采用改良的水稀释法提取卵黄抗体的试验

以鼠伤寒沙门氏菌免疫产蛋鸡后，收集卵黄液，用水稀释法提取卵黄抗体(IgY)。实验中所用的水稀释法，即将释释倍数和稀释时的pH值均重新调整，且采取关键性的滤纸过滤，再盐析和柱层析，最后得到IgY的纯度为90％以上，表明改良的水稀释法可以较好的提纯卵黄抗体，避免了常规方法中除脂不彻底的弊端。     

不同除脂条件对卵黄液除脂率及卵黄抗体纯度的影响

为研究提高卵黄液除脂率和卵黄抗体的纯度,建立适合大量生产卵黄抗体的工艺,比较了不同除脂条件对卵黄液除脂率及卵黄抗体纯度的影响。最终确定卵黄液与醋酸盐体积比为1：8、pH值调至5．2、2～8℃沉淀15h（过夜）时,除脂的效果最理想,且蛋白的纯度高,适合大量提取卵黄抗体。     

超滤/DEAE离子交换层析法分离纯化IgY

应用平板式膜超滤技术与DEAE离子交换层析法对卵黄免疫球蛋白（IgY）进行分离纯化。首先，卵黄液经过缓冲液稀释分离；然后，用平板式膜组件对其超滤，并且分析了各种因素对其的影响，确定分子截留量为100ku，操作压力差为0．12MPa、进料温度为30℃．pH5．2，截留液抗体回收率达到91．89％，纯度为86％。经DEAE离子交换层析得到高纯度的IgY。     

猪病毒性腹泻卵黄抗体提取纯化工艺的研究

为了研究适合于规模化制备卵黄抗体的联合方法,试验采用水稀释辛酸法,同时结合超滤法和硫酸铵盐析法,最终分离、纯化出目的蛋白。试验考察研究了不同比例水稀释液和辛酸对卵黄抗体除脂效果的影响,以及超滤液温度、p H值,截留分子质量和超滤压力对超滤效果的影响,并以单因素试验初步确定操作条件范围,L9(34)正交试验确定超滤条件的最佳参数。结果表明:分离出的卵黄液加入9倍纯化水和1%辛酸时除脂效果最好;超滤卵黄上清液的温度为25℃,p H值为7.5,采用截留分子质量为50 ku的膜包,超滤压力为0.025 MPa时,获得的浓缩液再经硫酸铵盐析,卵黄抗体提取率可达到90%,纯度为95%。     

非洲猪瘟病毒p54抗原蛋白卵黄抗体的制备及生物活性检测

为研究非洲猪瘟病毒(African swine fever virus,ASFV)p54抗原蛋白及其相应卵黄抗体的生物学特性,特制备ASFV p54蛋白及相应鸡卵黄抗体。可溶性表达制备高纯度ASFVp54抗原蛋白,并制定合理的免疫程序,免疫产蛋母鸡,定时采血并收集鸡蛋。卵黄液经粗提取后二次盐析,制备特异性卵黄抗体。酶联免疫吸附试验(ELISA)结果显示,在首次免疫后7d后的血清中即可检测出相应抗体,14d后在卵黄中提取到相应抗体,35d后IgY效价达到峰值。经SDS-PAGE检测,制备所得纯度达到90%,得率在8.8g/L以上。Western-blot检测结果显示,纯化的IgY具有高度的特异性。     

鹅卵黄IgG的纯化及兔抗鹅IgG酶标抗体的制备

采用三氯甲烷去脂、无水Na2S04盐析、DEAE23纤维素层析相结合的方法纯化鹅卵黄IgG,SDS-PAGE检测表明,所得鹅卵黄IgG纯度可达93%;用纯化的IgG免疫家兔,抗血清经双向琼脂扩散,证明兔抗鹅IgG抗血清效价约1:64,免疫电泳试验检测,证明得到了特异性抗血清,提取兔抗血清的IgG,用辣根过氧化物酶标记,制备了兔抗鹅IgG的酶标抗体,酶标抗体的效价为1:6400.     

不同方法提取卵黄抗体效果的比较

为了优化卵黄抗体提取工艺以及产业化生产提供技术参考,从众多方法中初步筛选了较为适宜的水稀释法、辛酸法、乙酸-乙酸钠法、酚沉淀法和海藻酸钠法,并比较了5种方法的提取工艺、生产成本、卵黄抗体提取量及其效价。试验结果表明,辛酸法的提取液体回收率最高,达到171％;辛酸法提取蛋白的浓度最高,为6．6mg／mL;辛酸法和海藻酸钠法提取卵黄抗体的凝集价最高,为1：128。综合各种因素考虑,辛酸法是提取卵黄抗体较为理想的方法。     

