虾蛋白过敏实验动物模型的建立

以卵白蛋白为阳性对照,以平衡盐溶液(PBS)为阴性对照,观察虾蛋白的全身过敏反应。同时,观察虾蛋白对致敏豚鼠离体回肠平滑肌过敏性收缩反应(Schultz-Dale 反应)的影响,以建立虾蛋白过敏实验动物模型。结果显示,用0.01～2g/100mL 卵白蛋白致敏并激发后,100% 豚鼠呈全身过敏反应阳性,0.1g/100mL 卵白蛋白组的豚鼠100% 死亡。相似质量浓度虾蛋白(0.01～1g/100mL)的全身过敏反应与卵白蛋白相近(与卵白蛋白组比较,P ＞ 0.05);Schultz-Dale 反应的实验结果与全身过敏反应结果相似。由此,初步建立虾蛋白过敏实验的动物模型。     

基于高压结合酶法制备的低敏虾制品体内体外致敏性检测的差异性分析

采用高压结合酶法处理凡纳滨对虾的虾蛋白、虾仁泥（虾肉）和虾仁,获得3 种低敏虾制品;采用酶联免疫吸附法检测3 种虾制品的过敏原性,采用全身性过敏反应（过敏性休克模型）及致敏离体回肠平滑肌收缩实验（Schultz-Dale反应）检测3 种低敏虾制品的致敏性,以分析体内与体外方法检测虾制品致敏性的差异性。结果显示：处理前的3 种原料过敏原性极高。经高压结合酶法处理的虾蛋白、虾肉和虾仁的过敏原性分别消减97.0%、94.1%和94.5%。而在动物实验中（以磷酸缓冲盐溶液为阴性对照,未处理虾蛋白为阳性对照,以豚鼠为受试对象）,未处理虾蛋白组的过敏反应发生率与死亡率均为100%,3 种低敏虾制品的过敏反应发生率也为100%,死亡率分别为16.7%（虾蛋白产物）、50%（虾肉产物）和83.3%（虾仁产物）。致敏的离体回肠受到3 种低敏虾制品攻击后,收缩力也明显增强,分别达到376.9%、766.2%和1 004.4%。上述结果表明,对高压结合酶法制备的低敏虾制品过敏原性的检测,体外检测与体内检测存在一定的差异性。     

色谱法在鸡蛋清主要过敏原分离纯化中研究进展

鸡蛋营养丰富,同时也是引起人体过敏的主要食物之一。蛋清中含有4种主要过敏原,包括卵白蛋白、卵转铁蛋白、卵类黏蛋白和溶菌酶。概述了鸡蛋中4种主要过敏原的理化特性及色谱法纯化过敏原的研究进展,旨在为规模化分离得到高纯度和高活性的过敏原提供参考。     

凡纳滨对虾酶解产物过敏原消减效果的评价

采用木瓜蛋白酶分解凡纳滨对虾的蛋白质,以消减其中的蛋白质过敏原;应用豚鼠全身过敏反应和离体回肠平滑肌过敏性收缩实验模型,对该蛋白酶酶解产物的致敏性进行评价。结果显示,虾蛋白和虾肉经木瓜蛋白酶水解后,其酶解产物所致的全身过敏反应明显减轻(与虾蛋白组和虾肉组比较,0.01相似文献   

桃过敏原的种类、制备、鉴定及检测技术研究进展

作为日常食用的植物源食品,水果可为人体提供糖类、维生素、矿物质等多种营养物质,从而调节机体的多项生理功能。然而,水果中的致敏成分可诱发过敏反应,由此引发的食品安全问题也越来越引起关注。桃是一种最常见的过敏水果,可引起轻微过敏症状和严重过敏反应甚至过敏性休克。文章综述桃过敏原的种类、亚类及其生物特性,阐述不同亚类桃过敏原在品种或地区的差异性,总结桃过敏原的分离制备方法和分子鉴定技术,并从过敏原基因检测、免疫检测技术和仪器检测技术3个方面对桃过敏原检测技术进行概括,以期为桃过敏原的致敏机制、消减技术和食品加工的安全控制提供研究基础。     

