虾类和蟹类过敏原的交叉反应性研究

目的：分析虾类和蟹类过敏原交叉反应性，探讨其在食物过敏症的预防、诊断和治疗中的意义。方法：采用SDS-PAGE分析虾蟹的蛋白组分，Westernblot分析其过敏原组分，Westernblot和ELISA抑制试验研究虾类和蟹类的过敏原交叉反应性。结果：虾类、蟹类过敏原蛋白组分相似性与其种属关系相关，相对分子量（Mr）在20000、36000、38000、44000、68000、75000、85000处具有相同条带；Mr为36000的蛋白是虾的主要过敏原，胁为36000、66000、85000的蛋白是蟹的主要过敏原；青蟹蛋白和日本沼虾蛋白对其余虾蟹过敏原有抑制作用，并且随着抑制物浓度增加抑制效应增强。结论：虾类和蟹类过敏原有相似性，其中Mr在36000处相互之间存在较强的交叉反应。     

中国人的虾、蟹致敏过敏原组分分析

目的：分析鉴定中国人群的虾、蟹致敏组分,确定主要过敏原及其致敏率,为深入研究食物过敏原检测及脱敏治疗提供依据。方法：通过46份虾蟹过敏症患者血清,对刀额新对虾、罗氏沼虾和锈斑鲟的蛋白粗提液进行Western blot 分析,统计数据得出其全部过敏原组分及其致敏率,并确定主要过敏原。结果：Western blot 结果显示,虾与过敏患者血清IgE的反应强于蟹,且虾、蟹间存在很多Mr相同的过敏原;32～38 kD原肌球蛋白（ TM）、40 kD精氨酸激酶（ AK）、60～80 kD血蓝蛋白（ Hc）和21 kD肌质钙结合蛋白（ SCP）是虾的主要致敏组分,TM、AK和Hc是虾、蟹共同的主要过敏原,其中TM的致敏率最高;与国外研究结果相比,AK、Hc和SCP的致敏率相对较高,且发现虾中48 kD蛋白组分（未知过敏原）也具有较高致敏率。结论：对中国人群而言,虾的致敏性强于蟹,且虾、蟹的主要致敏组分基本相同;中国人的虾蟹主要致敏组分及其致敏率与国外研究大致相同但略有差异;发现一种潜在的新型过敏原。     

不同方法提取和处理中华绒螯蟹组织蛋白的过敏原组分分析

目的:分析不同方法提取和处理中华绒螯蟹组织的蛋白组分及过敏原组分,为检测中华绒螯蟹特异性IgE提供最佳抗原制备方法。方法:分别采用PBS提取法、丙酮抽提法和裂解液提取法提取中华绒螯蟹组织蛋白,并用裂解液提取法分别提取加热前、后的蟹蛋白;采用SDS-PAGE和双向电泳分析蛋白组分,采用Western blot分析过敏原组分。结果:不同方法提取的蛋白组分、sIgE与蛋白结合的强度和所识别的蛋白组分存在一定差异。PBS提取液蛋白主要分布在94、85、76、66、18kD,丙酮提取液蛋白主要分布在94、85、76、36 kD,裂解液提取液蛋白主要分布在200、125、51、43、38 kD。PBS提取液与sIgE结合的阳性反应条带主要分布在76、66、53、43、38、18 kD;丙酮提取液主要分布在94、76、66、50、43、38、18 kD;裂解液提取液主要分布在200、105、94、76、43、38、18 kD。加热前、后蟹蛋白过敏原组分差别不大。结论:裂解液提取法提取的中华绒螯蟹过敏原更适于制备测定特异性IgE的抗原。加热不影响蟹过敏原组分和与特异性IgE的结合活性。     

抗CMTM4多克隆抗体的制备、纯化和鉴定

目的:制备抗CMTM4的多肽抗体并鉴定其性能.方法:通过TMHMM、DNAStar等软件对CMTM4的3种剪接体,CMTM4-v1,v2和v3的蛋白序列进行分析,选取了4段序列合成多肽并与钥孔戚血蓝素(KLH)偶联.其中第1、2、3条多肽为3种剪接体共有,混合后免疫家兔,制备Ab1;而第4条多肽为CMTM4-v1所特有,单独免疫家兔,制备Ab2.ELISA法检测抗体效价.免疫亲和层析法纯化后,进行Western blot和免疫组织化学检测,鉴定这2种抗体的特异性与适用范围.结果:得到兔抗人CMTM4多肽抗体Ab1和Ab2,效价分别达1:105和1:106.纯化后的Ab1用于Western blot可特异识别超表达的CMTM4-v1和v2,并可用于免疫组织化学实验;而Ab2仅可用于Western blot,特异性识别超表达的CMTM4-v1.Ab1还可特异识别小鼠内源性Cmtm4.结论:用多肽免疫家兔制备的2种抗CMTM4抗体不仅具有较高的效价以及特异性,并且Ab1还可以特异识别小鼠Cmtm4,为CMTM4的功能研究提供了有力的支持.     

