特异性吗啡抗原和单克隆抗体的制备

吗啡分子的不同部位与蛋白偶联诱导出的抗体的专一性差异很大。为减少交叉反应,提高抗体分子对游离吗啡的特异性识别,选择吗啡分子N位进行修饰,合成了半抗原降吗啡,并设计和合成不同的连接臂,将半抗原用不同的连接臂与不同的载体蛋白共价结合分别制备了免疫抗原和筛选抗原,经细胞融合和筛选,成功地获得了5株可分汔抗吗啡单克隆抗体的细胞株：28H10,29D5,36G3,42D5,43C4。     

半抗原的设计、修饰及人工抗原的制备

制备具有良好免疫原性的人工抗原是建立测定小分子化合物的免疫分析方法的最关键步骤.本文对半抗原的设计、修饰(修饰位点的选择、修饰物的制备、连接臂的选择)、载体的选择、半抗原与载体的偶联(偶联方式、偶联条件、最佳偶联率)、人工抗原的纯化与鉴定等方面作了详细的介绍.     

新型游离三碘甲腺原氨酸人工抗原的合成与表征

利用快速、温和的“Click Chemistry(点击化学)”反应,在游离三碘甲腺原氨酸(FT3)的羧基上引入一个带有三唑环的羧基“间接臂”,生成半抗原(FT3C)。 再用N-羟基琥珀酰亚胺活性酯法,将半抗原(FT3C)分别与牛血清白蛋白(BSA)和钥孔戚血蓝素(KLH)偶联,合成了免疫抗原(FT3C-BSA) 和包被抗原(FT3C-KLH)。 免疫抗原(FT3C-BSA)的紫外吸收光谱相对于FT3C和BSA有明显差异,表明成功实现了偶联,经计算得到偶联比为7∶1;用FT3C-BSA免疫Balb/c小鼠,获得高效价的抗FT3血清。 采用间接ELISA法检测抗体的IC50值为0.37 mg/L,抗血清效价可达6.24×104,是制备FT3人工抗原的一种新方法。     

催化抗体

催化抗体(又称抗体酶)是通过化学和免疫相结合的方法所获得的具有催化某化学反应活性的抗体,因此也可看作为一种模拟酶。通过设计和合成在立体形态和电性上与某一化学反应的过渡态相类似的化合物作为半抗原,并通过适当的连接臂与载体蛋白相连,便可获得某种抗原。当将此抗原注入小鼠体内,经体内免疫反应的结果,就有可能产生相应的抗体。这种抗体有可能具有催化原化学反应的活性。目前已获得对多种化学反应具有催化活性的抗体。催化抗体的发现为体外反应的酶促化开辟了新的途径。     

2-萘酚完全抗原的合成及其抗体的制备

以2-萘氧乙酸(2)为半抗原,牛血清蛋白(BSA)为载体蛋白,用活化酯法合成了2-萘酚完全抗原(1).通过调整反应时间,偶联剂二环已基碳二亚胺与2的质量比以及反应体系中的pH,制备了多种结合比的1′.给新西兰大白兔注射112.40进行免疫,获得了用于免疫分析法测定萘酚类物质的合格2-萘酚抗体.     

游离甲状腺素半抗原及人工抗原的合成及鉴定

选择游离甲状腺素(FT4)的羧基官能团为修饰位点,先用二碳酸二叔丁酯(Boc2O)保护氨基,再用HATU作为缩合剂与炔丙基胺通过酰胺键缩合,将端炔基引入FT4,然后在微量亚铜盐催化下与叠氮戊酸发生"Click Chemistry"反应,合成以三唑杂环作为"连接臂"的FT4人工半抗原(FT4H)。采用N-羟基琥珀亚胺活性酯法,将半抗原(FT4H)与牛血清白蛋白(BSA)、钥孔戚血蓝素(KLH)偶联,合成免疫原(FT4H-BSA)和包被原(FT4H-KLH),免疫原(FT4H-BSA)的紫外吸收图谱相对于FT4H和BSA有明显差异,表明偶联成功,并计算得到偶联比为12∶1。用FT4H-BSA(2×10!3g/mL,0.1 mg/只)免疫6～8周龄的Balb/c小鼠,5次免疫后,经尾部取血,获得抗FT4血清,采用ELISA间接法测定抗体血清的效价可达1.28×105。结果表明,含有较强决定簇(三唑环)的连接臂未对抗体血清识别FT4产生较大的干扰,为制备小分子的人工抗原提供一种新的方法。     