鸭源抗鹅细小病毒卵黄抗体的制备

利用GPV 98E株胚毒免疫产蛋鸭,收集高免鸭蛋,分离卵黄,经水稀释法去脂粗提,硫酸钠盐析获得纯化的鸭源抗鹅细小病毒卵黄抗体,测定其琼脂双扩散效价、含量和回收率;利用低日龄无母源抗体易感雏鹅检测其预防和治疗效果。结果表明:经GPV 98E株胚毒免疫的鸭可以很快产生高水平的特异性抗体,纯化的卵黄抗体琼扩效价为1∶32,含量为81.6%,总蛋白回收率为6.01mg/mL。在预防试验中,雏鹅的死亡率为0,在治疗试验中,使用一次预防试验用的剂量治疗发病雏鹅,其死亡率为59%,经二项分布显著性检验,鸭源抗GPV卵黄抗体对鹅细小病毒感染有极显著的预防和治疗效果。     

鹅卵黄抗体IgY的提纯及其酶标抗体的制备

本试验采用辛酸去脂、饱和硫酸铵溶液盐析法提纯鹅卵黄抗体IgY,采用SDS-PAGE方法分析其纯度;用纯化后的IgY免疫试验兔,收集血清,测定血清抗体效价;采用辛酸-硫酸铵法结合Protein G树脂亲和层析法纯化免血清IgG,用改良的高碘酸钠法进行辣根过氧化物酶标记,直接ELISA法测定标记物效价.结果表明,提纯的鹅卵黄IgY浓度为11.5 mg/mL,纯度约为92％;血清琼脂扩散抗体效价为1∶32;Western Blotting试验证明,兔血清中含有抗鹅卵黄抗体IgY重链及轻链的特异性抗体;直接ELISA法测得标记物效价为1:1 100.     

非洲猪瘟病毒p30蛋白卵黄抗体的制备及生物活性检测

为了制备非洲猪瘟病毒(African swine fever virus,ASFV)p30蛋白卵黄抗体,研究卵黄抗体的生物活性。试验构建了p ET-32a-p30原核表达载体,制定了科学的免疫程序和样本采集方法。提取卵黄液,进行二次盐析,得到对应的卵黄抗体。用酶联免疫吸附试验(enzyme-linked immunosorbentassay,ELISA)测定卵黄抗体效价,用免疫印迹（Westernblotting）技术对其生物活性进行鉴定。ELISA试验表明：首次免疫p30蛋白7d后,能够在蛋鸡的血清中检测出抗体（Ig Y）,14d后在卵黄中能够提取到Ig Y,35d后Ig Y效价达到最高值。IgY具备和哺乳动物产生的IgY不同的生物活性,并可具有较高的特异性和稳定性,在免疫学研究中具有重要的价值。利用Ig Y进行实验检测,具有突出优势。通过抗原即ASFV p30蛋白免疫蛋鸡,分离提纯免疫蛋白,检测其生物活性,可用于鉴定非洲猪瘟。     

泊洛沙姆-辛酸法对鸡卵黄脱脂条件的研究

本文就泊洛沙姆浓度、辛酸浓度、泊洛沙姆沉淀法沉淀离心条件对泊洛沙姆-辛酸法对鸡卵黄脱脂的影响进行了探讨。实验结果表明:泊洛沙姆浓度、辛酸浓度分别对卵黄脱脂存在不同程度影响,卵黄稀释液沉淀离心条件对卵黄脱脂影响不大。蛋黄稀释液不经离心直接纱布过滤,辛酸浓度为0.2%,泊洛沙姆浓度分别为0.6%、0.8%、1%、1.2%、1.4%、1.6%、1.8%的7个处理中,以1.2%浓度的提取效果最好;泊洛沙姆浓度为1.2%,辛酸浓度为0.2%,蛋黄稀释液经离心处理和纱布过滤处理对卵黄脱脂影响不大;泊洛沙姆浓度为1.2%,蛋黄稀释液纱布过滤处理,辛酸浓度分别为0、0.1%、0.2%、0.3%、0.4%、0.5%的6个处理中,以0.2%浓度的提取效果最好。     

抗猪流行性腹泻病毒卵黄抗体的制备及应用

本试验利用猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)SC株免疫产蛋鸡,收集高免卵黄,采用水稀释法和水稀释-盐析法获得鸡源抗PEDV卵黄抗体,采用已建立的ELISA方法对卵黄抗体效价进行测定。以3日龄无母源抗体的易感仔猪为试验动物,对抗PEDV卵黄抗体的治疗效果及安全性进行测定,并进一步利用自然发病猪场的治疗效果进行验证。结果表明,经PEDV SC株细胞毒免疫的鸡可在2次加强免疫后15 d产生高水平的特异性抗体。在实验室治疗试验中,攻毒治疗组仔猪的存活率达60%,攻毒对照组存活率为20%;用于自然发病猪场时,饲喂抗PEDV卵黄抗体饲料的仔猪存活率亦为60%,而自然发病对照组的存活率为10%。以上结果表明抗PEDV卵黄抗体对感染PEDV的仔猪有一定治疗作用。     

