双价抗蛇毒鸡卵黄抗体制备与生物活性研究

目的 通过双价抗蛇毒鸡卵黄抗体(bivalent anti-snake venom immunoglobulin yolk,双价IgY)的制备及其相关特性研究,为多价抗蛇毒IgY的制备和应用奠定基础.方法 两种单一抗原(舟山眼镜蛇、圆斑蝰泰国亚种)按顺序依次交替注入单只鸡体内,水稀释法制备双价IgY;测定双价IgY效价(间接ELISA法)、交叉免疫特性(双向免疫扩散试验)及对溶膜活性(溶膜试验)、半数致死量(LD50)的中和作用.结果 初次免疫后第28-42天,以水稀释法提取的双价IgY对眼镜蛇毒及蝰蛇毒的效价分别为1:12 800和1:6400.双价IgY与眼镜蛇亚科、蝰业科6种蛇毒有明显的交叉免疫反应,而与蝮亚科4种蛇毒的交叉免疫反应不明显.双价IgY能显著降低眼镜蛇、蝰蛇毒对鸡卵黄膜的溶膜作用,也能显著延长眼镜蛇和蝰蛇伤小鼠的存活时间(P<0.05),同等剂量的双价lgY提高眼镜蛇伤存活率优于蝰蛇伤.结论 双价IgY能够显著中和眼镜蛇、蝰蛇毒的溶膜和致死活性,能有效保护机体免受眼镜蛇毒和蝰蛇毒的攻击.     

双价抗蛇毒IgY灌胃对眼镜蛇、蝰蛇伤小鼠的保护作用

目的： 比较双价抗蛇毒鸡卵黄抗体(IgY) 经腹腔注射或灌胃对蝰蛇、眼镜蛇伤小鼠保护作用的差异,为其口服制剂的应用奠定理论基础。方法：2种单一抗原按顺序依次交替注入单只鸡体内,水稀释法制备双价抗蛇毒IgY;间接ELISA法观察双价抗蛇毒IgY在体外及其灌胃后小鼠血浆中的效价,通过胃排空试验确定灌胃给药的最佳时间,在此基础上,比较双价抗蛇毒IgY腹腔注射或灌胃对蛇伤小鼠的保护作用。结果：初次免疫后28 d至第42 d,以水稀释法提取的双价抗蛇毒IgY对眼镜蛇毒及蝰蛇毒的效价分别为1∶12 800和1∶6 400。不同浓度的双价抗蛇毒IgY灌胃2.5-3.5 h,小鼠的胃排空率均达68.9％以上,血浆中抗体浓度亦相应达高峰。该抗体腹腔注射或提前灌胃均能极显著延长眼镜蛇和蝰蛇毒中毒小鼠的存活时间（P<0.01）,同等剂量的双价抗蛇毒IgY提高眼镜蛇伤小鼠存活率优于蝰蛇伤,而灌胃有效剂量约为腹腔注射的10倍。结论：双价抗蛇毒IgY经2种给药途径（注射、口服）均能有效保护动物免受眼镜蛇毒和蝰蛇毒的攻击。     

抗眼镜王蛇毒鸡卵黄抗体的研制及初步应用

目的　研制抗眼镜王蛇毒鸡卵黄抗体 ,并研究该抗体在鸡卵黄中表达过程。方法　以甲醛减毒处理的眼镜王蛇粗毒免疫莱航母鸡 ,母鸡免疫应答后 ,在卵黄中产生抗眼镜王蛇毒抗体 ,应用嗜硫色谱柱HiTrapIgYPurificationHP从鸡卵黄中提取抗眼镜王蛇毒抗体 ;以间接ELISA法及双向免疫扩散测定抗体的效价、特异性及免疫活性 ;采用Lowry氏法测定蛋白含量 ;采用SDS PAGE法测定相对分子质量 (Mr)及鉴定抗体纯度。结果　母鸡初次免疫第 9天即有抗体产生 ,初次免疫 6 0d后抗体效价超过 1∶10 0 0 0 0 ,卵黄抗体经嗜硫色谱柱纯化后 ,经SDS PAGE检测为电泳纯 ,纯化后抗体效价较纯化前提高 4倍 ,每枚蛋中平均可获得较纯抗体 97.5mg。动物体外中和试验表明 ,特异性IgY能有效中和眼镜王蛇毒 ,阻止眼镜王蛇毒对小白鼠的攻击。结论　研制并鉴定了抗眼镜王蛇毒鸡卵黄抗体 ,分析抗体在产蛋期卵黄液中表达的进度 ,为今后该抗体的持续、高质量诱导奠定基础 ,同时也促进其他抗蛇毒鸡卵黄抗体的研究开发及蛇毒单克隆抗体的研制     