基于分子模拟的脱氧雪腐镰刀菌烯醇半抗原分子设计及免疫效果研究

运用分子模拟软件Hyperchem 7.5,对脱氧雪腐镰刀菌烯醇(DON)及其6种不同连接臂修饰后的DON衍生物的分子构型进行量化计算,通过对其结构参数以及分子轨道的计算比较,获得高特异性、高生物活性的DON半抗原结构,避免了半抗原设计方面的盲目性。同时合成了其中的3种半抗原,通过碳二亚胺(EDC)法与BSA进行偶联免疫Bal b/c小鼠,制备多抗血清,采用间接酶联免疫吸附法(ELISA)和间接竞争ELISA法进行抗体效果的比较。结果表明,分子模拟计算结果与免疫实验的结果相一致,分子模拟对半抗原结构设计具有指导性意义。     

基于高特异性单克隆抗体的间接竞争ELISA检测食品中胭脂红的研究

该研究设计合成了一种胭脂红半抗原,分别采用重氮化法和戊二醛法将半抗原与载体蛋白偶联制备人工抗原,通过免疫Bal b/c小鼠及杂交瘤技术成功筛选制备了胭脂红高特异性单克隆抗体,与苋菜红、柠檬黄等结构类似物无交叉反应.基于该抗体建立了间接竞争酶联免疫分析方法用于检测食品中胭脂红残留.该方法对胭脂红的半抑制浓度(IC50)和...     

去甲氯胺酮半抗原及其全抗原的合成与鉴定

在低温条件下,去甲氯胺酮与琥珀醛酸反应,合成了半抗原羧基-去甲氯胺酮,电喷雾质谱鉴定结果表明,目标半抗原合成成功;通过碳二亚胺法将半抗原与载体蛋白偶联制备人工抗原,红外光谱法鉴定结果表明,人工抗原合成成功,基质辅助激光解析电离飞行时间质谱鉴定表明去甲氯胺酮半抗原与牛血清白蛋白的偶联比为11:1。经动物免疫,获得高效价特异性多克隆抗体,抗血清效价可达5.12×104。     

烯效唑酶联免疫吸附分析方法研究

合成了半抗原烯效唑琥珀酸半酯,分别将半抗原与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联制备了免疫抗原和包被抗原,并成功建立了水和土壤中烯效唑残留的酶联免疫吸附分析法。用免疫抗原免疫新西兰大白兔得到多克隆抗体,抗体的效价达到1.02×106。方法的线性范围为0.005～10mg/L,检出限为1.82±0.83μg/L。除烯唑醇有一定的交叉反应外,与大部分三唑类杀菌剂都没有明显的交叉反应。在水和土壤中添加不同浓度的烯效唑,回收率分别在82.40%～105.92%和92.42%～100.08%之间。     

球状功能性烟草花叶病毒纳米颗粒的制备及表征

烟草花叶病毒(TMV)由于其良好的生物相容性、单分散性、多价性、低成本等优点,已作为功能材料的基本构筑单元应用于光电器件、组织工程、疫苗载体,无机纳米材料制备等研究领域。然而,相比于棒状的TMV,球状TMV纳米颗粒无核酸分子,抗环境影响能力更强,比表面积更大。本文利用蛋白质的热致变性原理,对经基因和化学改性后的棒状TMV如半胱氨酸突变体(TMV-Cys)、赖氨酸突变体(TMV-EPMK)和β-环糊精(β-CD)修饰的TMV(TMV-β-CD)进行热变性处理,探究其形成球型纳米颗粒(TMV-SNP)的能力及功能性。结果显示,改性后的TMV经历热变性后可得到形貌均一的球型纳米颗粒,且其暴露在纳米颗粒表面的功能基团Cys、Lys和β-CD仍具有反应活性。     

Synthesis and immunological study of a wall teichoic acid-based vaccine against E. faecium U0317

ABSTRACT

A repeat unit of cell wall teichoic acids (WTA) isolated from E. faecium U0317 was chemically synthesized efficiently by a stepwise strategy. It was derivatized with a 5-aminopentanyl linker to facilitate conjugation with carrier proteins KLH and HSA. Immunological studies of the KLH conjugate 1 demonstrated that it could provoke robust immune responses and high titers of IgG antibodies, which could successfully recognize the synthesized WTA repeat unit 3. This result suggested that synthetic glycoconjugate 1 could be a promising vaccine candidate against E. faecium for further studies.     