虾、蟹交叉过敏原的研究

目的分析不同虾蟹过敏原组分间的交叉反应,探讨交叉过敏原在虾、蟹等甲壳类过敏食物检测、诊断和疫苗设计中的意义。方法运用20例虾过敏患者血清和制备的凡纳滨对虾主要过敏原-原肌球蛋白的8株单克隆抗体(mAbs),通过Western blot和间接竞争ELISA分析凡纳滨对虾、日本沼虾和梭子蟹的交叉过敏反应及它们的主要交叉过敏原。结果 Westernblot的结果显示,凡纳滨对虾、日本沼虾和梭子蟹分别能与85%、85%和75%的虾过敏患者血清IgE特异性反应;间接竞争ELISA的结果显示,3种虾蟹粗提液均可显著抑制虾过敏患者血清IgE与凡纳滨对虾蛋白的结合,最大抑制率分别93%、84%、60%;8株凡纳滨对虾原肌球蛋白的mAbs与日本沼虾和梭子蟹的Western blot和间接竞争ELISA反应中,6株mAbs可与日本沼虾和梭子蟹的相对分子质量为36 000蛋白反应。结论凡纳滨对虾、日本沼虾和梭子蟹之间存在交叉过敏反应,且具有多个交叉过敏原,其中原肌球蛋白是主要的交叉过敏原。     

Structural features of allergens large and small with emphasis on recombinant allergens.

The application of recombinant DNA techniques to the study of allergen structure has increased our knowledge of primary structures and B- and T-cell determinants. Thus, knowledge of the molecular bases of isoallergens and allergenic cross-reactivities is about to be rapidly expanded. Findings from the early applications of molecular cloning strategies to the study of some polypeptide allergens, together with a summary of our current knowledge of drug allergenic determinants, are presented here.     

Studies on Alternaria allergens: I. Establishment of the radioallergosorbent test for measurement of Alternaria allergens

The ability to covalently couple Alternaria allergens to macrocrystalline cellulose particles has permitted not only the measurement of IgE antibodies to Alternaria in patient serums but also the identification of allergenic fractions from crude Alternaria extracts. Crude aqueous Alternaria extracts from 3 commerical suppliers were coupled to cellulose but failed to bind more than 5% of total radioactive counts (TRC) when reacted with serums from highly sensitive patients. Fractionation of a commercial extract through Sephadex G-25 showed that almost all allergenic activity was located in a protein and carbohydrate-containing peak eluting at the column void volume. These fractions were pooled and coupled to cellulose to yield a RAST polymer which produced up to 20% TRC binding when tested with serums from over 100 Alternariasensitive patients, and only up to 1% TRC binding with 17 nonallergic serums. The study of commercial Alternaria extracts by chromatographic and RAST inhibition techniques showed that present extracts are neither qualitatively or quantitatively comparable.     

Evolution in the understanding of cross-reactivities of respiratory allergens: the role of recombinant allergens

The aim of this review is to show the impact of the use of purified and recombinant allergens to discriminate between co- and cross-sensitization to respiratory allergens. The author describes the evolution of diagnostic tests over the last decades; the tests initially allowed the detection of simultaneously positive cutaneous tests and/or simultaneous positivity of specific IgE to different allergen extracts, but they did not differentiate cross-sensitization from co-sensitization. RAST inhibition studies with crude extracts then established cross-reactivity, but did not identify the cross-reactive allergens involved. Later, immunoblot and CRIE inhibition were able to detect multiple cross-reactive allergens and to assess their physicochemical properties. But it is only since purified and recombinant allergens have been used in the different investigations that identification of cross-reactive allergens has been made possible at a molecular level. This historical approach is illustrated by examples selected from some of the main respiratory allergen sources: tree pollen, grass pollen, weed pollen, acarids, cockroaches and mammalians. For each of these allergen sources, the author gives an updated presentation of major and minor cross-reactive allergen molecules and refers to the last decade's major publications concerning immunochemical investigations carried out in the field of cross-reactive respiratory allergens. Emphasis is placed on the clinical applications for allergic patients: improvement in the accuracy of the diagnosis of sensitization, new concepts of immunotherapy based on genetically engineered hypoallergenic variants of cross-reactive allergens used alone or in combination, evaluation of allergen load with environmental tests using monoclonal antibodies against cross-reactive allergens.