鸡卵黄抗体的制备以及金磁微粒为载体去除人血浆部分高丰度蛋白的研究

目的:以人血浆白蛋白(HSA)和IgG为免疫原,制备特异性鸡卵黄抗体IgY(Egg yolk immunoglobulin),并将其固定于金磁微粒表面,用于HSA和IgG的去除研究.方法:用HSA、IgG以及混合成分分别作免疫原免疫Roman母鸡.制备抗HSA和IgG鸡卵黄抗体IgY,并对IgY的分离提取条件进行优化.SDS-PAGE和间接ELISA检测IgY的纯度和效价.将高效价IgY固定于金磁颗粒表面进行血浆高丰度蛋白去除研究.结果:免疫后60～120 d内,鸡血清抗体效价可达1∶15 000～1∶25 000;收获鸡蛋,提取得到的卵黄抗体IgY效价可达1∶10000～1∶25000,纯度98%以上;采用金磁微粒载体固定IgY,可对血浆中的HSA,IgG进行特异性的去除.结论:人血浆中的高丰度蛋白成分HSA和IgG免疫产蛋母鸡后,可从鸡卵黄中分离提取到高效价、高纯度的卵黄抗体IgY;IgY偶联于金磁微粒表面可特异性的去除人血浆中的HSA和IgG,作为血浆蛋白质组学研究的一种新方法,有较好的应用前景.     

抗人蔗糖酶卵黄抗体的制备及其稳定性和体外活性研究

目的:制备抗人蔗糖酶(Sucrase,SUC)卵黄抗体(egg yolk immunoglobulin Y,IgY)并对其稳定性、体外活性进行研究。方法:采用人SUC 蛋白为抗原,免疫海兰灰蛋鸡,水稀释和盐析法提取纯化IgY;间接ELISA 法监测抗体效价变化并评价其稳定性;SDS-PAGE 和Western blot 分析IgY 的纯度和特异性;PNPG 法测IgY 对琢鄄葡萄糖苷酶的体外抑制效果。结果:初次免疫10 d 后检测到IgY,40 d 后效价最高达到1 12 800;提取的IgY 重链和轻链分别在65 kD 和25 kD 处,且能够与抗原蛋白特异性结合;29 ~69益范围内水浴15 min 和pH 4 ~7 之间37益水浴4 h,抗体效价无变化;胰蛋白酶与胃蛋白酶作用IgY2 h,抗体效价降至一半,延长作用时间,IgY 对胃蛋白酶耐受力较胰蛋白酶耐受力更强;IgY 对琢鄄葡萄糖苷酶具有一定的抑制作用,呈现剂量相关性,半抑制浓度(IC50)值为0郾540 mg/ ml。结论:抗人蔗糖酶卵黄抗体(S-IgY)的成功制备为后续用于2型糖尿病大鼠模型体内实验研究奠定基础。     

蝰蛇毒压电免疫传感器固定方法的研究

目的：为研制蝰蛇毒压电免疫传感器，研究抗蛇毒抗体固定于石英晶体银电极表面的固定技术。方法：采用马抗蝰蛇毒血清抗体和抗蝰蛇毒鸡卵黄抗体作为生物敏感材料，对比研究了胱胺自组装-PSS反相吸附法和PEI粘附-戊二醛交联法：比较了采用两种固定方法所制的压电免疫传感器的性能。结果：鸡卵黄抗体采用PEI粘附-戊二醛交联法效果较好，其制备的IgY压电免疫传感器检测蝰蛇毒灵敏度为0．5ug／mL；而马血清抗体用胱胺自组装-PSS反相吸附法较好，其制备的IgG’免疫传感器检测蝰蛇毒灵敏度为10ug／mL。结论：以PEI粘附-戊二醛交联法固定抗蝰蛇毒鸡卵黄抗体所制备的蝰蛇毒压电免疫传感器的性能稳定，特异性好，可实现蛇毒的快速检测。     

抗肠道病毒71型特异性卵黄抗体的制备及鉴定

目的:制备特异性抗肠道病毒71型(Enterovirus 71,EV71)的卵黄抗体并检测其生物学性能,这对EV71感染手足口病的预防和治疗具有重大的意义。方法:用纯化并灭活后EV71作为抗原免疫健康产蛋鸡。采用本实验室水提综合聚乙二醇法提取纯化鸡卵黄抗体;用Bradford法测定卵黄抗体提取液的蛋白含量;还原性SDS-PAGE凝胶电泳分析测定提取蛋白的纯度及相对分子质量;分别用ELISA、双向免疫琼脂扩散检测纯化特异性卵黄抗体抗EV71效价;Western blot分析特异性卵黄抗体的免疫反应性。结果:卵黄中卵黄抗体含量达7.76 mg/ml,卵黄抗体的纯度为94.86%。初免10天后蛋黄中可检测到特异性抗EV71卵黄抗体,初免40天后ELISA检测抗体效价高达1∶20 480,双向琼脂扩散检测效价达1∶16。提取的卵黄抗体具有良好的免疫反应性,能与EV71特异性结合。结论:水提综合聚乙二醇法提取纯化得到的抗EV71卵黄抗体产量和纯度高、效价好且具有良好的免疫反应性。     