加工对鸡蛋过敏原的影响

卵类黏蛋白、卵白蛋白、卵转铁蛋白和溶菌酶是鸡蛋中的主要过敏原,适当的物理、化学和生物加工可以降低它们的致敏性。其中物理法生产的低致敏性蛋制品可供鸡蛋轻微过敏人群食用或作为免疫治疗药物;而化学和生物法制备的低过敏鸡蛋制品存在安全风险,它能否应用于生产,还有待进一步研究。另外,各种加工方法可以影响过敏原蛋白二硫键及高级结构甚至一级结构,从而导致该蛋白的致敏性发生变化。总之,加工对鸡蛋过敏原结构和致敏性的影响仍然是值得深入探索的科学问题,对指导生产和研发低致敏性或无致敏性蛋制品具有重要作用。     

南美虾蛋白酶解产物过敏原消减效果研究

采用胰蛋白酶、木瓜蛋白酶和菠萝蛋白酶分解南美白对虾的蛋白质,以消减其中的蛋白质过敏原;应用全身过敏反应和离体回肠平滑肌过敏性收缩实验模型,对该工艺蛋白酶酶解产物的致敏性进行评价。结果显示,3种蛋白酶的虾蛋白酶解产物所致的全身过敏反应均明显减轻(与虾蛋白组比较,0.01 ＜ P ＜ 0.05 或P ＜ 0.01);同时,3种酶解产物致敏的离体回肠平滑肌对虾蛋白和酶解产物过敏原攻击的反应也明显减弱(与虾蛋白致敏组比较,0.01＜P ＜ 0.05 或P ＜ 0.01)。综合评价3 种酶解产物的致敏性,认为木瓜蛋白酶的酶解工艺较好,过敏原消减比较理想,食用更安全。     

BN大鼠致敏动物模型研究

验证BN大鼠作为评价转基因食物蛋白致敏性动物模型的可行性。方法 48只雌性BN大鼠随机分为对照组(灭菌水)、马铃薯酸性磷酸酶组(PAP)、鸡蛋清粗提蛋白质组(HEWP)、卵清蛋白低剂量组(OVA-L)、卵清蛋白中剂量组(OVA-M)、卵清蛋白高剂量组(OVA-H),每组8只。各组依次分别每天经口灌胃1ml灭菌水、1mg/ml PAP、10mg/ml HEWP、0.1mg/ml OVA、1mg/ml OVA、10mg/ml OVA溶液,持续6周。分别于第14、28和42天取血分离血清,测定特异性抗体IgG和血清总IgE。于第21和35天取血分离血浆,测定组胺。测定各组动物的血压变化及胃肠道渗透性。结果 不同浓度致敏原OVA均可激发BN大鼠过敏反应,包括特异性IgG和血清总IgE升高、组胺升高以及血压下降,其中1mg/ml OVA溶液为致敏最佳剂量。弱致敏原HEWP过敏反应较弱;非致敏原PAP无过敏反应;各组胃肠功能均未发生明显的生理变化。结论 BN大鼠致敏动物模型是评价转基因食物致敏性较为理想的动物模型。     

热加工与非热加工技术对水产品致敏性的影响研究进展

我国作为水产养殖和消费总量第一大国,水产品引发的过敏问题越来越受到关注,近些年来,因食用水产品而导致的过敏事件日益增多。该研究综述了近年来热加工技术（蒸、煮、高温压力）、非热加工技术（超高压、低温等离子体、超声波和辐照）以及两种加工技术联用对水产品过敏原消减的研究,指出热加工技术主要通过使蛋白质变性来消减过敏原的致敏性,非热加工技术则通过掩盖或破坏过敏原抗原表位来消减过敏原致敏性,为低致敏性水产品开发提供了重要基础和技术参考。不断探究过敏原诱导过敏反应发生的机理,加快推进低致敏性水产品加工技术在实际生产中的应用,有利于控制和降低水产品过敏所带来的风险。     

让食品致敏原不再“过敏”

食品致敏原是指食物中能使敏感个体产生免疫反应或过敏反应的蛋白质。食品过敏通常发展为系列反应,表现为支气管哮喘、变应性眼炎、荨麻疹、血管水肿、过敏性休克等,严重的甚至导致死亡。目前大约有160多种食品含有可以导致过敏反应的食品致敏原,主要包括八大类：蛋品、牛奶、花生、黄豆、小麦、树木坚果、鱼类和甲壳类食品。     

The allergenicity of ovomucoid and the effect of its elimination from hen's egg white

