家蝇幼虫分泌型抗菌肽对小鼠免疫功能影响

目的 探讨家蝇幼虫分泌型抗菌肽对正常小鼠免疫功能影响.方法 选用BalB/c小鼠,随机分为对照组(生理盐水)和家蝇幼虫分泌型抗菌肽(腹腔注射)5、10、20mg/kg组,每天1次,7d后处死小鼠,测量体重、胸腺/体重比值、小鼠腹腔巨噬细胞吞噬鸡红细胞能力、刀豆蛋白A诱导小鼠脾T淋巴细胞转化率、碳粒廓清能力及半数溶血值.结果 10、20mg/kg抗菌肽组小鼠脾脏指数分别为(7.41±0.93)和(7.56±1.05),胸腺指数分别为(3.80±0.69)和(3.51±1.02),巨噬细胞吞噬率为(38.81±7.88)%和(40.16±9.74)%,脾脏酸性磷酸酶活性分别为(268.60±36.64)、(270.48±54.62)U/g,脾T淋巴细胞转化率分别为(0.31±0.11)%和(0.32±0.09)%,与对照组比较,差异有统计学意义(P均<0.05).抗菌肽组小鼠体重及血清半数溶血值与对照组比较,差异无统计学意义(P>0.05).结论 家蝇幼虫分泌型抗菌肽对小鼠具有增强免疫功能作用.     

蝇蛆壳聚糖对糖尿病小鼠降血糖作用

目的 探讨蝇蛆壳聚糖对实验性糖尿病小鼠血糖调节作用.方法 将蝇蛆壳聚糖分别给予正常小鼠及糖尿病模型小鼠,经口灌胃,连续20 d,测定空腹血糖及糖耐量.结果 正常小鼠给予蝇蛆壳聚糖后血糖值为(8.86±1.12)mmol/L,与空白对照组比较差异无统计学意义(P>0.05).糖尿病小鼠给予高、中、低剂量蝇蛆壳聚糖后血糖分别为(11.92±3.36),(13.02±4.27),(16.39±2.65)mmol/L,均明显低于模型对照组(19.67±3.81)mmol/L(P<0.05),高、中、低剂量组糖耐量分别为(24.70±5.04),(27.58±5.30),(34.27±7.73)mm²,均明显低于模型对照组(40.49±9.80)mm²(P<0.05,P<0.01).结论 蝇蛆壳聚糖能明显降低糖尿病小鼠血糖,对四氧嘧啶所引起的胰岛β细胞破坏有一定抑制作用.     

纳米银溶液尾静脉注射致小鼠急性毒性作用

目的 探讨尾静脉注射纳米银溶液对小鼠的急性毒性作用。方法 将纳米银溶液12、3、0.75 mg/mL,按10 mL/kg剂量经小鼠尾静脉注射,对照组注射生理盐水,染毒7 d和14 d后分批处死小鼠,检测脏器指数、血清生化指标和组织病理学。结果 0.75 mg/mL纳米银组染毒7 d时总蛋白(TP)和白蛋白(ALB)含量分别为(50.17±4.71)和(13.83±1.47)g/L,低于对照组(P<0.05),乳酸脱氢酶(LDH)活力为(789.00±341.03)U/L,高于对照组(P<0.05),3 mg/mL纳米银组TP和ALB分别为(48.67±3.61)、(13.33±1.03)g/L,低于对照组(P<0.05);纳米银染毒14 d时,0.75 mg/mL组谷草转氨酶(100.00±17.19)U/L低于对照组(P<0.05),3 mg/mL组LDH(667.00±217.24)U/L与尿素氮(8.93±1.03)mmol/L,高于对照组(P<0.05);病理检查显示,高剂量组多数小鼠肺部出现炎细胞浸润及间质性炎症改变;肝细胞弥漫性水肿,胞浆疏松化。结论 尾静脉注射纳米银溶液可以影响小鼠肺脏、肝脏和肾脏的功能。     