胃癌特异性免疫毒IgY-RicinA的杀伤作用

以从人胃癌传代细胞MGC-803中提取的Myc基因产物P110蛋白为抗原,免疫产卵母鸡,由鸡卵黄中提取胃癌特异性抗体IgY,后者用SPDP法与蓖麻毒素A链合成了胃癌特异性免疫毒IgY-RicinA。为了验证IgY-RicinA的特异性,用IgY-RicinA对人胃癌传代细胞(MGC803)、人肝癌     

抗须癣毛癣菌细胞壁蛋白的卵黄抗体制备和鉴定

目的：提取须癣毛癣菌的细胞壁蛋白作为免疫原制备特异性卵黄抗体,并鉴定其生物活性,为卵黄抗体在预防与治疗皮肤癣疾病的应用奠定基础。方法：本研究采用冷碱抽提的方法提取须癣毛癣菌的细胞壁蛋白,并用其免疫健康的产蛋母鸡。采用聚乙二醇两步沉淀法及饱和硫酸铵盐析提纯卵黄抗体;用Bradford法检测卵黄抗体中蛋白含量;SDS-PAGE凝胶电泳分析测定卵黄抗体的纯度以及相对分子质量;ELISA检测纯化的卵黄抗体的效价;Western blot分析特异性卵黄抗体的免疫反应性。结果：提取的卵黄抗体中蛋白纯度达到87.27%。由细胞壁蛋白制备的特异性卵黄抗体在初免20 d后效价开始升高,到45天达到最高值（1∶32 000）。Western blot结果显示由细胞壁蛋白制备的卵黄抗体能与其良好的特异性结合,具有较好的免疫反应性。结论：本实验提取的须癣毛癣菌细胞壁蛋白作为免疫原可以制备出特异性较强的卵黄抗体,为须癣毛癣菌感染的皮肤疾病提供了治疗新思路。     

抗白色念珠菌IgY的稳定性及体内抗感染活性研究

目的观察抗白色念珠菌IgY的稳定性及体内抗感染活性。方法水稀释法从免疫鸡卵黄提取抗白色念珠菌IgY,酶联免疫吸附试验间接法和微量间接血凝试验测定其抗体效价,并观察其对热、酸碱度、胰蛋白酶及冻存时间的稳定性和对小鼠腹腔感染白色念珠菌的保护效果。结果水稀释法提取的抗白色念珠菌IgY效价为1∶5120;IgY在25~70℃处理15min,pH3.0~11.0、37℃处理2h,或普通冰箱冻存6年效价改变不明显;在37℃下与胰蛋白酶作用2h效价仍保持50%。IgY对免疫功能低下小鼠腹腔感染白色念珠菌有明显的保护作用(P<0.01)。结论抗白色念珠菌IgY具有良好的稳定性和较好的体内抗感染活性。     

特异性抗内毒素鸡蛋黄抗体的制备

目的：制备特异抗内毒素鸡蛋黄免疫球蛋白（Egg yolk immunoglobulin，IgY），探索防治内毒素血症的新途径。方法：用大肠杆菌J5株、内毒素（Lipopolysaccharide，LPS）及类脂A(Lipid A)作抗原免疫25周龄Roman鸡，改良水溶法提取抗体，进行紫外分光光度计检测、SDS-PAGE及Western blot免疫印迹分析，通过酶联染色反应检测其免疫学活性。结果：大肠杆菌J5株、LPS及Lipid A抗体含量分别为11.4、9.2、9.3mg/mL蛋白黄液，质量分数分别为92.3％、87.13％、90.4％，分子质量为180000u，初步鉴定其对内毒素具有特异性结合作用。结论：用大肠杆菌J5株、LPS及LipidA免疫鸡制备的IgY效价高、特异性强、产量大，将是一种防治内毒素血症的新方法。     

Comparative Analysis of Methods of Purification of Egg Yolk Immunoglobulin

This study is a critical comparison of reported methods of purification of IgY from hen egg yolk. Five methods of lipid removal were compared, followed by a comparison of three methods of immunoglobulin precipitation. Each of these methods was tested three times. Lowry assays were used to measure the protein content of the various purified fractions, and densitometric analysis of SDS-polyacrylamide gels was used to quantify the proportion of IgY. Peak IgY yields of 15.6 and 15.1 mg of IgY per ml of egg yolk, with greater than 60% purity, were obtained after lipid removal using dextran sulphate and calcium chloride or phosphotungstic acid and magnesium chloride, respectively. Further precipitation of IgY from these fractions using 12% PEG, the most effective method of immunoglobulin precipitation, recovered pure IgY preparations, with mean yields of 8.80 and 8.62 mg per ml of egg yolk. Alternatively, a simpler and more cost effective method of lipid removal by freezing and thawing of egg yolk at neutral pH recovered 13.1 mg of IgY per ml of egg yolk at a purity of 71.1%. Subsequent Ig precipitation also recovered a pure IgY preparation with a mean yield of 7.49 mg per ml of egg yolk.     