In order to remove the ovomucoid from hen's egg white, chitin and hydrazide polystyrene beads were used as affinity ligands with 8.9 and 7.1 mg trypsin g^?1 ligand respectively. Ovomucoid was successfully depleted using the trypsin affinity column without hydrolysation of the other egg white constituents. The components of the egg white were purified by high‐performance liquid chromatography, and then the allergenicity of each of these components was compared with that of pooled human serum derived from patients who are allergic to hen's eggs. The importance of using pure protein for studies of the allergenicity of egg white is highlighted, and it was determined (using an enzyme‐immunosorbent assay) that ovomucoid and ovalbumin are major allergenic proteins in egg white. The ovomucoid‐eliminated egg white preparation exhibited significantly less IgE‐binding activity than normal egg white. The ovomucoid‐specific IgE antibodies may have important implications with regard to the egg‐allergic reaction in humans. © 2001 Society of Chemical Industry     

虾制品致敏性诱发豚鼠相关细胞因子及Th1/Th2细胞平衡的变化

以消减致敏性南美白对虾的虾仁、虾肉和虾蛋白为样品,以pH 7.5的磷酸盐缓冲液为阴性对照,未处理的虾蛋白为阳性对照,建立豚鼠过敏模型,研究过敏豚鼠血清中相关细胞因子与食物过敏的相关性,并推断食物过敏对辅助性T（type 1/type 2 T-helper, Th1/Th2）细胞平衡的影响。收集过敏豚鼠的血清,采用酶联免疫吸附测定法检测血清中免疫球蛋白E（immunoglobulin E,IgE）、组胺（histamine,HIS）、相关细胞因子（白细胞介素（interleukin,IL）-1、IL-2、IL-3、IL-4、IL-6、IL-10、肿瘤坏死因子-α（tumor necrosis factor α,TNF-α）、干扰素-γ（interferon-γ,IFN-γ）质量浓度。结果表明,用未处理的虾蛋白致敏豚鼠,用致敏性消减程度不同的虾制品（虾蛋白、虾肉、虾仁）提取的蛋白激发,消减致敏性的虾蛋白、虾肉和虾仁提取蛋白激发后豚鼠血清中IgE含量分别为（3.905±0.120）、（4.813±0.188）、（5.199±0.327）U/mL,HIS质量浓度分别为（16.437±1.120）、（19.656±1.080）、（21.071±1.732）μg/mL,激发后血清中IgE和HIS质量浓度变化与致敏性程度呈正相关,致敏性越低,血清中IgE和HIS质量浓度越低。过敏豚鼠血清中IL-1、IL-2、IL-3、IL-4、IL-6、TNF-α质量浓度的变化与虾制品致敏程度呈正相关;同时,与IgE和HIS质量浓度变化规律具有一致性;血清中IL-10质量浓度变化与致敏性程度呈负相关;因此,这些细胞因子与食物过敏具有很好的相关性。过敏血清中IFN-γ没有呈现规律性变化,但IFN-γ/IL-4随着致敏性的增强而减小。因此,推测虾制品激发过敏豚鼠的Th1/Th2细胞平衡向Th2细胞偏移。     

Effect of soybean trypsin inhibitor and chicken ovomucoid on the immunogenic and sensitizing properties of various dietary proteins

Adult male guinea pigs were sensitized by intragastric administration of bovine serum albumin (BSA) and chick ovalbumin (OA) and their mixtures with soybean Kunitz trypsin inhibitor (SBTI) and chick ovomucoid (OM). Sensitization of the animals was evaluated by the anaphylactic shock reaction and also by the levels of serum specific IgG antibodies against BSA and OA as measured in the solid phase radioimmunoassay. The experiment revealed pronounced desensitizing properties of SBTI combined both with OA and BSA. OM produced no effect on the animal sensitization caused by OA and enhanced the BSA-induced sensitization. The results obtained demonstrate the necessity of differential approach to the evaluation of the action of varying trypsin inhibitors on food sensitization.     

Characteristics of food anaphylactic reactions to proteins and protein preparations in guinea pigs with different duration of hexenal-induced sleep]

The state of guinea pig sensitization was studied in the direct test in vivo by induction of active food anaphylaxis (FA). The animals were orally sensitized with food allergens: chick ovalbumin (OVA), bovine serum albumin, and protein preparations N 1 and N 2 (PP N 1 and N 2). In guinea pigs with null hexenal-induced sleep (NHS) and long hexenal-induced sleep (LHS), 40 min, the duration of HS is reliably reproduced in repeated testing. The intensity of FA reactions in guinea pigs with NHS was less manifested than in the animals with LHS with both food allergens. Significantly higher allergenic properties of PP N 2 were expressed in the animals with LHS. It was shown that varying anaphylactic sensitivity of guinea pigs in the above groups was not related with different permeability of the gastrointestinal tract of these animals for OVA macromolecules. Possibilities of metabolic validation of increasing anaphylactic sensitivity of guinea pigs with LHS have been considered.     