牛磺酸对锌中毒小鼠免疫功能影响

目的了解牛磺酸对锌中毒小鼠免疫因子及T淋巴细胞增殖功能影响。方法以不同浓度牛磺酸作用于锌中毒模型小鼠后,计算脏器指数,噻唑蓝(MTT)比色法测定T淋巴细胞增殖功能,酶联免疫吸附(ELISA)法测定白细胞介素-2(IL-2)、肿瘤坏死因子α(TNF-α)浓度。结果锌中毒模型组TNF-α、IL-2浓度分别为(9.02±1.34)、(1.411±0.082)pg/mL,T淋巴细胞增殖活性为(0.056 1±0.006),明显低于空白对照组(P<0.05),低剂量(200mg/kg)牛磺酸组TNF-α、IL-2分别为(15.92±2.32)、(1.928±0.103)pg/mL,T淋巴细胞增殖活性为(0.120 1±0.012),明显高于锌中毒模型组,差异有统计学意义(P<0.01)。结论牛磺酸可提高锌中毒小鼠外周血TNF-α、IL-2水平及促进T淋巴细胞增殖,对锌中毒小鼠免疫功能损伤有一定保护作用。     

益气解毒方对转基因小鼠上皮细胞及基因影响

目的研究益气解毒方对TgN(p53mt-LMP1)/HT转基因小鼠的鼻腔和鼻咽粘膜上皮细胞增殖及肿瘤坏死因子受体相关因子2(TRAF2)和p16基因表达的影响。方法苏木素-伊红(H-E)染色法观察小鼠鼻腔和鼻咽粘膜上皮细胞增殖特征;免疫组织化学染色法检测小鼠鼻腔和鼻咽粘膜上皮细胞TRAF2、p16基因的表达水平,并采用蛋白印迹(Westernblot)对基因表达进行验证。结果与TgN(p53mt-LMP1)/HT小鼠诱癌生理盐水对照组(TIC组)比较,TgN(p53mt-LMP1)/HT小鼠诱癌益气解毒方干预组(TIM组鼻腔和鼻咽粘膜上皮增生不明显,癌前病变率显著下降(P<0.01);其TRAF2基因表达水平(TIC组、TIM组鼻腔的分别为129.45±9.53和160.96±11.04,鼻咽的分别为126.38±12.69和160.88±6.84)显著降低(P<0.01);p16基因表达水平(TIC组、TIM组鼻腔的分别为157.21±10.44和131.72±10.06,鼻咽的分别为155.41±11.77和132.63±10.22)显著增高(P<0.01)。TIM组的TRAF2和p16基因表达水平接近野生型C₅₇BL/6J小鼠对照组(鼻腔和鼻咽的TRAF2基因表达水平分别为165.07±10.58和164.39±7.88,p16基因表达水平分别为129.62±12.16和129.12±11.67),差异无统计学意义。结论中药益气解毒方可阻逆二亚硝基哌嗪(DNP)对TgN(p53mt-LMP1)/HT小鼠鼻腔和鼻咽粘膜上皮细胞异常增殖的诱导效应,其阻逆作用的发挥与下调TRAF2基因表达和上调p16基因表达密切相关。     

小米多肽对小鼠免疫调节作用

目的研究小米多肽对小鼠的免疫调节作用。方法小米多肽分为高、中、低剂量组,分别为250、500、1 000 mg/(kg·d)喂饲小鼠30 d,通过淋巴细胞转化试验、半数溶血值(HC₅₀)、腹腔巨噬细胞吞噬功能、免疫器官指数的测定,研究小米多肽对小鼠免疫调节作用。结果不同剂量的小米多肽有明显的刺激淋巴细胞转化作用;500、1 000 mg/(kg·d)小米多肽剂量组HC₅₀分别为(171.33±8.77)、(175.91±9.22),吞噬率分别为(59.45±5.16)%、(65.7±4.31)%;吞噬指数分别为(0.83±0.11)、(0.88±0.09),与对照组比较差异有统计学意义(P<0.01),脾脏指数和胸腺指数均明显增加(P<0.01)。结论小米多肽具有明显的免疫调节作用。     

全氟辛烷磺酸对小鼠脾细胞NO分泌水平影响

目的 观察短期、高剂量全氟辛烷磺酸(PFOS)对C57BL/6雄性小鼠一氧化氮(NO)分泌水平影响.方法 选择雄性C57BL/6小鼠24只,PFOS经口灌胃染毒,剂量分别为5,20,40 mg/kg.每天1次,染毒7 d后,制备脾脏淋巴细胞悬液,细胞培养48 h后收取上清液,检测NO含量.结果 20,40 mg/kg PFOS染毒组小鼠体重明显下降(P<0.05);20 mg/kg PFOS染毒组小鼠脾脏和胸腺指数分别为(0.36±0.04)和(0.21±0.02),明显低于对照组(P<0.05).40 mg/kg PFOS染毒组NO分泌水平为(0.66±0.14)μmol/L,明显低于对照组(P<0.05).结论 高剂量PFOS暴露可降低小鼠脾淋巴细胞NO分泌水平,抑制小鼠巨噬细胞的活化.     