Conformational changes of hapten-protein conjugates resulting in improved broad-specificity and sensitivity of an ELISA for organophosphorus pesticides

The type of hapten linkage to a carrier protein can play an important role in determining the nature of the resulting antibody response. Generic haptens using three types of linkers were synthesized (a monocarboxylic acid, an unsaturated hydrocarbon and a carboxamido spacer). These haptens were conjugated to bovine serum albumin (BSA) and used as immunogens to produce broad-specificity monoclonal antibodies (MAbs) to organophosphorus pesticides (OPs). Three-dimensional (3D) structures of hapten-lysine conjugates were optimized using molecular modeling (MM) to mimic conformations of hapten-BSA conjugates. The results from MM studies revealed a change of the 3D conformation and electrostatic potential of hapten 1 when the monocarboxylic acid linker was coupled to lysine. This result was consistent with the observed high-cross-reactivity of the corresponding MAb-H1 for the OPs. The competitive indirect enzyme-linked immunosorbent assay based on MAb-H1 is ideally suited to be used as a screening method for OP contaminants.     

直接竞争酶联免疫吸附分析法测定氰戊菊酯

采用活性酯法,将氰戊菊酯半抗原N-[2-(4-氯苯基)-3-甲基丁酰基]-4-氨基丁酸与载体蛋白共价偶联合成突出氰戊菊酯分子结构特征的人工抗原和包被原.以人工抗原免疫新西兰白兔制备抗血清,采用(NH4)2SO4分步盐析和DEAE纤维素柱层析法从抗血清中分离纯化对氰戊菊酯具特异性亲和力的抗体,采用活性酯法,以辣根过氧化物酶标记半抗原N-[2-(4-氯苯基)-3-甲基丁酰基]-6-氨基己酸.采用固定抗体、氰戊菊酯和酶标半抗原直接竞争结合固相抗体的模式, 建立对氰戊菊酯具高特异性的酶联免疫吸附分析方法.在优化条件下, 测定氰戊菊酯标样检测的线性浓度范围为0.001～10.0 mg/L; 检出限0.001 mg/L; 相对标准偏差(RSD, n=5)为9.19%.小白菜中分别添加0.10和5.0 mg/kg氰戊菊酯,直接竞争酶联免疫吸附分析法(ELISA)测定,重复6次,回收率分别为83.8%～109%和93.6%～110%; RSD分别为11.7%和7.25%.对实际样品的有效检出限为0.007 mg/L.其它常用拟除虫菊酯类杀虫剂(氯氰菊酯、溴氰菊脂、功夫菊酯、醚菊酯、联苯菊酯)不干扰氰戊菊酯的测定.     

Chronic Low-Dose UVA Irradiation Induces Local Suppression of Contact Hypersensitivity, Langerhans Cell Depletion and Suppressor Cell Activation in C3H/HeJ Mice

Abstract— It has previously been demonstrated that chronic low-dose solar-simulated UV radiation could induce both local and systemic immunosuppression as well as tolerance to a topically applied hapten. In this study, we have used a chronic low-dose UV-irradiation protocol to investigate the effects of UVA on the skin immune system of C3H/HeJ mice. Irradiation with UVA+B significantly suppressed the local and systemic primary contact hypersensitivity (CHS) response to the hapten 2,4,6-trinitrochlo-robenzene. Furthermore UVA+B reduced Langerhans cell (LC) and dendritic epidermal T cell (DETC) densities in chronically UV-irradiated mice. Ultraviolet A irradiation induced local, but not systemic, immunosuppression and reduced LC (32%) but not DETC from the epidermis compared to the shaved control animals. Treatment of mice with both UVA+B and UVA radiation also induced an impaired secondary CHS response, and this tolerance was transferable with spleen cells. These results suggest that depletion of LC, but not DETC, may be involved in UVA-induced local immunosuppression in our model, and that tolerance was induced in the presence of normal numbers of DETC. Hence exposure of C3H/HeJ mice 5 days per week for 4 weeks with UVA can induce local immunosuppression and tolerance.     

