溶胶-凝胶非标记 CA15-3免疫传感器的研制与应用

采用溶胶-凝胶技术将乳腺癌抗体固定于电极表面,研制成用于检测乳腺癌抗原的非标记型溶胶-凝胶-抗体膜免疫传感器;用循环伏安法对电极的修饰过程进行表征,同时对乳腺癌抗原定量检测的可行性进行了探讨;随着抗体与抗原特异性反应的进行,形成的抗体-抗原免疫复合物使膜电位发生变化(△V),该变化的大小与溶胶-凝胶-抗体膜表面免疫反应进行的程度相关;本文以此为依据对CA15-3进行检测,在5～240U／mL范围内．△V／与lgCCA15-3呈良好的线性关系,线性相关系数r=O.998;该传感器响应迅速,灵敏度高,稳定性好,于4℃干态保存30d,其响应信号基本不变。     

微板式化学发光酶免疫分析法测定人血清中癌胚抗原

采用辣根过氧化物酶(HRP)催化鲁米诺(luminol)-H2O2化学发光体系,建立了一种测定人血清中癌胚抗原(CEA)的高灵敏度、高特异性、简便快速的微板式化学发光酶免疫分析方法。对免疫反应条件、酶结合物稀释度、发光反应时间、封闭液等进行了考察和优化。采用双抗体夹心法,室温静置1h,洗涤后加入100μL发光底物液,10min后检测。该方法的线性相关系数为0.9998;最低检出限为0.57μg/L;批内和批间变异均在10%之内;低、中、高3个不同浓度值样品的平均回收率分别为107.4%、93.3%和104.5%。使用本方法与进口发光试剂盒对40份人血清样品进行测定,结果表明,本方法显示了良好的相关性,其相关系数为0.9115。表明本分析体系稳定可靠,可用于商品化诊断试剂盒的开发和应用。     

菲人工抗原的合成与表征

通过Friedel-Crafts酰基化反应在菲分子上引入羧基,得到半抗原菲丁酸-γ-氧(1);通过活化酯法或混合酸酐法将1与牛血清蛋白偶联制得了菲人工抗原,其结构经UV,1H NMR,IR和MS表征.     

基于金粒子修饰二硫化钼纳米复合材料的电化学发光免疫传感器的构建及其应用研究

生物标志物的快速、精准检测对控制和预防疾病或病毒的暴发具有重要意义.该研究将三维花状Au@(MoS2/GO/o-MWNTs)纳米复合物(AMGMs)作为一种理想的基底,利用"三明治"免疫夹心组装法构筑一种高灵敏的电化学发光免疫传感器,并用于前列腺特异性抗原(PSA)的高灵敏检测.AMGMs不仅具有良好的导电性和生物相容...     

Fluorescent Immunoassay with a Copper Polymer as the Signal Label for Catalytic Oxidation of O-Phenylenediamine

This work suggested that Cu²⁺ ion coordinated by the peptide with a histidine (His or H) residue in the first position from the free N-terminal reveals oxidase-mimicking activity. A biotinylated polymer was prepared by modifying His residues on the side chain amino groups of lysine residues (denoted as K_H) to chelate multiple Cu²⁺ ions. The resulting biotin-poly-(K_H-Cu)₂₀ polymer with multiple catalytic sites was employed as the signal label for immunoassay. Prostate specific antigen (PSA) was determined as the model target. The captured biotin-poly-(K_H-Cu)₂₀ polymer could catalyze the oxidation of o-phenylenediamine (OPD) to produce fluorescent 2,3-diaminophenazine (OPDox). The signal was proportional to PSA concentration from 0.01 to 2 ng/mL, and the detection limit was found to be eight pg/mL. The high sensitivity of the method enabled the assays of PSA in real serum samples. The work should be valuable for the design of novel biosensors for clinical diagnosis.     

Genomic Intelligence as Über Bio-Cybersecurity: The Gödel Sentence in Immuno-Cognitive Systems

This paper gives formal foundations and evidence from gene science in the post Barbara McClintock era that the Gödel Sentence, far from being an esoteric construction in mathematical logic, is ubiquitous in genomic intelligence that evolved with multi-cellular life. Conditions uniquely found in the Adaptive Immune System (AIS) and Mirror Neuron System (MNS), termed the genomic immuno-cognitive system, coincide with three building blocks in computation theory of Gödel, Turing and Post (G-T-P). (i) Biotic elements have unique digital identifiers with gene codes executing 3D self-assembly for morphology and regulation of the organism using the recursive operation of Self-Ref (Self-Reference) with the other being a self-referential projection of self. (ii) A parallel offline simulation meta/mirror environment in 1–1 relation to online machine executions of self-codes gives G-T-P Self-Rep (Self-Representation). (iii) This permits a digital biotic entity to self-report that it is under attack by a biotic malware or non-self antigen in the format of the Gödel sentence, resulting in the “smarts” for contextual novelty production. The proposed unitary G-T-P recursive machinery in AIS and in MNS for social cognition yields a new explanation that the Interferon Gamma factor, known for friend-foe identification in AIS, is also integral to social behaviors. New G-T-P bio-informatics of AIS and novel anti-body production is given with interesting testable implications for COVID-19 pathology.     