枸杞多糖对染铅小鼠学习记忆及海马区PKC影响

目的 探讨枸杞多糖对染铅小鼠学习记忆功能和海马区蛋白激酶C(Protein kinase C,PKC)的影响。方法 将实验小鼠随机分为5组,即空白对照组、染铅模型组、枸杞多糖高、中、低3个剂量组,枸杞多糖各剂量组于染铅后第2d灌胃给药,每天1次,于第2,4周测小鼠到达迷宫避难台所需要的时间,第4周测血铅浓度和海马区PKC含量。结果 枸杞多糖各剂量组与染铅模型组比较,血铅浓度[枸杞多糖各剂量组(0.65±0.28)～(0.11±0.13)mg/L,模型组(1.68±0.19)mg/L]明显降低,到达避难台的时间也明显减少;而海马区PKC含量[枸杞多糖各剂量组(73.23±6.52)～(96.33±8.03)mmol/L,模型组(62.26±7.21)mmol/L]明显升高,差异有统计学意义(P<0.05或P<0.01)。结论 枸杞多糖可促进小鼠体内铅的排出,改善染铅小鼠的学习记忆功能,抑制海马区PKC含量降低。     

间充质干细胞对辐射诱发胸腺瘤β-catenin和c-myc基因影响

目的 探讨骨髓间充质干细胞(MSCs)对辐射诱发胸腺瘤过程中β-catenin和c-myc mRNA表达影响,为阐明MSCs在肿瘤发生发展中作用提供理论依据。方法全骨髓贴壁培养C57BL/6小鼠MSCs,X射线照射C57BL/6小鼠建立胸腺淋巴瘤模型,将小鼠随机分成对照组、辐射组及MSCs组,每组6只;逆转录-聚合酶链反应技术检测各组小鼠胸腺β-catenin和c-myc mRNA表达。结果 辐射组小鼠胸腺瘤β-catenin mRNA表达量(0.92±0.23)明显高于对照组(0.64±0.21)(P<0.05),MSCs组β-catenin mRNA表达量(0.77±0.24)下降;与对照组(1.48±0.34)比较,辐射组c-myc mRNA表达量(1.61±0.37)上调,MSCs组c-myc mRNA表达量(1.18±0.34)明显低于辐射组(P<0.05)。结论 MSCs可通过抑制β-catenin和c-myc基因异常表达,抑制肿瘤的增殖。     

环丙沙星对小鼠免疫毒性及肌肉品质影响

目的 研究环丙沙星对小鼠免疫毒性和肌肉品质的影响。方法 将小鼠分为对照组和环丙沙星高、中、低剂量组(44,11,5.5 mg/kg);每组10只动物,连续7 d腹腔注射给药,每日1次;通过计算小鼠胸腺和脾脏指数,观察脾淋巴细胞形态变化来探讨该药的免疫毒性;通过检测肌肉蛋白质含量、肌肉pH值,观察其对小鼠肌肉品质的影响。结果 对照组胸腺和脾脏系数分别为(9.1±2.3),(6.3±1.1)mg/g,高剂量组胸腺和脾脏系数分别为(6.5±1.6),(3.4±0.5)mg/g,与对照组比较,差异均有统计学意义(P<0.05或P<0.01);而中、低剂量组的脾脏指数与对照组比较,差异均有统计学意义(P<0.05);环丙沙星各剂量组与对照组比较,肌肉pH值变化不明显;环丙沙星高、中、低剂量肌肉蛋白质含量分别为(24.68±0.55),(22.48±0.54),(21.22±1.25)g/100 g,与对照组(31.83±2.36)g/100 g比较明显下降(P<0.05);与对照组比较,高剂量组脾淋巴细胞形态异常。结论 环丙沙星对小鼠具有一定的免疫毒性,明显减少了肌肉蛋白质含量。     

Clinical and laboratory investigation of allergy to genetically modified foods

Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying.     