Inter-laboratory evaluation studies of notified ELISA methods for allergic substances (egg)

Inter-laboratory evaluation studies were conducted for the notified ELISA methods for allergic substances (Egg). Standard extracts of egg spiked in extracts of sausage, sauce, cookie, bread and cereal at a level of 5-20 ng/mL as the sample solution were analyzed in replicate in 10 laboratories. Coefficients of variation (CVs) of all three ELISA methods using an Egg Protein ovalbumin ELISA Kit (ovalbumin kit), an Egg Protein ovomucoid ELISA Kit (ovomucoid kit) and a FASTKIT Egg ELISA kit (Egg ELISA kit) were mostly less than 10%. Mean recoveries of the standard extract of egg were over 40% in the three ELISA methods. Repeatability relative standard deviations of egg standard solution in five food extracts were in the ranges of 18.7-25.5%, 18.6-41.8%, 21.3-43.3% for the ovalbumin kit, the ovomucoid kit and the Egg ELISA kit, respectively. Reproducibility relative standard deviations of egg standard solution in five food extracts were 16.8-35.1%, 19.6-35.8%, 24.7-51.1% for the ovalbumin kit, the ovomucoid kit and the Egg ELISA kit, respectively. The detection limits of all the ELISA methods were 4-5 ng/mL in sample solutions. These results suggested that the notified ELISA methods are reliable and reproducible for the inspection of egg protein levels in extracts of sausage, sauce, cookie, bread and cereal.     

螺旋藻抑制致敏细胞释放组胺的研究

用鸡蛋清蛋白腹腔注射免疫豚鼠制备过敏症动物模型,研究螺旋藻对致敏细胞释放组胺的抑制效应。发现灌服螺旋藻对鸡蛋清蛋白过敏原体内外激发致敏豚鼠外周血及腹腔细胞组胺释放均具有明显抑制效应(p<0.05),对嗜碱性粒细胞和嗜酸性粒细胞数量也有一定下调作用。结果表明口服螺旋藻可抑制致敏细胞释放组胺,具有一定抗过敏效果。     

鸡卵类黏蛋白结构与性质研究进展

鸡卵类黏蛋白是鸡蛋中最主要也是过敏原性最强的过敏原蛋白。本文总结该蛋白的结构,包括氨基酸序列、糖基组成、二硫键位置、二级结构以及组成该蛋白的3 个结构域,并描述其理化性质,最后着重分析讨论其过敏原性,特别是其分子结构中二硫键、糖基和结构域等因素与过敏原性之间的内在联系。     

Evaluation of the allergenicity of goat milk, cow milk, and their lactosera in a guinea pig model

The object of this study was to determine the allergenicity of goat milk (GM) and cow milk (CM) and that of their respective lactosera (GML and CML), by in vivo and in vitro assays. Two systemic tests for anaphylaxis were carried out in guinea pigs, the animals being sensitized orally with the 2 types of milk and lactosera. Sera were taken from the orbital sinus of the experimental animals at 0 and 22 d of the experiment to perform the serological study and the passive cutaneous anaphylaxis test. For the latter, the guinea pigs were sensitized passively with antibodies against the 4 antigen solutions. Enzyme-linked immunosorbent assay and Western blot were used to determine the specific antibodies of the isotypes immunoglobulin G1 and immunoglobulin G(Fc) developed against the same 4 antigen solutions. From these anaphylaxis and antibody-production tests, it was concluded that GM is hypoallergenic when compared with CM. The lactosera produced more closely grouped results, with values always below those of the corresponding milk. None of the proteins in the 4 immunizing solutions were identified as being their main allergen. These results show the hypoallergenicity of GM versus CM, and also that both casein and lactoserum proteins may be responsible for allergy in each case. To analyze the possibility of producing an innocuous food for those allergic to milk proteins, it would be of interest to identify the epitope(s) responsible for such allergenicity.