Self-assembly in linker-modified microemulsions

Linker molecules are added to microemulsion systems to enhance the interaction between the surfactant and oil (lipophilic linkers) or water (hydrophilic linkers) phases. Previous results suggest that when lipophilic and hydrophilic linkers are combined they behave as a self-assembled surfactant at the oil/water interface. In this work we investigate this self-assembly phenomenon as a function of surfactant, linker and electrolyte concentration. We find that middle phase microemulsion appears at a specific concentration higher than the critical micelle concentration (CMC), which we denote as the critical middle phase microemulsion concentration (CmicroC). When the lipophilic linker dodecanol is added in equimolar ratio to the hydrophilic linker sodium mono- and dimethyl naphthalene sulfonate (SMDNS), the middle phase microemulsion did not appear until the surfactant sodium dihexyl sulfosuccinate (SDHS) concentration was larger than the CmicroC of the SDHS-alone system. Dodecanol is shown to segregate near the surfactant tails following a Langmuir-type adsorption process. This segregation is not affected by the electrolyte concentration but is significantly reduced when the surfactant (SDHS) concentration approaches the CmicroC. The data suggest that the self-assembly between hydrophilic and lipophilic linkers to form middle phase microemulsions is only possible if a minimum amount of surfactant is present.     

Investigation of Tomato Plant Defence Response to Tobacco Mosaic Virus by Determination of Methyl Salicylate with SPME-Capillary GC-MS

Headspace SPME was applied to investigation of tomato plant defence response to tobacco mosaic virus (TMV) by determination of compounds emitted from tomato plants at the extraction conditions of 25 °C and 15 min. It was found that TMV-inoculated tomato plant released large amount of methyl salicylate (MeSA) as response to TMV and MeSA concentration changed dramatically with time after inoculation. Gaseous MeSA as a signaling compound could induce in surrounding tomato plants to produce salicylic acid (SA) and synthesize and release MeSA. These results show that MeSA might be an airborne plant-signalling molecule in tomato plant response to TMV. The present method provided low detection limit of 2.0 ng L^–1 and needed little sample preparation time (15 min), so the method makes it easy to find the critical times of tomato plant response to TMV by fast determination of MeSA released from tomato plant.     

Fully synthetic Mincle-dependent self-adjuvanting cancer vaccines elicit robust humoral and T cell-dependent immune responses and protect mice from tumor development

A new strategy based on a macrophage-inducible C-type lectin (Mincle) agonist was established to construct synthetic cancer vaccines. Using sialyl-Tn (STn) as a model antigen, four conjugates with the Mincle agonist as a built-in adjuvant were designed and synthesized through a facile and efficient method. All conjugates could induce BMDMs to produce inflammatory cytokines in a Mincle-dependent manner and were found to elicit robust humoral and T cell-dependent immune responses alone in mice. The corresponding antibodies could recognize, bind and exhibit complement-dependent cytotoxicity to STn-positive cancer cells, leading to tumor cell lysis. Moreover, all conjugates could effectively inhibit tumor growth and prolong the mice survival time in vivo, with therapeutic effects better than STn-CRM197/Al. Notably, compared to conventional glycoprotein conjugate vaccines, these fully synthetic conjugate vaccines do not cause “epitope suppression.” Mincle ligands thus hold great potential as a platform for the development of new vaccine carriers with self-adjuvanting properties for cancer treatment. Preliminary structure–activity relationship analysis shows that a vaccine containing one STn antigen carried by vizantin exhibits the best efficacy, providing support for further optimization and additional investigation into Mincle agonists as the carrier of self-adjuvanting cancer vaccines.

A new strategy based on a Macrophage-inducible C-type lectin (Mincle) agonist was established to construct synthetic cancer vaccines.     

Triphenylantimony(V) Catecholates of the Type (3-RS-4,6-DBCat)SbPh3-Catechol Thioether Derivatives: Structure,Electrochemical Properties,and Antiradical Activity

A new series of triphenylantimony(V) 3-alkylthio/arylthio-substituted 4,6-di-tert-butylcatecholates of the type (3-RS-4,6-DBCat)SbPh₃, where R = n-butyl (1), n-hexyl (2), n-octyl (3), cyclopentyl (4), cyclohexyl (5), benzyl (6), phenyl (7), and naphthyl-2 (8), were synthesized from the corresponding catechol thioethers and Ph₃SbBr₂ in the presence of a base. The crystal structures of 1, 2, 3, and 5 were determined by single-crystal X-ray analysis. The coordination polyhedron of 1–3 is better described as a tetragonal pyramid with a different degree of distortion, while that for 5- was a distorted trigonal bipyramid (τ = 0.014, 0.177, 0.26, 0.56, respectively). Complexes demonstrated different crystal packing of molecules. The electrochemical oxidation of the complexes involved the catecholate group as well as the thioether linker. The introduction of a thioether fragment into the aromatic ring of catechol ligand led to a shift in the potential of the “catechol/o-semiquinone” redox transition to the anodic region, which indicated the electron-withdrawing nature of the RS group. The radical scavenging activity of the complexes was determined in the reaction with DPPH radical.