Nonmurine animal models of food allergy

Food allergy can present as immediate hypersensitivity [manifestations mediated by immunoglobulin (Ig)E], delayed-type hypersensitivity (reactions associated with specific T lymphocytes), and inflammatory reactions caused by immune complexes. For reasons of ethics and efficacy, investigations in humans to determine sensitization and allergic responses of IgE production to innocuous food proteins are not feasible. Therefore, animal models are used a) to bypass the innate tendency to develop tolerance to food proteins and induce specific IgE antibody of sufficient avidity/affinity to cause sensitization and upon reexposure to induce an allergic response, b) to predict allergenicity of novel proteins using characteristics of known food allergens, and c) to treat food allergy by using immunotherapeutic strategies to alleviate life-threatening reactions. The predominant hypothesis for IgE-mediated food allergy is that there is an adverse reaction to exogenous food proteins or food protein fragments, which escape lumen hydrolysis, and in a polarized helper T cell subset 2 (Th2) environment, immunoglobulin class switching to allergen-specific IgE is generated in the immune system of the gastrointestinal-associated lymphoid tissues. Traditionally, the immunologic characterization and toxicologic studies of small laboratory animals have provided the basis for development of animal models of food allergy; however, the natural allergic response in large animals, which closely mimic allergic diseases in humans, can also be useful as models for investigations involving food allergy.     

A human dendritic cell-based method to identify CD4+ T-cell epitopes in potential protein allergens

We developed an assay to determine the location of immunodominant CD4(+) T-cell epitopes in any protein. The method uses CD4(+) T cells from community donors in conjunction with dendritic cells derived in vitro. Synthetic peptides constructed to describe the sequence of the protein of interest are cocultured with dendritic cells and CD4(+) T cells, and T-cell proliferation is measured. Data are compiled over a large replicate of human donors to pinpoint immunodominant, usually promiscuous epitope regions. We have applied this technique to a known food allergen, the Brazil nut 2S storage globulin protein, and to two potential food allergens, the Cry1Ab and Cry3Aa proteins. We show epitope data for these three proteins. This assay can be used as a tool to guide the selection and qualification of future potential food transgenes.     

Allergenic potential and enzymatic resistance of buckwheat

Buckwheat is known as a health food but is one of the major food allergens triggering potentially fatal anaphylaxis in Asia, especially in Japan and Korea. This study was conducted to investigate the characteristic of enzymatic resistance of buckwheat protein and allergenic potential. Enzymatic resistance of buckwheat protein was performed with in vitro digestibility test in simulated gastric fluid (SGF), pH 1.2, using pepsin and simulated intestinal fluid (SIF) using chymotrypsin. Reactivity of buckwheat proteins to human IgE was performed using six allergic patients sensitized to buckwheat. Buckwheat''s IgE levels were measured using the Phadia UniCAP-system. Buckwheat protein, 16 kDa, still remained after 30 min treatment of pepsin on SDS-PAGE. Even though 16 kDa almost disappeared after 60 min treatment, two out of the six buckwheat patients'' sera showed reactivity to hydrolysate after 60 min treatment, indicating that allergenicity still remained. In simulated intestinal fluid (SIF) using chymotrypsin, buckwheat protein, 24 kDa, showed resistance to hydrolysis with chymotrypsin on SDS-PAGE, and still had allergenicity based on the result of ELISA. Our results suggest that buckwheat proteins have strong resistance to enzyme degradation. This may be attributed in part to the allergenic potential of buckwheat. Further study should be continued regarding buckwheat allergy.     

Pollen-related food allergy: cloning and immunological analysis of isoforms and mutants of Mal d 1, the major apple allergen, and Bet v 1, the major birch pollen allergen

