实验所制备的IMMS对人源IgG的最低检测值为50pg/mL.结论 本实验以人源IgG为肿瘤标记模型,成功地制备了一种高灵敏、高特异免疫磁性微球,制备简便,成本低廉,为肿瘤早期诊断提供了借鉴.     

丙型肝炎病毒包膜糖蛋白高变区1多抗原肽设计及？…

目的 应用多抗原肽（ＭＡＰ）研究丙型肝炎病毒包膜糖蛋白高变区１（ＨＶＲ１）的抗原性。方法 根据已经获得的ＨＣＶ－ＢＪ株Ｅ２／ＮＳ１区氨基酸序列,参照国内外得所报道的ＨＶ ＨＶＲ１序列及抗原性参数,设计并合成含ＨＣＶ ＨＶＲ１３９０－４１１ａａ序列２２个氨基酸的线性表位多肽（以ＬＰ表示）及ＭＡＰ（对称８分枝）,分别以ＬＰ和ＭＡＰ免疫Ｂａｌｂ／Ｃ小鼠及家兔,比较其免疫原性。结果 ＭＡＰ免疫原性明显强于     

Immunological studies on delayed hypersensitivity to phenytoin--I. A new method for preparing phenytoin antiserum

The present study was initiated to produce an antiserum to phenytoin with high specificity and sensitivity which would be suitable not only for determination of blood phenytoin concentration but also for induction of a hypersensitivity reaction to phenytoin in experimental animals. p-Aminophenytoin was synthesized and identified by means of IR, 1H-NMR and mass spectroscopy. BSA-phenytoin conjugate was prepared by using p-aminophenytoin, BSA and, as a coupling reagent, glutaraldehyde. Satisfactory response to immunization was achieved at a 9.8:1 molar ratio of p-aminophenytoin to BSA. The antiserum obtained from rabbits immunized with BSA-phenytoin conjugate exhibited practically no cross-reactivity with either phenytoin metabolites or other anti-epileptic drugs, indicating that this antiserum provides sufficiently high specificity. In our experiments, the lower limit for detecting phenytoin was 2 ng using RIA, whereas 200 ng was the minimum amount detectable by HPLC. Thus, by a difference of two orders of magnitude, the present RIA method shows a much higher sensitivity than that of HPLC, though we found a good correlation of simultaneous determinations of serum phenytoin between the two methods. Reproducibility of phenytoin determination in plasma was confirmed by calculating the coefficient of variance. The values were less than 10%.     

Engineering of immunogenic peptides by co-linear synthesis of determinants recognized by B and T cells

The potential of synthetic peptides as vaccines is restricted by their frequent lack of immunogenicity. As with haptens, coupling to a carrier protein is usually required to provide T cell help to anti-peptide antibody-producing B cells. In spite of their short length, a few natural or synthetic peptides are immunogenic: they all include both a determinant recognized by B cells and a proven or putative determinant recognized by T cells. We speculated that it should be possible to induce immunogenicity in peptide haptens by the inclusion of a well characterized determinant recognized by T cells. We thus synthesized two peptides, corresponding to different regions of the major protein VP6 of bovine rotavirus, co-linearly linked to a peptide of influenza virus hemagglutinin which had been shown to induce T helper cells in BALB/c mice. Both peptides induced anti-rotavirus antibodies and were more immunogenic than the corresponding bovine serum albumin-conjugated peptides.     

Synthesis and immunogenicity of hepatitis B virus envelope antigen expressed by recombinant vaccinia virus

Summary Five different recombinant vaccinia viruses expressing the envelope antigen of hepatitis B virus (HBsAg) under the control of the P_7·5 promoter were constructed. Cell cultures infected with some of the recombinant viruses synthesized both middle (M) and major surface (S) protein of HBsAg. It was shown that the length of the nontranslated sequence preceding preS2-ATG influenced the extracellular or intracellular HBV antigen distribution and the preS2:S antigen ratio. Some recombinants synthesized an M protein that was enlarged by additional 35 amino acids of preS1 domain and was entirely retained within the infected cells. Antibody responses to the S and preS2 antigens in mice revealed significant differences in the immunogenicity of individual recombinants.     

Direct immunization with synthetic peptidyl-polyamide resin. Comparison with antibody production from free peptide and conjugates with carrier proteins

An 11-amino acid residue peptidyl-linkage agent-polyamide resin complex was synthesized by the fluorenylmethyloxycarbonyl (Fmoc)-polyamide solid-phase system. Mice were immunized with the free peptide, peptidyl-resin and peptide coupled to the carrier proteins ovalbumin (Ova) and keyhole limpet haemocyanin (KLH). The immunogenicity of these materials was assessed by measurement of the capacity of the various antisera to bind the peptide in an enzyme-linked immunosorbent assay (ELISA). The peptidyl-resin exhibited enhanced immunogenicity compared to the free peptide. It is suggested that the time needed for screening for immunogenicity of large numbers of synthetic peptides thus be greatly shortened by using peptidyl-resins for immunization. This method eliminates laborious cleavage of peptide from resin, purification, coupling to carrier and the difficulties of handling peptides of low solubility.     

酵母表达的戊型肝炎病毒结构区ORF2蛋白的免疫原性研究

目的 研究巴氏毕赤酵母表达系统表达的戊型肝炎病毒（Hepatitis Evirus,HEV)结构区ORF2蛋白的免疫原性。方法 将重组蛋白免疫BALB/c小鼠。首先通过亲和捕获反转录PCR鉴定免疫小鼠抗血清是否能结合感染HEV恒河猴粪便及胆汁中的病毒颗粒,其次将重组蛋白分别以不同免疫途径,不同佐剂免疫小鼠,通过检测小鼠血清中抗-HEVORF2抗体阳转率及抗体滴度,观察其免疫原性。结果 亲和捕获反转录PCR阳性,表明免疫鼠抗血清可以捕获感染恒河猴粪便及胆汁样品中的HEV。在小鼠免疫实验中,肌内免疫优于腹腔免疫,抗原联合铝佐剂及CpG佐剂及CpG佐剂优于抗原联合铝佐剂,以抗原联合铝佐剂和CpG佐剂经股四头肌免疫小鼠,4周后加强一次的免疫效果最佳,ED500为0.023μg,实验表明,巴氏毕赤酵母表达的重组HEVORF2蛋白刺激小鼠产生的抗体,不仅可以特异性结合天然HEV,而且该蛋白在小鼠体内可以有效地诱发体液免疫反应。结论 巴氏毕赤酵母表达系统表达的HEVORF2蛋白具有良好的免疫原性,这为新型戊型肝炎疫苗的研制奠定了基础。     

Studies on antigenicity of the polyethylene glycol (PEG)-modified uricase

The purified uricase (urate: oxygen oxidoreductase, EC 1.7.3.3) from Candida utilis was modified to varying degrees with monomethoxypolyethylene glycol (PEG) of different molecular weights using cyanuric chloride as the coupling reagent. The PEG-uricase conjugates were examined on their immunological properties by means of ring test and passive cutaneous anaphylaxis (PCA). As increasing amounts of PEG were attached to uricase, it showed decreasing ability to elicit antibody production in rabbits. When sufficient polymers were attached, the modified uricase was devoid of the capacity to combine in vivo and in vitro with antibodies from guinea pigs injected with the unmodified uricase, however, were still able to react with antibodies to PEG-uricase conjugate. Antibodies against PEG-uricase conjugates also reacted with PEG modified superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1). These results indicate that the coupling of PEG to uricase resulted in the loss of original antigenicity and immunogenicity, but in the appearance of new antigenicity and immunogenicity which never showed any cross-reactions against the native uricase.