Egg yolk IgY: protection against rotavirus induced diarrhea and modulatory effect on the systemic and mucosal antibody responses in newborn calves

Bovine rotavirus (BRV) is an important cause of diarrhea in newborn calves. Local passive immunity is the most efficient protective strategy to control the disease. IgY technology (the use of chicken egg yolk immunoglobulins) is an economic and practical alternative to prevent BRV diarrhea in dairy calves. The aim of this study was to evaluate the protection and immunomodulation induced by the oral administration of egg yolk enriched in BRV specific IgY to experimentally BRV infected calves. All calves in groups Gp 1, 2 and 3 received control colostrum (CC; BRV virus neutralization Ab titer - VN=65,536; ELISA BRV IgG(1)=16,384) prior to gut closure. After gut closure, calves received milk supplemented with 6% BRV-immune egg yolk [(Gp 1) VN=2048; ELISA IgY Ab titer=4096] or non-immune control egg yolk [(Gp 2) VN<4; ELISA IgY Ab titer<4] twice a day, for 14 days. Calves receiving CC only or colostrum deprived calves (CD) fed antibody (Ab) free milk served as controls (Gp 3 and 4, respectively). Calves were inoculated with 10(5.85)focus forming units (FFU) of virulent BRV IND at 2 days of age. Control calves (Gp 3 and 4) and calves fed control IgY (Gp 2) were infected and developed severe diarrhea. Around 80% calves in Gp 1 (IgY 4096) were infected, but they showed 80% (4/5) protection against BRV diarrhea. Bovine RV-specific IgY Ab were detected in the feces of calves in Gp 1, indicating that avian antibodies (Abs) remained intact after passage through the gastrointestinal tract. At post infection day 21, the duodenum was the major site of BRV specific antibody secreting cells (ASC) in all experimental groups. Mucosal ASC responses of all isotypes were significantly higher in the IgY treated groups, independently of the specificity of the treatment, indicating that egg yolk components modulated the immune response against BRV infection at the mucosal level. These results indicate that supplementing newborn calves' diets for the first 14 days of life with egg yolk enriched in BRV-specific IgY represents a promising strategy to prevent BRV diarrhea. Moreover a strong active ASC immune response is induced in the intestinal mucosa following BRV infection after the administration of egg yolk, regardless the specificity of the treatment.     

抗奶牛乳腺炎多价卵黄抗体的制备及含量测定

本研究的目的是制备抗奶牛乳腺炎主要致病菌的多价卵黄抗体并检测特异性抗体的含量。采用金黄色葡萄球菌、无乳链球菌和大肠杆菌混合抗原免疫产蛋母鸡。通过水稀释法分离卵黄抗体。采用ELISA法检测抗体效价和特异性抗体含量。多价抗体与大肠杆菌的结合效价最高可达25600,与金黄色葡萄球菌和无乳链球菌的结合效价为12800。每毫升卵黄液中大肠杆菌、金黄色葡萄球菌和无乳链球菌特异性卵黄抗体（egg yolk immunoglobulin,IgY）的最高含量分别为2.13、2.01和1.92 mg。免疫后特异性抗体含量随时间变化趋势与抗体效价变化趋势一致。     

蛋黄中抗嗜水气单胞菌IgY的提取和纯化

通过对蛋黄中抗嗜水气单胞菌IgY的提取,分别进行了两种粗提方法(水稀释法、Pectin法)和纯化方法(硫酸铵法、PEG6000法)的比较。结果显示,当蛋黄液经pH5.0蒸馏水10倍稀释粗提后,上清液中脂肪和IgY残余率分别为32.69%和68.34%,效果较好。采用12%(w/v)PEG6000、33%(v/v)饱和硫酸铵纯化IgY,其免疫活性残余率分别为63.5%和64.1%。SDS-PAGE显示,水稀释法和Pectin法提取的上清液中杂蛋白减少,硫酸铵和PEG6000纯化后的上清液中几乎无其他杂带。研究表明,水稀释法和Pectin法提取IgY具有简便、高效和无污染的特点,硫酸铵和PEG6000适合纯化IgY。     

Passive protection of dogs against clinical disease due to Canine parvovirus-2 by specific antibody from chicken egg yolk

The protective effect of immunoglobulins derived from chicken egg yolk (IgY) against infection by Canine parvovirus 2 (CPV-2) was evaluated in 10 beagle dogs orally challenged with a strain of the virus. The 2-mo-old dogs were divided into 3 groups and treated with powders containing CPV-2 IgY or normal egg yolk for 7 d after the challenge. The 4 dogs receiving normal egg yolk (control group) demonstrated mild symptoms typical of CPV-2 infection, such as vomiting, diarrhea, and weight loss. No symptoms were observed by 16 d after challenge in the 3 dogs receiving 2 g of IgY powder. Of the 3 dogs receiving 0.5 g of IgY powder, 2 had clinical CPV-2 disease; however, the manifestations were less severe than in the control group. Furthermore, the IgY-treated groups had significantly greater weight gain and shorter duration of virus shedding than the control group. These results indicate that IgY is useful in protecting dogs from CPV-2-induced clinical disease.     