Summary Background: Mal d 1, the major apple allergen, cross-reacts with IgE specific for the major birch pollen allergen, Bet v 1, and is responsible for birch pollen related food allergy to apple. Isoforms of Bet v 1 showing minor sequence variations display different binding capacitiy for specific IgE antibodies from allergic patients. Moreover, strain-dependent variation of allergenicity has been reported for apples. Objective: To investigate the occurence of strain-dependent isoforms of Mal d 1 which may differ in their allergenic potential, to obtain data on structures essential for binding of Mal d 1 to the antibody, and to gain insights into the structures responsible for its IgE cross-reactivity to Bet v 1. Methods: The cDNA of Mal d 1 from various apple strains was amplified by a PCR strategy based on conserved regions of known Mal d 1-sequences, and sequenced. Two major isoforms of Mal d 1were expressed as recombinant proteins and purified, as were different variants of the major birch pollen allergen, Bet v 1. Together with already existing recombinant birch pollen and apple allergens, these were subjected to allergenicity testing by IgE-immunoblotting, enzyme allergo sorbent test and dose related mediator release. “Hot-spots” for IgE-reactivity were identified by site-directed mutagenesis. Results: Twelve Mal d 1-clones were sequenced from 7 apple varieties and compared to 3 known Mal d 1 sequences. The clones were clustered into two groups, each showing a high degree of sequence identity to one of the known sequences and specific differences to the third sequence. No strain-specific sequences were identified. In contrast, apple strains with reported differences in allergenicity showed different expression levels of the major allergen. Immunologic testing of recombinant allergens revealed high IgE binding capacity of 2 major isoforms, named GD26 and GS29, with a slightly higher IgE binding capacity of DG26. Moreover, the allergenicity was similar to another rMal d 1 reported in the literature, representing the isoform divergent from our clones. Mutational analysis of our Mal d 1 allergens identified serine in position 111 as essential for IgE binding. Allergenicity was almost depleted by changing this residue into a proline. Moreover, the corresponding serine residue, present in position 112 of Bet v 1, was in a similar manner crucial for the allergenicity of the birch pollen allergen. Conclusion: We conclude that divergent allergenicity of apple strains mainly depends on differnet expression levels of the major allergen. Introduction of a proline residue in position 111 of Mal d 1 and in position 112 of Bet v 1 led to a drastic reduction of allergenicity of both the pollen and the food allergen, obviously also removing the cross-reactive epitope. Mutants with reduced IgE-reactivity but maintained T-cell reactivity may represent new candidates for a safer specific immunotherapy with reduced side-effects. Received: 7 June 1999, Accepted: 30 July 1999     

1 878例过敏性疾病成年患者血清过敏原特异性IgE检测及流行病学特征分析

目的 分析确诊为过敏性疾病成年患者过敏原特异性IgE（specific IgE,sIgE）检测结果及过敏原特征。方法 以北京市某医院2019年1月1日至2020年12月31日进行过敏原特异性IgE检测的确诊过敏性疾病成年患者为研究对象,对病例特征及过敏原情况进行描述性分析。结果 吸入组和食物组过敏原sIgE阳性率分别为38.66%和21.99%,差异有统计学意义（P<0.05）。吸入组中排名前5位的过敏原分别为屋尘螨/粉尘螨（16.56%）、艾蒿（15.92%）、屋尘（10.97%）、豚草（7.29%）、蟑螂（6.39%）;食物组中排名前5位的主要过敏原分别为鳕鱼/龙虾/扇贝（6.87%）、黄豆（5.64%）、鲑鱼/鲈鱼/鲤鱼（5.22%）、蟹（4.31%）、虾（2.66%）。8—10月吸入组会出现屋尘螨/粉尘螨、艾蒿过敏原sIgE阳性率峰值;1—2月食物组会出现鳕鱼/龙虾/扇贝、鲑鱼/鲈鱼/鲤鱼过敏原sIgE阳性率峰值。吸入组和食物组不同性别患者的血清过敏原sIgE阳性率差异均无统计学意义（均P>0.05）。吸入组中,除蟑螂、狗上皮与点青/分枝孢/烟曲/交链孢霉3项外,青年、中年和老年血清过敏原sIgE阳性率差异均有统计学意义（均P<0.05）。食物组中,青年、中年和老年血清过敏原sIgE阳性率差异均无统计学意义（均P>0.05）。结论 过敏性疾病成年患者过敏原sIgE阳性主要过敏原是吸入性过敏原屋尘螨/粉尘螨、艾蒿、屋尘、豚草、蟑螂和食物性过敏原鳕鱼/龙虾/扇贝、黄豆、鲑鱼/鲈鱼/鲤鱼。过敏原sIgE阳性率在不同时间、不同年龄段人群中存在显著性差异,但不同性别的过敏原sIgE阳性率无显著性差异。     