A novel, cost-effective and efficient chicken egg IgY purification procedure

Chicken IgY antibodies have been touted to be a superior alternative to mammalian antibodies for use in various immunological, molecular biology and proteomics applications for several reasons. These include, but are not limited to, improved specificity due to maximum phylogenetic distance between host and recipient, cost effectiveness in maintaining commercial numbers of hens, IgY yield and the use of non-invasive methods used to isolate IgY from eggs as opposed to blood. Despite this, the routine use of IgY-based methodologies in the laboratory is not widespread. One reason for this reluctance may be derived from the difficulties and expense of isolating IgY antibodies from egg yolk in sufficient yield, with high purity at a realistic reasonable price. Here, we describe an extremely cost-effective ($5USD per egg), rapid (within 5 h), efficient and optimised technique to isolate high yields (60 mg) of high purity (~80%) chicken IgY from egg yolks using the common plant gums pectin and κ-carrageenan in the presence of calcium chloride to delipidate egg yolk mixtures whilst maintaining IgY in solution and then ammonium sulphate to subsequently precipitate the resulting IgY antibodies to higher purity. Our data demonstrates that this technique results in a high yield and purity of IgY that is comparable (if not superior to) existing commercial IgY isolation kits. The method also allows the isolation of immunologically active IgY which can be used for further downstream immunotechnological processes. Furthermore, it can also be easily implemented in a standard well equipped laboratory, and may be scaled up to commercial quantities (i.e., thousands of eggs).     

Comparison of four purification methods for the production of immunoglobulins from eggs laid by hens immunized with an enterotoxigenic E. coli strain

The importance of eggs as a source of specific antibodies is well recognized. Egg yolk contains 8–20 mg of immunoglobulins (IgY) per ml. However, the major problem in isolation is removal of lipids which are present in high concentrations. A method had been developed by employing water dilution to separate the yolk plasma proteins from the granules and lipids. Further purification of IgY from plasma proteins was achieved by a protocol involving salt precipitation and ultrafiltration. The water dilution method (WD) was compared with three other methods, namely, polyethylene glycol (PEG), dextran sulphate (DS) and xanthan gum (Xan) in terms of yield, purity, ease of use, potential scaling up and immunoactivity of IgY. The WD method gave the highest yield, followed by DS, Xan and PEG methods in that order. 9.8 mg IgY / ml egg yolk was routinely obtained from the WD method compared to 4.9 mg IgY / ml egg yolk with the popular PEG method with purities of 94% and 89% respectively. Purification methods had no adverse effect on the immunoactivities of IgY. WD was also found superior in terms of ease of use and large scale production of IgY. WD method therefore provides a simple, rapid and efficient means of purifying IgY with high activity.     

Affinity purification of immunoglobulins from chicken egg yolk using a new synthetic ligand

Due to the peculiar composition of the egg yolk and the lack of specific affinity ligands, Y immunoglobulins are normally purified using complex and time consuming procedures involving a combination of precipitation and chromatographic steps first to extract and capture and then to polish IgY. In this study, we have examined the applicability for IgY affinity purification of TG19318, a synthetic ligand for immunoglobulin, obtained from the screening of combinatorial libraries, and already characterized for its capability to purify immunoglobulins of class G, M, E and A. Soluble proteins were separated from the lipidic fraction of egg yolk by the water dilution method and loaded on to TG19318 affinity columns prepared by immobilizing the ligand on the commercially available support Emphaze. In a single chromatographic step TG19318 affinity columns led to an efficient capture of IgY directly from crude samples, and with a purity degree higher than 90%, as determined by densitometric scanning of SDS-PAGE analysis of bound fractions, and with full recovery of antibody activity, as determined by ELISA assay. Higher recovery and purity of IgY was obtained by using loading buffers at pH close to 6.5. Column capacity, determined by applying 4x excess IgY to 1 ml bed volume column, and eluting the retained immunoglobulins, was close to 65 mg of IgY per ml of resin. Chemical and chromatographic stability of TG19318/Emphaze was tested before and after various treatments. The derivatized matrix was found to be very stable, in terms of ligand leakage and maintenance of IgY binding capacity, under conditions of normal column usage, cleaning and storage.