Characterization of specific egg yolk immunoglobulin (IgY) against mastitis-causing Escherichia coli

The objective of this study was to estimate the in vitro activity of egg yolk immunoglobulin (IgY) against mastitis-causing Escherichia coli. Specific IgY was produced by hens immunized with formaldehyde killed E. coli O111 in long-standing immunization response (titer > or =6400 for 100 days) and was isolated from yolks with a purity of 86% by water dilution, salt precipitations and ultrafiltration. Enzyme-linked immunosorbent assay (ELISA) indicated the produced IgY specifically targeted E. coli O111 and five other E. coli strains which were isolated from mastitic cows. The growth inhibition activity of the specific IgY to bacteria was dose-dependent with an effective concentration of 20mg purified IgY per milliliter. The phagocytic activity of E. coli either by milk macrophages (MPhi) or by polymorphonuclear neutrophil leukocytes (PMN) in the presence of specific IgY was significantly higher than that with nonspecific IgY or without IgY (p<0.05), suggesting that it enhanced phagocytic activity. The current work suggests that this specific IgY has potential as a therapeutic treatment for mastitis in dairy cows.     

Correlation analysis of the total IgY level in hen serum,egg yolk and offspring serum

The correlation between IgY levels of the serum and the yolk has been well documented in wild and domestic birds. The levels of total yolk IgY can be an index of the general health status of birds and may contribute to breeding programs when fitness of the offspring is a concern. We measured the levels of total serum IgY and yolk IgY in three different breeds (White Leghorn, Silkie and Dongxiang blue-shell) using indirect ELISA, and found that there was a significantly positive correlation between the levels of total serum IgY and total yolk IgY in all three breeds (White Leghorn: r = 0.404, P < 0.001, n = 100; Silkie: r = 0.561, P < 0.001, n = 70; Dongxiang blue-shell: r = 0.619, P < 0.001, n = 30). We also measured the total serum IgY levels in the 3-day-old offspring hatched from the Silkie hens and results were significantly correlated for serum IgY levels (r = 0.535, P < 0.001, n = 70) and the yolk IgY levels (r = 0.481, P < 0.001, n = 70). The regression analysis showed simple linear regression between IgY levels in hen serum, yolk and offspring serum. Our results suggest that total IgY level could be used as an index for chicken fitness.     

抗猪流行性腹泻病毒变异株卵黄抗体的制备、纯化及其活性影响因素的研究

为制备抗猪流行性腹泻病毒（porcine epidemic diarrhea virus，PEDV）变异株卵黄抗体并探索卵黄抗体的纯化方法，本试验采用灭活的PEDV变异株CH/JX01全病毒免疫蛋鸡，收集免疫后所产的鸡蛋，分别用水稀释法、PEG-6000法和水稀释-硫酸铵二次沉淀法对鸡蛋中IgY进行提纯，然后运用间接ELISA和Western blotting方法鉴定和比较3种方法的提纯效果，获得可用于规模化生产的提纯方法；同时研究不同温度、pH条件下抗体活性，寻找对提纯IgY活性具有保护作用的物质。结果显示，本试验成功制备了抗PEDV变异株的卵黄抗体。浓度检测结果表明，水稀释法提取的IgY浓度最高，为6.204 mg/mL；PEG-6000方法提纯的IgY浓度次之，为4.673 mg/mL；水稀释-硫酸铵二次沉淀法IgY浓度最低，为3.359 mg/mL。间接ELISA检测结果表明，水稀释-硫酸铵二次沉淀法提纯的IgY效价最高，为1：12 800；其次是PEG-6000，为1：6 400；而水稀释法最低，为1：1 600。综合3种方法所提纯的卵黄抗体浓度与效价，发现水稀释-硫酸铵二次沉淀法的提纯效果优于其他两种方法。活性影响因素试验结果表明，提纯的IgY在37~60℃活性稳定；pH为4.0~11.0时具有良好的活性；在酸性条件下，20%硫糖铝对IgY活性具有较好的保护作用。本试验结果将为卵黄抗体的大规模生产运用与储存提供了有效的参考依据。