Assessment of the inherent allergenic potential of proteins in mice

There is considerable interest in the design of approaches that will permit the accurate identification and characterization of proteins that have the inherent potential to induce sensitization and cause food allergy. Among the methods used currently as part of such assessments are consideration of structural similarity to, or amino acid sequence homology with, known human allergens; whether there exists immunologic cross-reactivity with known allergens; and measurement of resistance to proteolytic digestion in a simulated gastric fluid. Although such approaches provide information that will contribute to a safety assessment, they do not--either individually or collectively--provide a direct evaluation of the ability of a novel protein to cause allergic sensitization. For this reason, work is in progress to design and evaluate suitable animal models that will provide a more holistic assessment of allergenic potential. In this laboratory, the approach we have taken has been to examine the characteristics of immune responses induced in mice following parenteral (intraperitoneal) exposure to test proteins. The basis of this method is to determine simultaneously the overall immunogenic potential of proteins [measured as a function of immunoglobulin (Ig) G antibody responses] and to compare this with their ability to provoke IgE antibody production, IgE being the antibody that effects allergic sensitization. Although this approach has not yet been evaluated fully, the results available to date suggest that it will be possible to distinguish proteins that have the inherent potential to induce allergic sensitization from those that do not. In this article we summarize progress to date in the context of the scientific background against which such methods are being developed.     

Assessment of the allergic potential of food protein extracts and proteins on oral application using the brown Norway rat model

The need for widely accepted and validated animal models to test the potential allergenicity and potency of novel (biotechnology-derived) proteins has become an important issue for their safety evaluation. In this article, we summarize the results of the development of an oral sensitization protocol for food proteins in the rat. Young Brown Norway rats were exposed to either various purified allergenic proteins (e.g., ovalbumin, partly purified), a whole food (cow's milk), or total protein extracts (hen's egg white, peanut) by daily gavage dosing during 42 days without the use of an adjuvant. The results showed that Brown Norway rats can be sensitized orally to the various allergenic food proteins tested, resulting in antigen-specific immunoglobulin (Ig) G and IgE responses, without the use of adjuvants. Animals orally exposed to cow's milk or total protein extracts of egg white also developed specific IgE and IgG antibodies that recognized the same proteins compared with antibodies from patients allergic to egg white or cow's milk. We also studied local and systemic immune-mediated effects. In ovalbumin-sensitized rats, some clinical symptoms of food allergy were studied upon an oral challenge with ovalbumin. The results demonstrated that gut permeability was increased and that in some animals breathing frequency and systolic blood pressure were temporarily decreased. The results obtained show that the Brown Norway rat provides a suitable animal model for food allergy research and for the study of relative allergenicity of existing and novel food proteins.     

蛋白过敏性研究——BN大鼠动物模型

目的　用BN大鼠模型探讨不同蛋白的过敏性。方法　通过腹腔注射 (1mg ml)或口服 (10mg ml)给予BN大鼠卵清蛋白 (OVA)或牛血清白蛋白 (BSA) ,时间为 6周。在不同时间取血清 ,进行被动皮肤致敏试验 (PCA) ;分离血浆进行组胺测定 ;此外 ,对OVA组和对照组的大鼠进行血压测定。结果　PCA试验结果表明OVA特异性IgE抗体滴度较高 (1 32～ 1 12 8) ,而BSA特异性IgE抗体滴度较低 (1 2～ 1 4 )。与对照组相比 ,腹腔注射或口服OVA均使组胺水平升高。口服OVA对大多数大鼠的血压没有明显的影响 ,然而 ,有 2只大鼠收缩压暂时降低。结论　该研究结果表明BN大鼠模型可能是一种较理想的蛋白过敏性模型。     

Effect of extrusion processing on immune activation properties of hazelnut protein in a mouse model

Although food processing can alter food allergenicity, the impact of extrusion processing on in vivo hazelnut allergenicity is unknown. Here, we tested the hypothesis that extrusion processing will alter the immune activation properties of hazelnut protein (HNP) in mice. Soluble extrusion-processed HNP (EHNP) was prepared and evaluated for immune response using an established transdermal sensitization mouse model. Mice were sensitized with identical amounts of EHNP versus raw HNP. After confirming systemic IgE, IgG1 and IgG2a antibody responses, oral hypersensitivity reaction was quantified by hypothermia shock response (HSR). Mechanism was studied by measuring mucosal mast cell (MMC) degranulation. Compared to raw HNP, the EHNP elicited slower but similar IgE antibody (Ab) response, lower IgG1 but higher IgG2a Ab response. The EHNP exhibited significantly lower oral HSR as well as MMC degranulation capacity. These results demonstrate that the extrusion technology can be used to produce soluble HNP with altered immune activation properties.