Synthesis and Antibody Binding Studies of Schistosome-Derived Oligo-α-(1-2)-l-Fucosides

Schistosomiasis is caused by blood-dwelling parasitic trematodes of the genus Schistosoma and is classified by the WHO as the second most socioeconomically devastating parasitic disease, second only to malaria. Schistosoma expresses a complex array of glycans as part of glycoproteins and glycolipids that can be targeted by both the adaptive and the innate part of the immune system. Some of these glycans can be used for diagnostic purposes. A subgroup of schistosome glycans is decorated with unique α-(1-2)-fucosides and it has been shown that these often multi-fucosylated fragments are prime targets for antibodies generated during infection. Since these α-(1-2)-fucosides cannot be obtained in sufficient purity from biological sources, we set out to develop an effective route of synthesis towards α-(1-2)-oligofucosides of varying length. Here we describe the exploration of two different approaches, starting from either end of the fucose chains. The oligosaccharides have been attached to gold nanoparticles and used in an enzyme-linked immunosorbent assay ELISA and a microarray format to probe antibody binding. We show that binding to the oligofucosides of antibodies in sera of infected people depends on the length of the oligofucose chains, with the largest glycans showing most binding.     

A Biodegradable Antigen Nanocapsule Promotes Anti-Tumor Immunity via the cGAS-STING Pathway

Materials-based antigen delivery systems can augment the immune response by improving antigen uptake in antigen-presenting cells, targeting lymph nodes, prolonging antigen exposure, enhancing cross-presentation, etc. Recent research revealed that some antigen carriers activate the innate immune pathways without additional adjuvant. Here, a vaccine delivery platform (antigen nanocapsules) constructed by a one-step in situ polymerization is reported, weaving a biodegradable polymer network around the antigen surface. This simple technology allowed us to study the immunomodulatory effect of various antigen carriers. An antigen nanocapsule (NC7) capable of inducing dendritic cell activation and cross-presentation is identified. Further mechanistic studies revealed that NC7 activated the cGAS-STING pathway in a cGAS-dependent manner. Moreover, the subcutaneously injected NC7 accumulated in the lymph nodes and elicited strong cytotoxic T cell immunity and T cell memory against established cancer. Collectively, the often-neglected immunomodulatory effect of various cationic antigen carriers, enabling potential application in cancer vaccines, is uncovered.     

Programmed Catalytic Therapy and Antigen Capture-Mediated Dendritic Cells Harnessing Cancer Immunotherapies by In Situ-Forming Adhesive Nanoreservoirs

T lymphocyte recruitment and infiltration promises to suppress the most devastating metastatic tumors for immunotherapy. However, the immune privilege and low vaccine immunogenicity usually reduces the presence of lymphocytes in tumors, especially for invading metastatic clusters. Here, an adhesive catalytic nanoreservoir (CN) containing manganese dioxide (MnO₂) and catechol-functionalized magnetic metal organic framework for the antigens capture and delivery is reported. The intravenously injected CN accumulates at tumor via the marginated target and in situ forming gel for antigen capture. At tumor site, CN releases Mn²⁺ for redox reactions by depleting glutathione (GSH) and Fenton-like activity, i.e., chemodynamic therapy (CDT). Accompanying with hyperthermia, CDT promote the tumor to release the tumor-associated antigens including neoantigens and damage-associated molecular patterns. Then, the gels with catechol groups act as antigen reservoirs and deliver the autologous tumor-associated antigens to dendritic cells, achieving sustained immune stimulation. The in situ-forming catalytic nanoreservoir at lung metastasis as a magnetothermal-induced antigen reservoir effectively inhibited the tumor in 60 days and increased the survival rate.     

Cationic Lipids-Mediated Dual-Targeting of Both Dendritic Cells and Tumor Cells for Potent Cancer Immunotherapy

Impaired antigen presentation either in dendritic cells (DCs) or tumor cells impedes the triggering of antitumor immunity or tumor cell killing, resulting in failures of multiple types of cancer immunotherapy. Herein, the strategy of using dual-targeting nanomedicines to simultaneously improve the presentation of tumor antigens by both DCs and tumor cells is proposed. It is shown that tuning of surface charge of nanoparticles (NPs) by incorporating different amounts of cationic lipids alters the in vivo NP tissue accumulation and cellular targeting profiles. NPs with moderately positive surface charge (≈20 mV) achieve efficient accumulation in tumors and lymph nodes and dual-targeting to both DCs and tumor cells. As a proof-of-concept demonstration, siRNA against YTH N6−methyladenosine RNA binding protein 1 (YTHDF1) is delivered by the dual-targeting NPs to inhibit excessive antigen degradation in both DCs and tumor cells. For DCs, YTHDF1 downregulation promotes tumor antigen cross-presentation and cross-priming of antigen-specific T cells. For tumor cells, it enhances the presentation of endogenous tumor antigens and hence improves both the recognition and killing of tumor cells by primed antigen-specific T cells. The dual-targeting nanomedicines generate efficient antitumor immunity.